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Sample records for affects odor discrimination

  1. Discrimination of Body Odor Using Odor Sieving Sensor System

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    Takamizawa, Tadashi; Miyagi, Kazuki; Miyauchi, Hitoshi; Imahashi, Masahiro; Hayashi, Kenshi

    2011-09-01

    We have been focusing on sebum for discriminating human body odor. In this study, we examined body odor sampled from 12 male examinees. Through the experiment, we detected statistically-significant differences between 56 pairs of examinees out of 66 pairs (approximately 85%). This result shows that our system and principle enabled discrimination of body odor between examinees to a certain extent.

  2. Effect of fragrance use on discrimination of individual body odor

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    Caroline eAllen

    2015-08-01

    Full Text Available Previous research suggests that artificial fragrances may be chosen to complement or enhance an individual’s body odor, rather than simply masking it, and that this may create an odor blend with an emergent quality that is perceptually distinguishable from body odor or fragrance alone. From this, it can be predicted that a new emergent odor might be more easily identified than an individual’s body odor in isolation. We used a triangle test paradigm to assess whether fragrance affects people’s ability to distinguish between individual odors. Six male and six female donors provided axillary odor samples in three conditions (without fragrance, wearing their own fragrance, and wearing an assigned fragrance. In total, 296 female and 131 male participants selected the odd one out from three odor samples (two from one donor, one from another; both of the same sex. We found that participants could discriminate between the odors at above chance levels in all three odour conditions. Olfactory identification ability (measured using Sniffin’ Sticks positively predicted discrimination performance, and sex differences in performance were also observed, with female raters being correct more often than men. Success rates were also higher for odors of male donors. Additionally, while performance was above chance in all conditions, individual odor discrimination varied across the three conditions. Discrimination rate was significantly higher in the ‘no fragrance’ condition than either of the fragranced conditions. Importantly, however, discrimination rate was also significantly higher in the ‘own fragrance’ condition than the ‘assigned fragrance’ condition, suggesting that naturally occurring variance in body odor is more preserved when blended with fragrances that people choose for themselves, compared with other fragrances. Our data are consistent with the idea that fragrance choices are influenced by fragrance interactions with an

  3. Odors Discrimination by Olfactory Epithelium Biosensor

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    Liu, Qingjun; Hu, Ning; Ye, Weiwei; Zhang, Fenni; Wang, Hua; Wang, Ping

    2011-09-01

    Humans are exploring the bionic biological olfaction to sense the various trace components of gas or liquid in many fields. For achieving the goal, we endeavor to establish a bioelectronic nose system for odor detection by combining intact bioactive function units with sensors. The bioelectronic nose is based on the olfactory epithelium of rat and microelectrode array (MEA). The olfactory epithelium biosensor generates extracellular potentials in presence of odor, and presents obvious specificity under different odors condition. The odor response signals can be distinguished with each other effectively by signal sorting. On basis of bioactive MEA hybrid system and the improved signal processing analysis, the bioelectronic nose will realize odor discrimination by the specific feature of signals response to various odors.

  4. Cell-Based Odorant Sensor Array for Odor Discrimination Based on Insect Odorant Receptors.

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    Termtanasombat, Maneerat; Mitsuno, Hidefumi; Misawa, Nobuo; Yamahira, Shinya; Sakurai, Takeshi; Yamaguchi, Satoshi; Nagamune, Teruyuki; Kanzaki, Ryohei

    2016-07-01

    The olfactory system of living organisms can accurately discriminate numerous odors by recognizing the pattern of activation of several odorant receptors (ORs). Thus, development of an odorant sensor array based on multiple ORs presents the possibility of mimicking biological odor discrimination mechanisms. Recently, we developed novel odorant sensor elements with high sensitivity and selectivity based on insect OR-expressing Sf21 cells that respond to target odorants by displaying increased fluorescence intensity. Here we introduce the development of an odorant sensor array composed of several Sf21 cell lines expressing different ORs. In this study, an array pattern of four cell lines expressing Or13a, Or56a, BmOR1, and BmOR3 was successfully created using a patterned polydimethylsiloxane film template and cell-immobilizing reagents, termed biocompatible anchor for membrane (BAM). We demonstrated that BAM could create a clear pattern of Sf21 sensor cells without impacting their odorant-sensing performance. Our sensor array showed odorant-specific response patterns toward both odorant mixtures and single odorant stimuli, allowing us to visualize the presence of 1-octen-3-ol, geosmin, bombykol, and bombykal as an increased fluorescence intensity in the region of Or13a, Or56a, BmOR1, and BmOR3 cell lines, respectively. Therefore, we successfully developed a new methodology for creating a cell-based odorant sensor array that enables us to discriminate multiple target odorants. Our method might be expanded into the development of an odorant sensor capable of detecting a large range of environmental odorants that might become a promising tool used in various applications including the study of insect semiochemicals and food contamination.

  5. Are odorant-binding proteins involved in odorant discrimination?

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    Steinbrecht, R A

    1996-12-01

    Pheromone-sensitive sensilla trichodea of nine moth species belonging to six families and three superfamilies of Lepidoptera were immunolabelled with an antiserum against the pheromone-binding protein of Antheraea polyphemus. Strong immunolabelling of the sensillum lymph was observed in all long sensilla trichodea of A. polyphemus, A. pernyi (Saturniidae), Bombyx mori (Bombycidae) and Manduca sexta (Sphingidae). Very weak labelling was found with all sensilla trichodea of Dendrolimus kikuchii (Lasiocampidae) and Lymantria dispar (Lymantriidae). In three noctuid species, some long sensilla trichodea were labelled strongly, some only weakly and some were not labelled at all. The fraction of long sensilla trichodea that were strongly labelled was large in Helicoverpa armigera, but small in Spodoptera littoralis and Autographa gamma. The observed cross-reactivity was not correlated with taxonomic relatedness of the species but rather with chemical relatedness of the pheromones used by these species, as a high labelling density was consistently observed in sensilla tuned to pheromones with an alcyl chain of 16 carbon atoms. The highly divergent specificity of pheromone-receptor cells in Noctuidae appears to be mirrored by a similar diversity of the pheromone-binding proteins in the sensilla trichodea. These data support the notion that pheromone-binding proteins participate in odorant discrimination.

  6. Segregation of odor identity and intensity during odor discrimination in Drosophila mushroom body.

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    Shouzhen Xia

    2007-10-01

    Full Text Available Molecular and cellular studies have begun to unravel a neurobiological basis of olfactory processing, which appears conserved among vertebrate and invertebrate species. Studies have shown clearly that experience-dependent coding of odor identity occurs in "associative" olfactory centers (the piriform cortex in mammals and the mushroom body [MB] in insects. What remains unclear, however, is whether associative centers also mediate innate (spontaneous odor discrimination and how ongoing experience modifies odor discrimination. Here we show in naïve flies that Galphaq-mediated signaling in MB modulates spontaneous discrimination of odor identity but not odor intensity (concentration. In contrast, experience-dependent modification (conditioning of both odor identity and intensity occurs in MB exclusively via Galphas-mediated signaling. Our data suggest that spontaneous responses to odor identity and odor intensity discrimination are segregated at the MB level, and neural activity from MB further modulates olfactory processing by experience-independent Galphaq-dependent encoding of odor identity and by experience-induced Galphas-dependent encoding of odor intensity and identity.

  7. Olfactory bulb size, odor discrimination and magnetic insensitivity in hummingbirds.

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    Ioalé, P; Papi, F

    1989-05-01

    Relative olfactory bulb size with respect to telencephalic hemispheres (olfactory ratio) was measured in five species of hummingbirds. Trochiliformes were found to be next to last among 25 avian orders with respect to olfactory bulb development. One hummingbird species, the White-vented Violetear (Colibri serrirostris), was trained in a successive go/no-go discrimination task, and learned to feed or not to feed from a container dependent on the olfactory stimuli associated with it. Test birds learned to discriminate amyl acetate vs. turpentine essence, jasmine essence vs. lavender essence, eucalyptus essence vs. no odor, beta-ionone vs. no odor, carvone vs. eucalyptol. In contrast, 1-phenylethanol vs. beta-ionone discrimination, two odorants which appear similar to humans, was unsuccessful. Using a similar procedure, attempts were made to condition a White-vented Violetear and a Versicolored Emerald (Amazilia versicolor) to magnetic stimuli. The birds were unable to discriminate between a normal field and an oscillating field (square wave, 1 Hz, amplitude +/- 0.40 G).

  8. Sweet reward increases implicit discrimination of similar odors

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    Eva Renata Pool

    2014-05-01

    Full Text Available Stimuli associated with emotional events signal the presence of potentially relevant situations, thus learning to rapidly identify this kind of stimuli can be highly beneficial. It has been demonstrated that individuals acquire a better perceptual representation of stimuli associated with negative and threatening emotional events. Here we investigated whether the same process occurs for stimuli associated with positive and rewarding emotional events. We used an appetitive Pavlovian conditioning paradigm during which one of two perceptually non-distinguishable odors was associated with a rewarding taste (i.e., chocolate. We investigated whether appetitive conditioning could improve the recognition of the odor associated with the reward, rendering it discriminable from its similar version that was never associated with the reward. Results revealed a dissociation between explicit perception and physiological reactions. Although participants were not able to explicitly perceive a difference, participants reacted faster, inhaled more and had higher skin conductance responses when confronted with the reward-associated odor compared to its similar version that was never associated with the reward. Our findings have demonstrated that positive emotional associations can improve the implicit perceptual representation of odors, by triggering different physiological responses to odors that do not seem to be otherwise distinguishable.

  9. Applying medicinal chemistry strategies to understand odorant discrimination

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    Poivet, Erwan; Peterlin, Zita; Tahirova, Narmin; Xu, Lu; Altomare, Clara; Paria, Anne; Zou, Dong-Jing; Firestein, Stuart

    2016-01-01

    Associating an odorant's chemical structure with its percept is a long-standing challenge. One hindrance may come from the adoption of the organic chemistry scheme of molecular description and classification. Chemists classify molecules according to characteristics that are useful in synthesis or isolation, but which may be of little importance to a biological sensory system. Accordingly, we look to medicinal chemistry, which emphasizes biological function over chemical form, in an attempt to discern which among the many molecular features are most important for odour discrimination. Here we use medicinal chemistry concepts to assemble a panel of molecules to test how heteroaromatic ring substitution of the benzene ring will change the odour percept of acetophenone. This work allows us to describe an extensive rule in odorant detection by mammalian olfactory receptors. Whereas organic chemistry would have predicted the ring size and composition to be key features, our work reveals that the topological polar surface area is the key feature for the discrimination of these odorants. PMID:27040654

  10. Applying medicinal chemistry strategies to understand odorant discrimination.

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    Poivet, Erwan; Peterlin, Zita; Tahirova, Narmin; Xu, Lu; Altomare, Clara; Paria, Anne; Zou, Dong-Jing; Firestein, Stuart

    2016-04-04

    Associating an odorant's chemical structure with its percept is a long-standing challenge. One hindrance may come from the adoption of the organic chemistry scheme of molecular description and classification. Chemists classify molecules according to characteristics that are useful in synthesis or isolation, but which may be of little importance to a biological sensory system. Accordingly, we look to medicinal chemistry, which emphasizes biological function over chemical form, in an attempt to discern which among the many molecular features are most important for odour discrimination. Here we use medicinal chemistry concepts to assemble a panel of molecules to test how heteroaromatic ring substitution of the benzene ring will change the odour percept of acetophenone. This work allows us to describe an extensive rule in odorant detection by mammalian olfactory receptors. Whereas organic chemistry would have predicted the ring size and composition to be key features, our work reveals that the topological polar surface area is the key feature for the discrimination of these odorants.

  11. Mice Lacking M1 and M3 Muscarinic Acetylcholine Receptors Have Impaired Odor Discrimination and Learning

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    Chan, Wilson; Singh, Sanmeet; Keshav, Taj; Dewan, Ramita; Eberly, Christian; Maurer, Robert; Nunez-Parra, Alexia; Araneda, Ricardo C.

