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Sample records for odour perception recognition

  1. Public perception of odour and environmental pollution attributed to MSW treatment and disposal facilities: A case study

    SciTech Connect

    De Feo, Giovanni; De Gisi, Sabino; Williams, Ian D.

    2013-04-15

    Highlights: ► Effects of closing MSW facilities on perception of odour and pollution studied. ► Residents’ perception of odour nuisance considerably diminished post closure. ► Odour perception showed an association with distance from MSW facilities. ► Media coverage increased knowledge about MSW facilities and how they operate. ► Economic compensation possibly affected residents’ views and concerns. - Abstract: If residents’ perceptions, concerns and attitudes towards waste management facilities are either not well understood or underestimated, people can produce strong opposition that may include protest demonstrations and violent conflicts such as those experienced in the Campania Region of Italy. The aim of this study was to verify the effects of the closure of solid waste treatment and disposal facilities (two landfills and one RDF production plant) on public perception of odour and environmental pollution. The study took place in four villages in Southern Italy. Identical questionnaires were administered to residents during 2003 and after the closure of the facilities occurred in 2008. The residents’ perception of odour nuisance considerably diminished between 2003 and 2009 for the nearest villages, with odour perception showing an association with distance from the facilities. Post closure, residents had difficulty in identifying the type of smell due to the decrease in odour level. During both surveys, older residents reported most concern about the potentially adverse health impacts of long-term exposure to odours from MSW facilities. However, although awareness of MSW facilities and concern about potentially adverse health impacts varied according to the characteristics of residents in 2003, substantial media coverage produced an equalisation effect and increased knowledge about the type of facilities and how they operated. It is possible that residents of the village nearest to the facilities reported lower awareness of and concern about

  2. Public perception of odour and environmental pollution attributed to MSW treatment and disposal facilities: a case study.

    PubMed

    De Feo, Giovanni; De Gisi, Sabino; Williams, Ian D

    2013-04-01

    If residents' perceptions, concerns and attitudes towards waste management facilities are either not well understood or underestimated, people can produce strong opposition that may include protest demonstrations and violent conflicts such as those experienced in the Campania Region of Italy. The aim of this study was to verify the effects of the closure of solid waste treatment and disposal facilities (two landfills and one RDF production plant) on public perception of odour and environmental pollution. The study took place in four villages in Southern Italy. Identical questionnaires were administered to residents during 2003 and after the closure of the facilities occurred in 2008. The residents' perception of odour nuisance considerably diminished between 2003 and 2009 for the nearest villages, with odour perception showing an association with distance from the facilities. Post closure, residents had difficulty in identifying the type of smell due to the decrease in odour level. During both surveys, older residents reported most concern about the potentially adverse health impacts of long-term exposure to odours from MSW facilities. However, although awareness of MSW facilities and concern about potentially adverse health impacts varied according to the characteristics of residents in 2003, substantial media coverage produced an equalisation effect and increased knowledge about the type of facilities and how they operated. It is possible that residents of the village nearest to the facilities reported lower awareness of and concern about odour and environmental pollution because the municipality received economic compensation for their presence. PMID:23321503

  3. Community modelling: a tool for correlating estimates of exposure with perception of odour from municipal solid waste (MSW) landfills.

    PubMed

    Sarkar, Ujjaini; Longhurst, Philip J; Hobbs, Stephen E

    2003-06-01

    Odours from municipal solid waste landfills have the potential to cause significant annoyance and impact to amenity in the environment surrounding sites. In order to assess the impact of odorous emissions on surrounding communities a quantitative model to predict annoyance was developed. The overall objective of this research was to develop the major components of the model namely, assessment of odorous emissions, dispersion and reception by the surrounding community around the landfill site. This study used community modelling as a tool to find a link between dispersion and perception of odour. The research completed a year-round monitoring program engaging people within the local community as regular odour monitors. Estimates of exposure from dispersion analysis were used to compare incidents causing complaint and intensity-concentration plots were fitted for each monitor whose reports were found to be logically consistent with regard to the intensity scaling. Human responses to the vast range of odour intensities, from highly intense source odours through to less intense dispersed odours at monitors' locations, were found to differ greatly. It was observed that the psychophysical models based on the Weber-Fechner law and Power law fitted the data consistently well for the entire range of the intensity scale used, 1-7. However, the other two models, based on Beidler's law and Laffort's equation showed an inconsistency with the intensity scales >3. PMID:12781753

  4. Consumption of garlic positively affects hedonic perception of axillary body odour.

    PubMed

    Fialová, Jitka; Roberts, S Craig; Havlíček, Jan

    2016-02-01

    Beneficial health properties of garlic, as well as its most common adverse effect - distinctive breath odour - are well-known. In contrast, analogous research on the effect of garlic on axillary odour is currently missing. Here, in three studies varying in the amount and nature of garlic provided (raw garlic in study 1 and 2, garlic capsules in study 3), we tested the effect of garlic consumption on the quality of axillary odour. A balanced within-subject experimental design was used. In total, 42 male odour donors were allocated to either a "garlic" or "non-garlic" condition, after which they wore axillary pads for 12 h to collect body odour. One week later, the conditions were reversed. Odour samples were then judged for their pleasantness, attractiveness, masculinity and intensity by 82 women. We found no significant differences in ratings of any characteristics in study 1. However, the odour of donors after an increased garlic dosage was assessed as significantly more pleasant, attractive and less intense (study 2), and more attractive and less intense in study 3. Our results indicate that garlic consumption may have positive effects on perceived body odour hedonicity, perhaps due to its health effects (e.g., antioxidant properties, antimicrobial activity). PMID:26551789

  5. Blending of heritable recognition cues among ant nestmates creates distinct colony gestalt odours but prevents within-colony nepotism.

    PubMed

    van Zweden, J S; Brask, J B; Christensen, J H; Boomsma, J J; Linksvayer, T A; d'Ettorre, P

    2010-07-01

    The evolution of sociality is facilitated by the recognition of close kin, but if kin recognition is too accurate, nepotistic behaviour within societies can dissolve social cohesion. In social insects, cuticular hydrocarbons act as nestmate recognition cues and are usually mixed among colony members to create a Gestalt odour. Although earlier studies have established that hydrocarbon profiles are influenced by heritable factors, transfer among nestmates and additional environmental factors, no studies have quantified these relative contributions for separate compounds. Here, we use the ant Formica rufibarbis in a cross-fostering design to test the degree to which hydrocarbons are heritably synthesized by young workers and transferred by their foster workers. Bioassays show that nestmate recognition has a significant heritable component. Multivariate quantitative analyses based on 38 hydrocarbons reveal that a subset of branched alkanes are heritably synthesized, but that these are also extensively transferred among nestmates. In contrast, especially linear alkanes are less heritable and little transferred; these are therefore unlikely to act as cues that allow within-colony nepotistic discrimination or as nestmate recognition cues. These results indicate that heritable compounds are suitable for establishing a genetic Gestalt for efficient nestmate recognition, but that recognition cues within colonies are insufficiently distinct to allow nepotistic kin discrimination. PMID:20492083

  6. Odour from municipal solid waste (MSW) landfills: a study on the analysis of perception.

    PubMed

    Sarkar, Ujjaini; Hobbs, Stephen E

    2002-03-01

    The objective of this work was to develop a relationship between odour intensity and odour concentration by using data collected from various sensitive areas of the municipal solid waste (MSW) landfill site. A number of well-known psychophysical models (e.g., Weber-Fechner law, Steven's power law, Beidler's and Laffort's models) have been discussed that can successfully relate the perceived intensity with the odour concentration. Respective parameters for each of the models were estimated by the nonlinear Levenburg-Marquardt parameter estimation method. The overall performance of the model was tested statistically against sets of data from the olfactometry analysis. The model based on the Weber-Fechner law was ranked 1 in case of five out of nine samples and it has been found more representative of the less intense odour samples. The model based on Laffort's equation has represented the intensity-concentration relationship better with extremely low uncertainties on both parameters k1 and k2 for comparatively more intense odour samples. PMID:11934115

  7. Understanding the Odour Spaces: A Step towards Solving Olfactory Stimulus-Percept Problem.

    PubMed

    Kumar, Ritesh; Kaur, Rishemjit; Auffarth, Benjamin; Bhondekar, Amol P

    2015-01-01

    Odours are highly complex, relying on hundreds of receptors, and people are known to disagree in their linguistic descriptions of smells. It is partly due to these facts that, it is very hard to map the domain of odour molecules or their structure to that of perceptual representations, a problem that has been referred to as the Structure-Odour-Relationship. We collected a number of diverse open domain databases of odour molecules having unorganised perceptual descriptors, and developed a graphical method to find the similarity between perceptual descriptors; which is intuitive and can be used to identify perceptual classes. We then separately projected the physico-chemical and perceptual features of these molecules in a non-linear dimension and clustered the similar molecules. We found a significant overlap between the spatial positioning of the clustered molecules in the physico-chemical and perceptual spaces. We also developed a statistical method of predicting the perceptual qualities of a novel molecule using its physico-chemical properties with high receiver operating characteristics(ROC). PMID:26484763

  8. Understanding the Odour Spaces: A Step towards Solving Olfactory Stimulus-Percept Problem

    PubMed Central

    Kumar, Ritesh; Bhondekar, Amol P.

    2015-01-01

    Odours are highly complex, relying on hundreds of receptors, and people are known to disagree in their linguistic descriptions of smells. It is partly due to these facts that, it is very hard to map the domain of odour molecules or their structure to that of perceptual representations, a problem that has been referred to as the Structure-Odour-Relationship. We collected a number of diverse open domain databases of odour molecules having unorganised perceptual descriptors, and developed a graphical method to find the similarity between perceptual descriptors; which is intuitive and can be used to identify perceptual classes. We then separately projected the physico-chemical and perceptual features of these molecules in a non-linear dimension and clustered the similar molecules. We found a significant overlap between the spatial positioning of the clustered molecules in the physico-chemical and perceptual spaces. We also developed a statistical method of predicting the perceptual qualities of a novel molecule using its physico-chemical properties with high receiver operating characteristics(ROC). PMID:26484763

  9. Speed and accuracy in nest-mate recognition: a hover wasp prioritizes face recognition over colony odour cues to minimize intrusion by outsiders

    PubMed Central

    Baracchi, D.; Petrocelli, I.; Chittka, L.; Ricciardi, G.; Turillazzi, S.

    2015-01-01

    Social insects have evolved sophisticated recognition systems enabling them to accept nest-mates but reject alien conspecifics. In the social wasp, Liostenogaster flavolineata (Stenogastrinae), individuals differ in their cuticular hydrocarbon profiles according to colony membership; each female also possesses a unique (visual) facial pattern. This species represents a unique model to understand how vision and olfaction are integrated and the extent to which wasps prioritize one channel over the other to discriminate aliens and nest-mates. Liostenogaster flavolineata females are able to discriminate between alien and nest-mate females using facial patterns or chemical cues in isolation. However, the two sensory modalities are not equally efficient in the discrimination of ‘friend’ from ‘foe’. Visual cues induce an increased number of erroneous attacks on nest-mates (false alarms), but such attacks are quickly aborted and never result in serious injury. Odour cues, presented in isolation, result in an increased number of misses: erroneous acceptances of outsiders. Interestingly, wasps take the relative efficiencies of the two sensory modalities into account when making rapid decisions about colony membership of an individual: chemical profiles are entirely ignored when the visual and chemical stimuli are presented together. Thus, wasps adopt a strategy to ‘err on the safe side’ by memorizing individual faces to recognize colony members, and disregarding odour cues to minimize the risk of intrusion from colony outsiders. PMID:25652836

  10. Speed and accuracy in nest-mate recognition: a hover wasp prioritizes face recognition over colony odour cues to minimize intrusion by outsiders.

    PubMed

    Baracchi, D; Petrocelli, I; Chittka, L; Ricciardi, G; Turillazzi, S

    2015-03-01

    Social insects have evolved sophisticated recognition systems enabling them to accept nest-mates but reject alien conspecifics. In the social wasp, Liostenogaster flavolineata (Stenogastrinae), individuals differ in their cuticular hydrocarbon profiles according to colony membership; each female also possesses a unique (visual) facial pattern. This species represents a unique model to understand how vision and olfaction are integrated and the extent to which wasps prioritize one channel over the other to discriminate aliens and nest-mates. Liostenogaster flavolineata females are able to discriminate between alien and nest-mate females using facial patterns or chemical cues in isolation. However, the two sensory modalities are not equally efficient in the discrimination of 'friend' from 'foe'. Visual cues induce an increased number of erroneous attacks on nest-mates (false alarms), but such attacks are quickly aborted and never result in serious injury. Odour cues, presented in isolation, result in an increased number of misses: erroneous acceptances of outsiders. Interestingly, wasps take the relative efficiencies of the two sensory modalities into account when making rapid decisions about colony membership of an individual: chemical profiles are entirely ignored when the visual and chemical stimuli are presented together. Thus, wasps adopt a strategy to 'err on the safe side' by memorizing individual faces to recognize colony members, and disregarding odour cues to minimize the risk of intrusion from colony outsiders. PMID:25652836

  11. Measuring odours in the environment vs. dispersion modelling: A review

    NASA Astrophysics Data System (ADS)

    Capelli, Laura; Sironi, Selena; Del Rosso, Renato; Guillot, Jean-Michel

    2013-11-01

    Source characterization alone is not sufficient to account for the effective impact of odours on citizens, which would require to quantify odours directly at receptors. However, despite a certain simplicity of odour measurement at the emission source, odour measurement in the field is a quite more complicated task. This is one of the main reasons for the spreading of odour impact assessment approaches based on odour dispersion modelling. Currently, just a very limited number of reports discussing the use of tracer gas dispersion experiments both in the field and in wind tunnels for model validation purposes can be found in literature. However, when dealing with odour emissions, it is not always possible to identify a limited number of tracer compounds, nor to relate analytical concentrations to odour properties, thus giving that considering single odorous compounds might be insufficient to account for effective odour perception. For these reasons, the possibility of measuring of odours in the field, both as a way for directly assessing odour annoyance or for verifying that modelled odour concentrations correspond to the effective odour perception by humans, is still an important objective. The present work has the aim to review the techniques that can be adopted for measuring odours in the field, particularly discussing how such techniques can be used in alternative or in combination with odour dispersion models for odour impact assessment purposes, and how the results of field odour measurements and model outputs can be related and compared to each other.

  12. Recognition of social parasites as nest-mates: adoption of colony-specific host cuticular odours by the paper wasp parasite Polistes sulcifer.

    PubMed Central

    Sledge, M. F.; Dani, F. R.; Cervo, R.; Dapporto, L.; Turillazzi, S.

    2001-01-01

    Colonies of the polistine wasp Polistes dominulus are parasitized by the permanent worker-less social parasite Polistes sulcifer. After usurpation of the host colony, parasite females are characterized by a change in the relative proportions of their cuticular hydrocarbons to match those of the host species. In this paper we present evidence from field data and laboratory experiments that P. sulcifer females adopt a colony-specific host odour that facilitates their acceptance by host females of the usurped colony. Presentation experiments demonstrate that parasite females are recognized as foreign individuals by workers of other parasitized nests. We show that the modification of parasite cuticular compounds is sufficient for this recognition. This provides evidence that, after invasion, P. sulcifer queens do not require appeasement or propaganda substances for their acceptance by host colonies. Furthermore, multivariate discriminant analysis of the cuticular hydrocarbon proportions of the parasites after usurpation assigns the parasites together with P. dominulus females of their own host colony. To the authors' knowledge, this is the first confirmation that social parasites adopt colony-specific host odours. PMID:11674873

  13. Recognition of social parasites as nest-mates: adoption of colony-specific host cuticular odours by the paper wasp parasite Polistes sulcifer.

    PubMed

    Sledge, M F; Dani, F R; Cervo, R; Dapporto, L; Turillazzi, S

    2001-11-01

    Colonies of the polistine wasp Polistes dominulus are parasitized by the permanent worker-less social parasite Polistes sulcifer. After usurpation of the host colony, parasite females are characterized by a change in the relative proportions of their cuticular hydrocarbons to match those of the host species. In this paper we present evidence from field data and laboratory experiments that P. sulcifer females adopt a colony-specific host odour that facilitates their acceptance by host females of the usurped colony. Presentation experiments demonstrate that parasite females are recognized as foreign individuals by workers of other parasitized nests. We show that the modification of parasite cuticular compounds is sufficient for this recognition. This provides evidence that, after invasion, P. sulcifer queens do not require appeasement or propaganda substances for their acceptance by host colonies. Furthermore, multivariate discriminant analysis of the cuticular hydrocarbon proportions of the parasites after usurpation assigns the parasites together with P. dominulus females of their own host colony. To the authors' knowledge, this is the first confirmation that social parasites adopt colony-specific host odours. PMID:11674873

  14. Hopfield's Model of Patterns Recognition and Laws of Artistic Perception

    NASA Astrophysics Data System (ADS)

    Yevin, Igor; Koblyakov, Alexander

    The model of patterns recognition or attractor network model of associative memory, offered by J.Hopfield 1982, is the most known model in theoretical neuroscience. This paper aims to show, that such well-known laws of art perception as the Wundt curve, perception of visual ambiguity in art, and also the model perception of musical tonalities are nothing else than special cases of the Hopfield’s model of patterns recognition.

  15. Behavioral model of visual perception and recognition

    NASA Astrophysics Data System (ADS)

    Rybak, Ilya A.; Golovan, Alexander V.; Gusakova, Valentina I.

    1993-09-01

    In the processes of visual perception and recognition human eyes actively select essential information by way of successive fixations at the most informative points of the image. A behavioral program defining a scanpath of the image is formed at the stage of learning (object memorizing) and consists of sequential motor actions, which are shifts of attention from one to another point of fixation, and sensory signals expected to arrive in response to each shift of attention. In the modern view of the problem, invariant object recognition is provided by the following: (1) separated processing of `what' (object features) and `where' (spatial features) information at high levels of the visual system; (2) mechanisms of visual attention using `where' information; (3) representation of `what' information in an object-based frame of reference (OFR). However, most recent models of vision based on OFR have demonstrated the ability of invariant recognition of only simple objects like letters or binary objects without background, i.e. objects to which a frame of reference is easily attached. In contrast, we use not OFR, but a feature-based frame of reference (FFR), connected with the basic feature (edge) at the fixation point. This has provided for our model, the ability for invariant representation of complex objects in gray-level images, but demands realization of behavioral aspects of vision described above. The developed model contains a neural network subsystem of low-level vision which extracts a set of primary features (edges) in each fixation, and high- level subsystem consisting of `what' (Sensory Memory) and `where' (Motor Memory) modules. The resolution of primary features extraction decreases with distances from the point of fixation. FFR provides both the invariant representation of object features in Sensor Memory and shifts of attention in Motor Memory. Object recognition consists in successive recall (from Motor Memory) and execution of shifts of attention and

  16. Impaired odour discrimination on desynchronization of odour-encoding neural assemblies

    NASA Astrophysics Data System (ADS)

    Stopfer, Mark; Bhagavan, Seetha; Smith, Brian H.; Laurent, Gilles

    1997-11-01

    Stimulus-evoked oscillatory synchronization of neural assemblies has been described in the olfactory and visual systems of several vertebrates and invertebrates. In locusts, information about odour identity is contained in the timing of action potentials in an oscillatory population response, suggesting that oscillations may reflect a common reference for messages encoded in time. Although the stimulus-evoked oscillatory phenomenon is reliable, its roles in sensation, perception, memory formation and pattern recognition remain to be demonstrated - a task requiring a behavioural paradigm. Using honeybees, we now demonstrate that odour encoding involves, as it does in locusts, the oscillatory synchronization of assemblies of projection neurons and that this synchronization is also selectively abolished by picrotoxin, an antagonist of the GABAA (γ-aminobutyric acid) receptor. By using a behavioural learning paradigm, we show that picrotoxin-induced desynchronization impairs the discrimination of molecularly similar odorants, but not that of dissimilar odorants. It appears, therefore, that oscillatory synchronization of neuronal assemblies is functionally relevant, and essential for fine sensory discrimination. This suggests that oscillatory synchronization and the kind of temporal encoding it affords provide an additional dimension by which the brain could segment spatially overlapping stimulus representations.

  17. Odour Detection Methods: Olfactometry and Chemical Sensors

    PubMed Central

    Brattoli, Magda; de Gennaro, Gianluigi; de Pinto, Valentina; Loiotile, Annamaria Demarinis; Lovascio, Sara; Penza, Michele

    2011-01-01

    The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective “analytical instrument” for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out

  18. Testing the Recognition and Perception of Errors in Context

    ERIC Educational Resources Information Center

    Brandenburg, Laura C.

    2015-01-01

    This study tests the recognition of errors in context and whether the presence of errors affects the reader's perception of the writer's ethos. In an experimental, posttest only design, participants were randomly assigned a memo to read in an online survey: one version with errors and one version without. Of the six intentional errors in…

  19. Tactile Perception and Braille Letter Recognition: Effects of Developmental Teaching.

    ERIC Educational Resources Information Center

    Mangold, Sally S.

    1978-01-01

    The extent to which a developmental program of tactile perception and braille letter recognition would affect errors in these abilities and reduce scrubbing and backtracking behaviors of 30 legally blind braille users (5-15 years old) was studied. (Author/BD)

  20. Conversion of the chemical concentration of odorous mixtures into odour concentration and odour intensity: A comparison of methods

    NASA Astrophysics Data System (ADS)

    Wu, Chuandong; Liu, Jiemin; Zhao, Peng; Piringer, Martin; Schauberger, Günther

    2016-02-01

    Continuous odour measurements both of emissions as well as ambient concentrations are seldom realised, mainly because of their high costs. They are therefore often substituted by concentration measurements of odorous substances. Then a conversion of the chemical concentrations C (mg m-3) into odour concentrations COD (ouE m-3) and odour intensities OI is necessary. Four methods to convert the concentrations of single substances to the odour concentrations and odour intensities of an odorous mixture are investigated: (1) direct use of measured concentrations, (2) the sum of the odour activity value SOAV, (3) the sum of the odour intensities SOI, and (4) the equivalent odour concentration EOC, as a new method. The methods are evaluated with olfactometric measurements of seven substances as well as their mixtures. The results indicate that the SOI and EOC conversion methods deliver reliable values. These methods use not only the odour threshold concentration but also the slope of the Weber-Fechner law to include the sensitivity of the odour perception of the individual substances. They fulfil the criteria of an objective conversion without the need of a further calibration by additional olfactometric measurements.

  1. Odour impact assessment by means of dynamic olfactometry, dispersion modelling and social participation

    NASA Astrophysics Data System (ADS)

    Sironi, Selena; Capelli, Laura; Céntola, Paolo; Del Rosso, Renato; Pierucci, Sauro

    2010-01-01

    This work discusses how it is possible to assess odour impact in presence of multiple similar sources by illustrating a case study. The study was conducted on an area of northern Italy comprising three small municipalities where four rendering plants are located near to each other. Based on the emission data resulting from olfactometric surveys conducted in different periods of the year the overall odour emission rate emitted by each plant were evaluated, showing that the major contributor to the odour impact on the territory was plant 2. These data were linked with meteorological and orographical data in order to evaluate odour dispersion with a model (Calpuff). The results of the odour dispersion modelling confirmed the outcomes of the olfactometric survey and they were further validated through a "questioning" survey, conducted with the aim of involving the population by means of questionnaires for reporting the perceived odour episodes, which showed a good correspondence (86.5%) between odour perceptions and simulated odour immissions.

  2. Odourant reception in the malaria mosquito Anopheles gambiae

    PubMed Central

    Carey, Allison; Wang, Guirong; Su, Chih-Ying; Zwiebel, Laurence J.; Carlson, John R.

    2010-01-01

    Summary The mosquito Anopheles gambiae is the major vector of malaria in sub-Saharan Africa. It locates its human hosts primarily through olfaction, but little is known about the molecular basis of this process. Here we functionally characterize the Anopheles gambiae Odourant Receptor (AgOr) repertoire. We identify receptors that respond strongly to components of human odour and that may act in the process of human recognition. Some of these receptors are narrowly tuned, and some salient odourants elicit strong responses from only one or a few receptors, suggesting a central role for specific transmission channels in human host-seeking behavior. This analysis of the Anopheles gambiae receptors permits a comparison with the corresponding Drosophila melanogaster odourant receptor repertoire. We find that odourants are differentially encoded by the two species in ways consistent with their ecological needs. Our analysis of the Anopheles gambiae repertoire identifies receptors that may be useful targets for controlling the transmission of malaria. PMID:20130575

  3. The scent of mixtures: rules of odour processing in ants

    PubMed Central

    Perez, Margot; Giurfa, Martin; d'Ettorre, Patrizia

    2015-01-01

    Natural odours are complex blends of numerous components. Understanding how animals perceive odour mixtures is central to multiple disciplines. Here we focused on carpenter ants, which rely on odours in various behavioural contexts. We studied overshadowing, a phenomenon that occurs when animals having learnt a binary mixture respond less to one component than to the other, and less than when this component was learnt alone. Ants were trained individually with alcohols and aldehydes varying in carbon-chain length, either as single odours or binary mixtures. They were then tested with the mixture and the components. Overshadowing resulted from the interaction between chain length and functional group: alcohols overshadowed aldehydes, and longer chain lengths overshadowed shorter ones; yet, combinations of these factors could cancel each other and suppress overshadowing. Our results show how ants treat binary olfactory mixtures and set the basis for predictive analyses of odour perception in insects. PMID:25726692

  4. How reliable are odour assessments?

    PubMed

    Bokowa, A; Beukes, J A

    2012-01-01

    This paper will demonstrate the differences found in odour test results, when odour sampling is performed at the same sources by two different consultants. By examining two case studies, this paper will highlight that the difference between the results can be significant. Both studies are based on odour sampling programs determining the odour removal efficiency of odour control units installed at two different facilities: a pet food facility and an oil/grease recycling facility. The first study is based on odour measurements at the inlet and outlet of the unit installed by Applied Plasma Physics AS at the pet food facility. Odour assessments were performed by two separate consultants at the same time. The second study is based on testing of the odour removal effectiveness of two units: a scrubber and a biofilter at an oil/grease recycling facility. During this study two odour sampling programs were performed by two consultants at different times, but under the same process conditions. This paper will show how varying results can play a role in choosing the adequate odour control technologies. The final results suggest that although, an odour control unit may appear to be insufficient, it actually is successful at removing the odours. PMID:22949233

  5. Dialogue procedures for the management of odour related community conflicts.

    PubMed

    Sucker, K

    2009-01-01

    In the German Guideline on Odour in Ambient Air (GOAA) statements about the degree of residential odour annoyance are based on the frequency of recognisable odours and hedonic tone. The use of olfactory standards to adequately estimate the annoyance impact is limited if, for example, worry about adverse health outcomes significantly influences the annoyance response of the population. This report introduces dialogue procedures as complementary measures to consider the complainants' subjective perceptions and worries adequately. At first, it is illustrated that odour exposure and number of odour complaints are not necessarily correlated. Then the "interest analysis" and the five steps of a dialogue procedure are presented. A dialogue procedure can be initiated in "quiet times" - where the focus is on trust building and on the development of adequate communication strategies to promote realistic risk reception - as well as in order to establish a successful conflict resolution process if the issue is complex and emotionally discussed. After that, two examples of handling odour complaints are shown. Finally, considerations applying dialogue procedures as a tool to advance odour annoyance mitigation are outlined. PMID:19273885

  6. Gibberellin Perception by the Gibberellin Receptor and its Effector Recognition

    NASA Astrophysics Data System (ADS)

    Hakoshima, Toshio; Murase, Kohji; Hirano, Yoshinori; Sun, Tai-Ping

    Gibberellins control a diverse range of growth and developmental processes in higher plants and have been widely utilized in the agricultural industry. By binding to a nuclear receptor GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression by promoting degradation of the transcriptional regulator DELLA proteins. The precise manner in which GID1 discriminates and becomes activated by bioactive gibberellins for specific binding to DELLA proteins remains unclear. We present the crystal structure of a ternary complex of Arabidopsis thaliana GID1A, a bioactive gibberellin and the N-terminal DELLA domain of GAI. In this complex, GID1a occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region, which in turn interacts with the DELLA domain containing DELLA, VHYNP and LExLE motifs. Our results establish a structural model of a plant hormone receptor which is distinct from the hormone-perception mechanism and effector recognition of the known auxin receptors.

  7. Identity Negative Priming: A Phenomenon of Perception, Recognition or Selection?

    PubMed Central

    Schrobsdorff, Hecke; Ihrke, Matthias; Behrendt, Jörg; Herrmann, J. Michael; Hasselhorn, Marcus

    2012-01-01

    The present study addresses the problem whether negative priming (NP) is due to information processing in perception, recognition or selection. We argue that most NP studies confound priming and perceptual similarity of prime-probe episodes and implement a color-switch paradigm in order to resolve the issue. In a series of three identity negative priming experiments with verbal naming response, we determined when NP and positive priming (PP) occur during a trial. The first experiment assessed the impact of target color on priming effects. It consisted of two blocks, each with a different fixed target color. With respect to target color no differential priming effects were found. In Experiment 2 the target color was indicated by a cue for each trial. Here we resolved the confounding of perceptual similarity and priming condition. In trials with coinciding colors for prime and probe, we found priming effects similar to Experiment 1. However, trials with a target color switch showed such effects only in trials with role-reversal (distractor-to-target or target-to-distractor), whereas the positive priming (PP) effect in the target-repetition trials disappeared. Finally, Experiment 3 split trial processing into two phases by presenting the trial-wise color cue only after the stimulus objects had been recognized. We found recognition in every priming condition to be faster than in control trials. We were hence led to the conclusion that PP is strongly affected by perception, in contrast to NP which emerges during selection, i.e., the two effects cannot be explained by a single mechanism. PMID:22427915

  8. On the Relationship between Memory and Perception: Sequential Dependencies in Recognition Memory Testing

    ERIC Educational Resources Information Center

    Malmberg, Kenneth J.; Annis, Jeffrey

    2012-01-01

    Many models of recognition are derived from models originally applied to perception tasks, which assume that decisions from trial to trial are independent. While the independence assumption is violated for many perception tasks, we present the results of several experiments intended to relate memory and perception by exploring sequential…

  9. Horses (Equus caballus) discriminate body odour cues from conspecifics.

    PubMed

    Péron, F; Ward, R; Burman, O

    2014-07-01

    Knowledge about social recognition and memory in animals can help us to determine appropriate management and husbandry techniques. In this study, we used a habituation-discrimination procedure to investigate the ability of horses (Equus caballus) to distinguish between the body odour samples of unfamiliar conspecifics. To pick up body odour, we rubbed material on the coat of horses and presented these unknown body odours to 16 different conspecifics of the same sex and similar age. The test consisted of two successive two-min presentations of a sample from one individual (e.g. individual 'A') and a simultaneous presentation of samples from individual 'A' and a novel individual (e.g. individual 'B') during a final third presentation. The results showed that horses, regardless of sex, decreased the time they spent investigating conspecific body odour across the initial two presentations-demonstrating habituation. In the final presentation, the results demonstrated successful discrimination of the previously experienced odour because horses investigated the novel olfactory sample ('B') significantly more than the pre-exposed sample ('A'). Taken together, these findings suggest, for the first time, that horses are able to discriminate two stimuli derived from body odours of unfamiliar conspecifics over short period of time. PMID:24305997

  10. Odour-based kin discrimination in the cooperatively breeding meerkat.

    PubMed

    Leclaire, Sarah; Nielsen, Johanna F; Thavarajah, Nathan K; Manser, Marta; Clutton-Brock, Tim H

    2013-02-23

    Kin recognition is a useful ability for animals, facilitating cooperation among relatives and avoidance of excessive kin competition or inbreeding. In meerkats, Suricata suricatta, encounters between unfamiliar kin are relatively frequent, and kin recognition by phenotype matching is expected to avoid inbreeding with close relatives. Here, we investigate whether female meerkats are able to discriminate the scent of unfamiliar kin from unfamiliar non-kin. Dominant females were presented with anal gland secretion from unfamiliar individuals that varied in their relatedness. Our result indicates that females spent more time investigating the scent of related than unrelated unfamiliar individuals, suggesting that females may use a phenotype matching mechanism (or recognition alleles) to discriminate the odour of their kin from the odour of their non-kin. Our study provides a key starting point for further investigations into the use of kin recognition for inbreeding avoidance in the widely studied meerkat. PMID:23234867

  11. Lexical support for phonetic perception during nonnative spoken word recognition.

    PubMed

    Samuel, Arthur G; Frost, Ram

    2015-12-01

    Second language comprehension is generally not as efficient and effective as native language comprehension. In the present study, we tested the hypothesis that lower-level processes such as lexical support for phonetic perception are a contributing factor to these differences. For native listeners, it has been shown that the perception of ambiguous acoustic–phonetic segments is driven by lexical factors (Samuel Psychological Science, 12, 348-351, 2001). Here, we tested whether nonnative listeners can use lexical context in the same way. Native Hebrew speakers living in Israel were tested with American English stimuli. When subtle acoustic cues in the stimuli worked against the lexical context, these nonnative speakers showed no evidence of lexical guidance of phonetic perception. This result conflicts with the performance of native speakers, who demonstrate lexical effects on phonetic perception even with conflicting acoustic cues. When stimuli without any conflicting cues were used, the native Hebrew subjects produced results similar to those of native English speakers, showing lexical support for phonetic perception in their second language. In contrast, native Arabic speakers, who were less proficient in English than the native Hebrew speakers, showed no ability to use lexical activation to support phonetic perception, even without any conflicting cues. These results reinforce previous demonstrations of lexical support of phonetic perception and demonstrate how proficiency modulates the use of lexical information in driving phonetic perception. PMID:26866066

  12. [Acoustic recognition of emotions and musical perceptive abilities in young deaf person].