    2017-01-01

    The cholinergic system has extensive projections to the olfactory bulb (OB) where it produces a state-dependent regulation of sensory gating. Previous work has shown a prominent role of muscarinic acetylcholine (ACh) receptors (mAChRs) in regulating the excitability of OB neurons, in particular the M1 receptor. Here, we examined the contribution of M1 and M3 mAChR subtypes to olfactory processing using mice with a genetic deletion of these receptors, the M1−/− and the M1/M3−/− knockout (KO) mice. Genetic ablation of the M1 and M3 mAChRs resulted in a significant deficit in odor discrimination of closely related molecules, including stereoisomers. However, the discrimination of dissimilar molecules, social odors (e.g., urine) and novel object recognition was not affected. In addition the KO mice showed impaired learning in an associative odor-learning task, learning to discriminate odors at a slower rate, indicating that both short and long-term memory is disrupted by mAChR dysfunction. Interestingly, the KO mice exhibited decreased olfactory neurogenesis at younger ages, a deficit that was not maintained in older animals. In older animals, the olfactory deficit could be restored by increasing the number of new born neurons integrated into the OB after exposing them to an olfactory enriched environment, suggesting that muscarinic modulation and adult neurogenesis could be two different mechanism used by the olfactory system to improve olfactory processing. PMID:28210219

  12. Pavlovian conditioning enhances resistance to disruption of dogs performing an odor discrimination.

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    Hall, Nathaniel J; Smith, David W; Wynne, Clive D L

    2015-05-01

    Domestic dogs are used to aid in the detection of a variety of substances such as narcotics and explosives. Under real-world detection situations there are many variables that may disrupt the dog's performance. Prior research on behavioral momentum theory suggests that higher rates of reinforcement produce greater resistance to disruption, and that this is heavily influenced by the stimulus-reinforcer relationship. The present study tests the Pavlovian interpretation of resistance to change using dogs engaged in an odor discrimination task. Dogs were trained on two odor discriminations that alternated every six trials akin to a multiple schedule in which the reinforcement probability for a correct response was always 1. Dogs then received several sessions of either odor Pavlovian conditioning to the S+ of one odor discrimination (Pavlovian group) or explicitly unpaired exposure to the S+ of one odor discrimination (Unpaired group). The remaining odor discrimination pair for each dog always remained an unexposed control. Resistance to disruption was assessed under presession feeding, a food-odor disruptor condition, and extinction, with baseline sessions intervening between disruption conditions. Equivalent baseline detection rates were observed across experimental groups and odorant pairs. Under disruption conditions, Pavlovian conditioning led to enhanced resistance to disruption of detection performance compared to the unexposed control odor discrimination. Unpaired odor conditioning did not influence resistance to disruption. These results suggest that changes in Pavlovian contingencies are sufficient to influence resistance to change.

  13. Spared piriform cortical single-unit odor processing and odor discrimination in the Tg2576 mouse model of Alzheimer's disease.

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    Xu, Wenjin; Lopez-Guzman, Mirielle; Schoen, Chelsea; Fitzgerald, Shane; Lauer, Stephanie L; Nixon, Ralph A; Levy, Efrat; Wilson, Donald A

    2014-01-01

    Alzheimer's disease is a neurodegenerative disorder that is the most common cause of dementia in the elderly today. One of the earliest reported signs of Alzheimer's disease is olfactory dysfunction, which may manifest in a variety of ways. The present study sought to address this issue by investigating odor coding in the anterior piriform cortex, the primary cortical region involved in higher order olfactory function, and how it relates to performance on olfactory behavioral tasks. An olfactory habituation task was performed on cohorts of transgenic and age-matched wild-type mice at 3, 6 and 12 months of age. These animals were then anesthetized and acute, single-unit electrophysiology was performed in the anterior piriform cortex. In addition, in a separate group of animals, a longitudinal odor discrimination task was conducted from 3-12 months of age. Results showed that while odor habituation was impaired at all ages, Tg2576 performed comparably to age-matched wild-type mice on the olfactory discrimination task. The behavioral data mirrored intact anterior piriform cortex single-unit odor responses and receptive fields in Tg2576, which were comparable to wild-type at all age groups. The present results suggest that odor processing in the olfactory cortex and basic odor discrimination is especially robust in the face of amyloid β precursor protein (AβPP) over-expression and advancing amyloid β (Aβ) pathology. Odor identification deficits known to emerge early in Alzheimer's disease progression, therefore, may reflect impairments in linking the odor percept to associated labels in cortical regions upstream of the primary olfactory pathway, rather than in the basic odor processing itself.

  14. Spared piriform cortical single-unit odor processing and odor discrimination in the Tg2576 mouse model of Alzheimer's disease.

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    Wenjin Xu

    Full Text Available Alzheimer's disease is a neurodegenerative disorder that is the most common cause of dementia in the elderly today. One of the earliest reported signs of Alzheimer's disease is olfactory dysfunction, which may manifest in a variety of ways. The present study sought to address this issue by investigating odor coding in the anterior piriform cortex, the primary cortical region involved in higher order olfactory function, and how it relates to performance on olfactory behavioral tasks. An olfactory habituation task was performed on cohorts of transgenic and age-matched wild-type mice at 3, 6 and 12 months of age. These animals were then anesthetized and acute, single-unit electrophysiology was performed in the anterior piriform cortex. In addition, in a separate group of animals, a longitudinal odor discrimination task was conducted from 3-12 months of age. Results showed that while odor habituation was impaired at all ages, Tg2576 performed comparably to age-matched wild-type mice on the olfactory discrimination task. The behavioral data mirrored intact anterior piriform cortex single-unit odor responses and receptive fields in Tg2576, which were comparable to wild-type at all age groups. The present results suggest that odor processing in the olfactory cortex and basic odor discrimination is especially robust in the face of amyloid β precursor protein (AβPP over-expression and advancing amyloid β (Aβ pathology. Odor identification deficits known to emerge early in Alzheimer's disease progression, therefore, may reflect impairments in linking the odor percept to associated labels in cortical regions upstream of the primary olfactory pathway, rather than in the basic odor processing itself.

  15. Lateral entorhinal modulation of piriform cortical activity and fine odor discrimination.

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    Chapuis, Julie; Cohen, Yaniv; He, Xiaobin; Zhang, Zhijan; Jin, Sen; Xu, Fuqiang; Wilson, Donald A

    2013-08-14

    The lateral entorhinal cortex (LEC) receives direct input from olfactory bulb mitral cells and piriform cortical pyramidal cells and is the gateway for olfactory input to the hippocampus. However, the LEC also projects back to the piriform cortex and olfactory bulb. Activity in the LEC is shaped by input from the perirhinal cortices, hippocampus, and amygdala, and thus could provide a rich contextual modulation of cortical odor processing. The present study further explored LEC feedback to anterior piriform cortex by examining how LEC top-down input modulates anterior piriform cortex odor evoked activity in rats. Retrograde viral tracing confirmed rich LEC projections to both the olfactory bulb and piriform cortices. In anesthetized rats, reversible lesions of the ipsilateral LEC increased anterior piriform cortical single-unit spontaneous activity. In awake animals performing an odor discrimination task, unilateral LEC reversible lesions enhanced ipsilateral piriform cortical local field potential oscillations during odor sampling, with minimal impact on contralateral activity. Bilateral LEC reversible lesions impaired discrimination performance on a well learned, difficult odor discrimination task, but had no impact on a well learned simple odor discrimination task. The simple discrimination task was impaired by bilateral reversible lesions of the anterior piriform cortex. Given the known function of LEC in working memory and multisensory integration, these results suggest it may serve as a powerful top-down modulator of olfactory cortical function and odor perception. Furthermore, the results provide potential insight into how neuropathology in the entorhinal cortex could contribute to early olfactory deficits seen in Alzheimer's disease.

  16. Sniff adjustment in an odor discrimination task in the rat: analytical or synthetic strategy?

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    Emmanuelle eCourtiol

    2014-05-01

    Full Text Available A growing body of evidence suggests that sniffing is not only the mode of delivery for odorant molecules but also contributes to olfactory perception. However, the precise role of sniffing variations remains unknown. The zonation hypothesis suggests that animals use sniffing variations to optimize the deposition of odorant molecules on the most receptive areas of the olfactory epithelium. Sniffing would thus depend on the physicochemical properties of odorants, particularly their sorption. Rojas-Líbano and Kay (2012 tested this hypothesis and showed that rats used different sniff strategies when they had to target a high-sorption molecule or a low-sorption molecule in a binary mixture. Which sniffing strategy is used by rats when they are confronted to discrimination between two similarly sorbent odorants remains unanswered. Particularly, is sniffing adjusted independently for each odorant according to its sorption properties (analytical processing, or is sniffing adjusted based on the pairing context (synthetic processing? We tested these hypotheses on rats performing a two-alternative choice discrimination of odorants with similar sorption properties. We recorded sniffing in a non-invasive manner using whole-body plethysmography during the behavioral task. We found that sniffing variations were not only a matter of odorant sorption properties and that the same odorant was sniffed differently depending on the odor pair in which it was presented. These results suggest that rather than being adjusted analytically, sniffing is instead adjusted synthetically and depends on the pair of odorants presented during the discrimination task. Our results show that sniffing is a specific sensorimotor act that depends on complex synthetic processes.

  17. Olfactory discrimination ability of Asian elephants (Elephas maximus) for structurally related odorants.

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    Rizvanovic, Alisa; Amundin, Mats; Laska, Matthias

    2013-02-01

    Using a food-rewarded two-choice instrumental conditioning paradigm, we assessed the ability of Asian elephants, Elephas maximus, to discriminate between 2 sets of structurally related odorants. We found that the animals successfully discriminated between all 12 odor pairs involving members of homologous series of aliphatic 1-alcohols, n-aldehydes, 2-ketones, and n-carboxylic acids even when the stimuli differed from each other by only 1 carbon. With all 4 chemical classes, the elephants displayed a positive correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length. The animals also successfully discriminated between all 12 enantiomeric odor pairs tested. An analysis of odor structure-activity relationships suggests that a combination of molecular structural properties rather than a single molecular feature may be responsible for the discriminability of enantiomers. Compared with other species tested previously on the same sets of odor pairs (or on subsets thereof), the Asian elephants performed at least as well as mice and clearly better than human subjects, squirrel monkeys, pigtail macaques, South African fur seals, and honeybees. Further comparisons suggest that neither the relative nor the absolute size of the olfactory bulbs appear to be reliable predictors of between-species differences in olfactory discrimination capabilities. In contrast, we found a positive correlation between the number of functional olfactory receptor genes and the proportion of discriminable enantiomeric odor pairs. Taken together, the results of the present study support the notion that the sense of smell may play an important role in regulating the behavior of Asian elephants.

  18. Repeated exposure to odors induces affective habituation of perception and sniffing

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    Camille eFerdenzi

    2014-04-01

    Full Text Available Olfactory perception, and especially hedonic evaluation of odors, is highly flexible, but some mechanisms involved in this flexibility remain to be elucidated. In the present study we aimed at better understanding how repeated exposure to odors can affect their pleasantness. We tested the hypothesis of an affective habituation to the stimuli, namely a decrease of emotional intensity over repetitions. More specifically, we tested whether this effect is subject to inter-individual variability and whether it can also be observed at the olfactomotor level. Twenty-six participants took part in the experiment during which they had to smell two odorants, anise and chocolate, presented twenty times each. On each trial, sniff duration and volume were recorded and paired with ratings of odor pleasantness and intensity. For each smell, we distinguished between likers and dislikers, namely individuals giving positive and negative initial hedonic evaluations. Results showed a significant decrease in pleasantness with time when the odor was initially pleasant (likers, while unpleasantness remained stable or slightly decreased when the odor was initially unpleasant (dislikers. This deviation towards neutrality was interpreted as affective habituation. This effect was all the more robust as it was observed for both odors and corroborated by sniffing, an objective measurement of odor pleasantness. Affective habituation to odors can be interpreted as an adaptive response to stimuli that prove over time to be devoid of positive or negative outcome on the organism. This study contributes to a better understanding of how olfactory preferences are shaped through exposure, depending on the individual’s own initial perception of the odor.

  19. How does long-term odor deprivation affect the olfactory capacity of adult mice?

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    Coppola David M

    2010-05-01

    Full Text Available Abstract Background Unilateral naris occlusion (UNO has been the most common method of effecting stimulus deprivation in studies of olfactory plasticity. However, despite the large corpus on the effects of this manipulation, dating back to the 19th century, little is known about its behavioral sequela. Here we report the results of standard olfactory habituation and discrimination studies on adult mice that had undergone perinatal UNO followed by adult contralateral olfactory bulbectomy (bulb-x. Methods The olfactory performance of UNO mice was compared to matched controls that had unilateral bulb-x but open nares. Both habituation and discrimination (operant experiments employed a protocol in which after successful dishabituation or discrimination to dilute individual odors (A = 0.01% isoamyl acetate; B = 0.01% ethyl butyrate; each v/v in mineral oil, mice were challenged with a single odor versus a mixture comparison (A vs. A + B. In a series of tests the volume portion of Odor B in the mixture was systematically decreased until dishabituation or discrimination thresholds were reached. Results For the habituation experiment, UNOs (n = 10 and controls (n = 9 dishabituated to a 10% mixture of Odor B in Odor A after being habituated to A alone, while both groups failed to show differential responding to a 2% mixture of B in A. However, the UNO group's increased investigation durations for the 2% mixture approached significance (p Conclusions Adult mice relying on an olfactory system deprived of odor by naris occlusion from near the time of birth display enhanced olfactory capacity compared to control mice. This counterintuitive result suggests that UNO is neither an absolute method of deprivation nor does it diminish olfactory capabilities. Enhanced olfactory capacity, as observed in the current study, that is a consequence of deprivation, is consistent with recent molecular and physiological evidence that stimulus deprivation triggers

  20. Affective priming as an indirect measure of food preferences acquired through odor conditioning.

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    Hermans, Dirk; Baeyens, Frank; Lamote, Sabine; Spruyt, Adriaan; Eelen, Paul

    2005-01-01

    The present study aimed at investigating affective priming for originally neutral food stimuli that recently acquired their affective meaning through odor conditioning. In a first phase, pictures of different brands of yogurts (CSs) were contingently presented with a positive or negative odor (US). In a subsequent phase, the yogurt CSs were used as primes in an affective priming procedure. Rating data showed that the acquisition procedure resulted in a reliable evaluative learning effect. This could be corroborated by the results of the priming task. Participants responded faster to positive target words and made fewer errors when they were preceded by a CS that had been associated with a positive odor, as compared to a CS that was associated with a negative odor. A reversed pattern was present for negative targets. Based on these findings, it is suggested that affective priming might be used as a demand-free measure of evaluative learning.

  1. Does gently clearing the nasal passage affect odor identification?

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    Mitchell G. Spring

    2014-12-01

    Full Text Available Identifying scents in a wine’s bouquet is considered one of the most important steps in the process of wine tasting. An individual’s ability to successfully do this is dependent on the sense of smell; thus, altering the nasal microenvironment could have a powerful effect on the wine tasting experience. In the present study, we examined olfactory performance in healthy participants who cleared their nasal cavity before odorant presentations. Fifty undergraduate participants were assessed with a standardized test of olfaction requiring the recognition of a battery of odors. Half of these participants cleared mucus from their nasal cavities (by gently blowing their noses prior to the assessment. No difference was found in performance between those who cleared their nasal passages and those who did not. Further, data were not different than known population data from the test. These data suggest that gently clearing the nasal cavity before presentation of odorants bears no effect on the ability to perceive those odor qualities.

  2. Enhanced odor discrimination and impaired olfactory memory by spatially controlled switch of AMPA receptors.

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    Derya R Shimshek

    2005-11-01

    Full Text Available Genetic perturbations of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs are widely used to dissect molecular mechanisms of sensory coding, learning, and memory. In this study, we investigated the role of Ca2+-permeable AMPARs in olfactory behavior. AMPAR modification was obtained by depletion of the GluR-B subunit or expression of unedited GluR-B(Q, both leading to increased Ca2+ permeability of AMPARs. Mice with this functional AMPAR switch, specifically in forebrain, showed enhanced olfactory discrimination and more rapid learning in a go/no-go operant conditioning task. Olfactory memory, however, was dramatically impaired. GluR-B depletion in forebrain was ectopically variable ("mosaic" among individuals and strongly correlated with decreased olfactory memory in hippocampus and cortex. Accordingly, memory was rescued by transgenic GluR-B expression restricted to piriform cortex and hippocampus, while enhanced odor discrimination was independent of both GluR-B variability and transgenic GluR-B expression. Thus, correlated differences in behavior and levels of GluR-B expression allowed a mechanistic and spatial dissection of olfactory learning, discrimination, and memory capabilities.

  3. Calmodulin affects sensitization of Drosophila melanogaster odorant receptors

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    Latha eMukunda

    2016-02-01

    Full Text Available Flying insects have developed a remarkably sensitive olfactory system to detect faint and turbulent odor traces. This ability is linked to the olfactory receptors class of odorant receptors (ORs, occurring exclusively in winged insects. ORs form heteromeric complexes of an odorant specific receptor protein (OrX and a highly conserved co-receptor protein (Orco. The ORs form ligand gated ion channels that are tuned by intracellular signaling systems. Repetitive subthreshold odor stimulation of olfactory sensory neurons sensitizes insect ORs. This OR sensitization process requires Orco activity. In the present study we first asked whether OR sensitization can be monitored with heterologously expressed OR proteins. Using electrophysiological and calcium imaging methods we demonstrate that D. melanogaster OR proteins expressed in CHO cells show sensitization upon repeated weak stimulation. This was found for OR channels formed by Orco as well as by Or22a or Or56a and Orco. Moreover, we show that inhibition of calmodulin (CaM action on OR proteins, expressed in CHO cells, abolishes any sensitization. Finally, we investigated the sensitization phenomenon using an ex vivo preparation of olfactory sensory neurons (OSNs expressing Or22a inside the fly’s antenna. Using calcium imaging, we observed sensitization in the dendrites as well as in the soma. Inhibition of calmodulin with W7 disrupted the sensitization within the outer dendritic shaft, whereas the sensitization remained in the other OSN compartments. Taken together, our results suggest that CaM action is involved in sensitizing the OR complex and that this mechanisms accounts for the sensitization in the outer dendrites, whereas further mechanisms contribute to the sensitization observed in the other OSN compartments. The use of heterologously expressed OR proteins appears to be suitable for further investigations on the mechanistic basis of OR sensitization, while investigations on native

  4. Odor discrimination in classical conditioning of proboscis extension in two stingless bee species in comparison to Africanized honeybees.

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    Mc Cabe, S I; Hartfelder, K; Santana, W C; Farina, W M

    2007-11-01

    Learning in insects has been extensively studied using different experimental approaches. One of them, the proboscis extension response (PER) paradigm, is particularly well suited for quantitative studies of cognitive abilities of honeybees under controlled conditions. The goal of this study was to analyze the capability of three eusocial bee species to be olfactory conditioned in the PER paradigm. We worked with two Brazilian stingless bees species, Melipona quadrifasciata and Scaptotrigona aff. depilis, and with the invasive Africanized honeybee, Apis mellifera. These three species present very different recruitment strategies, which could be related with different odor-learning abilities. We evaluated their gustatory responsiveness and learning capability to discriminate floral odors. Gustatory responsiveness was similar for the three species, although S. aff. depilis workers showed fluctuations along the experimental period. Results for the learning assays revealed that M. quadrifasciata workers can be conditioned to discriminate floral odors in a classical differential conditioning protocol and that this discrimination is maintained 15 min after training. During conditioning, Africanized honeybees presented the highest discrimination, for M. quadrifasciata it was intermediate, and S. aff. depilis bees presented no discrimination. The differences found are discussed considering the putative different learning abilities and procedure effect for each species.

  5. Associative encoding in posterior piriform cortex during odor discrimination and reversal learning.

    Science.gov (United States)

    Calu, Donna J; Roesch, Matthew R; Stalnaker, Thomas A; Schoenbaum, Geoffrey

    2007-06-01

    Recent proposals have conceptualized piriform cortex as an association cortex, capable of integrating incoming olfactory information with descending input from higher order associative regions such as orbitofrontal cortex and basolateral amygdala (ABL). If true, encoding in piriform cortex should reflect associative features prominent in these areas during associative learning involving olfactory cues. We recently reported that neurons in anterior piriform cortex (APC) in rats exhibited significant plasticity in their responses to odor cues during associative learning. Here, we have repeated this study, recording from neurons in posterior piriform cortex (PPC), a region of piriform cortex that receives much stronger input from ABL. If associative encoding in piriform cortex is driven by inputs from ABL, then we should see more plasticity in PPC neurons than we observed in APC. Consistent with this hypothesis, we found that PPC neurons were highly associative and appeared to be somewhat more likely than neurons recorded in APC to alter their responses to the odor cues after reversal of the odor-outcome associations in the task. Further, odor-selective PPC populations exhibited markedly different firing patterns based on the valence of the odor cue. These results suggest associative encoding in piriform cortex is represented in a topographical fashion, reflecting the stronger and more specific input from olfactory bulb concerning the sensory features of odors in anterior regions and stronger input from ABL concerning the meaning of odors in posterior regions.

  6. No effect of ambient odor on the affective appraisal of a desktop virtual environment with signs of disorder.

    Directory of Open Access Journals (Sweden)

    Alexander Toet

    Full Text Available BACKGROUND: Desktop virtual environments (VEs are increasingly deployed to study the effects of environmental qualities and interventions on human behavior and safety related concerns in built environments. For these applications it is essential that users appraise the affective qualities of the VE similar to those of its real world counterpart. Previous studies have shown that factors like simulated lighting, sound and dynamic elements all contribute to the affective appraisal of a desktop VE. Since ambient odor is known to affect the affective appraisal of real environments, and has been shown to increase the sense of presence in immersive VEs, it may also be an effective tool to tune the affective appraisal of desktop VEs. This study investigated if exposure to ambient odor can modulate the affective appraisal of a desktop VE with signs of public disorder. METHOD: Participants explored a desktop VE representing a suburban neighborhood with signs of public disorder (neglect, vandalism and crime, while being exposed to either room air or subliminal levels of unpleasant (tar or pleasant (cut grass ambient odor. Whenever they encountered signs of disorder they reported their safety related concerns and associated affective feelings. RESULTS: Signs of crime in the desktop VE were associated with negative affective feelings and concerns for personal safety and personal property. However, there was no significant difference between reported safety related concerns and affective connotations in the control (no-odor and in each of the two ambient odor conditions. CONCLUSION: Ambient odor did not affect safety related concerns and affective connotations associated with signs of disorder in the desktop VE. Thus, semantic congruency between ambient odor and a desktop VE may not be sufficient to influence its affective appraisal, and a more realistic simulation in which simulated objects appear to emit scents may be required to achieve this goal.

  7. Lateral Entorhinal Modulation of Piriform Cortical Activity and Fine Odor Discrimination

    OpenAIRE

    Chapuis, Julie; Cohen, Yaniv; He, Xiaobin; Zhang, Zhijan; Jin, Sen; Xu, Fuqiang; Wilson, Donald A.

    2013-01-01

    The lateral entorhinal cortex (LEC) receives direct input from olfactory bulb mitral cells and piriform cortical pyramidal cells and is the gateway for olfactory input to the hippocampus. However, the LEC also projects back to the piriform cortex and olfactory bulb. Activity in the LEC is shaped by input from the perirhinal cortices, hippocampus, and amygdala, and thus could provide a rich contextual modulation of cortical odor processing. The present study further explored LEC feedback to an...