    PubMed

    Fiol, L; Rousteau, G

    2012-01-01

    What influence does being deaf have on the ability to recognise emotions in other people? What perceptive abilities can be found in deaf people that are based on the acoustic recognition of emotions? Studies concerning the most useful acoustic clues in the recognition of emotions remain scarce. Beyond the uttered words, emotions are perceptible through the music of speech i.e. its words, its parameters (namely the intensity), the pitch and the timbre or colour of a sound, as well as its rhythm. The protocol of assessment developed in this study shows evidence of a correlation between the recognition of fundamental emotions and the perceptive musical abilities of deaf patients. This concept is relevant when regarding any deaf patient; irrespective of hearing aid type or re-education method. PMID:23074825

  13. Transcranial doppler assessment of cerebral flow velocity during perception and recognition of melodies.

    PubMed

    Matteis, M; Silvestrini, M; Troisi, E; Cupini, L M; Caltagirone, C

    1997-07-01

    The role of each cerebral hemisphere in the perception and recognition of musical information is not yet well understood. We studied cerebral blood flow changes during a melody perception task and a melody recognition task. Blood flow velocity in the two middle cerebral arteries of twenty right-handed musically naif volunteers were simultaneously measured by means of bilateral transcranial Doppler ultrasonography during two minutes of passive melody listening and two minutes of a melody recognition task. With respect to baseline values, a bilateral increase of flow velocity occurred in the middle cerebral arteries with a non-significant trend for the right artery during the melody perception task. During the melody recognition task, a significant increase in flow velocity was recorded on the right side with respect to the left side, where a slight simultaneous decrease was found. Our data suggest that melody perception requires bilateral activation of hemispheres and melody recognition mainly an activation of the right hemisphere. This study confirms the ability of transcranial Doppler ultrasonography to correlate artery flow dynamics with selective cerebral activation. PMID:9168166

  14. Bayesian Action–Perception Computational Model: Interaction of Production and Recognition of Cursive Letters

    PubMed Central

    Gilet, Estelle; Diard, Julien; Bessière, Pierre

    2011-01-01

    In this paper, we study the collaboration of perception and action representations involved in cursive letter recognition and production. We propose a mathematical formulation for the whole perception–action loop, based on probabilistic modeling and Bayesian inference, which we call the Bayesian Action–Perception (BAP) model. Being a model of both perception and action processes, the purpose of this model is to study the interaction of these processes. More precisely, the model includes a feedback loop from motor production, which implements an internal simulation of movement. Motor knowledge can therefore be involved during perception tasks. In this paper, we formally define the BAP model and show how it solves the following six varied cognitive tasks using Bayesian inference: i) letter recognition (purely sensory), ii) writer recognition, iii) letter production (with different effectors), iv) copying of trajectories, v) copying of letters, and vi) letter recognition (with internal simulation of movements). We present computer simulations of each of these cognitive tasks, and discuss experimental predictions and theoretical developments. PMID:21674043

  15. A Rhythm Recognition Computer Program to Advocate Interactivist Perception

    ERIC Educational Resources Information Center

    Buisson, Jean-Christophe

    2004-01-01

    This paper advocates the main ideas of the interactive model of representation of Mark Bickhard and the assimilation/accommodation framework of Jean Piaget, through a rhythm recognition demonstration program. Although completely unsupervised, the program progressively learns to recognize more and more complex rhythms struck on the user's keyboard.…

  16. Female-biased expression of odourant receptor genes in the adult antennae of the silkworm, Bombyx mori.

    PubMed

    Wanner, K W; Anderson, A R; Trowell, S C; Theilmann, D A; Robertson, H M; Newcomb, R D

    2007-02-01

    Olfaction plays an important role in the life history of insects, including key behaviours such as host selection, oviposition and mate recognition. Odour perception by insects is primarily mediated by the large diverse family of odourant receptors (Ors) that are expressed on the dendrites of olfactory neurones housed within chemosensilla. However, few Or sequences have been identified from the Lepidoptera, an insect order that includes some of the most important pest species worldwide. We have identified 41 Or gene sequences from the silkworm (Bombyx mori) genome, more than double the number of published Or sequences from the Lepidoptera. Many silkworm Ors appear to be orthologs of the 17 published tobacco budworm (Heliothis virescens) Ors indicating that many Or lineages may be conserved within the Lepidoptera. The majority of the Or genes are expressed in adult female and male antennae (determined by quantitative real-time PCR analysis), supporting their probable roles in adult olfaction. Several Or genes are expressed at high levels in both male and female antennae, suggesting they mediate the perception of common host or conspecific volatiles important to both sexes. BmOrs 45-47 group together in the same phylogenetic branch and all three are expressed at moderate female-biased ratios, six to eight times higher in female compared to male moth antennae. Interestingly, BmOrs19 and 30 appear to be expressed predominantly in female antennae, opposite to that of the published silkworm pheromone receptors BmOrs 1 and 3 that are specific to male antennae. These results suggest that BmOr19 and 30 may detect odours critical to female behaviour, such as oviposition cues or male-produced courtship pheromones. PMID:17257213

  17. Auditory perception vs. recognition: representation of complex communication sounds in the mouse auditory cortical fields.

    PubMed

    Geissler, Diana B; Ehret, Günter

    2004-02-01

    Details of brain areas for acoustical Gestalt perception and the recognition of species-specific vocalizations are not known. Here we show how spectral properties and the recognition of the acoustical Gestalt of wriggling calls of mouse pups based on a temporal property are represented in auditory cortical fields and an association area (dorsal field) of the pups' mothers. We stimulated either with a call model releasing maternal behaviour at a high rate (call recognition) or with two models of low behavioural significance (perception without recognition). Brain activation was quantified using c-Fos immunocytochemistry, counting Fos-positive cells in electrophysiologically mapped auditory cortical fields and the dorsal field. A frequency-specific labelling in two primary auditory fields is related to call perception but not to the discrimination of the biological significance of the call models used. Labelling related to call recognition is present in the second auditory field (AII). A left hemisphere advantage of labelling in the dorsoposterior field seems to reflect an integration of call recognition with maternal responsiveness. The dorsal field is activated only in the left hemisphere. The spatial extent of Fos-positive cells within the auditory cortex and its fields is larger in the left than in the right hemisphere. Our data show that a left hemisphere advantage in processing of a species-specific vocalization up to recognition is present in mice. The differential representation of vocalizations of high vs. low biological significance, as seen only in higher-order and not in primary fields of the auditory cortex, is discussed in the context of perceptual strategies. PMID:15009150

  18. Associative learning of complex odours in parasitoid host location.

    PubMed

    Meiners, Torsten; Wäckers, Felix; Lewis, Wallace Joe

    2003-03-01

    In this paper we address the question how hymenopteran parasitoids deal with complex odour bouquets, using Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) as a model. We examined the capacity of Microplitis croceipes to respond to individual compounds in flight chamber experiments after conditioning parasitoids with a mixture consisting of 2-octanone, methyl jasmonate and beta-caryophyllene. Parasitoids were given a choice between single compounds from the training mixture and beta-ocimene as an unrewarded alternative. When compared with control individuals lacking experience with the odour mixture, parasitoids trained to the odour blend showed an increased preference for 2-octanone and beta-caryophyllene, but not for methyl jasmonate. However, when trained with methyl jasmonate alone, parasitoids were able to respond to this compound. This demonstrates that parasitoids can learn to respond to individual compounds following experience with an odour mixture. However, for certain compounds of a mixture, learning can be blocked by other mixture components. Further experiments in which parasitoids were conditioned and challenged with two compound mixes confirmed that the olfactory background can affect recognition of individual compounds. PMID:12714445

  19. Sensing the intruder: a quantitative threshold for recognition cues perception in honeybees

    NASA Astrophysics Data System (ADS)

    Cappa, Federico; Bruschini, Claudia; Cipollini, Maria; Pieraccini, Giuseppe; Cervo, Rita

    2014-02-01

    The ability to discriminate among nestmates and non-nestmate is essential to defend social insect colonies from intruders. Over the years, nestmate recognition has been extensively studied in the honeybee Apis mellifera; nevertheless, the quantitative perceptual aspects at the basis of the recognition system represent an unexplored subject in this species. To test the existence of a cuticular hydrocarbons' quantitative perception threshold for nestmate recognition cues, we conducted behavioural assays by presenting different amounts of a foreign forager's chemical profile to honeybees at the entrance of their colonies. We found an increase in the explorative and aggressive responses as the amount of cues increased based on a threshold mechanism, highlighting the importance of the quantitative perceptual features for the recognition processes in A. mellifera.

  20. Plant odour plumes as mediators of plant-insect interactions.

    PubMed

    Beyaert, Ivo; Hilker, Monika

    2014-02-01

    Insect olfactory orientation along odour plumes has been studied intensively with respect to pheromonal communication, whereas little knowledge is available on how plant odour plumes (POPs) affect olfactory searching by an insect for its host plants. The primary objective of this review is to examine the role of POPs in the attraction of insects. First, we consider parameters of an odour source and the environment which determine the size, shape and structure of an odour plume, and we apply that knowledge to POPs. Second, we compare characteristics of insect pheromonal plumes and POPs. We propose a 'POP concept' for the olfactory orientation of insects to plants. We suggest that: (i) an insect recognises a POP by means of plant volatile components that are encountered in concentrations higher than a threshold detection limit and that occur in a qualitative and quantitative blend indicating a resource; (ii) perception of the fine structure of a POP enables an insect to distinguish a POP from an unspecific odorous background and other interfering plumes; and (iii) an insect can follow several POPs to their sources, and may leave the track of one POP and switch to another one if this conveys a signal with higher reliability or indicates a more suitable resource. The POP concept proposed here may be a useful tool for research in olfactory-mediated plant-insect interactions. PMID:23714000

  1. A new look at emotion perception: Concepts speed and shape facial emotion recognition.

    PubMed

    Nook, Erik C; Lindquist, Kristen A; Zaki, Jamil

    2015-10-01

    Decades ago, the "New Look" movement challenged how scientists thought about vision by suggesting that conceptual processes shape visual perceptions. Currently, affective scientists are likewise debating the role of concepts in emotion perception. Here, we utilized a repetition-priming paradigm in conjunction with signal detection and individual difference analyses to examine how providing emotion labels-which correspond to discrete emotion concepts-affects emotion recognition. In Study 1, pairing emotional faces with emotion labels (e.g., "sad") increased individuals' speed and sensitivity in recognizing emotions. Additionally, individuals with alexithymia-who have difficulty labeling their own emotions-struggled to recognize emotions based on visual cues alone, but not when emotion labels were provided. Study 2 replicated these findings and further demonstrated that emotion concepts can shape perceptions of facial expressions. Together, these results suggest that emotion perception involves conceptual processing. We discuss the implications of these findings for affective, social, and clinical psychology. PMID:25938612

  2. Development of a procedure to determine odour emissions from animal farming for regulatory purposes in Flanders.

    PubMed

    Van Langenhove, H; De Bruyn, G

    2001-01-01

    The purpose of the project described in this paper was to develop a procedure to determine odour emissions at existing and new intensive animal farming houses. The procedure should be scientifically valid and preferably applicable on a large scale at reasonable costs. In this project odour emissions were measured during one year at the same farm. Measurements included 20 olfactometric sampling days and 50 sniffing measurements, all spread over one year. For each olfactometric sampling day, samples were taken in duplicate for the different pig categories. The olfactometric analysis resulted in the determination of odour emission factors for growing/fattening pigs, weaned piglets, dry sows and farrowing sows. The influence of external parameters (ventilation rate, inside temperature, outside temperature, pen dirtiness, number of pigs and their weight) was examined. Good correlation between the odour emission and an external parameter could only be found for the ventilation rate (r = 0.98) and outside temperature (r = 0.87). The sniffing measurements resulted in maximal odour perception distances and odour emissions calculated with short and long term dispersion models. No significant influence of the outside temperature (season) could be found here. The results of the olfactometric and sniffing measurements will be presented, including a combination of both techniques to determine the odour emission of an agricultural construction. PMID:11762463

  3. Object recognition by triaural perception on a mobile robot

    NASA Astrophysics Data System (ADS)

    Peremans, Herbert; Van Campenhout, Jan M.

    1993-05-01

    To overcome some of the problems associated with the use of ultrasonic sensors for navigation purposes, we propose a measurement system composed of three ultrasonic sensors, one transmitting and three receiving, placed on a moving vehicle. By triangulation this tri-aural sensor is able to determine the position, both distance and bearing, of the objects in the field of view. In this paper, we derive a statistical test which combines consecutive sightings by the moving sensor, of the same object to determine whether it is an edge, a plane or a corner. This test is formulated as a sequential test which guarantees that the object will be recognized after the minimal number of measurements given predetermined error probabilities. We include experimental data showing the object recognition capabilities of the system.

  4. Genetic component of identification, intensity and pleasantness of odours: a Finnish family study.

    PubMed

    Knaapila, Antti; Keskitalo, Kaisu; Kallela, Mikko; Wessman, Maija; Sammalisto, Sampo; Hiekkalinna, Tero; Palotie, Aarno; Peltonen, Leena; Tuorila, Hely; Perola, Markus

    2007-05-01

    Although potential odorant receptor genes have been identified, the precise genetic component of perception of odours is still obscure. Although there is some evidence for heritability of a few olfactory-related traits, no genome-wide search for loci harboring underlying genes has been published to date. We performed a genome-wide scan to identify loci affecting the identification, intensity and pleasantness of 12 odours (cinnamon, turpentine, lemon, smoke, chocolate, rose, paint thinner, banana, pineapple, gasoline, soap, onion) using 146 Finnish adults from 26 families. Several of these traits showed heritable variation in the families. Suggestive evidence of linkage was found for the pleasantness of cinnamon odour (h(2)=61%) on chromosome 4q32.3 (multipoint logarithm of the odds (LOD) score 3.01), as well as for the perceived intensity of paint thinner odour (h(2)=31%) on chromosome 2p14 (multipoint LOD score 2.55). As these loci do not contain any known human odorant receptor genes, they may rather harbor genes that affect the central processing than the peripheral detection of the odour signal. Thus, perception of odours is potentially modified by genes other than those encoding odorant receptors. PMID:17342154

  5. Odours reduce the magnitude of object substitution masking for matching visual targets in females.

    PubMed

    Robinson, Amanda K; Laning, Julia; Reinhard, Judith; Mattingley, Jason B

    2016-08-01

    Recent evidence suggests that olfactory stimuli can influence early stages of visual processing, but there has been little focus on whether such olfactory-visual interactions convey an advantage in visual object identification. Moreover, despite evidence that some aspects of olfactory perception are superior in females than males, no study to date has examined whether olfactory influences on vision are gender-dependent. We asked whether inhalation of familiar odorants can modulate participants' ability to identify briefly flashed images of matching visual objects under conditions of object substitution masking (OSM). Across two experiments, we had male and female participants (N = 36 in each group) identify masked visual images of odour-related objects (e.g., orange, rose, mint) amongst nonodour-related distracters (e.g., box, watch). In each trial, participants inhaled a single odour that either matched or mismatched the masked, odour-related target. Target detection performance was analysed using a signal detection (d') approach. In females, but not males, matching odours significantly reduced OSM relative to mismatching odours, suggesting that familiar odours can enhance the salience of briefly presented visual objects. We conclude that olfactory cues exert a subtle influence on visual processes by transiently enhancing the salience of matching object representations. The results add to a growing body of literature that points towards consistent gender differences in olfactory perception. PMID:27306640

  6. Test battery for measuring the perception and recognition of facial expressions of emotion

    PubMed Central

    Wilhelm, Oliver; Hildebrandt, Andrea; Manske, Karsten; Schacht, Annekathrin; Sommer, Werner

    2014-01-01

    Despite the importance of perceiving and recognizing facial expressions in everyday life, there is no comprehensive test battery for the multivariate assessment of these abilities. As a first step toward such a compilation, we present 16 tasks that measure the perception and recognition of facial emotion expressions, and data illustrating each task's difficulty and reliability. The scoring of these tasks focuses on either the speed or accuracy of performance. A sample of 269 healthy young adults completed all tasks. In general, accuracy and reaction time measures for emotion-general scores showed acceptable and high estimates of internal consistency and factor reliability. Emotion-specific scores yielded lower reliabilities, yet high enough to encourage further studies with such measures. Analyses of task difficulty revealed that all tasks are suitable for measuring emotion perception and emotion recognition related abilities in normal populations. PMID:24860528

  7. Speech-perception training for older adults with hearing loss impacts word recognition and effort

    PubMed Central

    Kuchinsky, Stefanie E.; Ahlstrom, Jayne B.; Cute, Stephanie L.; Humes, Larry E.; Dubno, Judy R.; Eckert, Mark A.

    2014-01-01

    The current pupillometry study examined the impact of speech-perception training on word recognition and cognitive effort in older adults with hearing loss. Trainees identified more words at the follow-up than at the baseline session. Training also resulted in an overall larger and faster peaking pupillary response, even when controlling for performance and reaction time. Perceptual and cognitive capacities affected the peak amplitude of the pupil response across participants but did not diminish the impact of training on the other pupil metrics. Thus, we demonstrated that pupillometry can be used to characterize training-related and individual differences in effort during a challenging listening task. Importantly, the results indicate that speech-perception training not only affects overall word recognition, but also a physiological metric of cognitive effort, which has the potential to be a biomarker of hearing loss intervention outcome. PMID:24909603

  8. Test battery for measuring the perception and recognition of facial expressions of emotion.

    PubMed

    Wilhelm, Oliver; Hildebrandt, Andrea; Manske, Karsten; Schacht, Annekathrin; Sommer, Werner

    2014-01-01

    Despite the importance of perceiving and recognizing facial expressions in everyday life, there is no comprehensive test battery for the multivariate assessment of these abilities. As a first step toward such a compilation, we present 16 tasks that measure the perception and recognition of facial emotion expressions, and data illustrating each task's difficulty and reliability. The scoring of these tasks focuses on either the speed or accuracy of performance. A sample of 269 healthy young adults completed all tasks. In general, accuracy and reaction time measures for emotion-general scores showed acceptable and high estimates of internal consistency and factor reliability. Emotion-specific scores yielded lower reliabilities, yet high enough to encourage further studies with such measures. Analyses of task difficulty revealed that all tasks are suitable for measuring emotion perception and emotion recognition related abilities in normal populations. PMID:24860528

  9. Speech-perception training for older adults with hearing loss impacts word recognition and effort.

    PubMed

    Kuchinsky, Stefanie E; Ahlstrom, Jayne B; Cute, Stephanie L; Humes, Larry E; Dubno, Judy R; Eckert, Mark A

    2014-10-01

    The current pupillometry study examined the impact of speech-perception training on word recognition and cognitive effort in older adults with hearing loss. Trainees identified more words at the follow-up than at the baseline session. Training also resulted in an overall larger and faster peaking pupillary response, even when controlling for performance and reaction time. Perceptual and cognitive capacities affected the peak amplitude of the pupil response across participants but did not diminish the impact of training on the other pupil metrics. Thus, we demonstrated that pupillometry can be used to characterize training-related and individual differences in effort during a challenging listening task. Importantly, the results indicate that speech-perception training not only affects overall word recognition, but also a physiological metric of cognitive effort, which has the potential to be a biomarker of hearing loss intervention outcome. PMID:24909603

  10. Olfactory receptors on the cockroach antenna signal odour ON and odour OFF by excitation.

    PubMed

    Tichy, Harald; Hinterwirth, Armin; Gingl, Ewald

    2005-12-01

    A morphologically identifiable type of olfactory sensillum on the antenna of the American cockroach contains a pair of ON and OFF cells that responds oppositely to changes in the concentration of fruit odours. The odour of lemon oil was used to study the accuracy with which these cells can discriminate between rapid step-like, ramp-like and oscillating changes in odour concentration. The discharge rates of both cells are not only affected by the actual concentration at particular instants in time (instantaneous concentration) but also by the rate at which concentration changes. The impulse frequency of the fruit odour ON cell is high when odour concentration is high, but higher still when odour concentration is also rising. Conversely, the impulse frequency of the fruit odour OFF cell is high when odour concentration is low and higher still when odour concentration is also falling. Thus, the effect of odour concentration on the responses of both cells is reinforced by the rate of change. Sensitivity to the rate of concentration change becomes greater when the rate is low. Because of the high sensitivity to low rates of change, these cells are optimized to detect fluctuations in fruit odour concentration. Whereas the ON cell signals the arrival and presence of fruit odour, the OFF cell detects its termination and absence. These cells provide excitatory responses for both increase and decrease in fruit odour concentration and may therefore reinforce contrast information. PMID:16367781

  11. Usual variables and odour concentration to evaluate composting process and odour impact.

    PubMed

    Gutiérrez, M C; Martín, M A; Chica, A F

    2014-01-01

    Organic waste management by means of composting produces unpleasant odours. The odour emissions of composting piles composed of the organic fraction of municipal solid waste and sewage sludge were monitored and controlled by means of dynamic olfactometry. This technique is used to determine the odour concentration expressed in European odour units per cubic metres (ou(E)/m3). To validate the technique, we analysed both respirometric variables and traditional variables such as total organic carbon and pH during composting. Finally, a dispersion model was used to evaluate the impact of the odour emissions of the wastes on neighbouring areas, not finding any differences in the cases evaluated. PMID:24645451

  12. Process studies of odour emissions from effluent ponds using machine-based odour measurement

    NASA Astrophysics Data System (ADS)

    Sohn, J. H.; Smith, R. J.; Yoong, E.

    Replicable experimental studies using a novel experimental facility and a machine-based odour quantification technique were conducted to demonstrate the relationship between odour emission rates and pond loading rates. The odour quantification technique consisted of an electronic nose, AromaScan A32S, and an artificial neural network. Odour concentrations determined by olfactometry were used along with the AromaScan responses to train the artificial neural network. The trained network was able to predict the odour emission rates for the test data with a correlation coefficient of 0.98. Time averaged odour emission rates predicted by the machine-based odour quantification technique, were strongly correlated with volatile solids loading rate, demonstrating the increased magnitude of emissions from a heavily loaded effluent pond. However, it was not possible to obtain the same relationship between volatile solids loading rates and odour emission rates from the individual data. It is concluded that taking a limited number of odour samples over a short period is unlikely to provide a representative rate of odour emissions from an effluent pond. A continuous odour monitoring instrument will be required for that more demanding task.

  13. A natural polymorphism alters odour and DEET sensitivity in an insect odorant receptor

    PubMed Central

    Pellegrino, Maurizio; Steinbach, Nicole; Stensmyr, Marcus C.; Hansson, Bill S.; Vosshall, Leslie B.

    2011-01-01

    Blood-feeding insects such as mosquitoes are efficient vectors of human infectious diseases because they are strongly attracted by body heat, carbon dioxide, and odours produced by their vertebrate hosts. Insect repellents containing DEET (N,N-diethyl-meta-toluamide) are highly effective, but the mechanism by which this chemical wards off biting insects remains controversial despite decades of investigation1-11. DEET appears to act both at close range as a contact chemorepellent by acting on insect gustatory receptors12 and at long range by acting on the olfactory system1-11. Two opposing mechanisms for the observed behavioural effects of DEET in the gas phase have been proposed: that DEET interferes with the olfactory system to block host odour recognition1-7 or that DEET actively repels insects by activating olfactory neurons that elicit avoidance behaviour8-11. Here we show that the insect repellent DEET functions as a modulator of the odour-gated ion channel formed by the insect odorant receptor (OR) complex13, 14. The functional insect OR complex consists of a common co-receptor, Orco (ref. 15, formerly called Or83b, ref16), and one or more variable OR subunits that confer odour-selectivity17. DEET acts on this complex to potentiate or inhibit odour-evoked activity or to inhibit odour-evoked suppression of spontaneous activity. This modulation depends on the specific OR and the concentration and identity of the odour ligand. We identify a single amino acid polymorphism in the second transmembrane domain of Or59b in a Drosophila melanogaster strain from Brazil that renders this receptor insensitive to inhibition by the odour ligand and modulation by DEET. These data provide the first evidence that natural variation can modify the sensitivity of an odour-specific insect OR to odour ligands and DEET. Our data support the hypothesis that DEET acts as a molecular “confusant” that scrambles the insect odour code and provide a compelling explanation for the broad

  14. Visual Crowding: a fundamental limit on conscious perception and object recognition

    PubMed Central

    Whitney, David; Levi, Dennis M.

    2011-01-01

    Crowding, the inability to recognize objects in clutter, sets a fundamental limit on conscious visual perception and object recognition throughout most of the visual field. Despite how widespread and essential it is to object recognition, reading, and visually guided action, a solid operational definition of what crowding is has only recently become clear. The goal of this review is to provide a broad-based synthesis of the most recent findings in this area, to define what crowding is and is not, and to set the stage for future work that will extend crowding well beyond low-level vision. Here we define five diagnostic criteria for what counts as crowding, and further describe factors that both escape and break crowding. All of these lead to the conclusion that crowding occurs at multiple stages in the visual hierarchy. PMID:21420894

  15. Recognising the forest, but not the trees: an effect of colour on scene perception and recognition.

    PubMed

    Nijboer, Tanja C W; Kanai, Ryota; de Haan, Edward H F; van der Smagt, Maarten J

    2008-09-01

    Colour has been shown to facilitate the recognition of scene images, but only when these images contain natural scenes, for which colour is 'diagnostic'. Here we investigate whether colour can also facilitate memory for scene images, and whether this would hold for natural scenes in particular. In the first experiment participants first studied a set of colour and greyscale natural and man-made scene images. Next, the same images were presented, randomly mixed with a different set. Participants were asked to indicate whether they had seen the images during the study phase. Surprisingly, performance was better for greyscale than for coloured images, and this difference is due to the higher false alarm rate for both natural and man-made coloured scenes. We hypothesized that this increase in false alarm rate was due to a shift from scrutinizing details of the image to recognition of the gist of the (coloured) image. A second experiment, utilizing images without a nameable gist, confirmed this hypothesis as participants now performed equally on greyscale and coloured images. In the final experiment we specifically targeted the more detail-based perception and recognition for greyscale images versus the more gist-based perception and recognition for coloured images with a change detection paradigm. The results show that changes to images are detected faster when image-pairs were presented in greyscale than in colour. This counterintuitive result held for both natural and man-made scenes (but not for scenes without nameable gist) and thus corroborates the shift from more detailed processing of images in greyscale to more gist-based processing of coloured images. PMID:17716917

  16. Continuous odour measurement from fattening pig units

    NASA Astrophysics Data System (ADS)

    Romain, Anne-Claude; Nicolas, Jacques; Cobut, Pierre; Delva, Julien; Nicks, Baudouin; Philippe, François-Xavier

    2013-10-01

    A study in experimental slatted-system fattening pig units was conducted with the aim of estimating the odour emission factor (in ou s.pig-1), which can subsequently be used in dispersion models to assess the odour annoyance zone. Dynamic olfactometry measurements carried out at different development stages of pigs showed a logical trend of the mean assessed odour emission factor with the pig mass. However, the variation within the same mass class was much larger than variation between classes. Possible causes of such variation were identified as the evolution of ventilation rate during the day and the circadian rhythm of pig. To be able to monitor continuously the daily variation of the odour, an electronic nose was used with suitable regression model calibrated against olfactometric measurements. After appropriate validation check, the electronic nose proved to be convenient, as a complementary tool to dynamic olfactometry, to record the daily variation of the odour emission factor in the pig barn. It was demonstrated that, in the controlled conditions of the experimental pens, the daily variation of the odour emission rate could be mainly attributed to the sole influence of the circadian rhythm of pig. As a consequence, determining a representative odour emission factor in a real case cannot be based on a snapshot odour sampling.

  17. Neonatal representation of odour objects: distinct memories of the whole and its parts

    PubMed Central

    Coureaud, Gérard; Thomas-Danguin, Thierry; Wilson, Donald A.; Ferreira, Guillaume

    2014-01-01

    Extraction of relevant information from highly complex environments is a prerequisite to survival. Within odour mixtures, such information is contained in the odours of specific elements or in the mixture configuration perceived as a whole unique odour. For instance, an AB mixture of the element A (ethyl isobutyrate) and the element B (ethyl maltol) generates a configural AB percept in humans and apparently in another species, the rabbit. Here, we examined whether the memory of such a configuration is distinct from the memory of the individual odorants. Taking advantage of the newborn rabbit's ability to learn odour mixtures, we combined behavioural and pharmacological tools to specifically eliminate elemental memory of A and B after conditioning to the AB mixture and evaluate consequences on configural memory of AB. The amnesic treatment suppressed responsiveness to A and B but not to AB. Two other experiments confirmed the specific perception and particular memory of the AB mixture. These data demonstrate the existence of configurations in certain odour mixtures and their representation as unique objects: after learning, animals form a configural memory of these mixtures, which coexists with, but is relatively dissociated from, memory of their elements. This capability emerges very early in life. PMID:24990670

  18. Continuous Odour Measurement with Chemosensor Systems

    NASA Astrophysics Data System (ADS)

    Boeker, Peter; Haas, T.; Diekmann, B.; Lammer, P. Schulze

    2009-05-01

    The continuous odour measurement is a challenging task for chemosensor systems. Firstly, a long term and stable measurement mode must be guaranteed in order to preserve the validity of the time consuming and expensive olfactometric calibration data. Secondly, a method is needed to deal with the incoming sensor data. The continuous online detection of signal patterns, the correlated gas emission and the assigned odour data is essential for the continuous odour measurement. Thirdly, a severe danger of over-fitting in the process of the odour calibration is present, because of the high measurement uncertainty of the olfactometry. In this contribution we present a technical solution for continuous measurements comprising of a hybrid QMB-sensor array and electrochemical cells. A set of software tools enables the efficient data processing and calibration and computes the calibration parameters. The internal software of the measurement systems microcontroller processes the calibration parameters online for the output of the desired odour information.

  19. Towards biological plausibility of electronic noses: A spiking neural network based approach for tea odour classification.

    PubMed

    Sarkar, Sankho Turjo; Bhondekar, Amol P; Macaš, Martin; Kumar, Ritesh; Kaur, Rishemjit; Sharma, Anupma; Gulati, Ashu; Kumar, Amod

    2015-11-01

    The paper presents a novel encoding scheme for neuronal code generation for odour recognition using an electronic nose (EN). This scheme is based on channel encoding using multiple Gaussian receptive fields superimposed over the temporal EN responses. The encoded data is further applied to a spiking neural network (SNN) for pattern classification. Two forms of SNN, a back-propagation based SpikeProp and a dynamic evolving SNN are used to learn the encoded responses. The effects of information encoding on the performance of SNNs have been investigated. Statistical tests have been performed to determine the contribution of the SNN and the encoding scheme to overall odour discrimination. The approach has been implemented in odour classification of orthodox black tea (Kangra-Himachal Pradesh Region) thereby demonstrating a biomimetic approach for EN data analysis. PMID:26356597

  20. Associations between self-reported odour annoyance and volatile organic compounds in 'Chemical Valley', Sarnia, Ontario.

    PubMed

    Atari, Dominic Odwa; Luginaah, Isaac N; Gorey, Kevin; Xu, Xiaohong; Fung, Karen

    2013-06-01

    Annoyance produced by air pollution has been suggested as a useful proxy for determining ambient air pollution exposure. However, most of the studies, to date, have focused on nitrogen dioxide and sulphur dioxide, with no work done on volatile organic compounds (VOC). This study is aimed at examining the associations between odour annoyance and VOC in 'Chemical Valley', Sarnia, Ontario, Canada. Annoyance scores were extracted from a community health survey (N = 774), and exposures to VOC were estimated from respondents' six-digit alphanumeric postal codes using land use regression models. Univariate analyses were used to explore the relationships between odour annoyance and modelled pollutants, whilst multivariate ordinal logistic regression was utilized to examine the determinants of odour annoyance. The results indicate that odour annoyance is significantly associated with modelled benzene, toluene, ethylbenzene, o-xylene and (m + p) xylene (BTEX) pollutants. The findings also show that the determinants of odour annoyance in the context of VOC include gender, number of relatives in the community, perception of air pollution, community satisfaction, medical checkups, ability to cope with daily life demands and general symptoms. When compared, the analysis indicates that Sarnia residents respond to considerably lower BTEX concentrations than the allowable 'safe' levels in the province of Ontario. In general, the results exhibit a dose-response gradient with annoyance score increasing with rising modelled pollutant concentrations. The observed relationships suggest that odour annoyance might be a function of true exposure and may serve as a proxy for air quality and ambient air pollution monitoring. However, questionnaire-based odour annoyance scores need to be longitudinally validated across different geographical scales and pollutants if they are to be adopted at the national level. PMID:23014924

  1. Voiced Initial Consonant Perception Deficits in Older Listeners with Hearing Loss and Good and Poor Word Recognition

    ERIC Educational Resources Information Center

    Phillips, Susan L.; Richter, Scott J.; McPherson, David

    2009-01-01

    Purpose: This study examined differences in voiced consonant-vowel (CV) perception in older listeners with normal hearing and in 2 groups of older listeners with matched hearing losses: those with good and those with poor word recognition scores. Method: Thirty-six participants identified CVs from an 8-item display from the natural voiced initial…

  2. Effects of auditory recognition learning on the perception of vocal features in European starlings (Sturnus vulgaris)

    PubMed Central

    Daniel Meliza, C.

    2011-01-01

    Learning to recognize complex sensory signals can change the way they are perceived. European starlings (Sturnus vulgaris) recognize other starlings by their song, which consists of a series of complex, stereotyped motifs. Song recognition learning is accompanied by plasticity in secondary auditory areas, suggesting that perceptual learning is involved. Here, to investigate whether perceptual learning can be observed behaviorally, a same–different operant task was used to measure how starlings perceived small differences in motif structure. Birds trained to recognize conspecific songs were better at detecting variations in motifs from the songs they learned, even though this variation was not directly necessary to learn the associative task. Discrimination also improved as the reference stimulus was repeated multiple times. Perception of the much larger differences between different motifs was unaffected by training. These results indicate that sensory representations of motifs are enhanced when starlings learn to recognize songs. PMID:22087940

  3. Manipulation of body odour alters men's self-confidence and judgements of their visual attractiveness by women.

    PubMed

    Craig Roberts, S; Little, A C; Lyndon, A; Roberts, J; Havlicek, J; Wright, R L

    2009-02-01

    Human body odour is important in modulating self-perception and interactions between individuals. Artificial fragrances have been used for thousands of years to manipulate personal odour, but the nature and extent of influences on person perception are relatively unexplored. Here we test the effects of a double-blind manipulation of personal odour on self-confidence and behaviour. We gave to male participants either an aerosol spray containing a formulation of fragrance and antimicrobial agents or an otherwise identical spray that lacked these active ingredients. Over several days, we found effects between treatment groups on psychometric self-confidence and self-perceived attractiveness. Furthermore, although there was no difference between groups in mean attractiveness ratings of men's photographs by a female panel, the same women judged men using the active spray as more attractive in video-clips, suggesting a behavioural difference between the groups. Attractiveness of an individual male's non-verbal behaviour, independent of structural facial features, was predicted by the men's self-reported proclivity towards the provided deodorant. Our results demonstrate the pervasive influence of personal odour on self-perception, and how this can extend to impressions on others even when these impressions are formed in the absence of odour cues. PMID:19134127

  4. Round robin test for odour testing of migration waters.

    PubMed

    Rapp, Thomas; Günther, Herbert

    2015-04-15

    For a round robin test for EN 1420-1 (Odour assessment for organic materials in contact with drinking water) with 14 contributing laboratories from 10 European countries segments of a plastic pipe were sent to the laboratories which performed a migration test and an odour analysis of the migration waters (water that had contact with the organic material) according to the procedure described in the standard from 1999. In addition reference substances (Methyl tert-butyl ether, 1-butanol and hexanal) were investigated for their suitability to qualify the panels and the individual panellists. Methyl tert-butyl ether (MtBE) and 1-butanol proved to be suitable for this purpose, whereas hexanal showed a wide distribution of the individual odour threshold concentrations. Both possible testing options (unforced and forced choice) were performed and gave similar results. However, with respect to the qualification of the panellists and the data analysis the unforced choice procedure showed advantages. As human olfactory perception is used for the analysis, the reproducibility and the comparability between laboratories is of particular concern. For the pipe material the TON results of the different laboratories were in a range of ±1.5 dilutions based on a dilution factor of 2. This might be improved by taking the individual sensitivities of the panellists into account more strongly. Appropriate measures for the improvement of the test method appear to be the use of the proposed reference substances for the training of the panellists as well as the auditing and the selection of the panellists. The results of this round robin test are used in the revision process of the standard. PMID:25687419

  5. Appetitive floral odours prevent aggression in honeybees.

    PubMed

    Nouvian, Morgane; Hotier, Lucie; Claudianos, Charles; Giurfa, Martin; Reinhard, Judith

    2015-01-01

    Honeybees defend their colonies aggressively against intruders and release a potent alarm pheromone to recruit nestmates into defensive tasks. The effect of floral odours on this behaviour has never been studied, despite the relevance of these olfactory cues for the biology of bees. Here we use a novel assay to investigate social and olfactory cues that drive defensive behaviour in bees. We show that social interactions are necessary to reveal the recruiting function of the alarm pheromone and that specific floral odours-linalool and 2-phenylethanol-have the surprising capacity to block recruitment by the alarm pheromone. This effect is not due to an olfactory masking of the pheromone by the floral odours, but correlates with their appetitive value. In addition to their potential applications, these findings provide new insights about how honeybees make the decision to engage into defence and how conflicting information affects this process. PMID:26694599

  6. Differential Odour Coding of Isotopomers in the Honeybee Brain

    PubMed Central

    Paoli, Marco; Anesi, Andrea; Antolini, Renzo; Guella, Graziano; Vallortigara, Giorgio; Haase, Albrecht

    2016-01-01

    The shape recognition model of olfaction maintains that odorant reception probes physicochemical properties such as size, shape, electric charge, and hydrophobicity of the ligand. Recently, insects were shown to distinguish common from deuterated isotopomers of the same odorant, suggesting the involvement of other molecular properties to odorant reception. Via two-photon functional microscopy we investigated how common and deuterated isoforms of natural odorants are coded within the honeybee brain. Our results provide evidence that (i) different isotopomers generate different neuronal activation maps, (ii) isotopomer sensitivity is a general mechanism common to multiple odorant receptors, and (iii) isotopomer specificity is highly consistent across individuals. This indicates that honeybee’s olfactory system discriminates between isotopomers of the same odorant, suggesting that other features, such as molecular vibrations, may contribute to odour signal transduction. PMID:26899989

  7. Speech Perception, Word Recognition and the Structure of the Lexicon. Research on Speech Perception Progress Report No. 10.

    ERIC Educational Resources Information Center

    Pisoni, David B.; And Others

    The results of three projects concerned with auditory word recognition and the structure of the lexicon are reported in this paper. The first project described was designed to test experimentally several specific predictions derived from MACS, a simulation model of the Cohort Theory of word recognition. The second project description provides the…

  8. Biotechnology-based odour control: design criteria and performance data.

    PubMed

    Quigley, C; Easter, C; Burrowes, P; Witherspoon, J

    2004-01-01

    As neighbouring areas continue to encroach upon wastewater treatment plants, there is an increasing need for odour control to mitigate potential negative offsite odorous impacts. One technology that is gaining widespread acceptance is biotechnology, which utilises the inherent ability of certain microorganisms to biodegrade offensive odorous compounds. Two main advantages of this form of treatment over other odour control technologies include the absence of hazardous chemicals and relatively low operation and maintenance requirements. The purpose of this paper is to provide information related to odour control design criteria used in sizing/selecting biotechnology-based odour control technologies, and to provide odour removal performance data obtained from several different biotechnology-based odour control systems. CH2M HILL has collected biotechnology-based odour control performance data over the last several years in order to track the continued performance of various biofilters and biotowers over time. Specifically, odour removal performance data have been collected from soil-, organic- and inorganic-media biofilters and inert inorganic media biotowers. Results indicate that biotechnology-based odour control is a viable and consistent technology capable of achieving high removal performance for odour and hydrogen sulphide. It is anticipated that the information presented in this paper will be of interest to anyone involved with odour control technology evaluation/selection or design review. PMID:15484776

  9. Impact assessment of odours emitted by a wastewater treatment plant.

    PubMed

    Beghi, Sandra P; Santos, Jane Méri; Reis, Neyval Costa; de Sá, Leandro Melo; Goulart, Elisa Valentim; de Abreu Costa, Elza

    2012-01-01

    Complaints from the Domingos Martins population about sewage odours in the city made the district attorney order an impact assessment of the odours emitted by the city wastewater treatment plant (WWTP). This study comprised various techniques, models and population surveys. In 2007, an odour emission model proved that the main hydrogen sulphide emitter was the aeration tank of the WWTP (13.5 g h(-1)) and such emissions, according to CALPUFF model, should be perceived in the whole Domingos Martins city centre area. In this area, 58% of those interviewed were annoyed by the WWTP odours. However, in 2009, the odour monitoring panel recorded few odour occurrences. A second population survey showed that hereafter only 20% of those interviewed were annoyed by the WWTP emissions. Odour emission and dispersion models run with 2010 data proved a drastic reduction of the WWTP aeration tank emissions and consequently the city centre was not bothered by WWTP emissions anymore. The odour emission reduction was due to the modification of the WWTP aeration tank system. Despite the odour emission reduction, houses located southeast of the WWTP were still annoyed by sewage odours. However, in this part of the town, other sources of sewage odours have been found. PMID:22949255

  10. Odour emissions from poultry litter - A review litter properties, odour formation and odorant emissions from porous materials.

    PubMed

    Dunlop, Mark W; Blackall, Patrick J; Stuetz, Richard M

    2016-07-15

    Odour emissions from meat chicken sheds can at times cause odour impacts on surrounding communities. Litter is seen as the primary source of this odour. Formation and emission of odour from meat chicken litter during the grow-out period are influenced by various factors such as litter conditions, the environment, microbial activity, properties of the odorous gases and management practices. Odour emissions vary spatially and temporally. This variability has made it challenging to understand how specific litter conditions contribute to odour emissions from the litter and production sheds. Existing knowledge on odorants, odour formation mechanisms and emission processes that contribute to odour emissions from litter are reviewed. Litter moisture content and water thermodynamics (i.e. water activity, Aw) are also examined as factors that contribute to microbial odour formation, physical litter conditions and the exchange of individual odorant gases at the air-water interface. Substantial opportunities exist for future research on litter conditions and litter formation mechanisms and how these contribute to odour emissions. Closing this knowledge gap will improve management strategies that intercept and interfere with odour formation and emission processes leading to an overall reduction in the potential to cause community impacts. PMID:27111649

  11. Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male's odour

    PubMed Central

    2010-01-01

    Background Among invertebrates, specific pheromones elicit inherent (fixed) behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing for individual-specific choice? We hypothesized that male mouse urine contains a specific pheromonal component that invokes inherent sexual attraction to the scent and which also stimulates female memory and conditions sexual attraction to the airborne odours of an individual scent owner associated with this pheromone. Results Using wild-stock house mice to ensure natural responses that generalize across individual genomes, we identify a single atypical male-specific major urinary protein (MUP) of mass 18893Da that invokes a female's inherent sexual attraction to male compared to female urinary scent. Attraction to this protein pheromone, which we named darcin, was as strong as the attraction to intact male urine. Importantly, contact with darcin also stimulated a strong learned attraction to the associated airborne urinary odour of an individual male, such that, subsequently, females were attracted to the airborne scent of that specific individual but not to that of other males. Conclusions This involatile protein is a mammalian male sex pheromone that stimulates a flexible response to individual-specific odours through associative learning and memory, allowing female sexual attraction to be inherent but selective towards particular males. This 'darcin effect' offers a new system to investigate the neural basis of individual-specific memories in the brain and give new insights into the regulation of behaviour in complex social mammals. See associated Commentary http

  12. RecceMan: an interactive recognition assistance for image-based reconnaissance: synergistic effects of human perception and computational methods for object recognition, identification, and infrastructure analysis

    NASA Astrophysics Data System (ADS)

    El Bekri, Nadia; Angele, Susanne; Ruckhäberle, Martin; Peinsipp-Byma, Elisabeth; Haelke, Bruno

    2015-10-01

    This paper introduces an interactive recognition assistance system for imaging reconnaissance. This system supports aerial image analysts on missions during two main tasks: Object recognition and infrastructure analysis. Object recognition concentrates on the classification of one single object. Infrastructure analysis deals with the description of the components of an infrastructure and the recognition of the infrastructure type (e.g. military airfield). Based on satellite or aerial images, aerial image analysts are able to extract single object features and thereby recognize different object types. It is one of the most challenging tasks in the imaging reconnaissance. Currently, there are no high potential ATR (automatic target recognition) applications available, as consequence the human observer cannot be replaced entirely. State-of-the-art ATR applications cannot assume in equal measure human perception and interpretation. Why is this still such a critical issue? First, cluttered and noisy images make it difficult to automatically extract, classify and identify object types. Second, due to the changed warfare and the rise of asymmetric threats it is nearly impossible to create an underlying data set containing all features, objects or infrastructure types. Many other reasons like environmental parameters or aspect angles compound the application of ATR supplementary. Due to the lack of suitable ATR procedures, the human factor is still important and so far irreplaceable. In order to use the potential benefits of the human perception and computational methods in a synergistic way, both are unified in an interactive assistance system. RecceMan® (Reconnaissance Manual) offers two different modes for aerial image analysts on missions: the object recognition mode and the infrastructure analysis mode. The aim of the object recognition mode is to recognize a certain object type based on the object features that originated from the image signatures. The

  13. The Relationship between Odour Annoyance Scores and Modelled Ambient Air Pollution in Sarnia, “Chemical Valley”, Ontario

    PubMed Central

    Atari, Dominic Odwa; Luginaah, Isaac N.; Fung, Karen

    2009-01-01

    This study aimed at establishing the relationship between annoyance scores and modelled air pollution in “Chemical Valley”, Sarnia, Ontario (Canada). Annoyance scores were taken from a community health survey (N = 774); and respondents’ exposure to nitrogen dioxide (NO2) and sulphur dioxide (SO2) were estimated using land use regression (LUR) models. The associations were examined by univariate analysis while multivariate logistic regression was used to examine the determinants of odour annoyance. The results showed that odour annoyance was significantly correlated to modelled pollutants at the individual (NO2, r = 0.15; SO2, r = 0.13) and census tract (NO2, r = 0.56; SO2, r = 0.67) levels. The exposure-response relationships show that residents of Sarnia react to very low pollution concentrations levels even if they are within the Ontario ambient air quality criteria. The study found that exposure to high NO2 and SO2 concentrations, gender, and perception of health effects were significant determinants of individual odour annoyance reporting. The observed association between odour annoyance and modelled ambient pollution suggest that individual and census tract level annoyance scores may serve as proxies for air quality in exposed communities because they capture the within area spatial variability of pollution. However, questionnaire-based odour annoyance scores need to be validated longitudinally and across different scales if they are to be adopted for use at the national level. PMID:20054461

  14. Cockroach aggregation: discrimination between strain odours in Blattella germanica

    PubMed

    Rivault; Cloarec

    1998-01-01

    Behavioural experiments on gregariousness in larval German cockroaches, Blattella germanica (L.), confirmed that this species deposits an aggregation pheromone by body contact. Choice tests with groups of larvae indicated that they were preferentially attracted to papers conditioned by the odour of their conspecifics, although they were able to aggregate on clean paper in the absence of cockroach odour. Individual larvae were able to recognize the odour of their own population or strain in the absence of conspecifics. The odour was produced and perceived by larvae at all developmental stages. We report, for the first time, experiments comparing the relative attractiveness of odours of strains from different locations: larval cockroaches were able to discriminate and recognize the odour of members of their own strain. Our results showed that different strains have variations of a specific odour. All experimental strains had similar discriminatory capacities and all preferred the odour of their own strain. When larvae were presented with a choice between odours from two unfamiliar strains, they appeared to avoid these odours. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9480684

  15. Deficits in audiovisual speech perception in normal aging emerge at the level of whole-word recognition

    PubMed Central

    Stevenson, Ryan A.; Nelms, Caitlin; Baum, Sarah H.; Zurkovsky, Lilia; Barense, Morgan D.; Newhouse, Paul A.; Wallace, Mark T.

    2014-01-01

    Over the next two decades, a dramatic shift in the demographics of society will take place, with a rapid growth in the population of older adults. One of the most common complaints with healthy aging is a decreased ability to successfully perceive speech, particularly in noisy environments. In such noisy environments, the presence of visual speech cues (i.e., lip movements) provide striking benefits for speech perception and comprehension, but previous research suggests that older adults gain less from such audiovisual integration than their younger peers. To determine at what processing level these behavioral differences arise in healthy-aging populations, we administered a speech-in-noise task to younger and older adults. We compared the perceptual benefits of having speech information available in both the auditory and visual modalities and examined both phoneme and whole-word recognition across varying levels of signal-to-noise ratio (SNR). For whole-word recognition, older relative to younger adults showed greater multisensory gains at intermediate SNRs, but reduced benefit at low SNRs. By contrast, at the phoneme level both younger and older adults showed approximately equivalent increases in multisensory gain as SNR decreased. Collectively, the results provide important insights into both the similarities and differences in how older and younger adults integrate auditory and visual speech cues in noisy environments, and help explain some of the conflicting findings in previous studies of multisensory speech perception in healthy aging. These novel findings suggest that audiovisual processing is intact at more elementary levels of speech perception in healthy aging populations, and that deficits begin to emerge only at the more complex, word-recognition level of speech signals. PMID:25282337

  16. Appetitive floral odours prevent aggression in honeybees

    PubMed Central

    Nouvian, Morgane; Hotier, Lucie; Claudianos, Charles; Giurfa, Martin; Reinhard, Judith

    2015-01-01

    Honeybees defend their colonies aggressively against intruders and release a potent alarm pheromone to recruit nestmates into defensive tasks. The effect of floral odours on this behaviour has never been studied, despite the relevance of these olfactory cues for the biology of bees. Here we use a novel assay to investigate social and olfactory cues that drive defensive behaviour in bees. We show that social interactions are necessary to reveal the recruiting function of the alarm pheromone and that specific floral odours—linalool and 2-phenylethanol—have the surprising capacity to block recruitment by the alarm pheromone. This effect is not due to an olfactory masking of the pheromone by the floral odours, but correlates with their appetitive value. In addition to their potential applications, these findings provide new insights about how honeybees make the decision to engage into defence and how conflicting information affects this process. PMID:26694599

  17. Revisiting vocal perception in non-human animals: a review of vowel discrimination, speaker voice recognition, and speaker normalization

    PubMed Central

    Kriengwatana, Buddhamas; Escudero, Paola; ten Cate, Carel

    2015-01-01

    The extent to which human speech perception evolved by taking advantage of predispositions and pre-existing features of vertebrate auditory and cognitive systems remains a central question in the evolution of speech. This paper reviews asymmetries in vowel perception, speaker voice recognition, and speaker normalization in non-human animals – topics that have not been thoroughly discussed in relation to the abilities of non-human animals, but are nonetheless important aspects of vocal perception. Throughout this paper we demonstrate that addressing these issues in non-human animals is relevant and worthwhile because many non-human animals must deal with similar issues in their natural environment. That is, they must also discriminate between similar-sounding vocalizations, determine signaler identity from vocalizations, and resolve signaler-dependent variation in vocalizations from conspecifics. Overall, we find that, although plausible, the current evidence is insufficiently strong to conclude that directional asymmetries in vowel perception are specific to humans, or that non-human animals can use voice characteristics to recognize human individuals. However, we do find some indication that non-human animals can normalize speaker differences. Accordingly, we identify avenues for future research that would greatly improve and advance our understanding of these topics. PMID:25628583

  18. Calculation of odour emissions from aircraft engines at Copenhagen Airport.

    PubMed

    Winther, Morten; Kousgaard, Uffe; Oxbøl, Arne

    2006-07-31

    In a new approach the odour emissions from aircraft engines at Copenhagen Airport are calculated using actual fuel flow and emission measurements (one main engine and one APU: Auxiliary Power Unit), odour panel results, engine specific data and aircraft operational data for seven busy days. The calculation principle assumes a linear relation between odour and HC emissions. Using a digitalisation of the aircraft movements in the airport area, the results are depicted on grid maps, clearly reflecting aircraft operational statistics as single flights or total activity during a whole day. The results clearly reflect the short-term temporal fluctuations of the emissions of odour (and exhaust gases). Aircraft operating at low engine thrust (taxiing, queuing and landing) have a total odour emission share of almost 98%, whereas the shares for the take off/climb out phases (2%) and APU usage (0.5%) are only marginal. In most hours of the day, the largest odour emissions occur, when the total amount of fuel burned during idle is high. However, significantly higher HC emissions for one specific engine cause considerable amounts of odour emissions during limited time periods. The experimentally derived odour emission factor of 57 OU/mg HC is within the range of 23 and 110 OU/mg HC used in other airport odour studies. The distribution of odour emission results between aircraft operational phases also correspond very well with the results for these other studies. The present study uses measurement data for a representative engine. However, the uncertainties become large when the experimental data is used to estimate the odour emissions for all aircraft engines. More experimental data is needed to increase inventory accuracy, and in terms of completeness it is recommended to make odour emission estimates also for engine start and the fuelling of aircraft at Copenhagen Airport in the future. PMID:16194561

  19. Self-recognition in the perception of actions performed in synchrony with music.

    PubMed

    Sevdalis, Vassilis; Keller, Peter E

    2009-07-01

    This study investigated self-recognition in point-light displays depicting actions performed in synchrony with music. Participants were recorded executing three different actions (dancing, walking, and clapping) and were subsequently required to identify the agent (self versus other) from point-light displays with or without the accompanying music. Results indicate that while recognition accuracy was better than chance for all actions, it was best for the relatively complex dance actions. The presence of music did not affect accuracy, suggesting that self-recognition was based on information about personal movement kinematics rather than individual differences in synchrony between movements and music. PMID:19673830

  20. Odour-based recognition of nectar in cursorial spiders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasingly, carnivorous arthropods are known to feed on plant-derived foods, such as honeydew, pollen, and nectar. Consumption of saccharides from non-prey food in spiders that ambush or stalk their prey also appears to be more widespread than previously thought. This is not surprising, since in...

  1. Odour emission ability (OEA) and its application in assessing odour removal efficiency.

    PubMed

    Wang, Xinguang; Parcsi, Gavin; Sivret, Eric; Le, Hung; Wang, Bei; Stuetz, Richard M

    2012-01-01

    Odourous emissions from sewer networks and wastewater treatment plants (WWTPs) can significantly impact a local population. Sampling techniques such as wind tunnels and flux hood chambers are traditionally used to collect area source samples for subsequent quantification of odour emission rates using dilution olfactometry, however these methods are unsuitable for assessing liquid samples from point sources due to the large liquid volumes required. To overcome this limitation, a gas phase sample preparation method was developed for assessing the total Odour Emission Ability (OEA) from a liquid sample. The method was validated using two volatile organic sulphur compounds (VOSCs), dimethyl-trisulphide (DMTS) and bismethylthiomethane (BMTM) that are frequently detected from sewers and WWTPs and are relatively stable compared with common VOSCs like mercaptan or methyl mercaptan. The recovery rates of DMTS and BMTM were quantified by injecting a known volume of a standard liquid sample into Tedlar bags using a static injection and a dynamic injection methodology. It was confirmed that both dynamic and static injection methods at ambient condition achieved high recovery rates with no need to consider increasing evaporation by elevating the temperature. This method can also be used to assess odour removal effectiveness of liquids by comparing the OEA before and after the treatment tests. Two application examples were presented. PMID:22925852

  2. Odourant dominance in olfactory mixture processing: what makes a strong odourant?

    PubMed Central

    Schubert, Marco; Sandoz, Jean-Christophe; Galizia, Giovanni; Giurfa, Martin

    2015-01-01

    The question of how animals process stimulus mixtures remains controversial as opposing views propose that mixtures are processed analytically, as the sum of their elements, or holistically, as unique entities different from their elements. Overshadowing is a widespread phenomenon that can help decide between these alternatives. In overshadowing, an individual trained with a binary mixture learns one element better at the expense of the other. Although element salience (learning success) has been suggested as a main explanation for overshadowing, the mechanisms underlying this phenomenon remain unclear. We studied olfactory overshadowing in honeybees to uncover the mechanisms underlying olfactory-mixture processing. We provide, to our knowledge, the most comprehensive dataset on overshadowing to date based on 90 experimental groups involving more than 2700 bees trained either with six odourants or with their resulting 15 binary mixtures. We found that bees process olfactory mixtures analytically and that salience alone cannot predict overshadowing. After normalizing learning success, we found that an unexpected feature, the generalization profile of an odourant, was determinant for overshadowing. Odourants that induced less generalization enhanced their distinctiveness and became dominant in the mixture. Our study thus uncovers features that determine odourant dominance within olfactory mixtures and allows the referring of this phenomenon to differences in neural activity both at the receptor and the central level in the insect nervous system. PMID:25652840

  3. Parameters for the assessment of odour impacts on communities

    NASA Astrophysics Data System (ADS)

    Henshaw, Paul; Nicell, James; Sikdar, Anamika

    Odorous emissions are the cause of most air pollution complaints that are made by the public to regulatory agencies. Methods need to be developed to objectively access the impact of odours so that odour-producing facilities have a pro-active means of reducing their impact on surrounding communities. These methods must consider the sub- and supra-threshold effects of odour over the range of concentrations that can be experienced as the odour disperses over a community. In addition, the influence of local meteorological and terrain conditions can be accommodated through conventional dispersion models. However, metrics of odour impact need to be developed which take into account the concentration and frequency of odours at receptors, as well as the population density at those receptors. This paper proposes and demonstrates the use of six impact parameters that may be used as metrics of the impact of a stationary odour source on a community. These odour impact parameters are maximum concentration, maximum probability of response, footprint area, concentration-weighted footprint area, probability-weighted footprint area and population impact. The utility of these parameters were demonstrated by evaluating them to quantify the impact of an industrial facility that produces an odorous chemical.

  4. Reduction of odours in pilot-scale landfill biocovers.

    PubMed

    Capanema, M A; Cabana, H; Cabral, A R

    2014-04-01

    Unpleasant odours generated from waste management facilities represent an environmental and societal concern. This multi-year study documented odour and total reduced sulfur (TRS) abatement in four experimental landfill biocovers installed on the final cover of the Saint-Nicéphore landfill (Canada). Performance was evaluated based on the reduction in odour and TRS concentrations between the raw biogas collected from a dedicated well and the emitted gases at the surface. Odour analyses were carried out by the sensorial technique of olfactometry, whereas TRS analyses followed the pulse fluorescence technique. The large difference of 2-5 orders of magnitude between raw biogas (average odour concentration=2,100,000OUm(-3)) and emitted gases resulted in odour removal efficiencies of close to 100% for all observations. With respect to TRS concentrations, abatement efficiencies were all greater than 95%, with values averaging 21,000ppb of eq. SO2 in the raw biogas. The influence of water infiltration on odour concentrations was documented and showed that lower odour values were obtained when the 48-h accumulated precipitation prior to sampling was higher. PMID:24556264

  5. Social odours, sexual arousal and pairbonding in primates

    PubMed Central

    Snowdon, Charles T; Ziegler, Toni E; Schultz-Darken, Nancy J; Ferris, Craig F

    2006-01-01

    We describe the role of social odours in sexual arousal and maintaining pairbonds in biparental and cooperatively breeding primates. Social odours are complex chemical mixtures produced by an organism that can simultaneously provide information about species, kinship, sex, individuality and reproductive state. They are long lasting and have advantages over other modalities. Both sexes are sensitive to changes in odours over the reproductive cycle and experimental disruption of signals can lead to altered sexual behaviour within a pair. We demonstrate, using functional magnetic resonance imaging (fMRI), that social odours indicating reproductive state directly influence the brain areas responsible for sexual behaviour. Social odours also influence other brain areas typically involved in motivation, memory and decision making, suggesting that these signals have more complex functions in primates than mere sexual arousal. We demonstrate a rapid link between social odours and neuroendocrine responses that are modulated by a male's social status. Recent work on humans shows similar responses to social odours. We conclude with an integration of the importance of social odours on sexual arousal and maintaining pairbonds in socially biparental and cooperatively breeding species, suggesting new research directions to integrate social behaviour, neural activation and neuroendocrine responses. PMID:17118925

  6. Colour preferences influences odour learning in the hawkmoth, Macroglossum stellatarum

    NASA Astrophysics Data System (ADS)

    Balkenius, Anna; Kelber, Almut

    2006-05-01

    The hummingbird hawkmoth, Macroglossum stellatarum, learns colour fast and reliably. It has earlier been shown to spontaneously feed from odourless artificial flowers. Now, we have studied odour learning. The moths were trained to discriminate feeders of the same colour but marked with different odours. They did not learn to discriminate two natural flower odours when they were presented with the innately preferred colour blue, but they did learn this discrimination combined with yellow or green colours that are less attractive to the moth. The yellow colour could be trained to become as attractive as the innately preferred blue colour and the blue colour could be trained to become less attractive. This is the first proof of odour learning in a diurnal moth. The results show that M. stellatarum can use more than one modality in their foraging behaviour and that the system is plastic. By manipulating the preferences for the different colours, their influence on odour learning could be changed.

  7. Insulin modulates network activity in olfactory bulb slices: impact on odour processing.

    PubMed

    Kuczewski, Nicola; Fourcaud-Trocmé, Nicolas; Savigner, Agnès; Thevenet, Marc; Aimé, Pascaline; Garcia, Samuel; Duchamp-Viret, Patricia; Palouzier-Paulignan, Brigitte

    2014-07-01

    Odour perception depends closely on nutritional status, in animals as in humans. Insulin, the principal anorectic hormone, appears to be one of the major candidates for ensuring the link between olfactory abilities and nutritional status, by modifying processing in the olfactory bulb (OB), one of its main central targets. The present study investigates whether and how insulin can act in OB, by evaluating its action on the main output neurons activities, mitral cells (MCs), in acute rat OB slices. Insulin was found to act at two OB network levels: (1) on MCs, by increasing their excitability, probably by inhibiting two voltage-gated potassium (K(+)) channels; (2) on interneurons by modifying the GABAergic and on glutamatergic synaptic activity impinging on MCs, mainly reducing them. Insulin also altered the olfactory nerve (ON)-evoked excitatory postsynaptic currents in 60% of MCs. Insulin decreased or increased the ON-evoked responses in equal proportion and the direction of its effect depended on the initial neuron ON-evoked firing rate. Indeed, insulin tended to decrease the high and to increase the low ON-evoked firing rates, thereby reducing inter-MC response firing variability. Therefore, the effects of insulin on the evoked firing rates were not carried out indiscriminately in the MC population. By constructing a mathematical model, the impact of insulin complex effects on OB was assessed at the population activity level. The model shows that the reduction of variability across cells could affect MC detection and discrimination abilities, mainly by decreasing and, less frequently, increasing them, depending on odour quality. Thus, as previously proposed, this differential action of insulin on MCs across odours would allow this hormone to put the olfactory function under feeding signal control, given the discerning valence of an odour as a function of nutritional status. PMID:24710056

  8. Insulin modulates network activity in olfactory bulb slices: impact on odour processing

    PubMed Central

    Kuczewski, Nicola; Fourcaud-Trocmé, Nicolas; Savigner, Agnès; Thevenet, Marc; Aimé, Pascaline; Garcia, Samuel; Duchamp-Viret, Patricia; Palouzier-Paulignan, Brigitte

    2014-01-01

    Odour perception depends closely on nutritional status, in animals as in humans. Insulin, the principal anorectic hormone, appears to be one of the major candidates for ensuring the link between olfactory abilities and nutritional status, by modifying processing in the olfactory bulb (OB), one of its main central targets. The present study investigates whether and how insulin can act in OB, by evaluating its action on the main output neurons activities, mitral cells (MCs), in acute rat OB slices. Insulin was found to act at two OB network levels: (1) on MCs, by increasing their excitability, probably by inhibiting two voltage-gated potassium (K+) channels; (2) on interneurons by modifying the GABAergic and on glutamatergic synaptic activity impinging on MCs, mainly reducing them. Insulin also altered the olfactory nerve (ON)-evoked excitatory postsynaptic currents in 60% of MCs. Insulin decreased or increased the ON-evoked responses in equal proportion and the direction of its effect depended on the initial neuron ON-evoked firing rate. Indeed, insulin tended to decrease the high and to increase the low ON-evoked firing rates, thereby reducing inter-MC response firing variability. Therefore, the effects of insulin on the evoked firing rates were not carried out indiscriminately in the MC population. By constructing a mathematical model, the impact of insulin complex effects on OB was assessed at the population activity level. The model shows that the reduction of variability across cells could affect MC detection and discrimination abilities, mainly by decreasing and, less frequently, increasing them, depending on odour quality. Thus, as previously proposed, this differential action of insulin on MCs across odours would allow this hormone to put the olfactory function under feeding signal control, given the discerning valence of an odour as a function of nutritional status. PMID:24710056

  9. Sign Perception and Recognition in Non-Native Signers of ASL

    PubMed Central

    Morford, Jill P.; Carlson, Martina L.

    2011-01-01

    Past research has established that delayed first language exposure is associated with comprehension difficulties in non-native signers of American Sign Language (ASL) relative to native signers. The goal of the current study was to investigate potential explanations of this disparity: do non-native signers have difficulty with all aspects of comprehension, or are their comprehension difficulties restricted to some aspects of processing? We compared the performance of deaf non-native, hearing L2, and deaf native signers on a handshape and location monitoring and a sign recognition task. The results indicate that deaf non-native signers are as rapid and accurate on the monitoring task as native signers, with differences in the pattern of relative performance across handshape and location parameters. By contrast, non-native signers differ significantly from native signers during sign recognition. Hearing L2 signers, who performed almost as well as the two groups of deaf signers on the monitoring task, resembled the deaf native signers more than the deaf non-native signers on the sign recognition task. The combined results indicate that delayed exposure to a signed language leads to an overreliance on handshape during sign recognition. PMID:21686080

  10. Liberated Learning: Analysis of University Students' Perceptions and Experiences with Continuous Automated Speech Recognition

    ERIC Educational Resources Information Center

    Ryba, Ken; McIvor, Tom; Shakir, Maha; Paez, Di

    2006-01-01

    This study examined continuous automated speech recognition in the university lecture theatre. The participants were both native speakers of English (L1) and English as a second language students (L2) enrolled in an information systems course (Total N=160). After an initial training period, an L2 lecturer in information systems delivered three…

  11. Speech Recognition Software for Language Learning: Toward an Evaluation of Validity and Student Perceptions

    ERIC Educational Resources Information Center

    Cordier, Deborah

    2009-01-01

    A renewed focus on foreign language (FL) learning and speech for communication has resulted in computer-assisted language learning (CALL) software developed with Automatic Speech Recognition (ASR). ASR features for FL pronunciation (Lafford, 2004) are functional components of CALL designs used for FL teaching and learning. The ASR features…

  12. The Central Role of Recognition in Auditory Perception: A Neurobiological Model

    ERIC Educational Resources Information Center

    McLachlan, Neil; Wilson, Sarah

    2010-01-01

    The model presents neurobiologically plausible accounts of sound recognition (including absolute pitch), neural plasticity involved in pitch, loudness and location information integration, and streaming and auditory recall. It is proposed that a cortical mechanism for sound identification modulates the spectrotemporal response fields of inferior…

  13. Pigeon navigation: exposure to environmental odours prior to release is sufficient for homeward orientation, but not for homing.

    PubMed

    Gagliardo, Anna; Pollonara, Enrica; Wikelski, Martin

    2016-08-15

    The role of environmental olfactory information in pigeon navigation has been extensively studied by analysing vanishing bearing distributions and homing performances of homing pigeons subjected to manipulation of their olfactory perception and/or the olfactory information they were exposed to during transportation and at the release site. However, their behaviour during the homing flight remains undocumented. In this experiment we report the analysis of tracks of birds made anosmic at the release site by washing their olfactory mucosa with zinc sulfate. We thus can assess the role of local odours at the release site as well as the role of environmental odours perceived on the way, far from the release site. We observed that pigeons transported and kept at the release site in purified air and made anosmic at the release site were unable to orient towards home and were impaired at homing. By contrast, pigeons allowed to smell environmental odours during transportation and at the release site, although made anosmic prior to release, displayed unimpaired homeward orientation, but nevertheless showed impaired homing performance. These results are consistent with the view that local odours at the release site are critical for determining the direction of displacement (olfactory map) and suggest that pigeons consult the olfactory map also during their homing flight in order to be able to find their way home. PMID:27284069

  14. Sing that tune: infants' perception of melody and lyrics and the facilitation of phonetic recognition in songs.

    PubMed

    Lebedeva, Gina C; Kuhl, Patricia K

    2010-12-01

    To better understand how infants process complex auditory input, this study investigated whether 11-month-old infants perceive the pitch (melodic) or the phonetic (lyric) components within songs as more salient, and whether melody facilitates phonetic recognition. Using a preferential looking paradigm, uni-dimensional and multi-dimensional songs were tested; either the pitch or syllable order of the stimuli varied. As a group, infants detected a change in pitch order in a 4-note sequence when the syllables were redundant (experiment 1), but did not detect the identical pitch change with variegated syllables (experiment 2). Infants were better able to detect a change in syllable order in a sung sequence (experiment 2) than the identical syllable change in a spoken sequence (experiment 1). These results suggest that by 11 months, infants cannot "ignore" phonetic information in the context of perceptually salient pitch variation. Moreover, the increased phonetic recognition in song contexts mirrors findings that demonstrate advantages of infant-directed speech. Findings are discussed in terms of how stimulus complexity interacts with the perception of sung speech in infancy. PMID:20472295

  15. Odour emission characteristics of 22 recreational rivers in Nanjing.

    PubMed

    Wan, Yu; Ruan, Xiaohong; Wang, Xinguang; Ma, Qian; Lu, Xiaoming

    2014-10-01

    The odour emission characteristics of 22 recreational rivers in Nanjing were investigated and analysed. Eight odorous compounds (ammonia (NH₃), hydrogen sulphide (H₂S), sulphur dioxide (SO₂), carbon disulphide (CS₂), nitrobenzene (C₆H₅NO₂), aniline (C₆H₅NH₂), dimethylamine (C₂H₇N), and formaldehyde (HCHO)) were measured in odour emission samples collected using a custom-made emission flux hood chamber. The results showed that all odorants were detected in all monitoring rivers. NH₃ was the main odorant, with emission rates ranging from 4.86 to 15.13 μg/min m(2). The total odour emission rate of the Nan River, at 1 427.07 OU/s, was the highest of the all investigated rivers. H₂S, NH₃ and nitrobenzene were three key odour emission contributors according to their contributions to the total odour emission. A correlation analysis of the pollutants showed there was a significant positive correlation between the emission rate of NH₃ and the concentration of ammonia nitrogen (NH₄ (+)-N) and total nitrogen (TN). The H₂S and SO₂ emission rates had a significant positive correlation with sulphides (S(2-)) and available sulphur (AS) in the water and sediment. The content of TN, NH₄(+)-N, S(2-) and AS in the water and sediment affected the concentration of H₂S, SO₂ and NH₃ in the emission gases. NH₄(+)-N, S(2-) and AS are suggested as the key odour control indexes for reducing odours emitted from these recreational rivers. The study provides useful information for effective pollution control, especially for odour emission control for the recreational rivers of the city. It also provides a demonstrate example to show how to monitor and assess a contaminated river when odour emission and its control need to be focused on. PMID:24939710

  16. Odour emission factors for the prediction of odour emissions from plants for the mechanical and biological treatment of MSW

    NASA Astrophysics Data System (ADS)

    Sironi, Selena; Capelli, Laura; Céntola, Paolo; Del Rosso, Renato; Il Grande, Massimiliano

    In this study, the results of odour concentration measurements sampled from the principal odour sources of 40 dimensionally different and representative Italian waste mechanical and biological treatment (MBT) plants are presented. Experimental data are then used to estimate the odour emission factors (OEFs) relevant to single-process steps. An OEF is a representative value that relates the quantity of odour released to the atmosphere to a specific activity index, which may be for example the waste treatment capacity, the gross weight production, the site surface or a time unit. In this study, the OEFs were calculated as a function of the plant capacity, and expressed in ou E t -1, because of the existence of a proportionality between plant capacity and odour emissions. The results show that the major odour source of a waste MBT plant is represented by the aerobic biological treatment (with an OEF equal to 1.40×10 8 ou E t -1). In general, the OEFs calculated according to this approach represent a model for a rough prediction of odour emissions independently from the specific characteristics of the different plants.

  17. Kin recognition and the 'armpit effect': evidence of self-referent phenotype matching.

    PubMed

    Mateo, J M; Johnston, R E

    2000-04-01

    In species with multiple paternity or maternity, animals may best assess their relatedness to unfamiliar conspecifics by comparing their own phenotype(s) with those of unidentified individuals. Yet whether animals can recognize kin through self-matching is controversial. Because golden hamsters (Mesocricetus auratus) mate multiply and can produce multiply sired litters, they were tested for their ability to use self-matching for kin recognition. Hamsters that were reared only with non-kin since birth responded differentially to odours of unfamiliar relatives and non-relatives. Postnatal association with kin was not necessary for this discrimination. Prenatal learning was unlikely because of delayed production and perception of social odours. To our knowledge, this is the first demonstration that a vertebrate can use its own phenotype for kin-recognition purposes without prior experience with kin. By using itself as a referent, rather than its siblings or parents, a golden hamster may be better able to direct nepotism towards the most appropriate individuals. Kin discrimination via self-inspection may be especially important in nepotistic contexts (to identify most closely related conspecifics), whereas inclusion of the phenotypes of close kin as referents may be favoured in mate-choice contexts (to identify all related individuals). PMID:10821615

  18. Kiwifruit Flower Odor Perception and Recognition by Honey Bees, Apis mellifera.

    PubMed

    Twidle, Andrew M; Mas, Flore; Harper, Aimee R; Horner, Rachael M; Welsh, Taylor J; Suckling, David M

    2015-06-17

    Volatile organic compounds (VOCs) from male and female kiwifruit (Actinidia deliciosa 'Hayward') flowers were collected by dynamic headspace sampling. Honey bee (Apis mellifera) perception of the flower VOCs was tested using gas chromatography coupled to electroantennogram detection. Honey bees consistently responded to six compounds present in the headspace of female kiwifruit flowers and five compounds in the headspace of male flowers. Analysis of the floral volatiles by gas chromatography-mass spectrometry and microscale chemical derivatization showed the compounds to be nonanal, 2-phenylethanol, 4-oxoisophorone, (3E,6E)-α-farnesene, (6Z,9Z)-heptadecadiene, and (8Z)-heptadecene. Bees were then trained via olfactory conditioning of the proboscis extension response (PER) to synthetic mixtures of these compounds using the ratios present in each flower type. Honey bees trained to the synthetic mixtures showed a high response to the natural floral extracts, indicating that these may be the key compounds for honey bee perception of kiwifruit flower odor. PMID:26027748

  19. Linking ligand perception by PEPR pattern recognition receptors to cytosolic Ca2+ elevation and downstream immune signaling in plants

    PubMed Central

    Walker, Robin K.; Zhao, Yichen; Berkowitz, Gerald A.