  8. Which characteristic of Natto: appearance, odor, or taste most affects preference for Natto

    Directory of Open Access Journals (Sweden)

    Tsumura Yuki

    2012-05-01

    Full Text Available Abstract Background In Japan, consumption of Natto, a fermented bean dish, is recommended because of its high quality protein, digestibility in the gut and its preventive effect on blood clot formation due to high vitamin K content. However, consumption of Natto in Kansai and the Chugoku area (the western part of Honshu is less than that in the other areas of Japan probably because of a “food related cultural inhibition”. In this study, we determined which characteristic of Natto (appearance, odor or taste most affect subjects’ perception of sensory attributes by observation of brain hemodynamics in relation to subjects’ preference for Natto. Findings In this experiment, we defined each subject’s changes in brain hemodynamics as (+ or (− corresponding to an increase or a decrease in total hemoglobin concentration after stimuli compared to that before stimuli. As a result, there was no relation between preference for Natto and change in brain hemodynamics by the stimuli of “looking at” or “smelling”, while there was a significant relationship between preference and stimulus of “ingestion”; (+ : (− = 21:15 in the subjects of the “favorite” group and (+:(− = 30:7 in the subjects of the “non-favorite” group (P = 0.034. Conclusion This result indicated that characteristic “taste” of Natto most affects preference for Natto.

  9. Bias to pollen odors is affected by early exposure and foraging experience.

    Science.gov (United States)

    Arenas, A; Farina, W M

    2014-07-01

    In many pollinating insects, foraging preferences are adjusted on the basis of floral cues learned at the foraging site. In addition, olfactory experiences gained at early adult stages might also help them to initially choose food sources. To understand pollen search behavior of honeybees, we studied how responses elicited by pollen-based odors are biased in foraging-age workers according to (i) their genetic predisposition to collect pollen, (ii) pollen related information gained during foraging and (iii) different experiences with pollen gained at early adult ages. Bees returning to the hive carrying pollen loads, were strongly biased to unfamiliar pollen bouquets when tested in a food choice device against pure odors. Moreover, pollen foragers' orientation response was specific to the odors emitted by the pollen type they were carrying on their baskets, which suggests that foragers retrieve pollen odor information to recognize rewarding flowers outside the hive. We observed that attraction to pollen odor was mediated by the exposure to a pollen diet during the first week of life. We did not observe the same attraction in foraging-age bees early exposed to an artificial diet that did not contain pollen. Contrary to the specific response observed to cues acquired during foraging, early exposure to single-pollen diets did not bias orientation response towards a specific pollen odor in foraging-age bees (i.e. bees chose equally between the exposed and the novel monofloral pollen odors). Our results show that pollen exposure at early ages together with olfactory experiences gained in a foraging context are both relevant to bias honeybees' pollen search behavior.

  10. Sensory-specific appetite is affected by actively smelled food odors and remains stable over time in normal-weight women.

    Science.gov (United States)

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

    2014-08-01

    Understanding overconsumption starts with knowledge of how separate factors influence our eating behavior. Food cues such as food odors are known for their effect on general appetite and sensory-specific appetite (SSA). Active sniffing rather than passive exposure may induce satiation over time. The objective of this study was to investigate how actively sniffing banana odors affects general appetite, SSA, and subsequent food intake. In a crossover study, 61 women actively smelled cups containing natural banana, artificial banana odor, or water (no odor) for 10 min. Treatment order was randomly assigned as much as possible. General appetite and SSA were monitored by using 100-mm visual analog scales during the 10 min of active sniffing, followed by ad libitum intake of banana milkshake. Results showed that SSA was consistently high (+12 mm) during actively sniffing natural or artificial banana odors, with no decrease in SSA over time. Sniffing both banana odors increased the appetite for banana (+11 mm) and other sweet products (+4 mm), whereas the appetite for savory products decreased by 7 mm (all P appetite scores (P = 0.06). In conclusion, SSA scores during active sniffing were identical to the SSA found in a similar study that used passive smelling, suggesting that SSA is independent of the manner of sniffing and exposure time. Moreover, sweet/savory categorization may suggest that food odors communicate information about the nutrient composition of their associated foods. These data clearly show the appetizing effects of food odors.

  11. Grooming behavior in American cockroach is affected by novelty and odor.

    Science.gov (United States)

    Zhukovskaya, Marianna I

    2014-01-01

    The main features of grooming behavior are amazingly similar among arthropods and land vertebrates and serve the same needs. A particular pattern of cleaning movements in cockroaches shows cephalo-caudal progression. Grooming sequences become longer after adaptation to the new setting. Novelty related changes in grooming are recognized as a form of displacement behavior. Statistical analysis of behavior revealed that antennal grooming in American cockroach, Periplaneta americana L., was significantly enhanced in the presence of odor.

  12. Odor Emotional Quality Predicts Odor Identification.

    Science.gov (United States)

    Bestgen, Anne-Kathrin; Schulze, Patrick; Kuchinke, Lars

    2015-09-01

    It is commonly agreed upon a strong link between emotion and olfaction. Odor-evoked memories are experienced as more emotional compared with verbal, visual, and tactile stimuli. Moreover, the emotional quality of odor cues increases memory performance, but contrary to this, odors are poor retrieval cues for verbal labels. To examine the relation between the emotional quality of an odor and its likelihood of identification, this study evaluates how normative emotion ratings based on the 3-dimensional affective space model (that includes valence, arousal, and dominance), using the Self-Assessment Manikin by Bradley and Lang (Bradley MM, Lang PJ. 1994. Measuring emotion: the Self-Assessment Manikin and the Semantic Differential. J Behav Ther Exp Psychiatry. 25(1):49-59.) and the Positive and Negative Affect Schedule (Watson D, Clark LA, Tellegen A. 1988. Development and validation of brief measures of positive and negative affect: the PANAS scales. J Pers Soc Psychol. 54(6):1063-1070.) predict the identification of odors in a multiple choice condition. The best fitting logistic regression model includes squared valence and dominance and thus, points to a significant role of specific emotional features of odors as a main clue for odor identification.

  13. The Complexity of Background Clutter Affects Nectar Bat Use of Flower Odor and Shape Cues.

    Directory of Open Access Journals (Sweden)

    Nathan Muchhala

    Full Text Available Given their small size and high metabolism, nectar bats need to be able to quickly locate flowers during foraging bouts. Chiropterophilous plants depend on these bats for their reproduction, thus they also benefit if their flowers can be easily located, and we would expect that floral traits such as odor and shape have evolved to maximize detection by bats. However, relatively little is known about the importance of different floral cues during foraging bouts. In the present study, we undertook a set of flight cage experiments with two species of nectar bats (Anoura caudifer and A. geoffroyi and artificial flowers to compare the importance of shape and scent cues in locating flowers. In a training phase, a bat was presented an artificial flower with a given shape and scent, whose position was constantly shifted to prevent reliance on spatial memory. In the experimental phase, two flowers were presented, one with the training-flower scent and one with the training-flower shape. For each experimental repetition, we recorded which flower was located first, and then shifted flower positions. Additionally, experiments were repeated in a simple environment, without background clutter, or a complex environment, with a background of leaves and branches. Results demonstrate that bats visit either flower indiscriminately with simple backgrounds, with no significant difference in terms of whether they visit the training-flower odor or training-flower shape first. However, in a complex background olfaction was the most important cue; scented flowers were consistently located first. This suggests that for well-exposed flowers, without obstruction from clutter, vision and/or echolocation are sufficient in locating them. In more complex backgrounds, nectar bats depend more heavily on olfaction during foraging bouts.

  14. The perception of odor objects in everyday life: a review on the processing of odor mixtures

    Directory of Open Access Journals (Sweden)

    Thierry eThomas-Danguin

    2014-06-01

    Full Text Available Smelling monomolecular odors hardly ever occurs in everyday life, and the daily functioning of the sense of smell relies primarily on the processing of complex mixtures of volatiles that are present in the environment (e.g., emanating from food or conspecifics. Such processing allows for the instantaneous recognition and categorization of smells and also for the discrimination of odors among others to extract relevant information and to adapt efficiently in different contexts. The neurophysiological mechanisms underpinning this highly efficient analysis of complex mixtures of odorants is beginning to be unraveled and support the idea that olfaction, as vision and audition, relies on odor-objects encoding. This configural processing of odor mixtures, which is empirically subject to important applications in our societies (e.g., the art of perfumers, flavorists, and wine makers, has been scientifically studied only during the last decades. This processing depends on many individual factors, among which are the developmental stage, lifestyle, physiological and mood state, and cognitive skills; this processing also presents striking similarities between species. The present review gathers the recent findings, as observed in animals, healthy subjects, and/or individuals with affective disorders, supporting the perception of complex odor stimuli as odor objects. It also discusses peripheral to central processing, and cognitive and behavioral significance. Finally, this review highlights that the study of odor mixtures is an original window allowing for the investigation of daily olfaction and emphasizes the need for knowledge about the underlying biological processes, which appear to be crucial for our representation and adaptation to the chemical environment.

  15. An odor is not worth a thousand words: from multidimensional odors to unidimensional odor objects.

    Science.gov (United States)

    Yeshurun, Yaara; Sobel, Noam

    2010-01-01

    Olfaction is often referred to as a multidimensional sense. It is multidimensional in that approximately 1000 different receptor types, each tuned to particular odor aspects, together contribute to the olfactory percept. In humans, however, this percept is nearly unidimensional. Humans can detect and discriminate countless odorants, but can identify few by name. The one thing humans can and do invariably say about an odor is whether it is pleasant or not. We argue that this hedonic determination is the key function of olfaction. Thus, the boundaries of an odor object are determined by its pleasantness, which--unlike something material and more like an emotion--remains poorly delineated with words.

  16. Noncontact discrimination of animal and human blood with vacuum blood vessel and factors affect the discrimination

    Science.gov (United States)

    Zhang, Linna; Zhang, Shengzhao; Sun, Meixiu; Li, Hongxiao; Li, Yingxin; Fu, Zhigang; Guan, Yang; Li, Gang; Lin, Ling

    2017-03-01

    Discrimination of human and nonhuman blood is crucial for import-export ports and inspection and quarantine departments. Current methods are usually destructive, complicated and time-consuming. We had previously demonstrated that visible diffuse reflectance spectroscopy combining PLS-DA method can successfully realize human blood discrimination. In that research, the spectra were measured with the fiber probe under the surface of blood samples. However, open sampling may pollute the blood samples. Virulence factors in blood samples can also endanger inspectors. In this paper, we explored the classification effect with the blood samples measured in the original containers-vacuum blood vessel. Furthermore, we studied the impact of different conditions of blood samples, such as coagulation and hemolysis, on the prediction ability of the discrimination model. The calibration model built with blood samples in different conditions displayed a satisfactory prediction result. This research demonstrated that visible and near-infrared diffuse reflectance spectroscopy method was potential for noncontact discrimination of human blood.

  17. Facial Affect Recognition Using Regularized Discriminant Analysis-Based Algorithms

    Directory of Open Access Journals (Sweden)

    Cheng-Yuan Shih

    2010-01-01

    Full Text Available This paper presents a novel and effective method for facial expression recognition including happiness, disgust, fear, anger, sadness, surprise, and neutral state. The proposed method utilizes a regularized discriminant analysis-based boosting algorithm (RDAB with effective Gabor features to recognize the facial expressions. Entropy criterion is applied to select the effective Gabor feature which is a subset of informative and nonredundant Gabor features. The proposed RDAB algorithm uses RDA as a learner in the boosting algorithm. The RDA combines strengths of linear discriminant analysis (LDA and quadratic discriminant analysis (QDA. It solves the small sample size and ill-posed problems suffered from QDA and LDA through a regularization technique. Additionally, this study uses the particle swarm optimization (PSO algorithm to estimate optimal parameters in RDA. Experiment results demonstrate that our approach can accurately and robustly recognize facial expressions.

  18. Vibrotactile Discrimination Training Affects Brain Connectivity in Profoundly Deaf Individuals

    Science.gov (United States)

    González-Garrido, Andrés A.; Ruiz-Stovel, Vanessa D.; Gómez-Velázquez, Fabiola R.; Vélez-Pérez, Hugo; Romo-Vázquez, Rebeca; Salido-Ruiz, Ricardo A.; Espinoza-Valdez, Aurora; Campos, Luis R.