    2012-01-01

    Little is known about molecular steps linking perception of pathogen invasion by cell surface sentry proteins acting as pattern recognition receptors (PRRs) to downstream cytosolic Ca2+ elevation, a critical step in plant immune signaling cascades. Some PRRs recognize molecules (such as flagellin) associated with microbial pathogens (pathogen-associated molecular patterns, PAMPs), whereas others bind endogenous plant compounds (damage-associated molecular patterns, DAMPs) such as peptides released from cells upon attack. This work focuses on the Arabidopsis DAMPs plant elicitor peptides (Peps) and their receptors, PEPR1 and PEPR2. Pep application causes in vivo cGMP generation and downstream signaling that is lost when the predicted PEPR receptor guanylyl cyclase (GC) active site is mutated. Pep-induced Ca2+ elevation is attributable to cGMP activation of a Ca2+ channel. Some differences were identified between Pep/PEPR signaling and the Ca2+-dependent immune signaling initiated by the flagellin peptide flg22 and its cognate receptor Flagellin-sensing 2 (FLS2). FLS2 signaling may have a greater requirement for intracellular Ca2+ stores and inositol phosphate signaling, whereas Pep/PEPR signaling requires extracellular Ca2+. Maximal FLS2 signaling requires a functional Pep/PEPR system. This dependence was evidenced as a requirement for functional PEPR receptors for maximal flg22-dependent Ca2+ elevation, H2O2 generation, defense gene [WRKY33 and Plant Defensin 1.2 (PDF1.2)] expression, and flg22/FLS2-dependent impairment of pathogen growth. In a corresponding fashion, FLS2 loss of function impaired Pep signaling. In addition, a role for PAMP and DAMP perception in bolstering effector-triggered immunity (ETI) is reported; loss of function of either FLS2 or PEPR receptors impaired the hypersensitive response (HR) to an avirulent pathogen. PMID:23150556

  20. A comparative and critical evaluation of odour assessment methods on a landfill site

    NASA Astrophysics Data System (ADS)

    Capelli, Laura; Sironi, Selena; Del Rosso, Renato; Céntola, Paolo; Il Grande, Massimiliano

    This paper discusses the application of three different odour characterization techniques, i.e. chemical analyses, dynamic olfactometry and electronic noses, for the assessment of odour emissions from a landfill site. The results of the chemical analyses, which are useful to determine the chemical composition of odours, show no correlation with the odour concentration values measured by dynamic olfactometry. Olfactometric analyses enabled to measure odour concentration and thereby to quantify the sensory impact of odours. Finally, the continuous ambient air monitoring by electronic noses allowed to quantify the time percentage in which odours are detected at the landfill boundaries and at a receptor, which always turned out to be lower than 15%. This study represents a critical review of employing three different odour characterization methods for differing reasons on the same site, showing that, whilst the results don't necessarily correlate, they do have an intrinsic value, and therefore demonstrating the complexity of environmental odour measurement.

  1. Identification of gases responsible for the odour of human flatus and evaluation of a device purported to reduce this odour

    PubMed Central

    Suarez, F; Springfield, J; Levitt, M

    1998-01-01

    Background/Aims—While the social significance of flatus derives mainly from its odour, previous studies have focused on the non-odoriferous components of rectal gas. The aims of the present study were to determine the role of sulphur-containing gases in flatus odour and test the efficacy of a device purported to reduce this odour. 
Methods—Flatus was quantitatively collected via rectal tube from 16 healthy subjects who ingested pinto beans and lactulose to enhance flatus output. The concentrations of sulphur-containing gases in each passage were correlated with odour intensity assessed by two judges. Odour intensity was also determined after treatment of flatus samples with zinc acetate, which binds sulphydryl compounds (hydrogen sulphide and methanethiol), or activated charcoal. Utilising gas-tight Mylar pantaloons, the ability of a charcoal lined cushion to adsorb sulphur-containing gases instilled at the anus of eight subjects was assessed. 
Results—The main sulphur-containing flatus component was hydrogen sulphide (1.06 (0.2) µmol/l), followed by methanethiol (0.21(0.04) µmol/l) and dimethyl sulphide (0.08 (0.01) µmol/l) (means (SEM)). Malodour significantly correlated with hydrogen sulphide concentration (p⩽0.001). Zinc acetate reduced sulphur gas content but did not totally eliminate odour, while activated charcoal removed virtually all odour. The cushion adsorbed more than 90% of the sulphur gases. 
Conclusion—Sulphur-containing gases are the major, but not the only, malodorous components of human flatus. The charcoal lined cushion effectively limits the escape of these sulphur-containing gases into the environment. 

 Keywords: flatus; odour; sulphur containing gas; hydrogen sulphide; charcoal PMID:9771412

  2. Shape Beyond Recognition: Form-derived Directionality and its Effects on Visual Attention and Motion Perception

    PubMed Central

    Sigurdardottir, Heida M.; Michalak, Suzanne M.; Sheinberg, David L.

    2013-01-01

    The shape of an object restricts its movements and therefore its future location. The rules governing selective sampling of the environment likely incorporate any available data, including shape, that provide information about where important things are going to be in the near future so that the object can be located, tracked, and sampled for information. We asked people to assess in which direction several novel objects pointed or directed them. With independent groups of people, we investigated whether their attention and sense of motion were systematically biased in this direction. Our work shows that nearly any novel object has intrinsic directionality derived from its shape. This shape information is swiftly and automatically incorporated into the allocation of overt and covert visual orienting and the detection of motion, processes which themselves are inherently directional. The observed connection between form and space suggests that shape processing goes beyond recognition alone and may help explain why shape is a relevant dimension throughout the visual brain. PMID:23565670

  3. Responses of tadpoles to hybrid predator odours: strong maternal signatures and the potential risk/response mismatch.

    PubMed

    Chivers, Douglas P; Mathiron, Anthony; Sloychuk, Janelle R; Ferrari, Maud C O

    2015-06-22

    Previous studies have established that when a prey animal knows the identity of a particular predator, it can use this knowledge to make an 'educated guess' about similar novel predators. Such generalization of predator recognition may be particularly beneficial when prey are exposed to introduced and invasive species of predators or hybrids. Here, we examined generalization of predator recognition for woodfrog tadpoles exposed to novel trout predators. Tadpoles conditioned to recognize tiger trout, a hybrid derived from brown trout and brook trout, showed generalization of recognition of several unknown trout odours. Interestingly, the tadpoles showed stronger responses to odours of brown trout than brook trout. In a second experiment, we found that tadpoles trained to recognize brown trout showed stronger responses to tiger trout than those tadpoles trained to recognize brook trout. Given that tiger trout always have a brown trout mother and a brook trout father, these results suggest a strong maternal signature in trout odours. Tadpoles that were trained to recognize both brown trout and brook trout showed stronger response to novel tiger trout than those trained to recognize only brown trout or only brook trout. This is consistent with a peak shift in recognition, whereby cues that are intermediate between two known cues evoke stronger responses than either known cue. Given that our woodfrog tadpoles have no evolutionary or individual experience with trout, they have no way of knowing whether or not brook trout, brown trout or tiger trout are more dangerous. The differential intensity of responses that we observed to hybrid trout cues and each of the parental species indicates that there is a likely mismatch between risk and anti-predator response intensity. Future work needs to address the critical role of prey naivety on responses to invasive and introduced hybrid predators. PMID:26041358

  4. Responses of tadpoles to hybrid predator odours: strong maternal signatures and the potential risk/response mismatch

    PubMed Central

    Chivers, Douglas P.; Mathiron, Anthony; Sloychuk, Janelle R.; Ferrari, Maud C. O.

    2015-01-01

    Previous studies have established that when a prey animal knows the identity of a particular predator, it can use this knowledge to make an ‘educated guess' about similar novel predators. Such generalization of predator recognition may be particularly beneficial when prey are exposed to introduced and invasive species of predators or hybrids. Here, we examined generalization of predator recognition for woodfrog tadpoles exposed to novel trout predators. Tadpoles conditioned to recognize tiger trout, a hybrid derived from brown trout and brook trout, showed generalization of recognition of several unknown trout odours. Interestingly, the tadpoles showed stronger responses to odours of brown trout than brook trout. In a second experiment, we found that tadpoles trained to recognize brown trout showed stronger responses to tiger trout than those tadpoles trained to recognize brook trout. Given that tiger trout always have a brown trout mother and a brook trout father, these results suggest a strong maternal signature in trout odours. Tadpoles that were trained to recognize both brown trout and brook trout showed stronger response to novel tiger trout than those trained to recognize only brown trout or only brook trout. This is consistent with a peak shift in recognition, whereby cues that are intermediate between two known cues evoke stronger responses than either known cue. Given that our woodfrog tadpoles have no evolutionary or individual experience with trout, they have no way of knowing whether or not brook trout, brown trout or tiger trout are more dangerous. The differential intensity of responses that we observed to hybrid trout cues and each of the parental species indicates that there is a likely mismatch between risk and anti-predator response intensity. Future work needs to address the critical role of prey naivety on responses to invasive and introduced hybrid predators. PMID:26041358

  5. Food Preference and Appetite after Switching between Sweet and Savoury Odours in Women

    PubMed Central

    Ramaekers, Mariëlle G.; Luning, Pieternel A.; Lakemond, Catriona M. M.; van Boekel, Martinus A. J. S.; Gort, Gerrit; Boesveldt, Sanne

    2016-01-01

    Background Exposure to food odours increases the appetite for congruent foods and decreases the appetite for incongruent foods. However, the effect of exposure to a variety of food odours, as often occurs in daily life, is unknown. Objective Investigate how switching between sweet and savoury odours affects the appetite for sweet and savoury products. Design Thirty women (age: 18-45y; BMI: 18.5-25kg/m2) intensely smelled the contents of cups filled with banana, meat or water (no-odour) in a within-subject design with four combinations: no-odour/banana, no-odour/meat, meat/banana and banana/meat. Participants received one combination per test day. In each combination, two cups with different fillings were smelled for five minutes after each other. Treatment order was balanced as much as possible. The effects of previous exposure and current odour on the appetite for (in)congruent sweet and savoury products, and odour pleasantness were analysed. A change from meat to banana odour or banana to meat odour was referred to as switch, whereas a change from no-odour to meat odour or no-odour to banana odour was no-switch. Results The current odour (P<0.001), as opposed to the previous exposure (P = 0.71), determined the appetite for (in)congruent sweet and savoury products, already one minute after a switch between sweet and savoury odours. The pleasantness of the odour decreased during odour exposure (P = 0.005). Conclusions After a switch, the appetite for specific products quickly adjusted to the new odour and followed the typical pattern as found during odour exposure in previous studies. Interestingly, the appetite for the smelled food remained elevated during odour exposure, known as sensory-specific appetite, whereas the pleasantness of the odour decreased over time, previously termed olfactory sensory-specific satiety. This seeming contradiction may result from different mechanisms underlying the odour-induced anticipation of food intake versus the decrease in

  6. Elimination of seaweed odour and its effect on antioxidant activity

    NASA Astrophysics Data System (ADS)

    Keyimu, Xiren Guli; Abdullah, Aminah

    2014-09-01

    The objectives of this study were to determine the most effective method to remove odour from Sargassum muticum seaweeds and studied their antioxidant properties. Ten grams of wet seaweeds (10 grams dried seaweeds soaked in 100 ml water for 2 hours) were soaked in 100 mL of 1%, 3% and 5% of gum Arabic, rice flour, lemon juice, respectively, and 1% of vinegar. There effect of each treatment on antioxidant level were determined by using the total phenolic content (TPC), free radical scavenging ability expressed as a DPPH value, and oxygen radical absorbance capacity (ORAC) and compared to control seaweeds sample (soaked in water only). For sensory attribute, seven trained panellists were asked to evaluate the fishy odour of 11 treated seaweed samples. The fishy odour characteristics and antioxidant activity of treated seaweeds were compared against the control sample (soaked seaweeds), and subjected to statistical analysis. Results showed that 3% and 5% lemon juice and 5% rice flour were able to eliminate the fishy odour of seaweed. However, the antioxidant activity was significantly higher (P<0.05) only for seaweed treated with 5% lemon juice compared to other treatments. Therefore, 5% of lemon juice-treated seaweeds contained the least fishy odour and retained the highest antioxidant activity.

  7. Recent developments in the analysis of musty odour compounds in water and wine: A review.

    PubMed

    Callejón, R M; Ubeda, C; Ríos-Reina, R; Morales, M L; Troncoso, A M

    2016-01-01

    One of the most common taints in foods is a musty or earthy odour, which is commonly associated with the activity of microorganisms. Liquid foods, particularly wine and water, can be affected by this defect due to the presence of certain aromatic organic compounds at very low concentrations (ng/L) consistent with human threshold perception levels. The volatile compounds responsible for a mouldy off-aroma include approximately 20 compounds, namely, haloanisoles, geosmin, 2-methylisoborneol, several alkyl-methoxypyrazines, 1-octen-3-ol, 1-octen-3-one, trans-octenol, 3-octanone, fenchol and fenchone. Methods for determining these very low concentrations of odour compounds must be extremely sensitive and selective with efficient preconcentration treatments. A number of extraction techniques based on LLME (liquid-liquid microextraction), SPME (solid-phase microextraction) or SBSE (stir-bar sorptive extraction) can be applied and should be selected on a case-by-case basis. Moreover, recent developments in GC instrumentation coupled to different detection systems can effectively increase the selectivity and sensitivity of the analysis of target compounds. PMID:26372442

  8. Comparison of bimodal and bilateral cochlear implant users on speech recognition with competing talker, music perception, affective prosody discrimination and talker identification

    PubMed Central

    Cullington, Helen E; Zeng, Fan-Gang

    2010-01-01

    Objectives Despite excellent performance in speech recognition in quiet, most cochlear implant users have great difficulty with speech recognition in noise, music perception, identifying tone of voice, and discriminating different talkers. This may be partly due to the pitch coding in cochlear implant speech processing. Most current speech processing strategies use only the envelope information; the temporal fine structure is discarded. One way to improve electric pitch perception is to utilize residual acoustic hearing via a hearing aid on the non-implanted ear (bimodal hearing). This study aimed to test the hypothesis that bimodal users would perform better than bilateral cochlear implant users on tasks requiring good pitch perception. Design Four pitch-related tasks were used: Hearing in Noise Test (HINT) sentences spoken by a male talker with a competing female, male, or child talker. Montreal Battery of Evaluation of Amusia. This is a music test with six subtests examining pitch, rhythm and timing perception, and musical memory. Aprosodia Battery. This has five subtests evaluating aspects of affective prosody and recognition of sarcasm. Talker identification using vowels spoken by ten different talkers (three male, three female, two boys, and two girls). Bilateral cochlear implant users were chosen as the comparison group. Thirteen bimodal and thirteen bilateral adult cochlear implant users were recruited; all had good speech perception in quiet. Results There were no significant differences between the mean scores of the bimodal and bilateral groups on any of the tests, although the bimodal group did perform better than the bilateral group on almost all tests. Performance on the different pitch-related tasks was not correlated, meaning that if a subject performed one task well they would not necessarily perform well on another. The correlation between the bimodal users' hearing threshold levels in the aided ear and their performance on these tasks was weak

  9. Generalization and discrimination tasks yield concordant measures of perceived distance between odours and their binary mixtures in larval Drosophila

    PubMed Central

    Chen, Yi-chun; Gerber, Bertram

    2014-01-01

    Similarity between odours is notoriously difficult to measure. Widely used behavioural approaches in insect olfaction research are cross-adaptation, masking, as well as associative tasks based on olfactory learning and the subsequent testing for how specific the established memory is. A concern with such memory-based approaches is that the learning process required to establish an odour memory may alter the way the odour is processed, such that measures of perception taken at the test are distorted. The present study was therefore designed to see whether behavioural judgements of perceptual distance are different for two different memory-based tasks, namely generalization and discrimination. We used odour–reward learning in larval Drosophila as a study case. In order to challenge the larvae's olfactory system, we chose to work with binary mixtures and their elements (1-octanol, n-amyl acetate, 3-octanol, benzaldehyde and hexyl acetate). We determined the perceptual distance between each mixture and its elements, first in a generalization task, and then in a discrimination task. It turns out that scores of perceptual distance are correlated between both tasks. A re-analysis of published studies looking at element-to-element perceptual distances in larval reward learning and in adult punishment learning confirms this result. We therefore suggest that across a given set of olfactory stimuli, associative training does not grossly alter the pattern of perceptual distances. PMID:24920835

  10. PTR-MS monitoring of odour emissions from composting plants

    NASA Astrophysics Data System (ADS)

    Biasioli, Franco; Gasperi, Flavia; Odorizzi, Gino; Aprea, Eugenio; Mott, Daniela; Marini, Federico; Autiero, Gianmarco; Rotondo, Giampaolo; Märk, Tilmann D.

    2004-12-01

    We studied the possibility of monitoring with proton transfer reaction-mass spectrometry (PTR-MS) odours emitted in various situations related to composting plants of municipal solid waste (MSW), i.e., waste storage, waste management, and biofilters. Comparison of PTR-MS volatile profiles of the gaseous mixtures entering and exiting a biofilter suggests the possibility of fast and reliable monitoring biofilter efficiency. Moreover, we investigated the relationships between the olfactometric assessment of odour concentration and PTR-MS spectral line intensity finding a positive correlation between the former and several masses and their overall intensity. The application of multivariate calibration methods allows to determine odour concentrations based only on PTR-MS instrumental data. The possibility of avoiding the use of time consuming and expensive olfactometric methods and applications in monitoring waste treatments plants and, in particular, of biofilters is suggested.

  11. Learning to distinguish between predators and non-predators: understanding the critical role of diet cues and predator odours in generalisation

    PubMed Central

    Mitchell, Matthew D.; Chivers, Douglas P.; McCormick, Mark I.; Ferrari, Maud C.O.

    2015-01-01

    It is critical for prey to recognise predators and distinguish predators from non-threatening species. Yet, we have little understanding of how prey develop effective predator recognition templates. Recent studies suggest that prey may actually learn key predator features which can be used to recognise novel species with similar characteristics. However, non-predators are sometimes mislabelled as predators when generalising recognition. Here, we conduct the first comprehensive investigation of how prey integrate information on predator odours and predator diet cues in generalisation, allowing them to discriminate between predators and non-predators. We taught lemon damselfish to recognise a predator fed a fish diet, and tested them for their response to the known predator and a series of novel predators (fed fish diet) and non-predators (fed squid diet) distributed across a phylogenetic gradient. Our findings show that damselfish distinguish between predators and non-predators when generalising recognition. Additional experiments revealed that generalised recognition did not result from recognition of predator odours or diet cues, but that damselfish based recognition on what they learned during the initial conditioning. Incorporating multiple sources of information enables prey to develop highly plastic and accurate recognition templates that will increase survival in patchy environments where they have little prior knowledge. PMID:26358861

  12. Livestock odours and quality of life of neighbouring residents.

    PubMed

    Radon, Katja; Peters, Astrid; Praml, Georg; Ehrenstein, Vera; Schulze, Anja; Hehl, Oliver; Nowak, Dennis

    2004-01-01

    Neighbours of intensive livestock production facilities frequently complain of odour annoyance. They are also concerned about potential negative health effects of environmental exposures to livestock emissions. Quality of life (QoL) was assessed in residents of a rural community neighbouring an area with high concentration of animal farms. A postal cross-sectional survey was carried out among the 4,537 residents, aged 18-44 years. Of these, 3,112 (69 %) responded to questions on annoyance by livestock odours (4-point scale), on QoL (assessed by the short form 12, SF-12), and on potential confounders (age, gender, respiratory symptoms, smoking, living on or close to a farm, and employment status). SF-12 scores were available for 2745 (88 %) subjects. Sixty-one percent of the respondents complained about unpleasant odours, 91 % of these accused livestock as source of these odours. Physical and emotional SF-12 scores were inversely related to annoyance scores. Better risk communication might improve QoL in concerned neighbours of intensive livestock production facilities. PMID:15236499

  13. Cave-dwelling bats do not avoid TMT and 2-PT - components of predator odour that induce fear in other small mammals.

    PubMed

    Driessens, Tess; Siemers, Björn M

    2010-07-15

    Recognition and avoidance of predators is fundamental for the survival of prey animals. Here we conducted the first study assessing chemosensory predator recognition in cave-dwelling bats. We used a Y-maze approach to test the reaction of greater mouse-eared bats (Myotis myotis) to two synthetically derived components of predator odour (2,4,5-trimethyl-3-thiazoline, TMT, a component of fox faeces scent; and 2-propylthietane, 2-PT, a component of mustelid scent) and to the natural scent of the least weasel (Mustela nivalis). It is well documented that rodents and several other small mammals show strong and at least partly innate fear reactions when confronted with these odorants. By contrast, the bats did not show any avoidance or fear reaction, despite the fact that relatively high odorant concentrations were presented. Furthermore, they did not react differently towards predator scent and towards acrid but otherwise neutral odours (basil or goat). The number of entries into in the Y-maze arm with the odour source and the time spent in this arm as well as the bats' overall exploratory activity and several other behavioural variables were not affected by the odour treatments. Generally, the sense of smell is well developed in bats and plays an important role in bat behavioural ecology. It is thus somewhat surprising that the bats did not show any avoidance reaction to predator scent, even though direct contact with a mustelid or fox would result in death. We discuss ecological explanations that might have prevented bats from evolving olfactory predatory recognition and avoidance. PMID:20581275

  14. A butterfly's chemical key to various ant forts: intersection-odour or aggregate-odour multi-host mimicry?

    NASA Astrophysics Data System (ADS)

    Schlick-Steiner, Birgit C.; Steiner, Florian M.; Höttinger, Helmut; Nikiforov, Alexej; Mistrik, Robert; Schafellner, Christa; Baier, Peter; Christian, Erhard

    Deception is a crucial yet incompletely understood strategy of social parasites. In central Europe, the Mountain Alcon Blue, Maculinea rebeli, a highly endangered butterfly, parasitises several Myrmica ant species. Caterpillars gain access to host nests probably by faking the ants' odour. We analysed gas chromatography-mass spectrometry data of body surface hydrocarbons of pre-adoption and hibernated larvae of Maculinea rebeli and of their host species Myrmica sabuleti and M. schencki. Data were ordinated by different methods, based on similarities in the relative quantities of compounds between chromatograms. The two Myrmica species exhibit species-specific profiles. The Maculinea rebeli pre-adoption larva has a complex profile that simultaneously contains species-specific substances of the two investigated host species. This evidence leads to the interpretation that, in central Europe, Maculinea rebeli is predisposed for multi-host use by the chemical signature of its pre-adoption larva. The Maculinea rebeli larva clearly does not rely on an ``intersection-odour'' of compounds common to all host ant species, but synthesises an ``aggregate-odour'' containing specific compounds of each of the investigated hosts. We term this previously unknown chemical strategy ``aggregate-odour multi-host mimicry''.

  15. General Recognition Theory with Individual Differences: A New Method for Examining Perceptual and Decisional Interactions with an Application to Face Perception

    PubMed Central

    Soto, Fabian A.; Vucovich, Lauren; Musgrave, Robert; Ashby, F. Gregory

    2014-01-01

    A common question in perceptual science is to what extent different stimulus dimensions are processed independently. General recognition theory (GRT) offers a formal framework via which different notions of independence can be defined and tested rigorously, while also dissociating perceptual from decisional factors. This article presents a new GRT model that overcomes several shortcomings with previous approaches, including a clearer separation between perceptual and decisional processes and a more complete description of such processes. The model assumes that different individuals share similar perceptual representations, but vary in their attention to dimensions and in the decisional strategies they use. We apply the model to the analysis of interactions between identity and emotional expression during face recognition. The results of previous research aimed at this problem have been disparate. Participants identified four faces, which resulted from the combination of two identities and two expressions. An analysis using the new GRT model showed a complex pattern of dimensional interactions. The perception of emotional expression was not affected by changes in identity, but the perception of identity was affected by changes in emotional expression. There were violations of decisional separability of expression from identity and of identity from expression, with the former being more consistent across participants than the latter. One explanation for the disparate results in the literature is that decisional strategies may have varied across studies and influenced the results of tests of perceptual interactions, as previous studies lacked the ability to dissociate between perceptual and decisional interactions. PMID:24841236

  16. Effects of pH and microbial composition on odour in food waste composting

    PubMed Central

    Sundberg, Cecilia; Yu, Dan; Franke-Whittle, Ingrid; Kauppi, Sari; Smårs, Sven; Insam, Heribert; Romantschuk, Martin; Jönsson, Håkan

    2013-01-01

    A major problem for composting plants is odour emission. Slow decomposition during prolonged low-pH conditions is a frequent process problem in food waste composting. The aim was to investigate correlations between low pH, odour and microbial composition during food waste composting. Samples from laboratory composting experiments and two large scale composting plants were analysed for odour by olfactometry, as well as physico-chemical and microbial composition. There was large variation in odour, and samples clustered in two groups, one with low odour and high pH (above 6.5), the other with high odour and low pH (below 6.0). The low-odour samples were significantly drier, had lower nitrate and TVOC concentrations and no detectable organic acids. Samples of both groups were dominated by Bacillales or Actinobacteria, organisms which are often indicative of well-functioning composting processes, but the high-odour group DNA sequences were similar to those of anaerobic or facultatively anaerobic species, not to typical thermophilic composting species. High-odour samples also contained Lactobacteria and Clostridia, known to produce odorous substances. A proposed odour reduction strategy is to rapidly overcome the low pH phase, through high initial aeration rates and the use of additives such as recycled compost. PMID:23122203

  17. Water Environment Research Foundation (WERF) anaerobic digestion and related processes, odour and health effects study.

    PubMed

    Witherspoon, J R; Adams, G; Cain, W; Cometto-Muniz, E; Forbes, B; Hentz, L; Novack, J T; Higgins, M; Murthy, S; McEwen, D; Ong, H T; Daigger, G T

    2004-01-01

    Biosolids odour emissions can affect the ability of wastewater utilities to implement beneficial biosolids processing and reuse programs. Communities often become more sensitised and vocal about biosolids issues, once they experience odours emanating from a nearby site. Odour impacts from biosolids, including potential human health effects, have been targeted recently by many national and local newspapers, citizens' groups, and regulatory agencies, who have raised significant concerns, ranging from viable disposal methods/sites to outright bans. Many national and local regulatory agencies in the United States are considering biosolids disposal bans in their communities because of misinformation, poor science, and citizen pressure, but primarily because of odour impact concerns. The wastewater industry has a relatively poor understanding of the operations and treatment parameters that influence biosolids odour emissions. Thus, wastewater treatment plants are often unable to control the odour quality of the biosolids that are delivered into communities. A research study to demonstrate the influence of anaerobic digestion, mechanical dewatering, and storage design and operating parameters on the odour quality of the final product was performed and is the subject of this paper. Established and new sampling and analytical methods were used to measure biosolids odour emissions from 11 test sites in North America. By determining the impacts of these control variables on biosolids odour quality, design and operations of anaerobic digestion systems might be enhanced. This paper also summarises a corollary study performed as part of the WERF research study that addresses the health effects of biosolids odours. PMID:15484737

  18. Novel Insights into the Ontogeny of Nestmate Recognition in Polistes Social Wasps

    PubMed Central

    Signorotti, Lisa; Cappa, Federico; d’Ettorre, Patrizia; Cervo, Rita

    2014-01-01

    The importance of early experience in animals’ life is unquestionable, and imprinting-like phenomena may shape important aspects of behaviour. Early learning typically occurs during a sensitive period, which restricts crucial processes of information storage to a specific developmental phase. The characteristics of the sensitive period have been largely investigated in vertebrates, because of their complexity and plasticity, both in behaviour and neurophysiology, but early learning occurs also in invertebrates. In social insects, early learning appears to influence important social behaviours such as nestmate recognition. Yet, the mechanisms underlying recognition systems are not fully understood. It is currently believed that Polistes social wasps are able to discriminate nestmates from non-nestmates following the perception of olfactory cues present on the paper of their nest, which are learned during a strict sensitive period, immediately after emergence. Here, through differential odour experience experiments, we show that workers of Polistes dominula develop correct nestmate recognition abilities soon after emergence even in absence of what have been so far considered the necessary cues (the chemicals spread on nest paper). P. dominula workers were exposed for the first four days of adult life to paper fragments from their nest, or from a foreign conspecific nest or to a neutral condition. Wasps were then transferred to their original nests where recognition abilities were tested. Our results show that wasps do not alter their recognition ability if exposed only to nest material, or in absence of nest material, during the early phase of adult life. It thus appears that the nest paper is not used as a source of recognition cues to be learned in a specific time window, although we discuss possible alternative explanations. Our study provides a novel perspective for the study of the ontogeny of nestmate recognition in Polistes wasps and in other social insects

  19. Novel insights into the ontogeny of nestmate recognition in Polistes social wasps.

    PubMed

    Signorotti, Lisa; Cappa, Federico; d'Ettorre, Patrizia; Cervo, Rita

    2014-01-01

    The importance of early experience in animals' life is unquestionable, and imprinting-like phenomena may shape important aspects of behaviour. Early learning typically occurs during a sensitive period, which restricts crucial processes of information storage to a specific developmental phase. The characteristics of the sensitive period have been largely investigated in vertebrates, because of their complexity and plasticity, both in behaviour and neurophysiology, but early learning occurs also in invertebrates. In social insects, early learning appears to influence important social behaviours such as nestmate recognition. Yet, the mechanisms underlying recognition systems are not fully understood. It is currently believed that Polistes social wasps are able to discriminate nestmates from non-nestmates following the perception of olfactory cues present on the paper of their nest, which are learned during a strict sensitive period, immediately after emergence. Here, through differential odour experience experiments, we show that workers of Polistes dominula develop correct nestmate recognition abilities soon after emergence even in absence of what have been so far considered the necessary cues (the chemicals spread on nest paper). P. dominula workers were exposed for the first four days of adult life to paper fragments from their nest, or from a foreign conspecific nest or to a neutral condition. Wasps were then transferred to their original nests where recognition abilities were tested. Our results show that wasps do not alter their recognition ability if exposed only to nest material, or in absence of nest material, during the early phase of adult life. It thus appears that the nest paper is not used as a source of recognition cues to be learned in a specific time window, although we discuss possible alternative explanations. Our study provides a novel perspective for the study of the ontogeny of nestmate recognition in Polistes wasps and in other social insects

  20. Assessment of perception of morphed facial expressions using the Emotion Recognition Task: normative data from healthy participants aged 8-75.

    PubMed

    Kessels, Roy P C; Montagne, Barbara; Hendriks, Angelique W; Perrett, David I; de Haan, Edward H F

    2014-03-01

    The ability to recognize and label emotional facial expressions is an important aspect of social cognition. However, existing paradigms to examine this ability present only static facial expressions, suffer from ceiling effects or have limited or no norms. A computerized test, the Emotion Recognition Task (ERT), was developed to overcome these difficulties. In this study, we examined the effects of age, sex, and intellectual ability on emotion perception using the ERT. In this test, emotional facial expressions are presented as morphs gradually expressing one of the six basic emotions from neutral to four levels of intensity (40%, 60%, 80%, and 100%). The task was administered in 373 healthy participants aged 8-75. In children aged 8-17, only small developmental effects were found for the emotions anger and happiness, in contrast to adults who showed age-related decline on anger, fear, happiness, and sadness. Sex differences were present predominantly in the adult participants. IQ only minimally affected the perception of disgust in the children, while years of education were correlated with all emotions but surprise and disgust in the adult participants. A regression-based approach was adopted to present age- and education- or IQ-adjusted normative data for use in clinical practice. Previous studies using the ERT have demonstrated selective impairments on specific emotions in a variety of psychiatric, neurologic, or neurodegenerative patient groups, making the ERT a valuable addition to existing paradigms for the assessment of emotion perception. PMID:23409767

  1. Machine perception

    SciTech Connect

    Not Available

    1982-01-01

    The book is aimed at the level of a graduate student or the practising professional and discusses visual perception by computers. Topics covered include: pattern classification methods; polyhedra scenes; shape analysis and recognition; perception of brightness and colour; edge and curve detection; region segmentation; texture analysis; depth measurement analysis; knowledge-based systems and applications. A subject index is included.

  2. Infection and body odours: evolutionary and medical perspectives.

    PubMed

    Prugnolle, Franck; Lefèvre, Thierry; Renaud, François; Møller, Anders Pape; Missé, Dorothée; Thomas, Frédéric

    2009-09-01

    Infections are often followed by a change in body odours. For a long time, these changes were considered as non-specific (with no adaptive value) but recent evidences suggest that this may not always be true. Odour modifications due to an infection may either be of adaptive value for the parasite or the host. Here, we describe the observations in support of this idea, discuss the potential roles these modifications may play for the parasite and the host and propose a set of future directions that we think should allow to better understand the mechanisms at the origin of these modifications and how they may be used by both parasites and their human hosts. PMID:19439195

  3. Behavioural correlates of combinatorial versus temporal features of odour codes.

    PubMed

    Saha, Debajit; Li, Chao; Peterson, Steven; Padovano, William; Katta, Nalin; Raman, Baranidharan

    2015-01-01

    Most sensory stimuli evoke spiking responses that are distributed across neurons and are temporally structured. Whether the temporal structure of ensemble activity is modulated to facilitate different neural computations is not known. Here, we investigated this issue in the insect olfactory system. We found that an odourant can generate synchronous or asynchronous spiking activity across a neural ensemble in the antennal lobe circuit depending on its relative novelty with respect to a preceding stimulus. Regardless of variations in temporal spiking patterns, the activated combinations of neurons robustly represented stimulus identity. Consistent with this interpretation, locusts reliably recognized both solitary and sequential introductions of trained odourants in a quantitative behavioural assay. However, predictable behavioural responses across locusts were observed only to novel stimuli that evoked synchronized spiking patterns across neural ensembles. Hence, our results indicate that the combinatorial ensemble response encodes for stimulus identity, whereas the temporal structure of the ensemble response selectively emphasizes novel stimuli. PMID:25912016

  4. Behavioural correlates of combinatorial versus temporal features of odour codes

    PubMed Central

    Saha, Debajit; Li, Chao; Peterson, Steven; Padovano, William; Katta, Nalin; Raman, Baranidharan

    2015-01-01

    Most sensory stimuli evoke spiking responses that are distributed across neurons and are temporally structured. Whether the temporal structure of ensemble activity is modulated to facilitate different neural computations is not known. Here, we investigated this issue in the insect olfactory system. We found that an odourant can generate synchronous or asynchronous spiking activity across a neural ensemble in the antennal lobe circuit depending on its relative novelty with respect to a preceding stimulus. Regardless of variations in temporal spiking patterns, the activated combinations of neurons robustly represented stimulus identity. Consistent with this interpretation, locusts reliably recognized both solitary and sequential introductions of trained odourants in a quantitative behavioural assay. However, predictable behavioural responses across locusts were observed only to novel stimuli that evoked synchronized spiking patterns across neural ensembles. Hence, our results indicate that the combinatorial ensemble response encodes for stimulus identity, whereas the temporal structure of the ensemble response selectively emphasizes novel stimuli. PMID:25912016

  5. Study of Odours and taste for Space Food

    NASA Astrophysics Data System (ADS)

    Katayama, Naomi; Space Agriculture Task Force; Nakata, Seiichi; Teranishi, Masaaki; Sone, Michihiko; Nakashima, Tsutomu; Hamajima, Nobuyuki; Ito, Yoshihiro

    2012-07-01

    The sense of taste and smell come under some kind of influences in the space environment. In the space, the astronaut was changed their food habits from light taste and smell food to like strong taste and smells food. When an astronaut live in the space comes to have weak bone like osteoporosis. It may become the physiologic condition like the old man on the earth. Therefore this study performed fact-finding of the smell and the taste in the old man on the earth as test bed of astronaut in space. Based on this finding, it was intended to predict the taste and the olfactory change of the astronaut in the space. The study included 179 males and 251 females aged 30-90 years in Yakumo Town, Hokkaido, Japan. Odours were tested using a ``standard odours by odour stick identification''method of organoleptic testing. Taste were tested using a ``standard taste by taste disc identification'' method of chemical testing. Correct answers for identification odours consisted of average 6.0±3.0 in male subjects and average 6.9±2.8 in female subjects. Correct answers for identification of sweet taste consisted of 81% males and 87% females, salty taste consisted of 86% males and 91%, sour taste consisted of 75% males and 78% females, bitter taste consisted of 76% males and 88% females. It became clear that overall approximately 20% were in some kind of abnormality in sense of smell and taste. I want to perform the investigation that continued more in future.

  6. The accessibility of semantic knowledge for odours that can and cannot be named.

    PubMed

    Stevenson, Richard J; Mahmut, Mehmet K

    2013-01-01

    When faces, objects, or voices are encountered, naming lapses can occur, but this does not preclude knowing other specific semantic information about the nameless thing. In the experiments reported here, we examined whether this is also the case for odours, using a procedure based upon the Pyramid and Palm Trees test. In Experiment 1, participants were presented with a target odour, then two pictures, and had to pick the picture semantically associated with the target. In Experiment 2, participants were presented with a target odour, then two test odours, and again had to pick the semantically associated test stimulus. In each experiment, other tests followed, including a parallel verbal-based test, an odour-naming test, and various ratings. Neither experiment found any evidence of specific semantic knowledge about a target odour, unless the target odour name (Experiment 1) or all of the odour names (Experiment 2) were known. Additional tests suggested that these effects were independent of odour familiarity and similarity. We suggest that the absence of specific semantic information in the absence of a name may reflect poor connectivity between olfactory perceptual and semantic memory systems. PMID:23259738

  7. Identification of odour sources in an industrial park from resident diaries statistics

    NASA Astrophysics Data System (ADS)

    Nicolas, Jacques; Cors, Marie; Romain, Anne-Claude; Delva, Julien

    2010-05-01

    A methodology based on social participation through the use of resident diaries was applied to evaluate the odour annoyance in the surroundings of an industrial park in Belgium during one year. The studied area covers about 8 km 2 and includes13 potential odour emitting facilities. The network involved 44 residents in the survey, among whom 19 were particularly considered for a detailed analysis. The questionnaire aimed at providing an odour rating twice-daily on a 6-level scale together with an odour type. The fact that the response rate corresponding to "no-odour" was high (79%) is particularly discussed. Some tests are proposed to check the plausibility of the answers, the coherence within clusters of residents and the individual performance of respondents to discriminate among odour ratings. The odour rose is presented as an attractive and visual tool, particularly suited in the case of multi-source areas, to map the different odour emissions, to point out the most worrying ones, to identify others creating less annoyance and possibly new unpredicted ones. The resident diary method has proven to be particularly useful, conjointly to other ones, to the case of multi-sources facilities in large areas, when the purpose is the assessment of the long-term evolution of odour annoyance.

  8. Predator odours attract other predators, creating an olfactory web of information.

    PubMed

    Banks, Peter B; Daly, Andrew; Bytheway, Jenna P

    2016-05-01

    Many studies have reported the aversive reactions of prey towards a predator's odour signals (e.g. urine marks), a behaviour widely thought to reduce the risk of predation by the predator. However, because odour signals persist in the environment, they are vulnerable to exploitation and eavesdropping by predators, prey and conspecifics. As such, scent patches created by one species might attract other species interested in information about their enemies. We studied this phenomenon by examining red fox investigation of odours from conspecifics and competing species in order to understand what prey are responding to when avoiding the odours of a predator. Surprisingly, foxes showed limited interest in conspecific odours but were highly interested in the odours of their competitors (wild dogs and feral cats), suggesting that odours are likely to play an important role in mediating competitive interactions. Importantly, our results identify that simple, dyadic interpretations of prey responses to a predator odour (i.e. cat odour = risk of cat encounter = fear of cats) can no longer be assumed in ecological or psychology research. Instead, interactions mediated by olfactory cues are more complex than previously thought and are likely to form a complicated olfactory web of interactions. PMID:27194283

  9. Odours stimulate neuronal activity in the dorsolateral area of the hippocampal formation during path integration

    PubMed Central

    Jorge, P. E.; Phillips, J. B.; Gonçalves, A.; Marques, P. A. M.; Nĕmec, P.

    2014-01-01

    The dorsolateral area of the hippocampal formation of birds is commonly assumed to play a central role in processing information needed for geographical positioning and homing. Previous work has interpreted odour-induced activity in this region as evidence for an ‘olfactory map’. Here, we show, using c-Fos expression as a marker, that neuronal activation in the dorsolateral area of the hippocampal formation of pigeons is primarily a response to odour novelty, not to the spatial distribution of odour sources that would be necessary for an olfactory map. Pigeons exposed to odours had significantly more neurons activated in this area of the brain than pigeons exposed to filtered air with odours removed. This increased activity was observed only in response to unfamiliar odours. No change in activity was observed when pigeons were exposed to home odours. These findings are consistent with non-home odours activating non-olfactory components of the pigeon's navigation system. The pattern of neuronal activation in the triangular and dorsomedial areas of the hippocampal formation was, by contrast, consistent with the possibility that odours play a role in providing spatial information. PMID:24671977

  10. Influence of gonadal hormones on odours emitted by male meadow voles (Microtus pennsylvanicus).

    PubMed

    Ferkin, M H; Gorman, M R; Zucker, I

    1992-08-01

    Free-living male meadow voles (Microtus pennsylvanicus) emit odours that are attractive to females at the beginning, but not at the end, of the breeding season. The effect of gonadal hormones on female-attractant cues was examined in males born and reared in long (14 h light day-1) and short (10 h light day-1) photoperiods that simulate daylengths in the breeding and nonbreeding seasons, respectively. Gonadectomy affected the attractant properties of odours emitted by long photoperiod, but not short photoperiod, males. Long photoperiod females preferred odours of intact rather than those of gonadectomized long photoperiod males, and odours of gonadectomized long photoperiod males rather than those of intact short photoperiod males. Females did not show a preference between the odours of intact and castrated short photoperiod males. Gonadal hormone replacement in males affected female responses to the odours emitted by long photoperiod, but not short photoperiod, gonadectomized males. Long photoperiod females did not display a preference between odours of intact long photoperiod males and gonadectomized long photoperiod males treated with testosterone or oestradiol. We conclude that in spring and summer gonadal hormones increase attractiveness of male odours; this effect may require aromatization of testosterone to oestradiol. Substrates that control attractiveness of odour cues in male voles appear to be unresponsive to androgens during the nonbreeding season. PMID:1404090

  11. The Facial Expressive Action Stimulus Test. A test battery for the assessment of face memory, face and object perception, configuration processing, and facial expression recognition

    PubMed Central

    de Gelder, Beatrice; Huis in ‘t Veld, Elisabeth M. J.; Van den Stock, Jan

    2015-01-01

    There are many ways to assess face perception skills. In this study, we describe a novel task battery FEAST (Facial Expressive Action Stimulus Test) developed to test recognition of identity and expressions of human faces as well as stimulus control categories. The FEAST consists of a neutral and emotional face memory task, a face and shoe identity matching task, a face and house part-to-whole matching task, and a human and animal facial expression matching task. The identity and part-to-whole matching tasks contain both upright and inverted conditions. The results provide reference data of a healthy sample of controls in two age groups for future users of the FEAST. PMID:26579004

  12. Individual Differences in Language Ability Are Related to Variation in Word Recognition, Not Speech Perception: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    McMurray, Bob; Munson, Cheyenne; Tomblin, J. Bruce

    2014-01-01

    Purpose: The authors examined speech perception deficits associated with individual differences in language ability, contrasting auditory, phonological, or lexical accounts by asking whether lexical competition is differentially sensitive to fine-grained acoustic variation. Method: Adolescents with a range of language abilities (N = 74, including…

  13. Mental Health Literacy for Anxiety Disorders: How perceptions of symptom severity might relate to recognition of psychological distress

    PubMed Central

    Paulus, Daniel J.; Wadsworth, Lauren Page; Hayes-Skelton, Sarah A.

    2015-01-01

    Purpose Improving mental health literacy is an important consideration when promoting expedient and effective treatment seeking for psychological disorders. Low recognition serves as a barrier to treatment (Coles and Coleman, 2010), and this article examines recognition by lay individuals of severity for three psychological disorders: social anxiety, generalized anxiety, and major depression using a dimensional approach. Design Vignettes of mild/subclinical, moderate, and severe cases of each disorder were rated for severity by a team of expert assessors and 270 participants (mean age = 26.8; 76.7% women). Findings Difference ratings were calculated comparing participants’ responses to scores from the assessors. A within-groups factorial ANOVA with LSD follow-up was performed to examine the effects of Diagnosis and Severity on difference ratings. Both main effects [Diagnosis, F(2, 536)=35.26, Mse=1.24; Severity, F(2, 536)=9.44, Mse=1.93] and the interaction were significant [F(4, 1072)=13.70, Mse=1.13] all p’s < 0.001. Social anxiety cases were underrated in the mild/subclinical and moderate cases, generalized anxiety cases were underrated at all three severities, and major depression cases were overrated at all three severities. Social implications Judgments of severity may underlie the low recognition rates for social anxiety disorder and generalized anxiety disorder. Future efforts should focus on improved recognition and education regarding anxiety disorders in the population, particularly before they become severe. Value This project demonstrates the importance of considering judgments of symptom severity on a continuum, and in a range of cases, rather than just the ability to correctly label symptoms, when determining whether or not people recognize psychological disorders. PMID:26893607

  14. Olfactory receptor cells on the cockroach antennae: responses to the direction and rate of change in food odour concentration.

    PubMed

    Hinterwirth, Armin; Zeiner, Reinhard; Tichy, Harald

    2004-06-01

    In insects, information about food odour is encoded by olfactory receptor cells with characteristic response spectra, located in several types of cuticular sensilla. Within short, hair-like sensilla on the cockroach's antenna, antagonistic pairs of olfactory receptor cells shape information inflow to the CNS by providing excitatory responses for both increases and decreases in food odour concentration. The segregation of food odour information into parallel ON and OFF responses suggests that temporal concentration changes become enhanced in the sensory output. When food odour concentration changes slowly and continuously up and down with smooth transition from one direction to another, the ON and OFF olfactory cells not only signal a succession of odour concentrations but also the rate with which odour concentration happens to be changing. Access to the values of such cues is of great use to an insect orientating to an odour source. With them they may extract concentration gradients from odour plumes. PMID:15217396

  15. Assessment of odour problem in sewage-treated effluent in a closed loop irrigation system.

    PubMed

    Ahmad, Maqbool; Bajahlan, Ahmad Saeed; Miran, Mamdoh M

    2011-05-01

    Uses of wastewater drives significant economic activity, supports countless livelihoods particularly those for developing countries. While using wastewater, the challenge is to identify practical, affordable safeguards that do not threaten the health of users. In Yanbu Al-Sinaiyah, treated sewage effluent (TSE) is used for landscape purposes. In the present study, the odour problem caused by TSE in community area has been addressed. Samples were collected and analysed for total coliform, odour, trihalomethanes (THMs), total organic carbon (TOC) and other physicochemical parameters. Results show that in distribution network, residual chlorine was below the detection limit, turbidity, THMs, TOC and total coliform concentration was much higher than point source, and concentration of these parameters was further increased in problematic areas. It was also observed that areas with odourous problem were at the tail of irrigation network. This indicates that odour problem was due to less residual chlorine high turbidity, high rate of coliform and TOC. In odourous water samples, carbon disulphide and dimethyl sulphide were also identified by GC/MS, while in other areas where there was no odour, both these compounds were not detected. Odour problem was successfully resolved by improving sand filtration system to minimise turbidity the main cause of odour, increasing the residual chlorine at the treatment plant and regularly flushing the distribution network. PMID:20568010

  16. Interference competition: odours of an apex predator and conspecifics influence resource acquisition by red foxes.

    PubMed

    Leo, Viyanna; Reading, Richard P; Letnic, Mike

    2015-12-01

    Apex predators can impact smaller predators via lethal effects that occur through direct killing, and non-lethal effects that arise when fear-induced behavioural and physiological changes reduce the fitness of smaller predators. A general outcome of asymmetrical competition between co-existing predator species is that larger predators tend to suppress the abundances of smaller predators. Here, we investigate interference effects that an apex predator, the dingo (Canis dingo), has on the acquisition of food and water by the smaller red fox (Vulpes vulpes), by exposing free-ranging foxes to the odour of dingoes and conspecifics in an arid environment. Using giving-up densities we show that foxes foraged more apprehensively at predator-odour treatments than unscented controls, but their food intake did not differ between dingo- and fox-odour treatments. Using video analysis of fox behaviour at experimental water stations we show that foxes spent more time engaged in exploration behaviour at stations scented with fox odour and spent more time drinking at water stations scented with dingo odour. Our results provide support for the idea that dingo odour exerts a stronger interference effect on foxes than conspecific odour, but suggest that the odours of both larger dingoes and unfamiliar conspecifics curtailed foxes' acquisition of food resources. PMID:26296332

  17. Close encounters: contributions of carbon dioxide and human skin odour to finding and landing on a host in Aedes aegypti

    PubMed Central

    LACEY, EMERSON S.; RAY, ANANDASANKAR; CARDÉ, RING T.

    2014-01-01

    In a wind-tunnel study, the upwind flight and source location of female Aedes aegypti to plumes of carbon dioxide (CO2) gas and odour from human feet is tested. Both odour sources are presented singly and in combination. Flight upwind along the plumes is evident for both CO2 and odour from human feet when the odours are presented alone. Likewise, both odour sources are located by more than 70% of mosquitoes in less than 3 min. When both CO2 and odour from human feet are presented simultaneously in two different choice tests (with plumes superimposed or with plumes separated), there is no evidence that females orientate along the plume of CO2 and only a few mosquitoes locate its source. Rather, the foot odour plume is navigated and the source of foot odour is located by over 80% of female Ae. aegypti. When a female is presented a plume of CO2 within a broad plume of human foot odour of relatively low concentration, the source of CO2 is not located; instead, flight is upwind in the diffuse plume of foot odour. Although upwind flight by Ae. aegypti at long range is presumably induced by CO2 and the threshold of response to skin odours is lowered, our findings suggest that once females have arrived near a prospective human host, upwind orientation and landing are largely governed by the suite of odours from a human foot, while orientation is no longer influenced by CO2. PMID:24839345

  18. Optimizing chemical conditioning for odour removal of undigested sewage sludge in drying processes.

    PubMed

    Vega, Esther; Monclús, Hèctor; Gonzalez-Olmos, Rafael; Martin, Maria J

    2015-03-01

    Emission of odours during the thermal drying in sludge handling processes is one of the main sources of odour problems in wastewater treatment plants. The objective of this work was to assess the use of the response surface methodology as a technique to optimize the chemical conditioning process of undigested sewage sludges, in order to improve the dewaterability, and to reduce the odour emissions during the thermal drying of the sludge. Synergistic effects between inorganic conditioners (iron chloride and calcium oxide) were observed in terms of sulphur emissions and odour reduction. The developed quadratic models indicated that optimizing the conditioners dosage is possible to increase a 70% the dewaterability, reducing a 50% and 54% the emission of odour and volatile sulphur compounds respectively. The optimization of the conditioning process was validated experimentally. PMID:25438118

  19. Seasonal control of odour preferences of meadow voles (Microtus pennsylvanicus) by photoperiod and ovarian hormones.

    PubMed

    Ferkin, M H; Zucker, I

    1991-07-01

    During the spring-summer breeding season, female meadow voles prefer odours of males over those of females, but in the autumn-winter season of reproductive quiescence this preference is reversed. Females housed in long (14 h light/day) and short (10 h light/day) photoperiods, respectively, had odour preferences comparable to those of spring and autumn voles, respectively. The preference of long-photoperiod voles for male over female odours was reversed by ovariectomy and restored by treatment with oestradiol. By contrast, neither ovariectomy nor oestradiol affected odour preferences of short-photoperiod voles. Long days appear to influence olfactory preferences by altering ovarian hormone secretion. The failure of oestradiol to affect odour preferences in short photoperiods suggests that the neural substrates mediating this behavioural response are refractory to oestrogens during the nonbreeding season. PMID:1886099

  20. Testing Speech Recognition in Spanish-English Bilingual Children with the Computer-Assisted Speech Perception Assessment (CASPA): Initial Report.

    PubMed

    García, Paula B; Rosado Rogers, Lydia; Nishi, Kanae

    2016-01-01

    This study evaluated the English version of Computer-Assisted Speech Perception Assessment (E-CASPA) with Spanish-English bilingual children. E-CASPA has been evaluated with monolingual English speakers ages 5 years and older, but it is unknown whether a separate norm is necessary for bilingual children. Eleven Spanish-English bilingual and 12 English monolingual children (6 to 12 years old) with normal hearing participated. Responses were scored by word, phoneme, consonant, and vowel. Regardless of scores, performance across three signal-to-noise ratio conditions was similar between groups, suggesting that the same norm can be used for both bilingual and monolingual children. PMID:26862712

  1. Facial expression of fear in the context of human ethology: Recognition advantage in the perception of male faces.

    PubMed

    Trnka, Radek; Tavel, Peter; Tavel, Peter; Hasto, Jozef

    2015-01-01

    Facial expression is one of the core issues in the ethological approach to the study of human behaviour. This study discusses sex-specific aspects of the recognition of the facial expression of fear using results from our previously published experimental study. We conducted an experiment in which 201 participants judged seven different facial expressions: anger, contempt, disgust, fear, happiness, sadness and surprise (Trnka et al. 2007). Participants were able to recognize the facial expression of fear significantly better on a male face than on a female face. Females also recognized fear generally better than males. The present study provides a new interpretation of this sex difference in the recognition of fear. We interpret these results within the paradigm of human ethology, taking into account the adaptive function of the facial expression of fear. We argue that better detection of fear might be crucial for females under a situation of serious danger in groups of early hominids. The crucial role of females in nurturing and protecting offspring was fundamental for the reproductive potential of the group. A clear decoding of this alarm signal might thus have enabled the timely preparation of females for escape or defence to protect their health for successful reproduction. Further, it is likely that males played the role of guardians of social groups and that they were responsible for effective warnings of the group under situations of serious danger. This may explain why the facial expression of fear is better recognizable on the male face than on the female face. PMID:26071575

  2. Below and beyond the recognition of emotional facial expressions in alcohol dependence: from basic perception to social cognition

    PubMed Central

    D’Hondt, Fabien; Campanella, Salvatore; Kornreich, Charles; Philippot, Pierre; Maurage, Pierre

    2014-01-01

    Studies that have carried out experimental evaluation of emotional skills in alcohol-dependence have, up to now, been mainly focused on the exploration of emotional facial expressions (EFE) decoding. In the present paper, we provide some complements to the recent systematic literature review published by Donadon and de Lima Osório on this crucial topic. We also suggest research avenues that must be, in our opinion, considered in the coming years. More precisely, we propose, first, that a battery integrating a set of emotional tasks relating to different processes should be developed to better systemize EFE decoding measures in alcohol-dependence. Second, we propose to go below EFE recognition deficits and to seek for the roots of those alterations, particularly by investigating the putative role played by early visual processing and vision–emotion interactions in the emotional impairment observed in alcohol-dependence. Third, we insist on the need to go beyond EFE recognition deficits by suggesting that they only constitute a part of wider emotional deficits in alcohol-dependence. Importantly, since the efficient decoding of emotions is a crucial ability for the development and maintenance of satisfactory interpersonal relationships, we suggest that disruption of this ability in alcohol-dependent individuals may have adverse consequences for their social integration. One way to achieve this research agenda would be to develop the field of affective and social neuroscience of alcohol-dependence, which could ultimately lead to major advances at both theoretical and therapeutic levels. PMID:25429220

  3. Odorant binding proteins: a biotechnological tool for odour control.

    PubMed

    Silva, Carla; Matamá, Teresa; Azoia, Nuno G; Mansilha, Catarina; Casal, Margarida; Cavaco-Paulo, Artur

    2014-04-01

    The application of an odorant binding protein for odour control and fragrance delayed release from a textile surface was first explored in this work. Pig OBP-1 gene was cloned and expressed in Escherichia coli, and the purified protein was biochemically characterized. The IC₅₀ values (concentrations of competitor that caused a decay of fluorescence to half-maximal intensity) were determined for four distinct fragrances, namely, citronellol, benzyl benzoate, citronellyl valerate and ethyl valerate. The results showed a strong binding of citronellyl valerate, citronellol and benzyl benzoate to the recombinant protein, while ethyl valerate displayed weaker binding. Cationized cotton substrates were coated with porcine odorant binding protein and tested for their capacity to retain citronellol and to mask the smell of cigarette smoke. The immobilized protein delayed the release of citronellol when compared to the untreated cotton. According to a blind evaluation of 30 assessors, the smell of cigarette smoke, trapped onto the fabrics' surface, was successfully attenuated by porcine odorant binding protein (more than 60 % identified the weakest smell intensity after protein exposure compared to β-cyclodextrin-treated and untreated cotton fabrics). This work demonstrated that porcine odorant binding protein can be an efficient solution to prevent and/or remove unpleasant odours trapped on the large surface of textiles. Its intrinsic properties make odorant binding proteins excellent candidates for controlled release systems which constitute a new application for this class of proteins. PMID:24092006

  4. King penguins can detect two odours associated with conspecifics.

    PubMed

    Cunningham, Gregory B; Bonadonna, Francesco

    2015-11-01

    Recent studies on olfaction in penguins have focused on their use of odours while foraging. It has been proposed for some seabirds that an olfactory landscape shaped by odours coming from feeding areas exists. Islands and colonies, however, may also contribute to the olfactory landscape and may act as an orienting map. To test sensitivities to a colony scent we studied whether King penguins (Aptenodytes patagonicus) could detect the smell of sand, feathers or feces by holding presentations beneath their beaks while they naturally slept on the beach. Penguins had a significantly greater response to the feathers and feces presentations than to sand. Although only a first step in exploring a broader role of olfaction in this species, our results raise the possibility of olfaction being used by King penguins in three potential ways: (1) locating the colony from the water or the shore, (2) finding the rendezvous zone within the colony where a chick or partner may be found, or (3) recognizing individuals by scent, as in Humboldt penguins (Spheniscus demersus). PMID:26385329

  5. Perception of the Arabidopsis Danger Signal Peptide 1 Involves the Pattern Recognition Receptor AtPEPR1 and Its Close Homologue AtPEPR2*

    PubMed Central

    Krol, Elzbieta; Mentzel, Tobias; Chinchilla, Delphine; Boller, Thomas; Felix, Georg; Kemmerling, Birgit; Postel, Sandra; Arents, Michael; Jeworutzki, Elena; Al-Rasheid, Khaled A. S.; Becker, Dirk; Hedrich, Rainer

    2010-01-01

    Plasma membrane-borne pattern recognition receptors, which recognize microbe-associated molecular patterns and endogenous damage-associated molecular patterns, provide the first line of defense in innate immunity. In plants, leucine-rich repeat receptor kinases fulfill this role, as exemplified by FLS2 and EFR, the receptors for the microbe-associated molecular patterns flagellin and elongation factor Tu. Here we examined the perception of the damage-associated molecular pattern peptide 1 (AtPep1), an endogenous peptide of Arabidopsis identified earlier and shown to be perceived by the leucine-rich repeat protein kinase PEPR1. Using seedling growth inhibition, elicitation of an oxidative burst and induction of ethylene biosynthesis, we show that wild type plants and the pepr1 and pepr2 mutants, affected in PEPR1 and in its homologue PEPR2, are sensitive to AtPep1, but that the double mutant pepr1/pepr2 is completely insensitive. As a central body of our study, we provide electrophysiological evidence that at the level of the plasma membrane, AtPep1 triggers a receptor-dependent transient depolarization through activation of plasma membrane anion channels, and that this effect is absent in the double mutant pepr1/pepr2. The double mutant also fails to respond to AtPep2 and AtPep3, two distant homologues of AtPep1 on the basis of homology screening, implying that the PEPR1 and PEPR2 are responsible for their perception too. Our findings provide a basic framework to study the biological role of AtPep1-related danger signals and their cognate receptors. PMID:20200150

  6. Sensor fusion III: 3-D perception and recognition; Proceedings of the Meeting, Boston, MA, Nov. 5-8, 1990

    NASA Technical Reports Server (NTRS)

    Schenker, Paul S. (Editor)

    1991-01-01

    The volume on data fusion from multiple sources discusses fusing multiple views, temporal analysis and 3D motion interpretation, sensor fusion and eye-to-hand coordination, and integration in human shape perception. Attention is given to surface reconstruction, statistical methods in sensor fusion, fusing sensor data with environmental knowledge, computational models for sensor fusion, and evaluation and selection of sensor fusion techniques. Topics addressed include the structure of a scene from two and three projections, optical flow techniques for moving target detection, tactical sensor-based exploration in a robotic environment, and the fusion of human and machine skills for remote robotic operations. Also discussed are K-nearest-neighbor concepts for sensor fusion, surface reconstruction with discontinuities, a sensor-knowledge-command fusion paradigm for man-machine systems, coordinating sensing and local navigation, and terrain map matching using multisensing techniques for applications to autonomous vehicle navigation.

  7. Variation in nestmate recognition ability among polymorphic leaf-cutting ant workers.

    PubMed

    Larsen, Janni; Fouks, Bertrand; Bos, Nick; d'Ettorre, Patrizia; Nehring, Volker

    2014-11-01

    A key feature for the success of social insects is division of labour, allowing colony members to specialize on different tasks. Nest defence is a defining task for social insects since it is crucial for colony integrity. A particularly impressive and well-known case of worker specialization in complex hymenopteran societies is found in leaf-cutting ants of the genera Atta and Acromyrmex. We hypothesized that three morphological worker castes of Acromyrmex echinatior differ in their likelihood to attack intruders, and show that major workers are more aggressive towards non-nestmate workers than medium and minor workers. Moreover, minors do not discriminate between nestmate and non-nestmate brood, while larger workers do. We further show that A. echinatior ants use cuticular chemical compounds for nestmate recognition. We took advantage of the natural variation in the cuticular compounds between colonies to investigate the proximate factors that may have led to the observed caste differences in aggression. We infer that major workers differ from medium workers in their general propensity to attack intruders (the "action component" of the nestmate recognition system), while minors seem to be less sensitive to foreign odours ("perception component"). Our results highlight the importance of proximate mechanisms underlying social insect behaviour, and encourage an appreciation of intra-colony variation when analysing colony-level traits such as nest defence. PMID:25205477

  8. Evaluation of the odour reduction potential of alternative cover materials at a commercial landfill.

    PubMed

    Solan, P J; Dodd, V A; Curran, T P

    2010-02-01

    The availability of virgin soils and traditional landfill covers are not only costly and increasingly becoming scarce, but they also reduce the storage capacity of landfill. The problem can be overcome by the utilisation of certain suitable waste streams as alternative landfill covers. The objective of this study was to assess the suitability of Construction & Demolition fines (C&D), Commercial & Industrial fines (C&I) and woodchip (WC) as potential landfill cover materials in terms of odour control. Background odour analysis was conducted to determine if any residual odour was emitted from the cover types. It was deemed negligible for the three materials. The odour reduction performance of each of the materials was also examined on an area of an active landfill site. A range of intermediate cover compositions were also studied to assess their performance. Odour emissions were sampled using a Jiang hood and analysed. Results indicate that the 200 mm deep combination layer of C&D and wood chip used on-site is adequate for odour abatement. The application of daily cover was found to result in effective reduction allowing for the background odour of woodchip. PMID:19786346

  9. Preliminary observation on the effect of baking soda volume on controlling odour from discarded organic waste

    SciTech Connect

    Qamaruz-Zaman, N. Kun, Y.; Rosli, R.-N.

    2015-01-15

    Highlights: • Approximately 50 g baking soda reduced odour concentration by 70%. • Reducing volatile acid concentration reduces odour concentration. • Ammonia has less effect on odour concentration. - Abstract: Food wastes with high moisture and organic matter content are likely to emit odours as a result of the decomposition process. The management of odour from decomposing wastes is needed to sustain the interest of residents and local councils in the source separation of kitchen wastes. This study investigated the potential of baking soda (at 50 g, 75 g and 100 g per kg food waste) to control odour from seven days stored food waste. It was found that 50 g of baking soda, spread at the bottom of 8 l food wastes bin, can reduce the odour by about 70%. A higher amount (above 100 g) is not advised as a pH higher than 9.0 may be induced leading to the volatilization of odorous ammonia. This research finding is expected to benefit the waste management sector, food processing industries as well as the local authorities where malodour from waste storage is a pressing issue.

  10. Monitoring of pile composting process of OFMSW at full scale and evaluation of odour emission impact.

    PubMed

    Gutiérrez, M C; Martín, M A; Serrano, A; Chica, A F

    2015-03-15

    In this study, the evolution of odour concentration (ouE/m(3)STP) emitted during the pile composting of the organic fraction of municipal solid waste (OFMSW) was monitored by dynamic olfactometry. Physical-chemical variables as well as the respirometric variables were also analysed. The aim of this work was twofold. The first was to determine the relationship between odour and traditional variables to determine if dynamic olfactometry is a feasible and adequate technique for monitoring an aerobic stabilisation process (composting). Second, the composting process odour impact on surrounding areas was simulated by a dispersion model. The results showed that the decrease of odour concentration, total organic carbon and respirometric variables was similar (around 96, 96 y 98% respectively). The highest odour emission (5224 ouE/m(3)) was reached in parallel with the highest microbiological activity (SOUR and OD20 values of 25 mgO2/gVS · h and 70 mgO2/gVS, respectively). The validity of monitoring odour emissions during composting in combination with traditional and respirometric variables was demonstrated by the adequate correlation obtained between the variables. Moreover, the quantification of odour emissions by dynamic olfactometry and the subsequent application of the dispersion model permitted making an initial prediction of the impact of odorous emissions on the population. Finally, the determination of CO2 and CH4 emissions allowed the influence of composting process on carbon reservoirs and global warming to be evaluated. PMID:25572673

  11. MHC-correlated odour preferences in humans and the use of oral contraceptives

    PubMed Central

    Roberts, S. Craig; Gosling, L. Morris; Carter, Vaughan; Petrie, Marion

    2008-01-01

    Previous studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives have been reported to have the opposite preference, raising the possibility that oral contraceptives alter female preference towards MHC similarity, with possible fertility costs. Here we test directly whether contraceptive pill use alters odour preferences using a longitudinal design in which women were tested before and after initiating pill use; a control group of non-users were tested with a comparable interval between test sessions. In contrast to some previous studies, there was no significant difference in ratings between odours of MHC-dissimilar and MHC-similar men among women during the follicular cycle phase. However, single women preferred odours of MHC-similar men, while women in relationships preferred odours of MHC-dissimilar men, a result consistent with studies in other species, suggesting that paired females may seek to improve offspring quality through extra-pair partnerships. Across tests, we found a significant preference shift towards MHC similarity associated with pill use, which was not evident in the control group. If odour plays a role in human mate choice, our results suggest that contraceptive pill use could disrupt disassortative mate preferences. PMID:18700206

  12. Decomposition Odour Profiling in the Air and Soil Surrounding Vertebrate Carrion

    PubMed Central

    2014-01-01

    Chemical profiling of decomposition odour is conducted in the environmental sciences to detect malodourous target sources in air, water or soil. More recently decomposition odour profiling has been employed in the forensic sciences to generate a profile of the volatile organic compounds (VOCs) produced by decomposed remains. The chemical profile of decomposition odour is still being debated with variations in the VOC profile attributed to the sample collection technique, method of chemical analysis, and environment in which decomposition occurred. To date, little consideration has been given to the partitioning of odour between different matrices and the impact this has on developing an accurate VOC profile. The purpose of this research was to investigate the decomposition odour profile surrounding vertebrate carrion to determine how VOCs partition between soil and air. Four pig carcasses (Sus scrofa domesticus L.) were placed on a soil surface to decompose naturally and their odour profile monitored over a period of two months. Corresponding control sites were also monitored to determine the VOC profile of the surrounding environment. Samples were collected from the soil below and the air (headspace) above the decomposed remains using sorbent tubes and analysed using gas chromatography-mass spectrometry. A total of 249 compounds were identified but only 58 compounds were common to both air and soil samples. This study has demonstrated that soil and air samples produce distinct subsets of VOCs that contribute to the overall decomposition odour. Sample collection from only one matrix will reduce the likelihood of detecting the complete spectrum of VOCs, which further confounds the issue of determining a complete and accurate decomposition odour profile. Confirmation of this profile will enhance the performance of cadaver-detection dogs that are tasked with detecting decomposition odour in both soil and air to locate victim remains. PMID:24740412

  13. Predator odour and its impact on male fertility and reproduction in Phodopus campbelli hamsters.

    PubMed

    Vasilieva, N Y; Cherepanova, E V; von Holst, D; Apfelbach, R

    2000-07-01

    This study investigated the influence of cat urine odour in suppressing development and fertility in Campbell's hamster males. Exposure to this odour from postnatal day 11 until day 45 (sexual maturation) resulted in reduced sex organ weights, reduced testosterone levels and in an increase in abnormalities of the synaptonemal complex in both sex chromosomes and autosomes. Subsequent breeding experiments revealed a significant decrease in litter size. All these data indicate a severe effect of predator odour on the breeding success of potential prey species. It is assumed that these effects are caused by the sulphurous compounds in the urine; however, the underlying mechanisms are not yet known. PMID:11013879

  14. Predator odour and its impact on male fertility and reproduction in Phodopus campbelli hamsters

    NASA Astrophysics Data System (ADS)

    Vasilieva, N. Y.; Cherepanova, E. V.; von Holst, D.; Apfelbach, R.

    This study investigated the influence of cat urine odour in suppressing development and fertility in Campbell's hamster males. Exposure to this odour from postnatal day 11 until day 45 (sexual maturation) resulted in reduced sex organ weights, reduced testosterone levels and in an increase in abnormalities of the synaptonemal complex in both sex chromosomes and autosomes. Subsequent breeding experiments revealed a significant decrease in litter size. All these data indicate a severe effect of predator odour on the breeding success of potential prey species. It is assumed that these effects are caused by the sulphurous compounds in the urine; however, the underlying mechanisms are not yet known.

  15. Odour Mapping Under Strong Backgrounds With a Metal Oxide Sensor Array

    NASA Astrophysics Data System (ADS)

    Ziyatdinov, Andrey; Calvo, José María Blanco; Lechón, Miguel; Bermúdez i Badia, Sergi; Verschure, Paul F. M. J.; Marco, Santiago; Perera, Alexandre

    2011-09-01

    This work describes the data from navigation experiments with the mobile robot, equipped with the sensor array of three MOX gas sensors. Performed four series of measurements aim to explore the capabilities of sensor array to build the odour map with one or two odour sources in the wind tunnel space. It was demonstrated that the method based on Independent Component Analysis (ICA) is able to discriminate two odour sources, that in future can be used in the surge-and-cast robot navigation algorithm.

  16. Electronic Nose Aided Verification of an Odour Dispersion Model for Composting Plants' Applications

    NASA Astrophysics Data System (ADS)

    Artoni, Riccardo; Palmeri, Luca; Pittarello, Alberto; Benzo, Maurizio

    2009-05-01

    The dispersion of odour from a composting plant was calculated with the CALPUFF modeling system, where site specific meteorology and geophysical informations were taken into account. The odour emissions, both from forced and free-convection sources, were measured by means of dynamic olfactometry and implemented in the model. The results obtained from the model were verified with a MOS sensor based Electronic Nose equipped with a preconcentrator, placed in two target sites 50 m and 250 m far from the plant. Odour episodes, detected by electronic nose, were compared with model's forecast; a procedure for tuning the model parameters is needed, in order to reproduce Electronic Nose measurements.