    2017-01-01

    Early auditory deprivation has serious neurodevelopmental and cognitive repercussions largely derived from impoverished and delayed language acquisition. These conditions may be associated with early changes in brain connectivity. Vibrotactile stimulation is a sensory substitution method that allows perception and discrimination of sound, and even speech. To clarify the efficacy of this approach, a vibrotactile oddball task with 700 and 900 Hz pure-tones as stimuli [counterbalanced as target (T: 20% of the total) and non-target (NT: 80%)] with simultaneous EEG recording was performed by 14 profoundly deaf and 14 normal-hearing (NH) subjects, before and after a short training period (five 1-h sessions; in 2.5–3 weeks). A small device worn on the right index finger delivered sound-wave stimuli. The training included discrimination of pure tone frequency and duration, and more complex natural sounds. A significant P300 amplitude increase and behavioral improvement was observed in both deaf and normal subjects, with no between group differences. However, a P3 with larger scalp distribution over parietal cortical areas and lateralized to the right was observed in the profoundly deaf. A graph theory analysis showed that brief training significantly increased fronto-central brain connectivity in deaf subjects, but not in NH subjects. Together, ERP tools and graph methods depicted the different functional brain dynamic in deaf and NH individuals, underlying the temporary engagement of the cognitive resources demanded by the task. Our findings showed that the index-fingertip somatosensory mechanoreceptors can discriminate sounds. Further studies are necessary to clarify brain connectivity dynamics associated with the performance of vibrotactile language-related discrimination tasks and the effect of lengthier training programs. PMID:28220063

  19. The Turner Syndrome: Cognitive Deficits, Affective Discrimination, and Behavior Problems.

    Science.gov (United States)

    McCauley, Elizabeth; And Others

    1987-01-01

    The study attemped to link cognitive and social problems seen in girls with Turner syndrome by assessing the girls' ability to process affective cues. Seventeen 9- to 17-year-old girls diagnosed with Turner syndrome were compared to a matched control group on a task which required interpretation of affective intention from facial expression.…

  20. Hyperlipidemic diet causes loss of olfactory sensory neurons, reduces olfactory discrimination, and disrupts odor-reversal learning.

    Science.gov (United States)

    Thiebaud, Nicolas; Johnson, Melissa C; Butler, Jessica L; Bell, Genevieve A; Ferguson, Kassandra L; Fadool, Andrew R; Fadool, James C; Gale, Alana M; Gale, David S; Fadool, Debra A

    2014-05-14

    Currently, 65% of Americans are overweight, which leads to well-supported cardiovascular and cognitive declines. Little, however, is known concerning obesity's impact on sensory systems. Because olfaction is linked with ingestive behavior to guide food choice, its potential dysfunction during obesity could evoke a positive feedback loop to perpetuate poor ingestive behaviors. To determine the effect of chronic energy imbalance and reveal any structural or functional changes associated with obesity, we induced long-term, diet-induced obesity by challenging mice to high-fat diets: (1) in an obesity-prone (C57BL/6J) and obesity-resistant (Kv1.3(-/-)) line of mice, and compared this with (2) late-onset, genetic-induced obesity in MC4R(-/-) mice in which diabetes secondarily precipitates after disruption of the hypothalamic axis. We report marked loss of olfactory sensory neurons and their axonal projections after exposure to a fatty diet, with a concomitant reduction in electro-olfactogram amplitude. Loss of olfactory neurons and associated circuitry is linked to changes in neuronal proliferation and normal apoptotic cycles. Using a computer-controlled, liquid-based olfactometer, mice maintained on fatty diets learn reward-reinforced behaviors more slowly, have deficits in reversal learning demonstrating behavioral inflexibility, and exhibit reduced olfactory discrimination. When obese mice are removed from their high-fat diet to regain normal body weight and fasting glucose, olfactory dysfunctions are retained. We conclude that chronic energy imbalance therefore presents long-lasting structural and functional changes in the operation of the sensory system designed to encode external and internal chemical information and leads to altered olfactory- and reward-driven behaviors.

  1. Molecularly Imprinted Filtering Adsorbents for Odor Sensing

    Directory of Open Access Journals (Sweden)

    Sho Shinohara

    2016-11-01

    Full Text Available Versatile odor sensors that can discriminate among huge numbers of environmental odorants are desired in many fields, including robotics, environmental monitoring, and food production. However, odor sensors comparable to an animal’s nose have not yet been developed. An animal’s olfactory system recognizes odor clusters with specific molecular properties and uses this combinatorial information in odor discrimination. This suggests that measurement and clustering of odor molecular properties (e.g., polarity, size using an artificial sensor is a promising approach to odor sensing. Here, adsorbents composed of composite materials with molecular recognition properties were developed for odor sensing. The selectivity of the sensor depends on the adsorbent materials, so specific polymeric materials with particular solubility parameters were chosen to adsorb odorants with various properties. The adsorption properties of the adsorbents could be modified by mixing adsorbent materials. Moreover, a novel molecularly imprinted filtering adsorbent (MIFA, composed of an adsorbent substrate covered with a molecularly imprinted polymer (MIP layer, was developed to improve the odor molecular recognition ability. The combination of the adsorbent and MIP layer provided a higher specificity toward target molecules. The MIFA thus provides a useful technique for the design and control of adsorbents with adsorption properties specific to particular odor molecules.

  2. Primary somatosensory cortex discriminates affective significance in social touch

    NARCIS (Netherlands)

    Gazzola, Valeria; Spezio, Michael L.; Etzel, Joset A.; Castelli, Fulvia; Adolphs, Ralph; Keysers, Christian

    2012-01-01

    Another person's caress is one of the most powerful of all emotional social signals. How much the primary somatosensory cortices (SIs) participate in processing the pleasantness of such social touch remains unclear. Although ample empirical evidence supports the role of the insula in affective proce

  3. Olfactory Sensitivity for Six Predator Odorants in CD-1 Mice, Human Subjects, and Spider Monkeys

    Science.gov (United States)

    Sarrafchi, Amir; Odhammer, Anna M. E.; Hernandez Salazar, Laura Teresa; Laska, Matthias

    2013-01-01

    Using a conditioning paradigm, we assessed the olfactory sensitivity of six CD-1 mice (Mus musculus) for six sulfur-containing odorants known to be components of the odors of natural predators of the mouse. With all six odorants, the mice discriminated concentrations <0.1 ppm (parts per million) from the solvent, and with five of the six odorants the best-scoring animals were even able to detect concentrations <1 ppt (parts per trillion). Four female spider monkeys (Ateles geoffroyi) and twelve human subjects (Homo sapiens) tested in parallel were found to detect the same six odorants at concentrations <0.01 ppm, and with four of the six odorants the best-scoring animals and subjects even detected concentrations <10 ppt. With all three species, the threshold values obtained here are generally lower than (or in the lower range of) those reported for other chemical classes tested previously, suggesting that sulfur-containing odorants may play a special role in olfaction. Across-species comparisons showed that the mice were significantly more sensitive than the human subjects and the spider monkeys with four of the six predator odorants. However, the human subjects were significantly more sensitive than the mice with the remaining two odorants. Human subjects and spider monkeys significantly differed in their sensitivity with only two of the six odorants. These comparisons lend further support to the notion that the number of functional olfactory receptor genes or the relative or absolute size of the olfactory bulbs are poor predictors of a species’ olfactory sensitivity. Analysis of odor structure–activity relationships showed that in both mice and human subjects the type of alkyl rest attached to a thietane and the type of oxygen moiety attached to a thiol significantly affected olfactory sensitivity. PMID:24278296

  4. Normalized neural representations of natural odors

    CERN Document Server

    Zwicker, David

    2016-01-01

    The olfactory system removes correlations in natural odors using a network of inhibitory neurons in the olfactory bulb. It has been proposed that this network integrates the response from all olfactory receptors and inhibits them equally. However, how such global inhibition influences the neural representations of odors is unclear. Here, we study a simple statistical model of this situation, which leads to concentration-invariant, sparse representations of the odor composition. We show that the inhibition strength can be tuned to obtain sparse representations that are still useful to discriminate odors that vary in relative concentration, size, and composition. The model reveals two generic consequences of global inhibition: (i) odors with many molecular species are more difficult to discriminate and (ii) receptor arrays with heterogeneous sensitivities perform badly. Our work can thus help to understand how global inhibition shapes normalized odor representations for further processing in the brain.

  5. ALE meta-analysis reveals dissociable networks for affective and discriminative aspects of touch.

    Science.gov (United States)

    Morrison, India

    2016-04-01

    Emotionally-laden tactile stimulation-such as a caress on the skin or the feel of velvet-may represent a functionally distinct domain of touch, underpinned by specific cortical pathways. In order to determine whether, and to what extent, cortical functional neuroanatomy supports a distinction between affective and discriminative touch, an activation likelihood estimate (ALE) meta-analysis was performed. This meta-analysis statistically mapped reported functional magnetic resonance imaging (fMRI) activations from 17 published affective touch studies in which tactile stimulation was associated with positive subjective evaluation (n = 291, 34 experimental contrasts). A separate ALE meta-analysis mapped regions most likely to be activated by tactile stimulation during detection and discrimination tasks (n = 1,075, 91 experimental contrasts). These meta-analyses revealed dissociable regions for affective and discriminative touch, with posterior insula (PI) more likely to be activated for affective touch, and primary somatosensory cortices (SI) more likely to be activated for discriminative touch. Secondary somatosensory cortex had a high likelihood of engagement by both affective and discriminative touch. Further, meta-analytic connectivity (MCAM) analyses investigated network-level co-activation likelihoods independent of task or stimulus, across a range of domains and paradigms. Affective-related PI and discriminative-related SI regions co-activated with different networks, implicated in dissociable functions, but sharing somatosensory co-activations. Taken together, these meta-analytic findings suggest that affective and discriminative touch are dissociable both on the regional and network levels. However, their degree of shared activation likelihood in somatosensory cortices indicates that this dissociation reflects functional biases within tactile processing networks, rather than functionally and anatomically distinct pathways.

  6. Odors enhance visual attention to congruent objects.

    Science.gov (United States)

    Seo, Han-Seok; Roidl, Ernst; Müller, Friedrich; Negoias, Simona

    2010-06-01

    Although it is well known that visual stimuli affect olfactory performance, little is known about the reverse case: the influence of odor on visual performance. This study aimed to determine whether odors can enhance attention towards visually presented objects congruent with the odors. Sixty healthy participants were presented with four odors (orange, lavender, coffee, and liquorice) before and during the presentation of photographic slides containing one congruent and three incongruent objects with the presented odors. The participants' visual attention was assessed as the total number and time of eye fixations by using an eye tracking system. When the participants smelled an odor, they looked more frequently and longer at a corresponding object as compared to the odorless condition. In conclusion, our findings demonstrate for the first time an olfactory priming effect on visual selective attention: odor can increase attention towards a congruent visual object as compared to a non-odor condition.

  7. Optimization of the Odor Microclimate

    Directory of Open Access Journals (Sweden)

    M. V. Jokl

    2002-01-01

    Full Text Available The odor microclimate is formed by gaseous airborne components perceived either as an unpleasant smell or as a pleasant smell. Smells enter the building interior partly from outdoors (exhaust fumes - flower fragrance and partly from indoors (building materials, smoking cigarettes - cosmetics, dishes. They affect the human organism through the olfactory center which is connected to the part of brain that is responsible for controlling people's emotions and sexual feelings: smells therefore participate to a high level in mood formation. Sweet smells have a positive impact on human feelings and on human performance. Criteria for odor microclimate appraisal are presented together with ways of improving the odor microclimate (by stopping odors from spreading within a building, ventilation, air filtration, odor removal by plants, deodorization, etc., including so-called AIR DESIGN.

  8. Receptor arrays optimized for natural odor statistics

    CERN Document Server

    Zwicker, David; Brenner, Michael P

    2016-01-01

    Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information-theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction and it also suggests ways to improve artificial sensor...