  17. Individual differences in language ability are related to variation in word recognition, not speech perception: Evidence from eye-movements

    PubMed Central

    McMurray, Bob; Munson, Cheyenne; Tomblin, J. Bruce

    2013-01-01

    Purpose This study examined speech perception deficits associated with individual differences in language ability contrasting auditory, phonological or lexical accounts by asking if lexical competition is differentially sensitive to fine-grained acoustic variation. Methods 74 adolescents with a range of language abilities (including 35 impaired) participated in an experiment based on McMurray, Tanenhaus and Aslin (2002). Participants heard tokens from six 9-step Voice Onset Time (VOT) continua spanning two words (beach/peach, beak/peak, etc), while viewing a screen containing pictures of those words and two unrelated objects. Participants selected the referent while eye-movements to each picture were monitored as a measure of lexical activation. Fixations were examined as a function of both VOT and language ability. Results Eye-movements were sensitive to within-category VOT differences: as VOT approached the boundary, listeners made more fixations to the competing word. This did not interact with language ability, suggesting that language impairment is not associated with differential auditory sensitivity or phonetic categorization. Listeners with poorer language skills showed heightened competitors fixations overall, suggesting a deficit in lexical processes. Conclusions Language impairment may be better characterized by a deficit in lexical competition (inability to suppress competing words), rather than differences phonological categorization or auditory abilities. PMID:24687026

  18. Observations on the effects of odours on the homeopathic response.

    PubMed

    McGuigan, Moira

    2014-07-01

    Samuel Hahnemann described incidences where the homeopathic response was disrupted by noxious smells in the environment. An earlier paper proposed that homeopathic medicines may be sensed by vomeronasal cells (VNCs) i.e. microvillus or brush cells in the vomeronasal organ (VNO), the taste buds and associated with the trigeminal nerve and nervus terminalis. This paper proposes an extension to the theory and suggests that a subset of solitary chemosensory cells (SCCs) in the diffuse chemosensory system (DCS) that is morphologically similar to VNCs might also be receptive to homeopathic medicines. The types of odours that may interfere with this process are described. Two clinical cases of disruption of the homeopathic response are given as examples, showing that successful re-establishment of remedy action can be produced by timely repetition of the medicine. The ramifications on clinical homeopathic practice are discussed. PMID:24931752

  19. Properties of odour-binding glycoproteins from rat olfactory epithelium.

    PubMed

    Fesenko, E E; Novoselov, V I; Bystrova, M F

    1988-01-22

    The specific membrane glycoproteins with high affinity for camphor and decanal were isolated from rat olfactory epithelium. Antibodies to these glycoproteins inhibited both the electroolfactogram and the binding of odorants. The enzyme immunoassay has shown these glycoproteins to be present in the olfactory epithelium of rat, mouse, guinea-pig and hamster but not in that of frog and carp. The molecular mass of the odour-binding glycoproteins from rat olfactory epithelium solubilized by Triton X-100 was approx. 140 kDa. They consisted of two subunits (88 and 55 kDa). The 88 kDa subunit was capable of binding odorants. The data obtained suggest that the glycoproteins isolated have some properties that make them plausible candidates for olfactory receptor molecules. PMID:3337807

  20. Colorectal cancer screening with odour material by canine scent detection

    PubMed Central

    Kohnoe, Shunji; Yamazato, Tetsuro; Satoh, Yuji; Morizono, Gouki; Shikata, Kentaro; Morita, Makoto; Watanabe, Akihiro; Morita, Masaru; Kakeji, Yoshihiro; Inoue, Fumio; Maehara, Yoshihiko

    2011-01-01

    Objective Early detection and early treatment are of vital importance to the successful treatment of various cancers. The development of a novel screening method that is as economical and non-invasive as the faecal occult blood test (FOBT) for early detection of colorectal cancer (CRC) is needed. A study was undertaken using canine scent detection to determine whether odour material can become an effective tool in CRC screening. Design Exhaled breath and watery stool samples were obtained from patients with CRC and from healthy controls prior to colonoscopy. Each test group consisted of one sample from a patient with CRC and four control samples from volunteers without cancer. These five samples were randomly and separately placed into five boxes. A Labrador retriever specially trained in scent detection of cancer and a handler cooperated in the tests. The dog first smelled a standard breath sample from a patient with CRC, then smelled each sample station and sat down in front of the station in which a cancer scent was detected. Results 33 and 37 groups of breath and watery stool samples, respectively, were tested. Among patients with CRC and controls, the sensitivity of canine scent detection of breath samples compared with conventional diagnosis by colonoscopy was 0.91 and the specificity was 0.99. The sensitivity of canine scent detection of stool samples was 0.97 and the specificity was 0.99. The accuracy of canine scent detection was high even for early cancer. Canine scent detection was not confounded by current smoking, benign colorectal disease or inflammatory disease. Conclusions This study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating throughout the body. These odour materials may become effective tools in CRC screening. In the future, studies designed to identify cancer-specific volatile organic compounds will be important for the development of new methods for early detection of CRC

  1. Limitation of using synthetic human odours to test mosquito repellents

    PubMed Central

    Okumu, Fredros O; Titus, Emmanuel; Mbeyela, Edgar; Killeen, Gerry F; Moore, Sarah J

    2009-01-01

    Background Gold-standard tests of mosquito repellents involve exposing human volunteers to host-seeking mosquitoes, to assess the protective efficacy of the repellents. These techniques are not exposure-free and cannot be performed prior to toxicological evaluation. It is postulated that synthetic lures could provide a useful assay that mimics in-vivo conditions for use in high-throughput screening for mosquito repellents. Methods This paper reports on a semi-field evaluation of repellents using a synthetic blend of human derived attractants for the malaria vector, Anopheles gambiae sensu stricto Different concentrations of known repellents, N, N diethyl-3-methylbenzamide (deet) and Para-methane-3, 8, diol (PMD) were added into traps baited with the synthetic blend, and resulting changes in mosquito catches were measured. Results All test concentrations of deet (0.001% to 100%) reduced the attractiveness of the synthetic blend. However, PMD was repellent only at 0.25%. Above this concentration, it significantly increased the attractiveness of the blend. There was no relationship between the repellent concentrations and the change in mosquito catches when either deet (r2 = 0.033, P = 0.302) or PMD (r2 = 0.020, P = 0.578) was used. Conclusion It is concluded that while some repellents may reduce the attractiveness of synthetic human odours, others may instead increase their attractiveness. Such inconsistencies indicate that even though the synthetic attractants may provide exposure-free and consistent test media for repellents, careful selection and multiple-repellent tests are necessary to ascertain their suitability for use in repellent screening. The synthetic odour blend tested here is not yet sufficiently refined to serve as replacement for humans in repellent testing, but may be developed further and evaluated in different formats for exposure free repellent testing purposes. PMID:19583848

  2. Do you smell what I smell? Genetic variation in olfactory perception.

    PubMed

    Logan, Darren W

    2014-08-01

    The sense of smell is mediated by the detection of chemical odours by ORs (olfactory receptors) in the nose. This initiates a neural percept of the odour in the brain, which may provoke an emotional or behavioural response. Analogous to colour-blindness in the visual system, some individuals report a very different percept of specific odours to others, in terms of intensity, valence or detection threshold. A significant proportion of variance in odour perception is heritable, and recent advances in genome sequencing and genotyping technologies have permitted studies into the genes that underpin these phenotypic differences. In the present article, I review the evidence that OR genes are extremely variable between individuals. I argue that this contributes to a unique receptor repertoire in our noses that provides us each with a personalized perception of our environment. I highlight specific examples where known OR variants influence odour detection and discuss the wider implications of this for both humans and other mammals that use chemical communication for social interaction. PMID:25109969

  3. Preliminary observation on the effect of baking soda volume on controlling odour from discarded organic waste.

    PubMed

    Qamaruz-Zaman, N; Kun, Y; Rosli, R-N

    2015-01-01

    Food wastes with high moisture and organic matter content are likely to emit odours as a result of the decomposition process. The management of odour from decomposing wastes is needed to sustain the interest of residents and local councils in the source separation of kitchen wastes. This study investigated the potential of baking soda (at 50 g, 75 g and 100g per kg food waste) to control odour from seven days stored food waste. It was found that 50 g of baking soda, spread at the bottom of 8l food wastes bin, can reduce the odour by about 70%. A higher amount (above 100g) is not advised as a pH higher than 9.0 may be induced leading to the volatilization of odorous ammonia. This research finding is expected to benefit the waste management sector, food processing industries as well as the local authorities where malodour from waste storage is a pressing issue. PMID:25445259

  4. Comparison of different approaches for odour impact assessment: dispersion modelling (CALPUFF) vs field inspection (CEN/TC 264).

    PubMed

    Dentoni, Licinia; Capelli, Laura; Sironi, Selena; Guillot, Jean-Michel; Rossi, Andrea N

    2013-01-01

    Odour impact assessment has become an important environmental issue. Different approaches can be used in order to evaluate the odour impact on receptors, and therefore to regulate it. Among the different possible regulation approaches, the use of dispersion modelling is suggested or required by several national or regional legislations. The wide diffusion of this approach is probably due to the fact that odour dispersion modelling is relatively cheap and results are easily understandable. Another kind of approach attempts to evaluate the odour impact directly in the field relying on a panel of trained human assessors (field inspection). The growing importance of this odour impact assessment method is proved by the current draft of a European Standard (CEN/TC 264), which defines two different methodologies of field inspection: grid measurement and plume measurement. In this study two different approaches were compared, i.e. odour dispersion modelling and field inspection by plume measurement (with specific adaptation for the studied site), the latter consisting in using a panel of examiners for determining the absence or presence of odour downwind relative to the source, in order to evaluate the plume extent. The comparison was based on application of both methods to the assessment of the odour impact of a plant for the composting of sludge from an Italian food industry. The results show that the odour impacts assessed by the two strategies turned out to be quite comparable, thus indicating that, if opportunely applied, both approaches may be effective and complementary for odour impact assessment purposes. PMID:24185053

  5. Influence of odour immissions from cellulose-paper industry on some health indicators.

    PubMed

    Georgieff, D; Turnovska, T

    1999-01-01

    The population of the town of Stamboliisky, Bulgaria, is constantly exposed to air pollution which includes immissions of unpleasant odours like methylmercaptane, dimethylsulphide, hydrogen sulfide, etc. Most of these can cause serious olfactory damage even at concentrations well below the toxic levels. The aim of the present study was to analyse the effect of odour immissions on the health status of the people in the town of Stamboliisky. PMID:10462918

  6. The effect of complete versus incomplete information on odour discrimination in a parasitic wasp.

    PubMed

    Vet; De jong AG; Franchi; Papaj

    1998-05-01

    We studied the function of learning in the parasitoid Leptopilina heterotoma by looking at discrimination of odour stimuli used in foraging for a host. To optimize the rate of encounters with hosts, these parasitoids are expected to assess the extent to which variation in host-substrate odours is reliably associated with variation in the presence of hosts, that is, substrate profitability. Where the association is reliable, parasitoids should attend to variation in odours and discriminate between them; where it is not, they should ignore it. We hypothesized that foraging decisions are based on the completeness of information the animal has about differences in substrate profitabilities. Our laboratory studies showed that discrimination and non-discrimination of odour stimuli are dynamic behavioural decisions that can be related to the degree of substrate variation and to an animal's informational state. In wind-tunnel studies, females learned to discriminate between odours from substrates that were qualitatively different, for example, between odours from apple and pear substrates or between yeast substrates with different C6 compounds added. They did not discriminate when differences were small (e.g. between odours from two apple varieties or between yeast patches with different concentrations of ethyl acetate), unless unrewarding experiences provided evidence of the absence of hosts in one of the substrates. Hence, we suggest that non-discrimination between odour stimuli in L. heterotoma is not a lack of ability to discriminate but a functional decision by the parasitoid. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9632510

  7. Multi-stage absorption of rendering plant odours using sodium hypochlorite and other reagents

    NASA Astrophysics Data System (ADS)

    Pope, D.; Davis, B. J.; Moss, R. L.

    Conditions for using sodium hypochlorite solution as the main component of a multi-stage absorption system for the treatment of malodorous process emissions were studied, together with the additional reagents needed for effective odour control. In laboratory experiments, mixtures containing vpm levels in air of trimethylamine, hydrogen sulphide, methyl mercaptan, dimethyl disulphide, n-butanal and sometimes ammonia were passed through three bubble-plate columns containing some of the following: water, dilute sulphuric acid, sodium hypochlorite solutions (varying in pH and available chlorine content) sodium hydroxide and sodium hydrogen sulphite. Odour removal was monitored by Chromatographic and sensory methods. Conclusions from laboratory experiments were supported by field-tests at four rendering plants in the U.K., treating both ventilation and process gases. Alkaline hypochlorite with considerable excess available chlorine removes many sulphur-compounds and aldehydes but effective odour control requires an acid pre-wash to prevent the generation of odorous chlorinated compounds from ammonia and amines. Acidic hypochlorite solution followed by sodium hydrogen sulphite (to remove aldehyde) and sodium hydroxide was a most effective combination in both laboratory and field tests. Odour generated in chlorination reactions involving acidic hypochlorite solution was analysed by GC-MS and GC-MPD-odour-port and the odour key compounds identified.

  8. Odour emissions from a waste treatment plant using an inverse dispersion technique

    NASA Astrophysics Data System (ADS)

    Schauberger, Günther; Piringer, Martin; Knauder, Werner; Petz, Erwin

    2011-03-01

    The determination of the in situ emission rate of pollution sources can often not be done directly. In the absence of emission measurements, the emission rate of the source can be assessed by an inverse dispersion technique using ambient concentration measurements and meteorological parameters as input. The dispersion model used is the Austrian regulatory Gaussian model. The method is applied to a thermal waste recycling plant. Seven chemical species (butyl acetate, benzene, ethyl acetate, toluene, m/p-xylene, o-xylene and α-pinene), are identified as odorants and measured over a period of 1½ years in the prevailing wind direction leeward of the plant. The overall odour emission rate is calculated by adding the odour emission rate of all single species, using the individual odour threshold concentration. The estimated odour emission rates range between 206 and 8950 OU s -1, caused by the wide variety of the odour thresholds of the seven species. The higher value is in the upper range of odour emission rates of modern thermal treatment plants for waste.

  9. Olfactory experience shapes the evaluation of odour similarity in ants: a behavioural and computational analysis.

    PubMed

    Perez, Margot; Nowotny, Thomas; d'Ettorre, Patrizia; Giurfa, Martin

    2016-08-31

    Perceptual similarity between stimuli is often assessed via generalization, the response to stimuli that are similar to the one which was previously conditioned. Although conditioning procedures are variable, studies on how this variation may affect perceptual similarity remain scarce. Here, we use a combination of behavioural and computational analyses to investigate the influence of olfactory conditioning procedures on odour generalization in ants. Insects were trained following either absolute conditioning, in which a single odour (an aldehyde) was rewarded with sucrose, or differential conditioning, in which one odour (the same aldehyde) was similarly rewarded and another odour (an aldehyde differing in carbon-chain length) was punished with quinine. The response to the trained odours and generalization to other aldehydes were assessed. We show that olfactory similarity, rather than being immutable, varies with the conditioning procedure. Compared with absolute conditioning, differential conditioning enhances olfactory discrimination. This improvement is best described by a multiplicative interaction between two independent processes, the excitatory and inhibitory generalization gradients induced by the rewarded and the punished odour, respectively. We show that olfactory similarity is dramatically shaped by an individual's perceptual experience and suggest a new hypothesis for the nature of stimulus interactions underlying experience-dependent changes in perceptual similarity. PMID:27581883

  10. Olfactory experience shapes the evaluation of odour similarity in ants: a behavioural and computational analysis

    PubMed Central

    Perez, Margot; Nowotny, Thomas; d'Ettorre, Patrizia

    2016-01-01

    Perceptual similarity between stimuli is often assessed via generalization, the response to stimuli that are similar to the one which was previously conditioned. Although conditioning procedures are variable, studies on how this variation may affect perceptual similarity remain scarce. Here, we use a combination of behavioural and computational analyses to investigate the influence of olfactory conditioning procedures on odour generalization in ants. Insects were trained following either absolute conditioning, in which a single odour (an aldehyde) was rewarded with sucrose, or differential conditioning, in which one odour (the same aldehyde) was similarly rewarded and another odour (an aldehyde differing in carbon-chain length) was punished with quinine. The response to the trained odours and generalization to other aldehydes were assessed. We show that olfactory similarity, rather than being immutable, varies with the conditioning procedure. Compared with absolute conditioning, differential conditioning enhances olfactory discrimination. This improvement is best described by a multiplicative interaction between two independent processes, the excitatory and inhibitory generalization gradients induced by the rewarded and the punished odour, respectively. We show that olfactory similarity is dramatically shaped by an individual's perceptual experience and suggest a new hypothesis for the nature of stimulus interactions underlying experience-dependent changes in perceptual similarity. PMID:27581883

  11. Variation in complex olfactory stimuli and its influence on odour recognition.

    PubMed Central

    Wrigh, Geraldine A.; Smith, Brian H.

    2004-01-01

    Natural olfactory stimuli are often complex and highly variable. The olfactory systems of animals are likely to have evolved to use specific features of olfactory stimuli for identification and discrimination. Here, we train honeybees to learn chemically defined odorant mixtures that systematically vary from trial to trial and then examine how they generalize to each odorant present in the mixture. An odorant that was present at a constant concentration in a mixture becomes more representative of the mixture than other variable odorants. We also show that both variation and intensity of a complex olfactory stimulus affect the rate of generalization by honeybees to subsequent olfactory stimuli. These results have implications for the way that all animals perceive and attend to features of olfactory stimuli. PMID:15058390

  12. Distributed nestmate recognition in ants

    PubMed Central

    Esponda, Fernando; Gordon, Deborah M.

    2015-01-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  13. Distributed nestmate recognition in ants.

    PubMed

    Esponda, Fernando; Gordon, Deborah M

    2015-05-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  14. Odour-evoked responses to queen pheromone components and to plant odours using optical imaging in the antennal lobe of the honey bee drone Apis mellifera L.

    PubMed

    Sandoz, Jean-Christophe

    2006-09-01

    The primordial functional role of honey bee males (drones) is to mate with virgin queens, a behaviour relying heavily on the olfactory detection of queen pheromone. In the present work I studied olfactory processing in the drone antennal lobe (AL), the primary olfactory centre of the insect brain. In drones, the AL consists of about 103 ordinary glomeruli and four enlarged glomeruli, the macroglomeruli (MG). Two macroglomeruli (MG1 and MG2) and approximately 20 ordinary glomeruli occupy the anterior surface of the antennal lobe and are thus accessible to optical recordings. Calcium imaging was used to measure odour-evoked responses to queen pheromonal components and plant odours. MG2 responded specifically to the main component of the queen mandibular pheromone, 9-ODA. The secondary components HOB and HVA each triggered activity in one, but not the same, ordinary glomerulus. MG1 did not respond to any of the tested stimuli. Plant odours induced signals only in ordinary glomeruli in a combinatorial manner, as in workers. This study thus shows that the major queen pheromonal component is processed in the most voluminous macroglomerulus of the drone antennal lobe, and that plant odours, as well as some queen pheromonal components, are processed in ordinary glomeruli. PMID:16943499

  15. Use of electronic noses for detection of odour from animal production facilities: a review.

    PubMed

    Nimmermark, S

    2001-01-01

    In the field of controlling livestock and poultry odours in the internal and external environment and in derived food products, one main obstacle is how to measure the odour in a suitable way. Olfactometry and a human panel have been used in most studies of farm odour until now. Alternatives like electronic noses are interesting considering disadvantages for olfactometry regarding cost and labour requirement. An electronic device can produce an almost instant response which is useful in many applications. Studies have shown detection of farm odour for some electronic noses and also response to odour concentrations. Other studies have shown very high odour threshold values compared to human noses. Electronic noses with a large number of sensors have been developed since a base was formed in the 1950s. The fast progress in data processing and sensor development in the latest years have made the electronic noses interesting for a large number of industrial applications in the food processing industry, as well as in other areas. Materials like manure produce a complex mixture of odorous compounds and the interaction between these creates a unique odour where no specific dominating and characterising compound seems to exist. Related to swine farms almost 200 different odorous compounds have been reported. The electronic noses can, depending on the sensitivity of its sensors, detect some compounds at lower levels than the human nose, while other compounds offensive to a human nose cannot be detected. Proper function of the electronic noses with sensitivity for the odorous gases in the application must be followed by satisfying properties regarding ageing, temperature stability, humidity and other environmental factors. PMID:11762481

  16. Habitats as Complex Odour Environments: How Does Plant Diversity Affect Herbivore and Parasitoid Orientation?

    PubMed Central

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  17. Computer image processing and recognition

    NASA Technical Reports Server (NTRS)

    Hall, E. L.

    1979-01-01

    A systematic introduction to the concepts and techniques of computer image processing and recognition is presented. Consideration is given to such topics as image formation and perception; computer representation of images; image enhancement and restoration; reconstruction from projections; digital television, encoding, and data compression; scene understanding; scene matching and recognition; and processing techniques for linear systems.

  18. Identification of the origin of odour episodes through social participation, chemical control and numerical modelling

    NASA Astrophysics Data System (ADS)

    Gallego, E.; Soriano, C.; Roca, F. X.; Perales, J. F.; Alarcón, M.; Guardino, X.

    Odour episodes and environmental air quality are topics of worldwide concern, mainly due to the fact that industrial facilities are often located very close to inhabited areas. Several atmospheric pollutants, mainly volatile organic compounds (VOCs), are responsible for odour episodes of varying degrees of annoyance. A methodology based on the simultaneous application of social participation (by building databases of odour episodes and acquiring air samples), chemical control and the computation of back trajectories allows us to identify the origin of odour episodes. A validated analytical method, based on thermal desorption (TD) coupled with gas chromatography (GC) and mass spectrometry (MS), is used to identify and determine a wide range of VOCs that cause odour nuisance and affect air quality in outdoor air. Back-trajectory modelling is used to track the origin of the air mass responsible for the discomfort backwards in time, mainly to find possible VOC sources outside the urban area. The procedure combines, on one hand, an analytical approach based on the acquisition of samples, which requires the participation of the affected population (which means that social participation is used as a scientific tool), and on the other hand, a modelling approach. Three examples are described to illustrate the methodology.

  19. Odour cues influence predation risk at artificial bat roosts in urban bushland.

    PubMed

    Threlfall, Caragh; Law, Bradley; Banks, Peter B

    2013-06-23

    Odours that accumulate from roosting can attract predators and increase predation risk. Consequently, selection should favour strategies that allow prey to evade detection by predators, including changing roosts. Insectivorous bats that roost in tree hollows regularly switch roosts and roost in different sized groups, strategies that would alter the accumulation of roost odours and are hypothesized to reduce predation risk. We experimentally manipulated the amount and refresh rate of roosting odour cues at 90 artificial bat roosts in Sydney, Australia, to test the hypothesis that odours increase predator visitation. Predators visited roosts with bat faeces significantly more often than untreated control roosts. Roosts with small amounts of faeces mimicking sites used by solitary bats had the greatest rate of visitation. This suggests that bats roosting alone, rather than in groups, have a greater likelihood of disturbance or predation. Roost switching probably decreases the predictability of finding occupied roosts; however, we show that all roosts (those currently or recently occupied) were visited by predators, suggesting generalist urban predators readily investigate potential roosts. This is the first demonstration that bat odours are attractive to predators that use olfactory cues, showing that bats are at risk of predation in visually cryptic roosts. PMID:23637390

  20. Comparison of emission rate values for odour and odorous chemicals derived from two sampling devices

    NASA Astrophysics Data System (ADS)

    Hudson, N.; Ayoko, G. A.

    Field and laboratory measurements identified a complex relationship between odour emission rates provided by the US EPA dynamic emission chamber and the University of New South Wales wind tunnel. Using a range of model compounds in an aqueous odour source, we demonstrate that emission rates derived from the wind tunnel and flux chamber are a function of the solubility of the materials being emitted, the concentrations of the materials within the liquid; and the aerodynamic conditions within the device - either velocity in the wind tunnel, or flushing rate for the flux chamber. The ratio of wind tunnel to flux chamber odour emission rates (OU m -2 s) ranged from about 60:1 to 112:1. The emission rates of the model odorants varied from about 40:1 to over 600:1. These results may provide, for the first time, a basis for the development of a model allowing an odour emission rate derived from either device to be used for odour dispersion modelling.

  1. Characterisation of free and glycosidically bound odourant compounds of Aragonez clonal musts by GC-O.

    PubMed

    Botelho, Goreti; Mendes-Faia, Arlete; Clímaco, Maria Cristina

    2010-01-11

    To evaluate the potential aroma of Aragonez clonal red musts, several free and glycosidically bound odourant compounds were extracted. Then, the gas chromatography-olfactometry (GC-O) posterior intensity method was used to evaluate their odour intensity and the compounds were identified by gas chromatography-mass spectrometry (GC-MS). A group of eight sniffers evaluated free and bound fractions of Aragonez musts and perceived forty-three and twenty-two odourant peaks respectively. Furaneol (burnt sugar, candy-cotton) and vanillin (vanilla, sweet) were identified in both free and bound fractions of Aragonez musts, indicating their grape-derived origin. Principal component analysis (PCA) was applied to the posterior intensity method data and a relationship between the different odourant compound variables and the free fractions was established. Two principal components (PCs) were found which together explained 100% of the total variance. A large number of potentially important but yet unknown odourants was detected by the GC-O analysis. PMID:20005332

  2. Colour and odour drive fruit selection and seed dispersal by mouse lemurs

    PubMed Central

    Valenta, Kim; Burke, Ryan J.; Styler, Sarah A.; Jackson, Derek A.; Melin, Amanda D.; Lehman, Shawn M.

    2013-01-01

    Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by mouse lemurs. We show that both fruit colour and odour significantly predict fruit consumption and seed dispersal by Microcebus ravelobensis and M. murinus. Our study is the first to quantify and examine the role of bimodal fruit signals on seed dispersal in light of the sensory abilities of the disperser. PMID:23939534

  3. Shades of yellow: interactive effects of visual and odour cues in a pest beetle

    PubMed Central

    Stevenson, Philip C.; Belmain, Steven R.

    2016-01-01

    Background: The visual ecology of pest insects is poorly studied compared to the role of odour cues in determining their behaviour. Furthermore, the combined effects of both odour and vision on insect orientation are frequently ignored, but could impact behavioural responses. Methods: A locomotion compensator was used to evaluate use of different visual stimuli by a major coleopteran pest of stored grains (Sitophilus zeamais), with and without the presence of host odours (known to be attractive to this species), in an open-loop setup. Results: Some visual stimuli—in particular, one shade of yellow, solid black and high-contrast black-against-white stimuli—elicited positive orientation behaviour from the beetles in the absence of odour stimuli. When host odours were also present, at 90° to the source of the visual stimulus, the beetles presented with yellow and vertical black-on-white grating patterns changed their walking course and typically adopted a path intermediate between the two stimuli. The beetles presented with a solid black-on-white target continued to orient more strongly towards the visual than the odour stimulus. Discussion: Visual stimuli can strongly influence orientation behaviour, even in species where use of visual cues is sometimes assumed to be unimportant, while the outcomes from exposure to multimodal stimuli are unpredictable and need to be determined under differing conditions. The importance of the two modalities of stimulus (visual and olfactory) in food location is likely to depend upon relative stimulus intensity and motivational state of the insect. PMID:27478707

  4. Prospects for Developing Odour Baits To Control Glossina fuscipes spp., the Major Vector of Human African Trypanosomiasis

    PubMed Central

    Omolo, Maurice O.; Hassanali, Ahmed; Mpiana, Serge; Esterhuizen, Johan; Lindh, Jenny; Lehane, Mike J.; Solano, Philippe; Rayaisse, Jean Baptiste; Vale, Glyn A.; Torr, Steve J.; Tirados, Inaki

    2009-01-01

    We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed on a black target (1×1 m). In addition responses to monitor lizard (Varanus niloticus) were assessed in Kenya. The effects of all four odours on the proportion of tsetse that entered a biconical trap were also determined. Sources of natural host odour were produced by placing live hosts in a tent or metal hut (volumes≈16 m3) from which the air was exhausted at ∼2000 L/min. Odours from cattle, pigs and humans had no significant effect on attraction of G. f. fuscipes but lizard odour doubled the catch (P<0.05). Similarly, mammalian odours had no significant effect on landing or trap entry whereas lizard odour increased these responses significantly: landing responses increased significantly by 22% for males and 10% for females; the increase in trap efficiency was relatively slight (5–10%) and not always significant. For G. f. quanzensis, only pig odour had a consistent effect, doubling the catch of females attracted to the source and increasing the landing response for females by ∼15%. Dispensing CO2 at doses equivalent to natural hosts suggested that the response of G. f. fuscipes to lizard odour was not due to CO2. For G. f. quanzensis, pig odour and CO2 attracted similar numbers of tsetse, but CO2 had no material effect on the landing response. The results suggest that identifying kairomones present in lizard odour for G. f. fuscipes and pig odour for G. f. quanzensis may improve the performance of targets for controlling these species. PMID:19434232

  5. Early recognition of speech

    PubMed Central

    Remez, Robert E; Thomas, Emily F

    2013-01-01

    Classic research on the perception of speech sought to identify minimal acoustic correlates of each consonant and vowel. In explaining perception, this view designated momentary components of an acoustic spectrum as cues to the recognition of elementary phonemes. This conceptualization of speech perception is untenable given the findings of phonetic sensitivity to modulation independent of the acoustic and auditory form of the carrier. The empirical key is provided by studies of the perceptual organization of speech, a low-level integrative function that finds and follows the sensory effects of speech amid concurrent events. These projects have shown that the perceptual organization of speech is keyed to modulation; fast; unlearned; nonsymbolic; indifferent to short-term auditory properties; and organization requires attention. The ineluctably multisensory nature of speech perception also imposes conditions that distinguish language among cognitive systems. WIREs Cogn Sci 2013, 4:213–223. doi: 10.1002/wcs.1213 PMID:23926454

  6. Factors influencing separation distances against odour annoyance calculated by Gaussian and Lagrangian dispersion models

    NASA Astrophysics Data System (ADS)

    Piringer, Martin; Knauder, Werner; Petz, Erwin; Schauberger, Günther

    2016-09-01

    Direction-dependent separation distances to avoid odour annoyance, calculated with the Gaussian Austrian Odour Dispersion Model AODM and the Lagrangian particle diffusion model LASAT at two sites, are analysed and compared. The relevant short-term peak odour concentrations are calculated with a stability-dependent peak-to-mean algorithm. The same emission and meteorological data, but model-specific atmospheric stability classes are used. The estimate of atmospheric stability is obtained from three-axis ultrasonic anemometers using the standard deviations of the three wind components and the Obukhov stability parameter. The results are demonstrated for the Austrian villages Reidling and Weissbach with very different topographical surroundings and meteorological conditions. Both the differences in the wind and stability regimes as well as the decrease of the peak-to-mean factors with distance lead to deviations in the separation distances between the two sites. The Lagrangian model, due to its model physics, generally calculates larger separation distances. For worst-case calculations necessary with environmental impact assessment studies, the use of a Lagrangian model is therefore to be preferred over that of a Gaussian model. The study and findings relate to the Austrian odour impact criteria.

  7. Exposure to extreme stress impairs contextual odour discrimination in an animal model of PTSD.

    PubMed

    Cohen, Hagit; Liberzon, Israel; Richter-Levin, Gal

    2009-04-01

    Post-traumatic stress disorder (PTSD) patients respond to trauma-related danger cues even in objectively safe environments as if they were in the original event, seemingly unable to adequately modulate their responses based on the contextual cues present. In order to model this inability to utilize contextualized memory, in an animal model of PTSD, a novel experimental paradigm of contextual cue processing was developed--the differential contextual odour conditioning (DCOC) paradigm--and tested in trauma-exposed animals and controls. In the DCOC paradigm, animals encountered cinnamon odour in both an aversive environment and a rewarding (safe) environment. Response (freezing) to cinnamon odour was tested in a third, neutral environment to examine the ability of animals to modulate their responses based on the contextual cues. The effect of exposure to traumatic stressors, e.g. predator scent stress (PSS) and underwater trauma (UWT), on contextual cue discrimination was assessed. Rats trained in the DCOC paradigm acquired the ability to modulate their behavioural responses to odour cue based on contextual cues signalling safe vs. dangerous environment. The PSS and UWT stressors abolished the ability to modulate their responses based on contextual cues, both when exposure preceded DCOC training, and when it followed successfully completed training. The DCOC paradigm offers a promising model for studying the neurobiological basis of contextual modulation of response to potential threat in animals, a process that is disrupted by exposure to severe stress/trauma, and thus might be particularly salient for the study of PTSD. PMID:18700055

  8. Advances in the use of odour as forensic evidence through optimizing and standardizing instruments and canines

    PubMed Central

    Furton, Kenneth G.; Caraballo, Norma Iris; Cerreta, Michelle M.; Holness, Howard K.

    2015-01-01

    This paper explores the advances made in identifying trace amounts of volatile organic compounds (VOCs) that originate from forensic specimens, such as drugs, explosives, live human scent and the scent of death, as well as the probative value for detecting such odours. The ability to locate and identify the VOCs liberated from or left by forensic substances is of increasing importance to criminal investigations as it can indicate the presence of contraband and/or associate an individual to a particular location or object. Although instruments have improved significantly in recent decades—with sensitivities now rivalling that of biological detectors—it is widely recognized that canines are generally still more superior for the detection of odourants due to their speed, versatility, ruggedness and discriminating power. Through advancements in the detection of VOCs, as well as increased standardization efforts for instruments and canines, the reliability of odour as evidence has continuously improved and is likely to continue to do so. Moreover, several legal cases in which this novel form of evidence has been accepted into US courts of law are discussed. As the development and implementation of best practice guidelines for canines and instruments increase, their reliability in detecting VOCs of interest should continue to improve, expanding the use of odour as an acceptable form of forensic evidence. PMID:26101287

  9. Mating-induced differential coding of plant odour and sex pheromone in a male moth.

    PubMed

    Barrozo, Romina B; Jarriault, David; Deisig, Nina; Gemeno, Cesar; Monsempes, Christelle; Lucas, Philippe; Gadenne, Christophe; Anton, Sylvia

    2011-05-01

    Innate behaviours in animals can be influenced by several factors, such as the environment, experience, or physiological status. This behavioural plasticity originates from changes in the underlying neuronal substrate. A well-described form of plasticity is induced by mating. In both vertebrates and invertebrates, males experience a post-ejaculatory refractory period, during which they avoid new females. In the male moth Agrotis ipsilon, mating induces a transient inhibition of responses to the female-produced sex pheromone. To understand the neural bases of this inhibition and its possible odour specificity, we carried out a detailed analysis of the response characteristics of the different neuron types from the periphery to the central level. We examined the response patterns of pheromone-sensitive and plant volatile-sensitive neurons in virgin and mated male moths. By using intracellular recordings, we showed that mating changes the response characteristics of pheromone-sensitive antennal lobe (AL) neurons, and thus decreases their sensitivity to sex pheromone. Individual olfactory receptor neuron (ORN) recordings and calcium imaging experiments indicated that pheromone sensory input remains constant. On the other hand, calcium responses to non-pheromonal odours (plant volatiles) increased after mating, as reflected by increased firing frequencies of plant-sensitive AL neurons, although ORN responses to heptanal remained unchanged. We suggest that differential processing of pheromone and plant odours allows mated males to transiently block their central pheromone detection system, and increase non-pheromonal odour detection in order to efficiently locate food sources. PMID:21488987

  10. Female odours promote the activation of sheltered kissing bug Rhodnius prolixus males and modulate their orientation.

    PubMed

    Pontes, G; Zacharias, C A; Manrique, G; Lorenzo, M G

    2014-09-01

    The existence of a pheromone emitted during copulation has been reported for Rhodnius prolixus (Hemiptera: Reduviidae) Stål. Adults possess one pair of metasternal glands (MGs) from which female R. prolixus release volatiles mainly at night. We investigated whether these volatiles emitted by adult R. prolixus can modulate sexual-related behaviours of opposite and/or same sex individuals. We first used a shelter bioassay to test if adult activity patterns can be affected by chemical signals emitted by opposite sex conspecifics. We observed that males left the shelter more frequently in the presence of females, showing higher activity and an increase of intrasexual copulation attempts. Females showed no shelter-related activation in the presence of male odours. Second, we used a locomotion compensator device to investigate whether females or males show oriented responses to odours emitted by adults. We found that males oriented towards air currents carrying female odours but females did not orient towards odours emitted by adults. Finally, we observed that males oriented towards the female MG compounds. Thus, a volatile chemical signal emitted by females from their MGs promoted the activation of sheltered males and modulated orientation to air currents. PMID:25855829

  11. Study of the effect of DMSO on VOS odour production in a wastewater plant.

    PubMed

    Cheng, X; Peterkin, E D; Burlingame, G A

    2007-01-01

    Odours caused by volatile organic sulphides (VOS) have a history spanning over 20 years for Philadelphia's Northeast Water Pollution Control Plant (NEWPCP). A "canned corn" type of odour has caused residential complaints. Traditional odour control approaches based on hydrogen sulphide failed. This study confirmed that dimethyl sulphoxide (DMSO) from a chemical facility was the dominant cause of the "canned corn" nuisance odour in the form of dimethyl sulphide (DMS). During a discharge, DMSO concentrations up to 12 mg/L were found in the influent of the NEWPCP. Each DMSO concentration peak induced a DMS peak. DMS concentrations increased from less than 50 microg/L to 6 mg/L with a corresponding decrease in DMSO. Approximately 79% of DMSO from the primary sedimentation influent was passed to the effluent, and to downstream processes, such as the aeration tanks where the DMS was volatilised by the aeration. The DMS partial pressure in ambient air of NEWPCP can be between 0.03 and 0.18 x 10(-3) atm during a DMSO discharge. From the above information, the potential of VOS production is estimated and a practical plan for remediation can be designed. PMID:17489426

  12. Behavioural responses of stable flies to cattle manure slurry associated odourants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundan...

  13. Unconscious Odour Conditioning 25 Years Later: Revisiting and Extending "Kirk-Smith, Van Toller and Dodd"

    ERIC Educational Resources Information Center

    Zucco, Gesualdo M.; Paolini, Michela; Schaal, Benoist

    2009-01-01

    The pioneering work by Kirk-Smith, Van Toller, and Dodd [Kirk-Smith, M. D., Van Toller, C., & Dodd, G. H. (1983). "Unconscious odour conditioning in human subjects." "Biological Psychology," 17, 221-231], established that an unnoticed odorant paired with an emotionally meaningful task can influence mood and attitudes when the odorant alone is…

  14. Advances in the use of odour as forensic evidence through optimizing and standardizing instruments and canines.

    PubMed

    Furton, Kenneth G; Caraballo, Norma Iris; Cerreta, Michelle M; Holness, Howard K

    2015-08-01

    This paper explores the advances made in identifying trace amounts of volatile organic compounds (VOCs) that originate from forensic specimens, such as drugs, explosives, live human scent and the scent of death, as well as the probative value for detecting such odours. The ability to locate and identify the VOCs liberated from or left by forensic substances is of increasing importance to criminal investigations as it can indicate the presence of contraband and/or associate an individual to a particular location or object. Although instruments have improved significantly in recent decades-with sensitivities now rivalling that of biological detectors-it is widely recognized that canines are generally still more superior for the detection of odourants due to their speed, versatility, ruggedness and discriminating power. Through advancements in the detection of VOCs, as well as increased standardization efforts for instruments and canines, the reliability of odour as evidence has continuously improved and is likely to continue to do so. Moreover, several legal cases in which this novel form of evidence has been accepted into US courts of law are discussed. As the development and implementation of best practice guidelines for canines and instruments increase, their reliability in detecting VOCs of interest should continue to improve, expanding the use of odour as an acceptable form of forensic evidence. PMID:26101287

  15. Use of non-thermal plasma and UV-light for removal of odour from sludge treatment.

    PubMed

    Andersen, K B; Feilberg, A; Beukes, J A

    2012-01-01

    Non-thermal plasma (NTP) systems can be used for abatement of odour nuisances. Odour reductions are achieved by radical-initiated oxidation and dust collection in the plasma reactor. For some emissions a sequence of NTP followed by UV-light can improve the odour reduction further. This study was conducted to evaluate the efficiency of NTP technology combined with UV-light towards odour emissions from sludge treatment. Air from a pilot sludge dryer was treated with a pilot NTP and a UV unit. The effect of using an acid scrubber upstream the NTP system was also tested. Thermal desorption gas chromatography and mass spectrometry (TD-GC/MS) was used to analyse samples taken from the inlet and the outlet of the NTP system. The TD-GC/MS used was also equipped with a sniffing port that made it possible to record odour-active compounds eluting from the column. Relative amounts of odour-active compounds in the inlet and the outlet flow from the NTP system were compared. Bag samples from inlet and outlet were also separately analysed by an external lab and by two operators using a one-man olfactometer, a modified NasalRanger(TM). These results indicated a significant odour removal efficiency of 70-90% depending on the settings and combinations of abatement equipment. PMID:22907448

  16. Odour enrichment increases adult-born dopaminergic neurons in the mouse olfactory bulb.

    PubMed

    Bonzano, Sara; Bovetti, Serena; Fasolo, Aldo; Peretto, Paolo; De Marchis, Silvia

    2014-11-01

    The olfactory bulb (OB) is the first brain region involved in the processing of olfactory information. In adult mice, the OB is highly plastic, undergoing cellular/molecular dynamic changes that are modulated by sensory experience. Odour deprivation induces down-regulation of tyrosine hydroxylase (TH) expression in OB dopaminergic interneurons located in the glomerular layer (GL), resulting in decreased dopamine in the OB. Although the effect of sensory deprivation is well established, little is known about the influence of odour enrichment on dopaminergic cells. Here we report that prolonged odour enrichment on C57BL/6J strain mice selectively increases TH-immunopositive cells in the GL by nearly 20%. Following odour enrichment on TH-green fluorescent protein (GFP) transgenic mice, in which GFP identified both mature TH-positive cells and putative immature dopaminergic cells expressing TH mRNA but not TH protein, we found a similar 20% increase in GFP-expressing cells, with no changes in the ratio between TH-positive and TH-negative cells. These data suggest that enriched conditions induce an expansion in the whole dopaminergic lineage. Accordingly, by using 5-bromo-2-deoxyuridine injections to label adult-generated cells in the GL of TH-GFP mice, we found an increase in the percentage of 5-bromo-2-deoxyuridine-positive dopaminergic cells in enriched compared with control conditions, whereas no differences were found for calretinin- and calbindin-positive subtypes. Strikingly, the fraction of newborn cells among the dopaminergic population doubled in enriched conditions. On the whole, our results demonstrate that odour enrichment drives increased integration of adult-generated dopaminergic cells that could be critical to adapt the OB circuits to the environmental incoming information. PMID:25216299

  17. Modulation by cyclic GMP of the odour sensitivity of vertebrate olfactory receptor cells

    NASA Technical Reports Server (NTRS)

    Leinders-Zufall, T.; Shepherd, G. M.; Zufall, F.

    1996-01-01

    Recent evidence has indicated a significant role for the cGMP second messenger system in vertebrate olfactory transduction but no clear functions have been identified for cGMP so far. Here, we have examined the effects of 8-Br-cGMP and carbon monoxide (CO) on odour responses of salamander olfactory receptor neurons using perforated patch recordings. We report that 8-Br-cGMP strongly down-regulates the odour sensitivity of the cells, with a K1/2 of 460 nM. This adaptation-like effect can be mimicked by CO, an activator of soluble guanylyl cyclase, with a K1/2 of 1 microM. Sensitivity modulation is achieved through a regulatory chain of events in which cGMP stimulates a persistent background current due to the activation of cyclic nucleotide-gated channels. This in turn leads to sustained Ca2+ entry providing a negative feedback signal. One consequence of the Ca2+ entry is a shift to the right of the stimulus-response curve and a reduction in saturating odour currents. Together, these two effects can reduce the sensory generator current by up to twenty-fold. Thus, cGMP functions to control the gain of the G-protein coupled cAMP pathway. Another consequence of the action of cGMP is a marked prolongation of the odour response kinetics. The effects of CO/cGMP are long-lasting and can continue for minutes. Hence, we propose that cGMP helps to prevent saturation of the cell's response by adjusting the operational range of the cAMP cascade and contributes to olfactory adaptation by decreasing the sensitivity of olfactory receptor cells to repeated odour stimuli.

  18. Natural host odours as possible attractants for Glossina tachinoides and G. longipalpis (Diptera: Glossinidae).

    PubMed

    Späth, J

    1997-11-01

    As strictly haematophagous insects, tsetse flies feed on a wide variety of wild and domestic animals. Although these are mainly mammals, some tsetse species also feed on reptiles. The present study investigated whether the odours of several potential natural tsetse hosts may be used as novel attractants to improve the catch of Glossina tachinoides or G. longipalpis in biconical traps. The odour of a living monitor lizard (Varanus niloticus) had no effect on the catch of G. tachinoides. Hexane skin washings of monitor lizard and warthog (Phacochoerus aethiopicus) dispensed in small quantities improved the catch of G. tachinoides significantly by factors of up to 1.34 and 1.46, respectively. Skin washing of bushbuck (Tragelaphus scriptus) did not increase the catch of G. tachinoides, but the synthetic phenolic fraction of bushbuck urine enhanced it significantly by 1.81 times. The catch of G. longipalpis was improved significantly by the urines of warthog, domestic pig and bushbuck by factors of 1.58, 1.91 and 2.51, respectively. In relation to the quantity of evaporated odour, bushbuck and warthog urine seem to be of particular interest for further attractant studies. The effect of tested host odours on the catch of G. tachinoides and G. longipalpis is compared with data of other tsetse species and with the frequency these hosts are fed on by tsetse flies. Bushbuck is one of the principal natural hosts of both Glossina species investigated, and of all odours tested, bushbuck urine and its synthetic phenolic fraction improved the catch of both tsetse species the most. PMID:9386790

  19. Perception and Hierarchical Dynamics

    PubMed Central

    Kiebel, Stefan J.; Daunizeau, Jean; Friston, Karl J.

    2009-01-01

    In this paper, we suggest that perception could be modeled by assuming that sensory input is generated by a hierarchy of attractors in a dynamic system. We describe a mathematical model which exploits the temporal structure of rapid sensory dynamics to track the slower trajectories of their underlying causes. This model establishes a proof of concept that slowly changing neuronal states can encode the trajectories of faster sensory signals. We link this hierarchical account to recent developments in the perception of human action; in particular artificial speech recognition. We argue that these hierarchical models of dynamical systems are a plausible starting point to develop robust recognition schemes, because they capture critical temporal dependencies induced by deep hierarchical structure. We conclude by suggesting that a fruitful computational neuroscience approach may emerge from modeling perception as non-autonomous recognition dynamics enslaved by autonomous hierarchical dynamics in the sensorium. PMID:19649171

  20. Disinhibition of olfactory bulb granule cells accelerates odour discrimination in mice

    PubMed Central

    Nunes, Daniel; Kuner, Thomas

    2015-01-01

    Granule cells are the dominant cell type of the olfactory bulb inhibiting mitral and tufted cells via dendrodendritic synapses; yet the factors regulating the strength of their inhibitory output, and, therefore, their impact on odour discrimination, remain unknown. Here we show that GABAAR β3-subunits are distributed in a somatodendritic pattern, mostly sparing the large granule cell spines also known as gemmules. Granule cell-selective deletion of β3-subunits nearly abolishes spontaneous and muscimol-induced currents mediated by GABAA receptors in granule cells, yet recurrent inhibition of mitral cells is strongly enhanced. Mice with disinhibited granule cells require less time to discriminate both dissimilar as well as highly similar odourants, while discrimination learning remains unaffected. Hence, granule cells are controlled by an inhibitory drive that in turn tunes mitral cell inhibition. As a consequence, the olfactory bulb inhibitory network adjusts the speed of early sensory processing. PMID:26592770

  1. Disinhibition of olfactory bulb granule cells accelerates odour discrimination in mice.

    PubMed

    Nunes, Daniel; Kuner, Thomas

    2015-01-01

    Granule cells are the dominant cell type of the olfactory bulb inhibiting mitral and tufted cells via dendrodendritic synapses; yet the factors regulating the strength of their inhibitory output, and, therefore, their impact on odour discrimination, remain unknown. Here we show that GABAAR β3-subunits are distributed in a somatodendritic pattern, mostly sparing the large granule cell spines also known as gemmules. Granule cell-selective deletion of β3-subunits nearly abolishes spontaneous and muscimol-induced currents mediated by GABAA receptors in granule cells, yet recurrent inhibition of mitral cells is strongly enhanced. Mice with disinhibited granule cells require less time to discriminate both dissimilar as well as highly similar odourants, while discrimination learning remains unaffected. Hence, granule cells are controlled by an inhibitory drive that in turn tunes mitral cell inhibition. As a consequence, the olfactory bulb inhibitory network adjusts the speed of early sensory processing. PMID:26592770

  2. Impact of a non-attentively perceived odour on subsequent food choices.

    PubMed

    Gaillet-Torrent, M; Sulmont-Rossé, C; Issanchou, S; Chabanet, C; Chambaron, S

    2014-05-01

    Current research in psychology suggests that unconscious processes influence a significant proportion of choices and decisions. To study the impact of a non-attentively perceived odour on food choices, we used a priming paradigm. We had previously shown that non-attentively perceived fruity odours could impact food choice intentions (on a menu card), guiding participants toward items containing more fruit and/or vegetables. The present study was designed to extend these findings, in a real-life consumption setting. One hundred and fifteen participants took part in this study, and were assigned randomly to either a control or a scented condition. On arrival in the laboratory, they were seated in a waiting room. For the scented condition, they were unobtrusively exposed to a pear odour, while under the control condition the waiting room was non-odorised. Following this waiting period, all participants moved into a non-odorised test room where they were asked to choose, from dishes served buffet-style, the starter, main course and dessert that they would actually eat for lunch. The results showed that participants subjected to the scented condition chose to consume the 'fruity' dessert (compote) more frequently than those who had waited under the control condition, who chose more frequently the dessert without fruit (brownie). In line with the findings of our previous study, these results confirm the idea of priming effects 'specific to the food cue'. To conclude, a non-attentively perceived fruity odour was shown to influence actual food choices, guiding individuals towards more fruity desserts. The involvement of implicit processes in food choices should be taken into account in guidelines and strategies designed to promote healthy eating. PMID:24462492

  3. Major histocompatibility complex peptide ligands as olfactory cues in human body odour assessment

    PubMed Central

    Milinski, Manfred; Croy, Ilona; Hummel, Thomas; Boehm, Thomas

    2013-01-01

    In many animal species, social communication and mate choice are influenced by cues encoded by the major histocompatibility complex (MHC). The mechanism by which the MHC influences sexual selection is a matter of intense debate. In mice, peptide ligands of MHC molecules activate subsets of vomeronasal and olfactory sensory neurons and influence social memory formation; in sticklebacks, such peptides predictably modify the outcome of mate choice. Here, we examine whether this evolutionarily conserved mechanism of interindividual communication extends to humans. In psychometric tests, volunteers recognized the supplementation of their body odour by MHC peptides and preferred ‘self’ to ‘non-self’ ligands when asked to decide whether the modified odour smelled ‘like themselves’ or ‘like their favourite perfume’. Functional magnetic resonance imaging indicated that ‘self’-peptides specifically activated a region in the right middle frontal cortex. Our results suggest that despite the absence of a vomeronasal organ, humans have the ability to detect and evaluate MHC peptides in body odour. This may provide a basis for the sensory evaluation of potential partners during human mate choice. PMID:23345577

  4. Major histocompatibility complex peptide ligands as olfactory cues in human body odour assessment.

    PubMed

    Milinski, Manfred; Croy, Ilona; Hummel, Thomas; Boehm, Thomas

    2013-03-22

    In many animal species, social communication and mate choice are influenced by cues encoded by the major histocompatibility complex (MHC). The mechanism by which the MHC influences sexual selection is a matter of intense debate. In mice, peptide ligands of MHC molecules activate subsets of vomeronasal and olfactory sensory neurons and influence social memory formation; in sticklebacks, such peptides predictably modify the outcome of mate choice. Here, we examine whether this evolutionarily conserved mechanism of interindividual communication extends to humans. In psychometric tests, volunteers recognized the supplementation of their body odour by MHC peptides and preferred 'self' to 'non-self' ligands when asked to decide whether the modified odour smelled 'like themselves' or 'like their favourite perfume'. Functional magnetic resonance imaging indicated that 'self'-peptides specifically activated a region in the right middle frontal cortex. Our results suggest that despite the absence of a vomeronasal organ, humans have the ability to detect and evaluate MHC peptides in body odour. This may provide a basis for the sensory evaluation of potential partners during human mate choice. PMID:23345577

  5. Thermogenesis, Flowering and the Association with Variation in Floral Odour Attractants in Magnolia sprengeri (Magnoliaceae)

    PubMed Central

    Wang, Ruohan; Xu, Sai; Liu, Xiangyu; Zhang, Yiyuan; Wang, Jianzhong; Zhang, Zhixiang

    2014-01-01

    Magnolia sprengeri Pamp. is an ornamentally and ecologically important tree that blooms at cold temperatures in early spring. In this study, thermogenesis and variation in the chemical compounds of floral odours and insect visitation in relation to flowering cycles were studied to increase our understanding of the role of floral thermogenesis in the pollination biology of M. sprengeri. There were five distinct floral stages across the floral cycle of this species: pre-pistillate, pistillate, pre-staminate, staminate and post-staminate. Floral thermogenesis during anthesis and consisted of two distinct peaks: one at the pistillate stage and the other at the staminate stage. Insects of five families visited M. sprengeri during the floral cycle, and sap beetles (Epuraea sp., Nitidulidae) were determined to be the most effective pollinators, whereas bees (Apis cerana, Apidae) were considered to be occasional pollinators. A strong fragrance was released during thermogenesis, consisting of 18 chemical compounds. Although the relative proportions of these compounds varied at different floral stages across anthesis, linalool, 1-iodo-2-methylundecane and 2,2,6-trimethyl-6-vinyltetrahydro-2H-pyran-3-ol were dominant. Importantly, we found that the floral blends released during the pistillate and staminate stages were very similar, and coincided with flower visitation by sap beetles and the two thermogenic episodes. Based on these results, we propose that odour acts as a signal for a reward (pollen) and that an odour mimicry of staminate-stage flowers occurs during the pistillate stage. PMID:24922537

  6. A specific area of olfactory cortex involved in stress hormone responses to predator odours.

    PubMed

    Kondoh, Kunio; Lu, Zhonghua; Ye, Xiaolan; Olson, David P; Lowell, Bradford B; Buck, Linda B

    2016-04-01

    Instinctive reactions to danger are critical to the perpetuation of species and are observed throughout the animal kingdom. The scent of predators induces an instinctive fear response in mice that includes behavioural changes, as well as a surge in blood stress hormones that mobilizes multiple body systems to escape impending danger. How the olfactory system routes predator signals detected in the nose to achieve these effects is unknown. Here we identify a specific area of the olfactory cortex in mice that induces stress hormone responses to volatile predator odours. Using monosynaptic and polysynaptic viral tracers, we found that multiple olfactory cortical areas transmit signals to hypothalamic corticotropin-releasing hormone (CRH) neurons, which control stress hormone levels. However, only one minor cortical area, the amygdalo-piriform transition area (AmPir), contained neurons upstream of CRH neurons that were activated by volatile predator odours. Chemogenetic stimulation of AmPir activated CRH neurons and induced an increase in blood stress hormones, mimicking an instinctive fear response. Moreover, chemogenetic silencing of AmPir markedly reduced the stress hormone response to predator odours without affecting a fear behaviour. These findings suggest that AmPir, a small area comprising <5% of the olfactory cortex, plays a key part in the hormonal component of the instinctive fear response to volatile predator scents. PMID:27001694

  7. Valuing autonomy, struggling for an identity and a collective voice, and seeking role recognition: community mental health nurses' perceptions of their roles.

    PubMed

    White, Jane H; Kudless, Mary

    2008-10-01

    Leaders in this community mental health system approached the problem of job frustration, morale issues, and turnover concerns of their Community Mental Health Nurses (CMHNs) by designing a qualitative study using Participant Action Research (PAR) methodology based on the philosophy of Habermas. Six focus groups were conducted to address the nurses' concerns. The themes of Valuing Autonomy, Struggling for an Identity and Collective Voice, and Seeking Role Recognition best explained the participants' concerns. The study concluded with an action plan, the implementation of the plan, and a discussion of the plan's final outcomes. PMID:18853347

  8. Neurobiological correlates of visual and olfactory recognition in sheep.

    PubMed

    Kendrick, K M

    1994-12-01

    ability to selectively recognise the odour signatures of its own lambs within the first few hours of giving birth. Electrophysiological recordings from mitral cells in the olfactory bulb have shown that none of them respond preferentially to lamb odours pre-partum, when the ewes show no interest in lambs, whereas 60% of them do so after ewes have bonded with their lambs. A sub-population of mitral cells also responds differentially to own and alien lamb odours post-partum. Neurochemical studies have shown that lamb odours do not evoke transmitter release within the olfactory bulb pre-partum whereas, post-partum, own lamb odours stimulate release of the intrinsic amino acid transmitters, GABA and glutamate whereas both own and alien lamb odours evoke equivalent increases in the release of the centrifugal pathway transmitters, acetylcholine and nonadrenaline. Overall these experiments provide compelling evidence that the sheep, which is after all a social animal, makes use of sophisticated visual cues from the face and body and of olfactory cues from the body and wool to recognise different individuals. The neural pathways which are involved in both of these recognition processes also show remarkable evidence of plasticity. However, there appears to be a much closer link between recognition and emotional significance demonstrated in the coding strategies employed by the neural circuits involved in individual recognition in the sheep brain compared to that of a primate and, indeed, they seem to be organised more for identifying a small number of different categories of individuals rather than for a large number of individuals per se. It is possible therefore that social evolutionary pressures to specifically identify large numbers of individuals of similar emotional significance has been achieved by weakening the organisational influence of affect on coding strategies of cells in the temporal cortex in favour of a more extensive feature detection system allowing accurate

  9. Taste and/or Odour Disturbances in Pediatric Patients Undergoing IV Flush with Normal Saline Administered by Prefilled Syringe

    PubMed Central

    Celetti, Steven J; Vaillancourt, Régis; Pascuet, Elena; Sharp, Diane

    2012-01-01

    Background: At the Children’s Hospital of Eastern Ontario, more than 6000 inpatients per year undergo IV saline flushes by prefilled syringe to assess and maintain patency of IV tubing. In studies involving adults, it has been reported that volatile substances may leach from syringe materials into the saline, leading to taste and/or odour disturbances. Objective: To determine the incidence of taste and/or odour disturbances in pediatric patients after flushing of IV tubing with 0.9% sodium chloride (normal saline [NS]) from prefilled syringes. Methods: Inpatients aged 5–18 years who had undergone routine flushing of central or peripheral IV tubing with commercially available prefilled NS syringes were interviewed. Children aged 5–10 years used a visual hedonic scale to rate taste and odour sensations, and those aged 11–18 years used a numeric rating scale. Results: During the study period (April to July 2011), a total of 104 pediatric inpatients (21 aged 5–10 years and 83 aged 11–18 years) underwent NS flushing of central (10 patients [10%]) or peripheral (94 patients [90%]) tubing. For 100 of these patients, BD Posiflush NaCl 0.9% 10-mL sterile prefilled syringes were used, and for 4 patients BD Saline XS NaCl 0.9% 10-mL sterile prefilled syringes were used. Taste and/or odour disturbances were reported by 76 (73%) of the patients. Twelve patients described more than one taste or odour sensation. Taste and odour disturbances were detected by children in both age groups. Conclusions: Flushing of IV tubing with prefilled NS syringes resulted in taste and/or odour disturbances in a pediatric population. PMID:23129865

  10. Developing Recognition Programs for Units within Student Affairs.

    ERIC Educational Resources Information Center

    Avery, Cynthia M.

    2001-01-01

    According to many psychologists, the connections between motivation and rewards and recognition are crucial to employee satisfaction. A plan for developing a multi-layered recognition program within a division of student affairs is described. These recognitions programs are designed taking into account the differences in perceptions of awards by…

  11. Prospects for the Development of Odour Baits to Control the Tsetse Flies Glossina tachinoides and G. palpalis s.l.

    PubMed Central

    Rayaisse, J. B.; Tirados, I.; Kaba, D.; Dewhirst, S. Y.; Logan, J. G.; Diarrassouba, A.; Salou, E.; Omolo, M. O.; Solano, P.; Lehane, M. J.; Pickett, J. A.; Vale, G. A.; Torr, S. J.; Esterhuizen, J.

    2010-01-01

    Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (∼5×) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent results. For G. p. gambiensis both human and cattle odour increased (>2×) the trap catch significantly but not the catch from electric targets. For G. p. palpalis, odours from pigs and humans increased (∼5×) the numbers of tsetse attracted to the vicinity of the odour source but had little effect on landing or trap-entry. For G. tachinoides a blend of POCA (P = 3-n-propylphenol; O = 1-octen-3-ol; C = 4-methylphenol; A = acetone) alone or synthetic cattle odour (acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol with carbon dioxide) consistently caught more tsetse than natural cattle odour. For G. p. gambiensis, POCA consistently increased catches from both traps and targets. For G. p. palpalis, doses of carbon dioxide similar to those produced by a host resulted in similar increases in attraction. Baiting traps with super-normal (∼500 mg/h) doses of acetone also consistently produced significant but slight (∼1.6×) increases in catches of male flies. The results suggest that odour-baited traps and insecticide-treated targets could assist the AU-Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) in its current efforts to monitor and control Palpalis group tsetse in West Africa. For all three species, only ∼50% of the flies attracted to the vicinity of the trap were actually caught by it, suggesting that better traps might be developed by an analysis of the visual responses and identification of any semiochemicals involved in short

  12. Odour-tracking capability of a silkmoth driving a mobile robot with turning bias and time delay.

    PubMed

    Ando, N; Emoto, S; Kanzaki, R

    2013-03-01

    The reconstruction of mechanisms behind odour-tracking behaviours of animals is expected to enable the development of biomimetic robots capable of adaptive behaviour and effectively locating odour sources. However, because the behavioural mechanisms of animals have not been extensively studied, their behavioural capabilities cannot be verified. In this study, we have employed a mobile robot driven by a genuine insect (insect-controlled robot) to evaluate the behavioural capabilities of a biological system implemented in an artificial system. We used a male silkmoth as the 'driver' and investigated its behavioural capabilities to imposed perturbations during odour tracking. When we manipulated the robot to induce the turning bias, it located the odour source by compensatory turning of the on-board moth. Shifting of the orientation paths to the odour plume boundaries and decreased orientation ability caused by covering the visual field suggested that the moth steered with bilateral olfaction and vision to overcome the bias. An evaluation of the time delays of the moth and robot movements suggested an acceptable range for sensory-motor processing when the insect system was directly applied to artificial systems. Further evaluations of the insect-controlled robot will provide a 'blueprint' for biomimetic robots and strongly promote the field of biomimetics. PMID:23385386

  13. Volatile trace compounds released from municipal solid waste at the transfer stage: Evaluation of environmental impacts and odour pollution.

    PubMed

    Zhao, Yan; Lu, Wenjing; Wang, Hongtao

    2015-12-30

    Odour pollution caused by municipal solid waste is a public concern. This study quantitatively evaluated the concentration, environmental impacts, and olfaction of volatile trace compounds released from a waste transfer station. Seventy-six compounds were detected, and ethanol presented the highest releasing rate and ratio of 14.76 kg/d and 12.30 g/t of waste, respectively. Life cycle assessment showed that trichlorofluoromethane and dichlorodifluoromethane accounted for more than 99% of impact potentials to global warming and approximately 70% to human toxicity (non-carcinogenic). The major contributor for both photochemical ozone formation and ecotoxicity was ethanol. A detection threshold method was also used to evaluate odour pollution. Five compounds including methane thiol, hydrogen sulphide, ethanol, dimethyl disulphide, and dimethyl sulphide, with dilution multiples above one, were considered the critical compounds. Methane thiol showed the highest contribution to odour pollution of more than 90%, as indicated by its low threshold. Comparison of the contributions of the compounds to different environmental aspects indicated that typical pollutants varied based on specific evaluation targets and therefore should be comprehensively considered. This study provides important information and scientific methodology to elucidate the impacts of odourant compounds to the environment and odour pollution. PMID:26292056

  14. Prevention of volatile fatty acids production and limitation of odours from winery wastewaters by denitrification.

    PubMed

    Bories, André; Guillot, Jean-Michel; Sire, Yannick; Couderc, Marie; Lemaire, Sophie-Andréa; Kreim, Virginie; Roux, Jean-Claude

    2007-07-01

    The effect of the addition of nitrate to winery wastewaters to control the formation of VFA in order to prevent odours during storage and treatment was studied in batch bioreactors at different NO(3)/chemical oxygen demand (COD) ratios and at full scale in natural evaporation ponds (2 x 7000 m(2)) by measuring olfactory intensity. In the absence of nitrate, butyric acid (2304 mgL(-1)), acetic acid (1633 mgL(-1)), propionic acid (1558 mgL(-1)), caproic acid (499 mgL(-1)) and valeric acid (298 mgL(-1)) were produced from reconstituted winery wastewater. For a ratio of NO(3)/COD=0.4 gg(-1), caproic and valeric acids were not formed. The production of butyric and propionic acids was reduced by 93.3% and 72.5%, respectively, at a ratio of NO(3)/COD=0.8, and by 97.4% and 100% at a ratio of NO(3)/COD=1.2 gg(-1). Nitrate delayed and decreased butyric acid formation in relation to the oxidoreduction potential. Studies in ponds showed that the addition of concentrated calcium nitrate (NITCAL) to winery wastewaters (3526 m(3)) in a ratio of NO(3)/COD=0.8 inhibited VFA production, with COD elimination (94%) and total nitrate degradation, and no final nitrite accumulation. On the contrary, in ponds not treated with nitrate, malodorous VFA (from propionic to heptanoïc acids) represented up to 60% of the COD. Olfactory intensity measurements in relation to the butanol scale of VFA solutions and the ponds revealed the pervasive role of VFA in the odour of the untreated pond as well as the clear decrease in the intensity and not unpleasant odour of the winery wastewater pond enriched in nitrates. The results obtained at full scale underscored the feasibility and safety of the calcium nitrate treatment as opposed to concentrated nitric acid. PMID:17467770

  15. A rapid chemical odour profiling method for the identification of rhinoceros horns.

    PubMed

    Ueland, Maiken; Ewart, Kyle; Troobnikoff, Amanda N; Frankham, Greta; Johnson, Rebecca N; Forbes, Shari L

    2016-09-01

    Illegal poaching causes great harm to species diversity and conservation. A vast amount of money is involved in the trade of illegal or forged animal parts worldwide. In many cases, the suspected animal part is unidentifiable and requires costly and invasive laboratory analysis such as isotopic fingerprinting or DNA testing. The lack of rapid and accurate methods to identify wildlife parts at the point of detection represents a major hindrance in the enforcement and prosecution of wildlife trafficking. The ability of wildlife detector dogs to alert to different wildlife species demonstrates that there is a detectable difference in scent profile of illegally traded animal parts. This difference was exploited to develop a rapid, non-invasive screening method for distinguishing rhinoceros horns of different species. The method involved the collection of volatile organic compounds (VOC) by headspace solid-phase microextraction (HS-SPME) and analysis by comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC×GC-TOFMS). It was hypothesised that the use of the specific odour profile as a screening method could separate and differentiate geographic origin or exploit the difference in diets of different species within a family (such as white rhinoceros and black rhinoceros from the Rhinocerotidae family). Known black and white rhinoceros horn samples were analysed using HS-SPME-GC×GC-TOFMS and multivariate statistics were applied to identify groupings in the data set. The black rhinoceros horn samples were distinctly different from the white rhinoceros horn samples. This demonstrated that seized rhinoceros horn samples can be identified based on their distinct odour profiles. The chemical odour profiling method has great potential as a rapid and non-invasive screening method in order to combat and track illegal trafficking of wildlife parts. PMID:27240958

  16. Differential Interactions of Sex Pheromone and Plant Odour in the Olfactory Pathway of a Male Moth

    PubMed Central

    Deisig, Nina; Kropf, Jan; Vitecek, Simon; Pevergne, Delphine; Rouyar, Angela; Sandoz, Jean-Christophe; Lucas, Philippe; Gadenne, Christophe

    2012-01-01

    Most animals rely on olfaction to find sexual partners, food or a habitat. The olfactory system faces the challenge of extracting meaningful information from a noisy odorous environment. In most moth species, males respond to sex pheromone emitted by females in an environment with abundant plant volatiles. Plant odours could either facilitate the localization of females (females calling on host plants), mask the female pheromone or they could be neutral without any effect on the pheromone. Here we studied how mixtures of a behaviourally-attractive floral odour, heptanal, and the sex pheromone are encoded at different levels of the olfactory pathway in males of the noctuid moth Agrotis ipsilon. In addition, we asked how interactions between the two odorants change as a function of the males' mating status. We investigated mixture detection in both the pheromone-specific and in the general odorant pathway. We used a) recordings from individual sensilla to study responses of olfactory receptor neurons, b) in vivo calcium imaging with a bath-applied dye to characterize the global input response in the primary olfactory centre, the antennal lobe and c) intracellular recordings of antennal lobe output neurons, projection neurons, in virgin and newly-mated males. Our results show that heptanal reduces pheromone sensitivity at the peripheral and central olfactory level independently of the mating status. Contrarily, heptanal-responding olfactory receptor neurons are not influenced by pheromone in a mixture, although some post-mating modulation occurs at the input of the sexually isomorphic ordinary glomeruli, where general odours are processed within the antennal lobe. The results are discussed in the context of mate localization. PMID:22427979

  17. Technological and life cycle assessment of organics processing odour control technologies.

    PubMed

    Bindra, Navin; Dubey, Brajesh; Dutta, Animesh

    2015-09-15

    As more municipalities and communities across developed world look towards implementing organic waste management programmes or upgrading existing ones, composting facilities are emerging as a popular choice. However, odour from these facilities continues to be one of the most important concerns in terms of cost & effective mitigation. This paper provides a technological and life cycle assessment of some of the different odour control technologies and treatment methods that can be implemented in organics processing facilities. The technological assessment compared biofilters, packed tower wet scrubbers, fine mist wet scrubbers, activated carbon adsorption, thermal oxidization, oxidization chemicals and masking agents. The technologies/treatment methods were evaluated and compared based on a variety of operational, usage and cost parameters. Based on the technological assessment it was found that, biofilters and packed bed wet scrubbers are the most applicable odour control technologies for use in organics processing faculties. A life cycle assessment was then done to compare the environmental impacts of the packed-bed wet scrubber system, organic (wood-chip media) bio-filter and inorganic (synthetic media) bio-filter systems. Twelve impact categories were assessed; cumulative energy demand (CED), climate change, human toxicity, photochemical oxidant formation, metal depletion, fossil depletion, terrestrial acidification, freshwater eutrophication, marine eutrophication, terrestrial eco-toxicity, freshwater eco-toxicity and marine eco-toxicity. The results showed that for all impact categories the synthetic media biofilter had the highest environmental impact, followed by the wood chip media bio-filter system. The packed-bed system had the lowest environmental impact for all categories. PMID:25981938

  18. Kin-recognition abilities and nepotism as a function of sociality.

    PubMed

    Mateo, Jill M

    2002-04-01

    Despite widespread interest in kin selection and nepotism, relatively little is known about the perceptual abilities of animals to recognize their relatives. Here I show that a highly nepotistic species, Belding's ground squirrels (Spermophilus beldingi), produces odours from at least two sources that correlate with relatedness ('kin labels'), and that ground squirrels can use these odours to make accurate discriminations among never before encountered ('unfamiliar') kin. Recognition odours appear to vary linearly with relatedness, rather than in an all-or-none fashion, allowing precise estimates of kinship even among distant relatives. Thus S. beldingi are able to recognize their distant kin and male kin, even though they do not treat them preferentially. I also show that a closely related species (S. lateralis) similarly produces kin labels and discriminates among kin, although it shows no evidence of kin-directed behaviour. Thus, contrary to a commonly held assumption, kin favouritism and recognition abilities can evolve independently, depending on variation in the costs and benefits of nepotism for a given species. PMID:11934364

  19. Classification of Odours for Mobile Robots Using an Ensemble of Linear Classifiers

    NASA Astrophysics Data System (ADS)

    Trincavelli, Marco; Coradeschi, Silvia; Loutfi, Amy

    2009-05-01

    This paper investigates the classification of odours using an electronic nose mounted on a mobile robot. The samples are collected as the robot explores the environment. Under such conditions, the sensor response differs from typical three phase sampling processes. In this paper, we focus particularly on the classification problem and how it is influenced by the movement of the robot. To cope with these influences, an algorithm consisting of an ensemble of classifiers is presented. Experimental results show that this algorithm increases classification performance compared to other traditional classification methods.