  9. Receptor arrays optimized for natural odor statistics.

    Science.gov (United States)

    Zwicker, David; Murugan, Arvind; Brenner, Michael P

    2016-05-17

    Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) Each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction, and it also suggests ways to improve artificial sensor arrays.

  10. Odor Beater

    Institute of Scientific and Technical Information of China (English)

    杨树仁

    1995-01-01

    Ever wonder why dirty socks and rotten eggs smell bad? It’s the mercaptans—hydrogen sulfide molecules.With today’s best technology, carbon filters, you can remove five percent of these molecules. But soon 95 percent of the odor will be eliminated by a catalytic deodorizer, accidentally discovered by scientists at Niopik, a Russian laser dye laboratory. The catalyst is phtalocyanine, a compound that causes hydrogen sulfides

  11. Disability in people affected by leprosy: the role of impairment, activity, social participation, stigma and discrimination

    OpenAIRE

    Wilder-Smith, Annelies; Wim H Van Brakel; Sihombing, Benyamin; Djarir, Hernani; Beise, Kerstin; Kusumawardhani, Laksmi; Yulihane, Rita; Kurniasari, Indra; Kasim, Muhammad; Kesumaningsih, Kadek I.

    2012-01-01

    Background: Leprosy-related disability is a challenge to public health, and social and rehabilitation services in endemic countries. Disability is more than a mere physical dysfunction, and includes activity limitations, stigma, discrimination, and social participation restrictions. We assessed the extent of disability and its determinants among persons with leprosy-related disabilities after release from multi drug treatment. Methods: We conducted a survey on disability among persons affecte...

  12. The Impact of Odors

    OpenAIRE

    M. V. Jokl

    2002-01-01

    The odor microclimate is formed by gaseous airborne components perceived either as an unpleasant smell or as a pleasant smell. Smells enter the building interior partly from outdoors (exhaust fumes - flower fragrance) and partly from indoors (building materials, smoking cigarettes - cosmetics, dishes). They affect the human organism through the olfactory center which is connected to the part of brain that is responsible for controlling people’s emotions and sexual feelings: smells therefore p...

  13. Odor Mortis

    Energy Technology Data Exchange (ETDEWEB)

    Vass, Arpad Alexander [ORNL

    2012-01-01

    This study, the third of a series on the odor signature of human decomposition, reports on the intermittent nature of chemical evolution from decomposing human remains, and focuses primarily on headspace analysis from soil associated with older human remains (10-60+ years) from different environments around the globe. Fifty grams of soil were collected in 40mL glass vials with polypropylene sealed lids from soil above known or suspected graves and from subsurface chemical plumes associated with human decompositional events. One hundred eighty six separate samples were analyzed using gas chromatography-mass spectrometry (GC-MS). After comparison to relevant soil controls, approximately fifty volatile chemical compounds were identified as being associated with human remains. This manuscript reports these findings and identifies when and where they are most likely to be detected showing an overall decrease in cyclic and halogenated compounds and an increase in aldehydes and alkanes as time progresses. This research identifies the 'odor signatures' unique to the decomposition of human remains with projected ramifications on cadaver dog training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  14. Rapid encoding and perception of novel odors in the rat.

    Directory of Open Access Journals (Sweden)

    Daniel W Wesson

    2008-04-01

    Full Text Available To gain insight into which parameters of neural activity are important in shaping the perception of odors, we combined a behavioral measure of odor perception with optical imaging of odor representations at the level of receptor neuron input to the rat olfactory bulb. Instead of the typical test of an animal's ability to discriminate two familiar odorants by exhibiting an operant response, we used a spontaneously expressed response to a novel odorant-exploratory sniffing-as a measure of odor perception. This assay allowed us to measure the speed with which rats perform spontaneous odor discriminations. With this paradigm, rats discriminated and began responding to a novel odorant in as little as 140 ms. This time is comparable to that measured in earlier studies using operant behavioral readouts after extensive training. In a subset of these trials, we simultaneously imaged receptor neuron input to the dorsal olfactory bulb with near-millisecond temporal resolution as the animal sampled and then responded to the novel odorant. The imaging data revealed that the bulk of the discrimination time can be attributed to the peripheral events underlying odorant detection: receptor input arrives at the olfactory bulb 100-150 ms after inhalation begins, leaving only 50-100 ms for central processing and response initiation. In most trials, odor discrimination had occurred even before the initial barrage of receptor neuron firing had ceased and before spatial maps of activity across glomeruli had fully developed. These results suggest a coding strategy in which the earliest-activated glomeruli play a major role in the initial perception of odor quality, and place constraints on coding and processing schemes based on simple changes in spike rate.

  15. Fabrication of Odor Sensor Using Peptide

    Science.gov (United States)

    Hotokebuchi, Yuta; Hayashi, Kenshi; Toko, Kiyoshi; Chen, Ronggang; Ikezaki, Hidekazu

    We report fabrication of an odor sensor using peptides. Peptides were designed to acquire the specific reception for a target odor molecule. Au surface of the sensor electrode was coated by the designed peptide using the method of self assembled monolayers (SAMs). Functionalized Au surfaces by the peptides were confirmed by ellipsometry and cyclic voltammetry. The odorants of vanillin, phenethyl alcohol and hexanol were discriminated by QCM sensor with the peptide surface. Moreover, we verified specific interaction between amino acid (Trp) and vanillin by fluorescence assay.

  16. How discrimination and stress affects self-esteem among Dominican immigrant women: an exploratory study.

    Science.gov (United States)

    Panchanadeswaran, Subadra; Dawson, Beverly Araujo

    2011-01-01

    Understanding the factors that contribute to the health disparities among racial and ethnic minorities in the United States is very important given the growing Latina population. Although researchers have investigated the health and mental health status among Latinas, the relationship between mental health and self-esteem has not been given a lot of attention. Given that self-esteem is a proxy for mental health status, investigations exploring the factors that can negatively affect self-esteem are needed. Therefore, the current study examined the influence of discrimination and stress on self-esteem among Dominican immigrant women. A cross-sectional study was undertaken among 235 immigrant Dominican women in New York City. Women (age 18-49 years) and in the United States for fewer than 20 years were more likely to report experiencing discrimination compared to women older than age 50 years and in the United States for more than 20 years. After controlling for age, time in the United States, educational level, and income, high levels of discrimination (-0.09, p stress (-0.69, p self-esteem. Interventions with Latino/a populations, especially women, need to acknowledge their individual evaluations of the discriminatory and stressful experiences that negatively influence their self-esteem and subsequently their mental health status.

  17. Odor Signals of Immune Activation and CNS Inflammation

    Science.gov (United States)

    2014-12-01

    injury. Using an animal model, we first trained biosensor mice to distinguish between urine odors from lipopolysaccharide-treated and control mice...Lipopolysaccharide (LPS) is a general elicitor of inflammation. Trained biosensors could distinguish between the odors of LPS-treated and control...injury (LFPI) or surgery without brain injury were employed as urine donors. Biosensors trained to discriminate LPS-treated mouse odors from

  18. Objective Display and Discrimination of Floral Odors from Amorphophallus titanum, Bloomed on Different Dates and at Different Locations, Using an Electronic Nose

    Directory of Open Access Journals (Sweden)

    Keiichi Ikeda

    2012-02-01

    Full Text Available As olfactory perceptions vary from person to person, it is difficult to describe smells objectively. In contrast, electronic noses also detect smells with their sensors, but in addition describe those using electronic signals. Here we showed a virtual connection method between a human nose perceptions and electronic nose responses with the smell of standard gases. In this method, Amorphophallus titanum flowers, which emit a strong carrion smell, could objectively be described using an electronic nose, in a way resembling the skill of sommeliers. We could describe the flower smell to be close to that of a mixture of methyl mercaptan and propionic acid, by calculation of the dilution index from electronic resistances. In other words, the smell resembled that of “decayed cabbage, garlic and pungent sour” with possible descriptors. Additionally, we compared the smells of flowers which bloomed on different dates and at different locations and showed the similarity of odor intensities visually, in standard gas categories. We anticipate our assay to be a starting point for a perceptive connection between our noses and electronic noses.

  19. Recognition of Bread Key Odorants by Using Polymer Coated QCMs

    Science.gov (United States)

    Nakai, Takashi; Kouno, Shinji; Hiruma, Naoya; Shuzo, Masaki; Delaunay, Jean-Jacques; Yamada, Ichiro

    Polyisobutylene (PIB) polymer and methylphenylsiloxane (25%) diphenylsiloxane (75%) copolymer (OV25) were coated on Quartz Crystal Microbalance (QCM) sensors and used in recognition of bread key odorants. Representative compounds of key roasty odorants of bread were taken as 3-acetylpyridine and benzaldehyde, and representative key fatty odorants were hexanal and (E)-2-nonenal. Both OV25- and PIB-coated QCM fabricated sensors could detect concentration as low as 0.9 ppm of 3-acetylpyridine and 1.2 ppm of (E)-2-nonenal. The sensitivity to 3-acetylpyridine of the OV25-coated QCM was about 1000 times higher than that of ethanol, the major interference compound in bread key odorant analysis. Further, the OV25-coated QCM response was 5-6 times and 2-3 times larger than that of the PIB-coated QCM when exposed to roasty odorants and to fatty odorants, respectively. The difference in sensitivity of the OV25- and PIB-coated QCMs we fabricated made possible to discriminate roasty from fatty odorants as was evidenced by the odor recognition map representing the frequency shifts of the OV25-coated QCM against the frequency shift of the PIB-coated QCM. In conclusion, we found that the combination of an OV25-coated QCM and a PIB-coated QCM was successful in discriminating roasty odorants from fatty odorants at the ppm level.

  20. Inseparability of Go and Stop in Inhibitory Control: Go Stimulus Discriminability Affects Stopping Behavior

    Directory of Open Access Journals (Sweden)

    Ning eMa

    2016-03-01

    Full Text Available Inhibitory control, the ability to stop or modify preplanned actions under changing task conditions, is an important component of cognitive functions. Two lines of models of inhibitory control have previously been proposed for human response in the classical stop-signal task, in which subjects must inhibit a default go response upon presentation of an infrequent stop signal: (1 the race model, which posits two independent go and stop processes that race to determine the behavioral outcome, go or stop; and (2 an optimal decision-making model, which posits that observers decides whether and when to go based on continually (Bayesian updated information about both the go and stop stimuli. In this work, we probe the relationship between go and stop processing by explicitly manipulating the discrimination difficulty of the go stimulus. While the race model assumes the go and stop processes are independent, and therefore go stimulus discriminability should not affect the stop stimulus processing, we simulate the optimal model to show that it predicts harder go discrimination results in a longer go reaction time (RT, a lower stop error rate, as well as a faster stop-signal RT. We then present novel behavioral data that validate these model predictions. The results thus favor a fundamentally inseparable account of go and stop processing, in a manner consistent with the optimal model, and contradicting the independence assumption of the race model. More broadly, our findings contribute to the growing evidence that the computations underlying inhibitory control are systematically modulated by cognitive influences in a Bayes-optimal manner, thus opening new avenues for interpreting neural responses underlying inhibitory control.

  1. Inseparability of Go and Stop in Inhibitory Control: Go Stimulus Discriminability Affects Stopping Behavior.

    Science.gov (United States)

    Ma, Ning; Yu, Angela J

    2016-01-01

    Inhibitory control, the ability to stop or modify preplanned actions under changing task conditions, is an important component of cognitive functions. Two lines of models of inhibitory control have previously been proposed for human response in the classical stop-signal task, in which subjects must inhibit a default go response upon presentation of an infrequent stop signal: (1) the race model, which posits two independent go and stop processes that race to determine the behavioral outcome, go or stop; and (2) an optimal decision-making model, which posits that observers decides whether and when to go based on continually (Bayesian) updated information about both the go and stop stimuli. In this work, we probe the relationship between go and stop processing by explicitly manipulating the discrimination difficulty of the go stimulus. While the race model assumes the go and stop processes are independent, and therefore go stimulus discriminability should not affect the stop stimulus processing, we simulate the optimal model to show that it predicts harder go discrimination should result in longer go reaction time (RT), lower stop error rate, as well as faster stop-signal RT. We then present novel behavioral data that validate these model predictions. The results thus favor a fundamentally inseparable account of go and stop processing, in a manner consistent with the optimal model, and contradicting the independence assumption of the race model. More broadly, our findings contribute to the growing evidence that the computations underlying inhibitory control are systematically modulated by cognitive influences in a Bayes-optimal manner, thus opening new avenues for interpreting neural responses underlying inhibitory control.