  20. Voice recognition.

    PubMed

    Mehta, Amit; McLoud, Theresa C

    2003-07-01

    Voice recognition represents one of the new technologies that are changing the practice of radiology. Thirty percent of radiology practices are either currently or plan to have voice recognition (VR) systems. VR software encompasses 4 core processes: spoken recognition of human speech, synthesis of human readable characters into speech, speaker identification and verification, and comprehension. Many software packages are available offering VR. All these packages should contain an interface with the radiology information system. The benefits include decreased turnaround time and cost savings. Its advantages include the transfer of secretarial duties to the radiologist with a result in decreased productivity. PMID:12867815

  1. Scent of a Dragonfly: Sex Recognition in a Polymorphic Coenagrionid

    PubMed Central

    Conti, Eric; Rebora, Manuela; Salerno, Gianandrea

    2015-01-01

    In polymorphic damselflies discrimination of females from males is complex owing to the presence of androchrome and gynochrome females. To date there is no evidence that damselflies use sensory modalities other than vision (and tactile stimuli) in mate searching and sex recognition. The results of the present behavioural and electrophysiological investigations on Ischnura elegans, a polymorphic damselfly, support our hypothesis that chemical cues could be involved in Odonata sex recognition. The bioassays demonstrate that males in laboratory prefer female to male odour, while no significant difference was present in male behavior between stimuli from males and control. The bioassays suggest also some ability of males to distinguish between the two female morphs using chemical stimuli. The ability of male antennae to perceive odours from females has been confirmed by electrophysiological recordings. These findings are important not only to get insight into the chemical ecology of Odonata, and to shed light into the problem of olfaction in Paleoptera, but could be useful to clarify the controversial aspects of the mating behavior of polymorphic coenagrionids. Behavioural studies in the field are necessary to investigate further these aspects. PMID:26305118

  2. Scent of a Dragonfly: Sex Recognition in a Polymorphic Coenagrionid.

    PubMed

    Frati, Francesca; Piersanti, Silvana; Conti, Eric; Rebora, Manuela; Salerno, Gianandrea

    2015-01-01

    In polymorphic damselflies discrimination of females from males is complex owing to the presence of androchrome and gynochrome females. To date there is no evidence that damselflies use sensory modalities other than vision (and tactile stimuli) in mate searching and sex recognition. The results of the present behavioural and electrophysiological investigations on Ischnura elegans, a polymorphic damselfly, support our hypothesis that chemical cues could be involved in Odonata sex recognition. The bioassays demonstrate that males in laboratory prefer female to male odour, while no significant difference was present in male behavior between stimuli from males and control. The bioassays suggest also some ability of males to distinguish between the two female morphs using chemical stimuli. The ability of male antennae to perceive odours from females has been confirmed by electrophysiological recordings. These findings are important not only to get insight into the chemical ecology of Odonata, and to shed light into the problem of olfaction in Paleoptera, but could be useful to clarify the controversial aspects of the mating behavior of polymorphic coenagrionids. Behavioural studies in the field are necessary to investigate further these aspects. PMID:26305118

  3. Odour Maps in the Brain of Butterflies with Divergent Host-Plant Preferences

    PubMed Central

    Schäpers, Alexander; Mozuraitis, Raimondas; Hansson, Bill S.; Janz, Niklas

    2011-01-01

    Butterflies are believed to use mainly visual cues when searching for food and oviposition sites despite that their olfactory system is morphologically similar to their nocturnal relatives, the moths. The olfactory ability in butterflies has, however, not been thoroughly investigated. Therefore, we performed the first study of odour representation in the primary olfactory centre, the antennal lobes, of butterflies. Host plant range is highly variable within the butterfly family Nymphalidae, with extreme specialists and wide generalists found even among closely related species. Here we measured odour evoked Ca2+ activity in the antennal lobes of two nymphalid species with diverging host plant preferences, the specialist Aglais urticae and the generalist Polygonia c-album. The butterflies responded with stimulus-specific combinations of activated glomeruli to single plant-related compounds and to extracts of host and non-host plants. In general, responses were similar between the species. However, the specialist A. urticae responded more specifically to its preferred host plant, stinging nettle, than P. c-album. In addition, we found a species-specific difference both in correlation between responses to two common green leaf volatiles and the sensitivity to these compounds. Our results indicate that these butterflies have the ability to detect and to discriminate between different plant-related odorants. PMID:21901154

  4. Characterization and biological abatement of diffuse methane emissions and odour in an innovative wastewater treatment plant.

    PubMed

    Barcón, Tamara; Hernández, Jerónimo; Gómez-Cuervo, Santiago; Garrido, Juan M; Omil, Francisco

    2015-01-01

    An innovative and patented process for medium-high strength sewage which comprises an anaerobic step followed by a hybrid anoxic-aerobic chamber and a final ultrafiltration stage was characterized in terms of methane fugitive emissions as well as odours. The operation at ambient temperature implies higher methane content in the liquid anaerobic effluent, which finally causes concentrations around 0.01-2.4% in the off-gas released in the anoxic-aerobic chamber (1.25% average). Mass balances indicate that these emissions account for up to 30-35% of the total methane generated in the anaerobic reactor. A conventional biofilter (BF) operated at an empty bed residence time of 4 min was used to treat these emissions for 70 d. In spite of the fluctuations in the methane inlet concentrations derived from the operation of the wastewater treatment plant (WWTP), it was possible to operate at pseudo-steady-state conditions, achieving average removal efficiencies of 76.5% and maximum elimination capacities of 30.1 g m(-3) h(-1). Odour removal was quantified as 99.1%. Fluorescence in situ hybridization probes as well as metabolic activity assays demonstrated the suitability of the biomass developed in the WWTP as inoculum to start up the BF due to the presence of methanotrophic bacteria. PMID:25749282

  5. Elimination of sulphur odours at landfills by bioconversion and the corona discharge plasma technique.

    PubMed

    Xia, Fangfang; Liu, Xin; Kang, Ying; He, Ruo; Wu, Zucheng

    2015-01-01

    Hydrogen sulphide (H2S) contributes a lot to odours at landfills, which is a threat to the environment and the health of the staff therein. To mitigate its emission, the bioconversion within landfill cover soils (LCSs) was introduced. H2S emission and concentration both in the field air above the landfill and in microcosm testing were surveyed. Results indicated that H2S emission and concentration in the landfill varied with landfill seasons and sites. There existed relationship between H2S concentration and fluxes spatially and temporally. To characterize and assess the spatial and temporal diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) in the LCSs, the terminal-restriction fragment length polymorphism technique was employed. Using the functional genes of dsrB and soxB, SOB, including Halothiobacillus, Rhodothalassium, Paracocccus, Allochromatium, and Thiobacillus, and SRB, including Desulfovibrio, Syntrophobacter, Desulfomonile and Desulfobacca, were identical and exhibited the dominant role in the LCSs. By employing an alternative available corona reactor, more than 90% removal efficiencies of sulphides were demonstrated, suggesting that the LCSs for eliminating odours in a lower concentration would be feasible. PMID:25244028

  6. Supersensitive detection and discrimination of enantiomers by dorsal olfactory receptors: evidence for hierarchical odour coding

    PubMed Central

    Sato, Takaaki; Kobayakawa, Reiko; Kobayakawa, Ko; Emura, Makoto; Itohara, Shigeyoshi; Kizumi, Miwako; Hamana, Hiroshi; Tsuboi, Akio; Hirono, Junzo

    2015-01-01

    Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (−)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite “supersensitivity” to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 108-fold differential sensitivity of ΔD mice to (−)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >1010-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (−)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This “enantiomer odour discrimination paradox” indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification. PMID:26361056

  7. Habitat complexity reduces parasitoid foraging efficiency, but does not prevent orientation towards learned host plant odours.

    PubMed

    Kruidhof, H M; Roberts, A L; Magdaraog, P; Muñoz, D; Gols, R; Vet, L E M; Hoffmeister, T S; Harvey, J A

    2015-10-01

    It is well known that many parasitic wasps use herbivore-induced plant odours (HIPVs) to locate their inconspicuous host insects, and are often able to distinguish between slight differences in plant odour composition. However, few studies have examined parasitoid foraging behaviour under (semi-)field conditions. In nature, food plants of parasitoid hosts are often embedded in non-host-plant assemblages that confer both structural and chemical complexity. By releasing both naïve and experienced Cotesia glomerata females in outdoor tents, we studied how natural vegetation surrounding Pieris brassicae-infested Sinapis arvensis and Barbarea vulgaris plants influences their foraging efficiency as well as their ability to specifically orient towards the HIPVs of the host plant species on which they previously had a positive oviposition experience. Natural background vegetation reduced the host-encounter rate of naïve C. glomerata females by 47 %. While associative learning of host plant HIPVs 1 day prior to foraging caused a 28 % increase in the overall foraging efficiency of C. glomerata, it did not reduce the negative influence of natural background vegetation. At the same time, however, females foraging in natural vegetation attacked more host patches on host-plant species on which they previously had a positive oviposition experience. We conclude that, even though the presence of natural vegetation reduces the foraging efficiency of C. glomerata, it does not prevent experienced female wasps from specifically orienting towards the host-plant species from which they had learned the HIPVs. PMID:26001606

  8. Avian Egg Odour Encodes Information on Embryo Sex, Fertility and Development

    PubMed Central

    Webster, Ben; Hayes, William; Pike, Thomas W.

    2015-01-01

    Avian chemical communication is a rapidly emerging field, but has been hampered by a critical lack of information on volatile chemicals that communicate ecologically relevant information (semiochemicals). A possible, but as yet unexplored, function of olfaction and chemical communication in birds is in parent-embryo and embryo-embryo communication. Communication between parents and developing embryos may act to mediate parental behaviour, while communication between embryos can control the synchronicity of hatching. Embryonic vocalisations and vibrations have been implicated as a means of communication during the later stages of development but in the early stages, before embryos are capable of independent movement and vocalisation, this is not possible. Here we show that volatiles emitted from developing eggs of Japanese quail (Coturnix japonica) convey information on egg fertility, along with the sex and developmental status of the embryo. Specifically, egg volatiles changed over the course of incubation, differed between fertile and infertile eggs, and were predictive of embryo sex as early as day 1 of incubation. Egg odours therefore have the potential to facilitate parent-embryo and embryo-embryo interactions by allowing the assessment of key measures of embryonic development long before this is possible through other modalities. It also opens up the intriguing possibility that parents may be able to glean further relevant information from egg volatiles, such as the health, viability and heritage of embryos. By determining information conveyed by egg-derived volatiles, we hope to stimulate further investigation into the ecological role of egg odours. PMID:25629413

  9. How floral odours are learned inside the bumblebee ( Bombus terrestris) nest

    NASA Astrophysics Data System (ADS)

    Molet, Mathieu; Chittka, Lars; Raine, Nigel E.

    2009-02-01

    Recruitment in social insects often involves not only inducing nestmates to leave the nest, but also communicating crucial information about finding profitable food sources. Although bumblebees transmit chemosensory information (floral scent), the transmission mechanism is unknown as mouth-to-mouth fluid transfer (as in honeybees) does not occur. Because recruiting bumblebees release a pheromone in the nest that triggers foraging in previously inactive workers, we tested whether this pheromone helps workers learn currently rewarding floral odours, as found in food social learning in rats. We exposed colonies to artificial recruitment pheromone, paired with anise scent. The pheromone did not facilitate learning of floral scent. However, we found that releasing floral scent in the air of the colony was sufficient to trigger learning and that learning performance was improved when the chemosensory cue was provided in the nectar in honeypots; probably because it guarantees a tighter link between scent and reward, and possibly because gustatory cues are involved in addition to olfaction. Scent learning was maximal when anise-scented nectar was brought into the nest by demonstrator foragers, suggesting that previously unidentified cues provided by successful foragers play an important role in nestmates learning new floral odours.

  10. Speech recognition based on pattern recognition techniques

    NASA Astrophysics Data System (ADS)

    Rabiner, Lawrence R.

    1990-05-01

    Algorithms for speech recognition can be characterized broadly as pattern recognition approaches and acoustic phonetic approaches. To date, the greatest degree of success in speech recognition has been obtained using pattern recognition paradigms. The use of pattern recognition techniques were applied to the problems of isolated word (or discrete utterance) recognition, connected word recognition, and continuous speech recognition. It is shown that understanding (and consequently the resulting recognizer performance) is best to the simplest recognition tasks and is considerably less well developed for large scale recognition systems.

  11. Gas recognition using a neural network approach to plasma optical emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Hyland, Mark; Mariotti, Davide; Dubitzky, Werner; McLaughlin, James A.; Maguire, Paul

    2000-10-01

    A system has been developed which enables the detection and recognition of various gases. Plasma emission spectroscopy has been used to record spectra from volatile species of acetone, vinegar, and coffee beans, along with air and nitrogen spectra. The spectra have been uniquely processed and fed into an artificial neural network program for training and recognition of unknown gases. The system as a whole can be grouped into the emerging and diverse area of artificial nose technology. The sy stem has shown to provide a solution to the recognition of simple gases and odours (air, nitrogen, acetone) and could also satisfactorily recognise more complex samples (vinegar and coffee beans). Recognition is performed in seconds; this being a positive aspect for many artificial nose applications.

  12. Analysis of airborne microorganisms, MVOC and odour in the surrounding of composting facilities and implications for future investigations.

    PubMed

    Fischer, Guido; Albrecht, Andreas; Jäckel, Udo; Kämpfer, Peter

    2008-03-01

    Emission and dispersal of microorganisms and odours from composting facilities were studied in a 3-year project at nine different composting facilities in Germany. Measurements were carried out under so-called 'normal-case', i.e. typical local climate conditions and working activities within the facilities, and 'real worst-case' conditions ('drainage flow' conditions) being characterized by the translocation of cold air mostly at night, and containing large amounts of bioaerosols. Highest concentrations of microorganisms were observed during turning of compost with a maximum of 2.4x10(6)cfu m(-3) for thermophilic actinomycetes. Other groups of microorganisms were detected in concentrations of about 10(5)cfu m(-3). During shredding of fresh organic material, the concentrations of all microorganisms reached 10(4)cfu m(-3). Here, odour concentrations turned out to be highest (up to 1,367 odour units (OU)m(-3)). At facilities equipped with a biofilter (odour reduction), a decrease in OU by a factor of 10 was observed. In the surrounding of the facilities, highest concentrations ranged between 10(1)-10(3)cfu m(-3) upwind and from 10(1)-10(4)cfu m(-3) downwind. The specific local meteorological situations must be considered carefully in advance and during sampling. Especially 'drainage flow' situations can lead to high microorganism concentrations (>10(4)-10(5)cfu m(-3) of thermophilic actinomycetes and thermophilic fungi) in the surroundings of composting facilities. PMID:17936684

  13. Wind tunnels vs. flux chambers: Area source emission measurements and the necessity for VOC and odour correction factors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind tunnels and flux chambers have been used to measure fluxes of volatile organic compounds (VOC), odour, and ammonia (NH3) with little regard to air velocity or sweep air flow rates. As a result, flux measurements have been highly variable and scientists have been in disagreement as to the better...

  14. Identification of food spoilage in the smart home based on neural and fuzzy processing of odour sensor responses.

    PubMed

    Green, Geoffrey C; Chan, Adrian D C; Goubran, Rafik A

    2009-01-01

    Adopting the use of real-time odour monitoring in the smart home has the potential to alert the occupant of unsafe or unsanitary conditions. In this paper, we measured (with a commercial metal-oxide sensor-based electronic nose) the odours of five household foods that had been left out at room temperature for a week to spoil. A multilayer perceptron (MLP) neural network was trained to recognize the age of the samples (a quantity related to the degree of spoilage). For four of these foods, median correlation coefficients (between target values and MLP outputs) of R > 0.97 were observed. Fuzzy C-means clustering (FCM) was applied to the evolving odour patterns of spoiling milk, which had been sampled more frequently (4h intervals for 7 days). The FCM results showed that both the freshest and oldest milk samples had a high degree of membership in "fresh" and "spoiled" clusters, respectively. In the future, as advancements in electronic nose development remove the present barriers to acceptance, signal processing methods like those explored in this paper can be incorporated into odour monitoring systems used in the smart home. PMID:19965227

  15. Digit ratio (2D:4D) predicts facial, but not voice or body odour, attractiveness in men

    PubMed Central

    Ferdenzi, Camille; Lemaître, Jean-François; Leongómez, Juan David; Roberts, S. Craig

    2011-01-01

    There is growing evidence that human second-to-fourth digit ratio (or 2D:4D) is related to facial features involved in attractiveness, mediated by in utero hormonal effects. The present study extends the investigation to other phenotypic, hormone-related determinants of human attractiveness: voice and body odour. Pictures of faces with a neutral expression, recordings of voices pronouncing vowels and axillary odour samples captured on cotton pads worn for 24 h were provided by 49 adult male donors. These stimuli were rated on attractiveness and masculinity scales by two groups of 49 and 35 females, approximately half of these in each sample using hormonal contraception. Multivariate regression analyses showed that males' lower (more masculine) right 2D:4D and lower right-minus-left 2D:4D (Dr−l) were associated with a more attractive (and in some cases more symmetrical), but not more masculine, face. However, 2D:4D and Dr−l did not predict voice and body odour masculinity or attractiveness. The results were interpreted in terms of differential effects of prenatal and circulating testosterone, male facial shape being supposedly more dependent on foetal levels (reflected by 2D:4D ratio), whereas body odour and vocal characteristics could be more dependent on variation in adult circulating testosterone levels. PMID:21508034

  16. Asymmetrical generalisation between pheromonal and floral odours in appetitive olfactory conditioning of the honey bee (Apis mellifera L.).

    PubMed

    Sandoz, J C; Pham-Delègue, M H; Renou, M; Wadhams, L J

    2001-09-01

    The capacity to generalise between similar but not identical olfactory stimuli is crucial for honey bees, allowing them to find rewarding food sources with varying volatile emissions. We studied bees' generalisation behaviour with odours having different biological values: typical floral odours or alarm compounds. Bees' behavioural and peripheral electrophysiological responses were investigated using a combined proboscis extension response conditioning-electroantennogram assay. Bees were conditioned to pure linalool (floral) or to pure isoamyl acetate (alarm) and were tested with different concentrations of both compounds. Electrophysiological responses were not influenced by conditioning, suggesting that the learning of individual compounds does not rely on modulations of peripheral sensitivity. Behaviourally, generalisation responses of bees conditioned to the alarm compound were much higher than those of bees conditioned to the floral odour. We further demonstrated such asymmetrical generalisation between alarm and floral odours by using differential conditioning procedures. Conditioning to alarm compounds (isoamyl acetate or 2-heptanone) consistently induced more generalisation than conditioning to floral compounds (linalool or phenylacetaldehyde). Interestingly, generalisation between the two alarm compounds, which are otherwise chemically different, was extremely high. These results are discussed in relation to the neural representation of compounds with different biological significance for bees. PMID:11730303

  17. Larval memory affects adult nest-mate recognition in the ant Aphaenogaster senilis

    PubMed Central

    Signorotti, Lisa; Jaisson, Pierre; d'Ettorre, Patrizia

    2014-01-01

    Prenatal olfactory learning has been demonstrated in a wide variety of animals, where it affects development and behaviour. Young ants learn the chemical signature of their colony. This cue-learning process allows the formation of a template used for nest-mate recognition in order to distinguish alien individuals from nest-mates, thus ensuring that cooperation is directed towards group members and aliens are kept outside the colony. To date, no study has investigated the possible effect of cue learning during early developmental stages on adult nest-mate recognition. Here, we show that odour familiarization during preimaginal life affects recognition abilities of adult Aphaenogaster senilis ants, particularly when the familiarization process occurs during the first larval stages. Ants eclosed from larvae exposed to the odour of an adoptive colony showed reduced aggression towards familiar, adoptive individuals belonging to this colony compared with alien individuals (true unfamiliar), but they remained non-aggressive towards adult individuals of their natal colony. Moreover, we found that the chemical similarity between the colony of origin and the adoptive colony does not influence the degree of aggression, meaning that the observed effect is likely to be due only to preimaginal learning experience. These results help understanding the developmental processes underlying efficient recognition systems. PMID:24258719

  18. Characterization of volatile metabolites associated with confinement odour during the shelf-life of vacuum packed lamb meat under different storage conditions.

    PubMed

    Reis, Marlon M; Reis, Mariza G; Mills, John; Ross, Colleen; Brightwell, Gale

    2016-03-01

    Confinement odour was investigated. Volatiles were extracted directly from the pack, using solid phase microextraction and analysed by gas chromatography-mass spectrometry. Sensory evaluation and microbiological analysis of the meat surface were also performed. Commercial samples of vacuum packed lamb legs (n=85), from two meat processing plants, were kept for 7weeks at -1.5°C then at different regimes of temperature (-1.5 to +4°C) until 11, 12 or 13weeks. Persistent odour was observed in 66% of samples, confinement odour in 24% and no odour in 11%. Volatiles associated with confinement odour (3-methyl-butanal, 3-hydroxy-2-butanone and sulphur dioxide) corresponded with end/sub products of glucose fermentation and catabolism of amino acids by bacteria (all bacteria naturally found in meat and do not represent a risk to health). Confinement odour could indicate a stage at which the environment for bacteria growth is becoming favourable for the production of volatiles with strong odours that are noticed by the consumer. PMID:26624794

  19. Interactions of carbon dioxide and food odours in Drosophila: olfactory hedonics and sensory neuron properties.

    PubMed

    Faucher, Cécile P; Hilker, Monika; de Bruyne, Marien

    2013-01-01

    Behavioural responses of animals to volatiles in their environment are generally dependent on context. Most natural odours are mixtures of components that can each induce different behaviours when presented on their own. We have investigated how a complex of two olfactory stimuli is evaluated by Drosophila flies in a free-flying two-trap choice assay and how these stimuli are encoded in olfactory receptor neurons. We first observed that volatiles from apple cider vinegar attracted flies while carbon dioxide (CO2) was avoided, confirming their inherent positive and negative values. In contradiction with previous results obtained from walking flies in a four-field olfactometer, in the present assay the addition of CO2 to vinegar increased rather than decreased the attractiveness of vinegar. This effect was female-specific even though males and females responded similarly to CO2 and vinegar on their own. To test whether the female-specific behavioural response to the mixture correlated with a sexual dimorphism at the peripheral level we recorded from olfactory receptor neurons stimulated with vinegar, CO2 and their combination. Responses to vinegar were obtained from three neuron classes, two of them housed with the CO2-responsive neuron in ab1 sensilla. Sensitivity of these neurons to both CO2 and vinegar per se did not differ between males and females and responses from female neurons did not change when CO2 and vinegar were presented simultaneously. We also found that CO2-sensitive neurons are particularly well adapted to respond rapidly to small concentration changes irrespective of background CO2 levels. The ability to encode temporal properties of stimulations differs considerably between CO2- and vinegar-sensitive neurons. These properties may have important implications for in-flight navigation when rapid responses to fragmented odour plumes are crucial to locate odour sources. However, the flies' sex-specific response to the CO2-vinegar combination and the

  20. Ammonia and odour emissions from UK pig farms and nitrogen leaching from outdoor pig production. A review.

    PubMed

    Webb, J; Broomfield, Mark; Jones, Stephanie; Donovan, Brian

    2014-02-01

    We reviewed specific literature for emissions of ammonia (NH3) and odours from all stages of pig production together with nitrogen (N) leaching from raising pigs outdoors. Emissions of NH3 decrease with decreases in the crude protein (CP) content of pig diets, at all stages of manure management. The CPs of pig diets have been greatly reduced by matching the CP content to the protein required at each stage of the animals' growth and by using synthetic essential amino acids to minimise total CP intake. The CP contents of the dietary ingredients needed to provide energy for the animals impose further limits to reductions in dietary CP. Housing systems have been designed and evaluated which offer potential for reducing NH3 emissions. However such designs may not be applicable at all stages of the pigs' development and the careful management needed to ensure their effective working may be costly and difficult to implement on commercial farms. The factors behind odour emissions are less well characterised. Reducing diet CP to 160 g CP kg(-1) has been shown to reduce odour emissions but further CP reductions may increase them. Some reductions in odour emissions from buildings can be achieved by careful management of the ventilation rate but the most effective measures to reduce emissions of NH3 and odours are to cover slurry stores and to inject slurry into soil. Changes in the feeding and management of outdoor pigs mean that N leaching losses may be up to 50% less than previously reported. No studies have been undertaken that compare the N leached from pigs raised outdoors, versus that arising from the application of pig manure from an equal number of housed pigs. As a precursor to any field study, current models could be used to provide a first estimate of any systematic differences. PMID:24211346

  1. Empirical model derived from dispersion calculations to determine separation distances between livestock buildings and residential areas to avoid odour nuisance

    NASA Astrophysics Data System (ADS)

    Schauberger, Günther; Schmitzer, Rainer; Kamp, Martin; Sowa, Andreas; Koch, Roman; Eckhof, Wilfried; Eichler, Franziska; Grimm, Ewald; Kypke, Joachim; Hartung, Eberhard

    2012-01-01

    A new VDI guideline is under development in Germany to calculate the separation distance S (m) required between livestock and residential areas to avoid odour annoyance by an empirical model. On the basis of model calculations for 23 sites by a Lagrangian dispersion model (AUSTAL2000) a regression model was developed, using a power function S = aE b. The power function is defined by three input parameters which were restricted for an improved fit of the regression model. The basis of the power function is the odour emission flow rate E (ou E s -1) in the range between 500 ou E s -1 ≤ E ≤ 50,000 ou E s -1. The two other predictors are the relative frequency of the wind direction F (‰) of a 10° sector (10‰ ≤ F ≤ 60‰) and the odour exceedance probability P (%) (7% ≤ P ≤ 40%) of the odour impact criterion, which define the exponent b and the multiplicative factor a of the power function. One of the requirements for this empirical model was a conservative assessment, which results in only a 12% underestimation of the separation distance compared to the dispersion model. The model can be used in a "paper and pencil" mode, which enabling a simple and straightforward first evaluation of a planned livestock building. For a more detailed assessment, a dispersion model can be applied with the entire meteorological information available (e.g. stability of the atmosphere, wind velocity), the geometry of the emission source, a time dependant odour emission rate, as well as the orography of the site.

  2. Indoor mildew odour in old housing was associated with adult allergic symptoms, asthma, chronic bronchitis, vision, sleep and self-rated health: USA NHANES, 2005-2006.

    PubMed

    Shiue, Ivy

    2015-09-01

    A recent systematic review and meta-analysis has shown the effect of indoor mildew odour on allergic rhinitis risk, but its relation to other common chronic health outcomes in adults has not been investigated. Therefore, it was aimed to examine the relationship of indoor mildew odour and common health outcomes in adults in a national and population-based setting. Data was retrieved from the United States National Health and Nutrition Examination Surveys, 2005-2006, including the available information on demographics, housing characteristics, self-reported health conditions and urinary concentrations of environmental chemicals. T test, chi-squared test and survey-weighted logistic regression modelling were performed. Of all American adults (n = 4979), 744 (15.1%) reported indoor mildew odour or musty smell in their households. People who reported indoor mildew odour or musty smell also reported poorer self-rated health, sleep complaints, chronic bronchitis, asthma attack, itchy rash, sneezing and poor vision. In addition, people who reported indoor mildew odour or musty smell also tended to reside in older housing that were built 20 years earlier. However, there were no significant statistical associations found between indoor mildew odour or musty smell and urinary concentrations of environmental chemicals, which was also found to be associated with old housing. People who lived in older housing with indoor mildew odour or musty smell tended to have chronic health problems. To protect occupants in old housing from chronic illnesses associated with indoor mildew odour, elimination of the odour sources should be explored in future research and therefore public health and housing programs. Graphical abstract Pathway from old housing to musty smell, environmental chemicals and then health outcomes. PMID:25971810

  3. Context Effects in Letter Perception: Comparison of Two Theories.

    ERIC Educational Resources Information Center

    Richman, Howard B.; Simon, Herbert A.

    1989-01-01

    This study showed that the Elementary Perceiver and Memorizer (EPAM) can explain letter recognition phenomena earlier simulated by the connectionist Interactive Activation Model of word perception. EAPM, a model of learning and recognition in the form of a computer program, has previously explained many aspects of learning and perception. (TJH)

  4. Parasite-induced alteration of odour responses in an amphipod-acanthocephalan system.

    PubMed

    Stone, Charles F; Moore, Janice

    2014-11-01

    Odour-related behaviours in aquatic invertebrates are important and effective anti-predator behaviours. Parasites often alter invertebrate host behaviours to increase transmission to hosts. This study investigated the responses of the amphipod Hyalella azteca when presented with two predator chemical cues: (i) alarm pheromones produced by conspecifics and (ii) kairomones produced by a predatory Green Sunfish (Lepomis cyanellus). We compared the responses of amphipods uninfected and infected with the acanthocepalan parasite Leptorhynchiodes thecatus. Uninfected amphipods reduced activity and increased refuge use after detecting both the alarm pheromones and predator kairomones. Infected amphipods spent significantly more time being active and less time on the refuge than uninfected amphipods, and behaved as if they had not detected the chemical stimulus. Therefore, L. thecatus infections disrupt the amphipods' anti-predator behaviours and likely make their hosts more susceptible to predation. PMID:25200352

  5. Comparison of different types of electronic nose instruments for evaluation of odour nuisance from landfill

    NASA Astrophysics Data System (ADS)

    Gebicki, Jacek; Dymerski, Tomasz; Namieśnik, Jacek

    2014-08-01

    The paper presents and compares the results of investigation on classification of atmospheric air samples collected in a vicinity of municipal landfill with respect to their odour nuisance. The research was conducted using a prototype of electronic nose instrument and a commercial electronic nose of Fast/Flash GC type - HERACLES II. The prototype was equipped with six semiconductor sensors of TGS type. Classification of the air samples with respect to the place of collection relative to the landfill was performed using quadratic discriminant function (QDA) supported with cross-validation method. More than 80% of the samples were correctly classified employing the analysis with HERACLES II. The prototype of electronic nose provided correct classification of 50% of the samples.

  6. UV/chlorine control of drinking water taste and odour at pilot and full-scale.

    PubMed

    Wang, Ding; Bolton, James R; Andrews, Susan A; Hofmann, Ron

    2015-10-01

    Advanced oxidation processes (AOPs) can be used to destroy taste and odour-causing compounds in drinking water. This work investigated both pilot- and full-scale performance of the novel ultraviolet (UV)/chlorine AOP for the destruction of geosmin, 2-methylisoborneol (MIB) and caffeine (as a surrogate) in two different surface waters. The efficiency of the UV/chlorine process at pH 7.5 and 8.5 was comparable to that of the UV/hydrogen peroxide (UV/H2O2) process under parallel conditions, and was superior at pH 6.5. Caffeine was found to be a suitable surrogate for geosmin and MIB, and could be used as a more economical alternative to geosmin or MIB spiking for site-specific full-scale testing. PMID:26025188

  7. Behavioural responses of stable flies to cattle manure slurry associated odourants.

    PubMed

    Tangtrakulwanich, K; Albuquerque, T A; Brewer, G J; Baxendale, F P; Zurek, L; Miller, D N; Taylor, D B; Friesen, K A; Zhu, J J

    2015-03-01

    Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundance of stable flies increased significantly in grasslands or crop fields when cattle manure slurry was applied. Major volatile compounds emanating from manure slurry were collected and identified. Behavioural responses of stable flies to those compounds were investigated in laboratory bioassays and field-trapping studies. Results from olfactometer assays revealed that phenol, p-cresol and m-cresol were attractive to adult stable flies. When tested individually, attraction was higher with lower dosages. Stable flies were most attracted to blends of phenol and m-cresol or p-cresol. Traps with binary blend lures caught more stable flies in field trials as well. PMID:25557192

  8. Odour sampling. 2. Comparison of physical and aerodynamic characteristics of sampling devices: a review.

    PubMed

    Hudson, N; Ayoko, G A

    2008-07-01

    Sampling devices differing greatly in shape, size and operating condition have been used to collect air samples to determine rates of emission of volatile substances, including odour. However, physical chemistry principles, in particular the partitioning of volatile substances between two phases as explained by Henrys Law and the relationship between wind velocity and emission rate, suggests that different devices cannot be expected to provide equivalent emission rate estimates. Thus several problems are associated with the use of static and dynamic emission chambers, but the more turbulent devices such as wind tunnels do not appear to be subject to these problems. In general, the ability to relate emission rate estimates obtained from wind tunnel measurements to those derived from device-independent techniques supports the use of wind tunnels to determine emission rates that can be used as input data for dispersion models. PMID:17512194

  9. Floral odour chemistry defines species boundaries and underpins strong reproductive isolation in sexually deceptive orchids

    PubMed Central

    Peakall, Rod; Whitehead, Michael R.

    2014-01-01

    Background and Aims The events leading to speciation are best investigated in systems where speciation is ongoing or incomplete, such as incipient species. By examining reproductive barriers among incipient sister taxa and their congeners we can gain valuable insights into the relative timing and importance of the various barriers involved in the speciation process. The aim of this study was to identify the reproductive barriers among sexually deceptive orchid taxa in the genus Chiloglottis. Methods The study targeted four closely related taxa with varying degrees of geographic overlap. Chemical, morphological and genetic evidence was combined to explore the basis of reproductive isolation. Of primary interest was the degree of genetic differentiation among taxa at both nuclear and chloroplast DNA markers. To objectively test whether or not species boundaries are defined by the chemistry that controls pollinator specificity, genetic analysis was restricted to samples of known odour chemistry. Key Results Floral odour chemical analysis was performed for 600+ flowers. The three sympatric taxa were defined by their specific chiloglottones, the semiochemicals responsible for pollinator attraction, and were found to be fully cross-compatible. Multivariate morphometric analysis could not reliably distinguish among the four taxa. Although varying from very low to moderate, significant levels of genetic differentiation were detected among all pairwise combinations of taxa at both nuclear and chloroplast loci. However, the levels of genetic differentiation were lower than expected for mature species. Critically, a lack of chloroplast DNA haplotype sharing among the morphologically indistinguishable and most closely related taxon pair confirmed that chemistry alone can define taxon boundaries. Conclusions The results confirmed that pollinator isolation, mediated by specific pollinator attraction, underpins strong reproductive isolation in these taxa. A combination of large

  10. Odour-Mediated Orientation of Beetles Is Influenced by Age, Sex and Morph

    PubMed Central

    Arnold, Sarah E. J.; Stevenson, Philip C.; Belmain, Steven R.

    2012-01-01

    The behaviour of insects is dictated by a combination of factors and may vary considerably between individuals, but small insects are often considered en masse and thus these differences can be overlooked. For example, the cowpea bruchid Callosobruchus maculatus F. exists naturally in two adult forms: the active (flight) form for dispersal, and the inactive (flightless), more fecund but shorter-lived form. Given that these morphs show dissimilar biology, it is possible that they differ in odour-mediated orientation and yet studies of this species frequently neglect to distinguish morph type, or are carried out only on the inactive morph. Along with sex and age of individual, adult morph could be an important variable determining the biology of this and similar species, informing studies on evolution, ecology and pest management. We used an olfactometer with motion-tracking to investigate whether the olfactory behaviour and orientation of C. maculatus towards infested and uninfested cowpeas and a plant-derived repellent compound, methyl salicylate, differed between morphs or sexes. We found significant differences between the behaviour of male and female beetles and beetles of different ages, as well as interactive effects of sex, morph and age, in response to both host and repellent odours. This study demonstrates that behavioural experiments on insects should control for sex and age, while also considering differences between adult morphs where present in insect species. This finding has broad implications for fundamental entomological research, particularly when exploring the relationships between physiology, behaviour and evolutionary biology, and the application of crop protection strategies. PMID:23145074