  2. Orthogonal Design Study on Factors Affecting the Determination of Common Odors in Water Samples by Headspace Solid-Phase Microextraction Coupled to GC/MS

    OpenAIRE

    Shifu Peng; Zhen Ding; Weiwen Xia; Hao Zheng; Yuting Xia; Xiaodong Chen

    2013-01-01

    Geosmin and 2-MIB are responsible for the majority of earthy and musty events related to the drinking water. These two odorants have extremely low odor threshold concentrations at ng L−1 level in the water, so a simple and sensitive method for the analysis of such trace levels was developed by headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry. In this study, the orthogonal experiment design L32 (49) was applied to arrange and optimize experimental condition...

  3. No effect of ambient odor on the affective appraisal of a desktop virtual environment with signs of disorder

    NARCIS (Netherlands)

    Toet, A.; Schaik, M.G. van; Theunissen, N.C.M.

    2013-01-01

    Background : Desktop virtual environments (VEs) are increasingly deployed to study the effects of environmental qualities and interventions on human behavior and safety related concerns in built environments. For these applications it is essential that users appraise the affective qualities of the V

  4. Noradrenergic Control of Odor Recognition in a Nonassociative Olfactory Learning Task in the Mouse

    Science.gov (United States)

    Veyrac, Alexandra; Nguyen, Veronique; Marien, Marc; Didier, Anne; Jourdan, Francois

    2007-01-01

    The present study examined the influence of pharmacological modulations of the locus coeruleus noradrenergic system on odor recognition in the mouse. Mice exposed to a nonrewarded olfactory stimulation (training) were able to memorize this odor and to discriminate it from a new odor in a recall test performed 15 min later. At longer delays (30 or…

  5. Neural sensitivity to odorants in deprived and normal olfactory bulbs.

    Directory of Open Access Journals (Sweden)

    Francisco B Rodríguez

    Full Text Available Early olfactory deprivation in rodents is accompanied by an homeostatic regulation of the synaptic connectivity in the olfactory bulb (OB. However, its consequences in the neural sensitivity and discrimination have not been elucidated. We compared the odorant sensitivity and discrimination in early sensory deprived and normal OBs in anesthetized rats. We show that the deprived OB exhibits an increased sensitivity to different odorants when compared to the normal OB. Our results indicate that early olfactory stimulation enhances discriminability of the olfactory stimuli. We found that deprived olfactory bulbs adjusts the overall excitatory and inhibitory mitral cells (MCs responses to odorants but the receptive fields become wider than in the normal olfactory bulbs. Taken together, these results suggest that an early natural sensory stimulation sharpens the receptor fields resulting in a larger discrimination capability. These results are consistent with previous evidence that a varied experience with odorants modulates the OB's synaptic connections and increases MCs selectivity.

  6. What are the odds? How demographic similarity affects the prevalence of perceived employment discrimination.

    Science.gov (United States)

    Avery, Derek R; McKay, Patrick F; Wilson, David C

    2008-03-01

    Because research is needed to identify the conditions that facilitate or impede the prevalence of perceived workplace discrimination, the authors examined the effects of demographics and demographic similarity on the prevalence of sex- and race/ethnicity-based perceived workplace discrimination. Results from a national survey of 763 full-time, United States employees show perceived sex-based discrimination at work was more prevalent among female than male employees, and perceived race-based discrimination at work was more prevalent among Black and Hispanic than White employees. Additionally, perceived racial/ethnic discrimination was less prevalent among those with same-race/ethnicity supervisors. The effect of employee-coworker sex similarity on perceived sex discrimination was significant only for women, and the effects of supervisor-subordinate racial similarity on the prevalence of perceived racial discrimination varied between Black and White respondents, depending on employee-residential-community racial similarity.

  7. Disability in people affected by leprosy: the role of impairment, activity, social participation, stigma and discrimination

    Directory of Open Access Journals (Sweden)

    Wim H. van Brakel

    2012-07-01

    Full Text Available Background: Leprosy-related disability is a challenge to public health, and social and rehabilitation services in endemic countries. Disability is more than a mere physical dysfunction, and includes activity limitations, stigma, discrimination, and social participation restrictions. We assessed the extent of disability and its determinants among persons with leprosy-related disabilities after release from multi drug treatment. Methods: We conducted a survey on disability among persons affected by leprosy in Indonesia, using a Rapid Disability Appraisal toolkit based on the International Classification of Functioning, Disability and Health. The toolkit included the Screening of Activity Limitation and Safety Awareness (SALSA scale, Participation Scale, Jacoby Stigma Scale (anticipated stigma, Explanatory Model Interview Catalogue (EMIC stigma scale and Discrimination assessment. Community members were interviewed using a community version of the stigma scale. Multivariate linear regression was done to identify factors associated with social participation. Results: Overall 1,358 persons with leprosy-related disability (PLD and 931 community members were included. Seventy-seven percent of PLD had physical impairments. Impairment status deteriorated significantly after release from treatment (from 59% to 77%. Around 60% of people reported activity limitations and participation restrictions and 36% anticipated stigma. As for participation restrictions and stigma, shame, problems related to marriage and difficulties in employment were the most frequently reported problems. Major determinants of participation were severity of impairment and level of education, activity and stigma. Reported severity of community stigma correlated with severity of participation restrictions in the same districts. Discussion: The majority of respondents reported problems in all components of disability. The reported physical impairment after release from treatment

  8. Avian influenza infection alters fecal odor in mallards.

    Directory of Open Access Journals (Sweden)

    Bruce A Kimball

    Full Text Available Changes in body odor are known to be a consequence of many diseases. Much of the published work on disease-related and body odor changes has involved parasites and certain cancers. Much less studied have been viral diseases, possibly due to an absence of good animal model systems. Here we studied possible alteration of fecal odors in animals infected with avian influenza viruses (AIV. In a behavioral study, inbred C57BL/6 mice were trained in a standard Y-maze to discriminate odors emanating from feces collected from mallard ducks (Anas platyrhynchos infected with low-pathogenic avian influenza virus compared to fecal odors from non-infected controls. Mice could discriminate odors from non-infected compared to infected individual ducks on the basis of fecal odors when feces from post-infection periods were paired with feces from pre-infection periods. Prompted by this indication of odor change, fecal samples were subjected to dynamic headspace and solvent extraction analyses employing gas chromatography/mass spectrometry to identify chemical markers indicative of AIV infection. Chemical analyses indicated that AIV infection was associated with a marked increase of acetoin (3-hydroxy-2-butanone in feces. These experiments demonstrate that information regarding viral infection exists via volatile metabolites present in feces. Further, they suggest that odor changes following virus infection could play a role in regulating behavior of conspecifics exposed to infected individuals.

  9. Odor annoyance of environmental chemicals: sensory and cognitive influences.

    Science.gov (United States)

    van Thriel, Christoph; Kiesswetter, Ernst; Schäper, Michael; Juran, Stephanie A; Blaszkewicz, Meinolf; Kleinbeck, Stefan

    2008-01-01

    In low concentrations, environment pollutants like volatile organic compounds (VOCs) may be perceived via olfaction. Modulators of odor-mediated health effects include age, gender, or personality traits related to chemical sensitivity. Severe multi-organ symptoms in response to odors also characterize a syndrome referred to as idiopathic environmental intolerance (IEI). One prominent feature of IEI is self-reported odor hypersensitivity that is usually not accompanied by enhanced olfactory functioning. The impact of interindividual differences in olfactory functioning on chemosensory perceptions is sparsely investigated, and therefore this study addressed the influences of different types of modulators, including olfactory functioning. In a psychophysical scaling experiment, an age-stratified sample of 44 males and females was examined. After controlled application of nine concentrations of six chemicals by flow-olfactometry, the participants rated four olfactory and nine trigeminal perceptions. Weak effects were found for gender and age, as well as some modulating effects of self-reported chemical sensitivity and odor discrimination ability. For chemical sensitivity, the results were as expected: Subjects with higher sensitivity reported stronger perceptions. The individual odor threshold (n-butanol) exerted no influence on the subjects' ratings of olfactory and trigeminal perceptions. Surprisingly, above-average odor discrimination ability was associated with lower ratings of odor intensity and nausea. This particular aspect of olfactory functioning might be a reflection of a more objective odor evaluation model buffering emotional responses to environmental odors.

  10. Affective Reactions to Difference and their Impact on Discrimination and Self-Disclosure at Work: A Social Identity Perspective

    Directory of Open Access Journals (Sweden)

    Maria Kakarika

    2012-08-01

    Full Text Available Based on Social Identity Theory and related concepts, the present paper argues that a negative affective state is caused by dissimilarity at the workplace, which in turn influences discrimination and self-disclosure. Based on a review of the literature, it develops propositions about the positive effects of surface- and deep-level dissimilarity on this affective state and perceived interpersonal discrimination at work, as well as on the decision to self-disclose personal information to peers. Self-disclosure is further linked to perceptions of discrimination in two opposing ways. An individual’s perceived degree of difference from others on demographic and underlying characteristics serve as moderators of the proposed relationships, strengthening the effects of actual dissimilarity on feelings. The paper concludes by examining implications and contributions of the proposed theoretical framework to the diversity literature.

  11. Olfactory repeated discrimination reversal in rats: effects of chlordiazepoxide, dizocilpine, and morphine.

    Science.gov (United States)

    Galizio, Mark; Miller, Laurence; Ferguson, Adam; McKinney, Patrick; Pitts, Raymond C

    2006-10-01

    Effects of a benzodiazepine (chlordiazepoxide), an N-methyl-D-aspartate receptor antagonist (dizocilpine), and an opiate agonist (morphine) were studied with a procedure designed to assess effects of drugs and other manipulations on nonspatial learning in rats. In each session, rats were exposed to 2 different 2-choice odor-discrimination problems with food reinforcement for correct responses. One problem (performance discrimination) remained the same throughout the study. That is, 1 odor was always correct (S+) and the other was never correct (S-). For the other problem (reversal discrimination), stimuli changed every session. Six different odors were used to program the reversal discrimination; on any given session, S+ was a stimulus that had served as S- the last time it had appeared, S- was a stimulus that had been S+ on its last appearance. Thus, in each session, learning a discrimination reversal could be studied along with the performance of a comparable, but previously learned, discrimination. Chlordiazepoxide interfered with reversal learning at doses that had no effect on the performance discrimination. Morphine and dizocilpine also impaired reversal learning but only at doses that also affected performance of the well-learned performance discrimination.

  12. The Impact of Odors

    Directory of Open Access Journals (Sweden)

    M. V. Jokl

    2002-01-01

    Full Text Available The odor microclimate is formed by gaseous airborne components perceived either as an unpleasant smell or as a pleasant smell. Smells enter the building interior partly from outdoors (exhaust fumes - flower fragrance and partly from indoors (building materials, smoking cigarettes - cosmetics, dishes. They affect the human organism through the olfactory center which is connected to the part of brain that is responsible for controlling people’s emotions and sexual feelings: smells therefore participate to a high level in mood formation. The sense of smell diminishes slowly in people over the age of 60, but all female age categories have a better sense of smell than males. Smell is extremely sensitive, e.g., during pregnancy, or if an illness is coming. Bad smells cause a decrease in human performance, loss of concentration, and loss of taste. Sweet smells have a positive impact on human feelings and on human performance. Criteria for odor microclimate appraisal are presented (concentration limits of CO2 , TVOC, plf, decipol, decicarbdiox, decitvoc.

  13. Searching for Housing as a Battered Woman: Does Discrimination Affect Reported Availability of a Rental Unit?

    Science.gov (United States)

    Barata, Paula C.; Stewart, Donna E.

    2010-01-01

    Individual battered women have reported experiencing housing discrimination, but the extent of this problem has not been examined. This research used two experiments and a survey to determine if landlord discrimination could keep women from accessing rental units. In Study 1, a confederate asked 181 landlords about the availability of a rental…

  14. Does the experience of discrimination affect health? A cross-sectional study of Korean elders.

    Science.gov (United States)

    Chun, Heeran; Kang, Minah; Cho, Sung-il; Jung-Choi, Kyunghee; Jang, Soong-Nang; Khang, Young-Ho

    2015-03-01

    This study was conducted among 992 Koreans aged 60 to 89 to examine the effects of perceived discrimination on the health of an ethnically homogenous older population. Perceived discrimination was measured with a self-report instrument. Health outcomes included depressive symptoms, poor self-rated health, and chronic diseases. Of the elderly Koreans surveyed, 23.5% reported having experienced discrimination based on education, age, birthplace, birth order, or gender. Among women, 23.1% reported experiencing gender discrimination, compared to 0.9% among men. Men reported education and age discrimination most frequently-9.4% and 7.7%, respectively. Those who reported experiencing any discrimination were 2.19 times more likely to report depressive symptoms (95% confidence interval = 1.50-3.22) and 1.40 times more likely to report poor self-rated health (95% confidence interval = 1.02-1.93). The health effects of educational discrimination appeared most prominent. This study supports the positive associations between perceived discrimination and poorer health, particularly mental health, in later life.

  15. Sensory-specific appetite is affected by actively smelled food odors and remains stable over time in normal-wight women

    NARCIS (Netherlands)

    Ramaekers, M.G.; Boesveldt, S.; Lakemond, C.M.M.; Boekel, van M.A.J.S.; Luning, P.A.

    2014-01-01

    Understanding overconsumption starts with knowledge of how separate factors influence our eating behavior. Food cues such as food odors are known for their effect on general appetite and sensory-specific appetite (SSA). Active sniffing rather than passive exposure may induce satiation over time. The

  16. Depletion of Serotonin Selectively Impairs Short-Term Memory without Affecting Long-Term Memory in Odor Learning in the Terrestrial Slug "Limax Valentianus"

    Science.gov (United States)

    Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi; Shirahata, Takaaki; Tsunoda, Makoto

    2006-01-01

    The terrestrial slug "Limax" is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC…

  17. Mammalian odorant receptors: functional evolution and variation.

    Science.gov (United States)

    Jiang, Yue; Matsunami, Hiroaki

    2015-10-01

    In mammals, the perception of smell starts with the activation of odorant receptors (ORs) by volatile molecules in the environment. The mammalian OR repertoire has been subject to rapid evolution, and is highly diverse within the human population. Recent advances in the functional expression and ligand identification of ORs allow for functional analysis of OR evolution, and reveal that changes in OR protein sequences translate into high degrees of functional variations. Moreover, in several cases the functional variation of a single OR affects the perception of its cognate odor ligand, providing clues as to how an odor is coded at the receptor level.

  18. Odor Perception in Children with Autism Spectrum Disorder and its Relationship to Food Neophobia.

    Science.gov (United States)

    Luisier, Anne-Claude; Petitpierre, Genevieve; Ferdenzi, Camille; Clerc Bérod, Annick; Giboreau, Agnes; Rouby, Catherine; Bensafi, Moustafa

    2015-01-01

    Atypical sensory functioning in Autism Spectrum Disorder (ASD) has been well documented in the last decade for the visual, tactile and auditory systems, but olfaction in ASD is still understudied. The aim of the present study was to examine whether children with ASD and neuro-typically (NT) developed children differed in odor perception, at the cognitive (familiarity and identification ability), sensorimotor (olfactory exploration) and affective levels (hedonic evaluation). Because an important function of the sense of smell is its involvement in eating, from food selection to appreciation and recognition, a potential link between odor perception and food neophobia was also investigated. To these ends, 10 children between 6 and 13 years old diagnosed with ASD and 10 NT control children were tested. To compare performance, 16 stimuli were used and food neophobia was assessed by the parents on a short food neophobia scale. Results revealed that (i) significant hedonic discrimination between attractive and aversive odors was observed in NT (p = 0.005; d = 2.378) and ASD children (p = 0.042; d = 0.941), and (ii) hedonic discrimination level was negatively correlated with food neophobia scores in ASD (p = 0.007) but not NT children. In conclusion, this study offers new insights into odor perception in ASD children, highlighting a relationship between odor hedonic reactivity and eating behavior. This opens up new perspectives on both (i) the role of olfaction in the construction of eating behavior in ASD children, and (ii) the measurement and meaning of food neophobia in this population.

  19. Odor perception in children with autism spectrum disorder and its relationship to food neophobia

    Directory of Open Access Journals (Sweden)

    Anne-Claude eLuisier

    2015-12-01

    Full Text Available Atypical sensory functioning in Autism Spectrum Disorder (ASD has been well documented in the last decade for the visual, tactile and auditory systems, but olfaction in ASD is still understudied. The aim of the present study was to examine whether children with ASD and neuro-typically (NT developed children differed in odor perception, at the cognitive (familiarity and identification ability, sensorimotor (olfactory exploration and affective levels (hedonic evaluation. Because an important function of the sense of smell is its involvement in eating, from food selection to appreciation and recognition, a potential link between odor perception and food neophobia was also investigated. To these ends, 10 children between 6 and 13 years old diagnosed with ASD and 10 NT control children were tested. To compare performance, 16 stimuli were used and food neophobia was assessed by the parents on a short food neophobia scale. Results revealed that (i significant hedonic discrimination between attractive and aversive odors was observed in NT (p=0.005; d=2.378 and ASD children (p=0.042; d=0.941, and (ii hedonic discrimination level was negatively correlated with food neophobia scores in ASD (p=0.007 but not NT children. In conclusion, this study offers new insights into odor perception in ASD children, highlighting a relationship between odor hedonic reactivity and eating behavior. This opens up new perspectives on both (i the role of olfaction in the construction of eating behavior in ASD children, and (ii the measurement and meaning of food neophobia in this population.

  20. Nurse odor perception in various Japanese hospital settings

    Directory of Open Access Journals (Sweden)

    Masami Horiguchi

    2015-12-01

    Full Text Available Because unpleasant hospital odors affect the nursing environment, we investigated nurses' perceptions of the odors of various hospital settings: hospital rooms, nurse stations, and human waste disposal rooms to discard the urine, stools and diapers. A questionnaire based on the Japanese Ministry of the Environment's guidelines on odor index regulation was used to assess nurses' perceptions of odor intensity, comfort, tolerability, and description in the aforementioned settings. Questionnaires were distributed to nursing department directors at three Japanese hospitals, who then disseminated the questionnaires to nursing staff. Of the 1,151 questionnaires distributed, 496 nurses participated. Human waste disposal rooms had greater odor intensity and were perceived as more uncomfortable than the other settings. Unpleasant odors in disposal rooms, hospital rooms, and nurse stations were rated as slightly intolerable in comparison. Hospital and disposal rooms were mainly described as having a “pungent odor such as of urine and stool.” In contrast, nurse stations were described as having other unpleasant odors, such as chemical, human-body-related, or sewage-like odors. Given that nurses spend much of their time in hospital rooms and nurse stations, odor management in these two settings would likely improve nurses' working conditions at hospitals. Improving odors at nurse stations is feasible. Such improvements could have indirect effects on nurse turnover and burnout.

  1. Discrimination of conspecific sex and reproductive condition using chemical cues in axolotls ( Ambystoma mexicanum).

    Science.gov (United States)

    Park, D; McGuire, J M; Majchrzak, A L; Ziobro, J M; Eisthen, H L

    2004-05-01

    Chemosensory cues play an important role in the daily lives of salamanders, mediating foraging, conspecific recognition, and territorial advertising. We investigated the behavioral effects of conspecific whole-body odorants in axolotls, Ambystoma mexicanum, a salamander species that is fully aquatic. We found that males increased general activity when exposed to female odorants, but that activity levels in females were not affected by conspecific odorants. Although males showed no difference in courtship displays across testing conditions, females performed courtship displays only in response to male odorants. We also found that electro-olfactogram responses from the olfactory and vomeronasal epithelia were larger in response to whole-body odorants from the opposite sex than from the same sex. In males, odorants from gravid and recently spawned females evoked different electro-olfactogram responses at some locations in the olfactory and vomeronasal epithelia; in general, however, few consistent differences between the olfactory and vomeronasal epithelia were observed. Finally, post hoc analyses indicate that experience with opposite-sex conspecifics affects some behavioral and electrophysiological responses. Overall, our data indicate that chemical cues from conspecifics affect general activity and courtship behavior in axolotls, and that both the olfactory and vomeronasal systems may be involved in discriminating the sex and reproductive condition of conspecifics.

  2. Distinct memories of odor intensity and quality in Drosophila.

    Science.gov (United States)

    Masek, Pavel; Heisenberg, Martin

    2008-10-14

    Even in a simple Pavlovian memory task an animal may form several associations that can be independently assessed by the appropriate tests. Studying conditioned odor discrimination of the fruit fly Drosophila melanogaster we found that animals store quality and intensity of an odor as separate memory traces. The trace of odor intensity is short-lived, decaying in <3 h. Only the last intensity value is stored. In contrast to odor-quality memory, odor-intensity memory does not require the rutabaga-dependent cAMP signaling pathway. Flies rely on their memory of intensity in a narrow concentration range in which they can generalize intensity. Larger concentration differences they treat like different qualities. This study shows that the perceptual identity of an odor is based on at least three lines of processing in the brain: (i) a memory of odor quality, (ii) a memory of odor intensity, and (iii) a range of intensities (and qualities), in which the odor is generalized.

  3. Altered olfactory processing of stress-related body odors and artificial odors in patients with panic disorder.

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    Gloria-Beatrice Wintermann

    Full Text Available BACKGROUND: Patients with Panic Disorder (PD direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD. METHODS: A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry as well as artificial odors (peach, artificial sweat as non-fearful non-body odors. PRINCIPAL FINDINGS: The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology. CONCLUSIONS: The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear

  4. The Stigma of Obesity: Does Perceived Weight Discrimination Affect Identity and Physical Health?

    Science.gov (United States)

    Schafer, Markus H.; Ferraro, Kenneth F.

    2011-01-01

    Obesity is widely recognized as a health risk, but it also represents a disadvantaged social position. Viewing body weight within the framework of stigma and its effects on life chances, we examine how perceived weight-based discrimination influences identity and physical health. Using national survey data with a 10-year longitudinal follow-up, we…

  5. Color Discrimination Is Affected by Modulation of Luminance Noise in Pseudoisochromatic Stimuli

    Science.gov (United States)

    Cormenzana Méndez, Iñaki; Martín, Andrés; Charmichael, Teaire L.; Jacob, Mellina M.; Lacerda, Eliza M. C. B.; Gomes, Bruno D.; Fitzgerald, Malinda E. C.; Ventura, Dora F.; Silveira, Luiz C. L.; O'Donell, Beatriz M.; Souza, Givago S.

    2016-01-01

    Pseudoisochromatic stimuli have been widely used to evaluate color discrimination and to identify color vision deficits. Luminance noise is one of the stimulus parameters used to ensure that subject's response is due to their ability to discriminate target stimulus from the background based solely on the hue between the colors that compose such stimuli. We studied the influence of contrast modulation of the stimulus luminance noise on threshold and reaction time color discrimination. We evaluated color discrimination thresholds using the Cambridge Color Test (CCT) at six different stimulus mean luminances. Each mean luminance condition was tested using two protocols: constant absolute difference between maximum and minimum luminance of the luminance noise (constant delta protocol, CDP), and constant contrast modulation of the luminance noise (constant contrast protocol, CCP). MacAdam ellipses were fitted to the color discrimination thresholds in the CIE 1976 color space to quantify the color discrimination ellipses at threshold level. The same CDP and CCP protocols were applied in the experiment measuring RTs at three levels of stimulus mean luminance. The color threshold measurements show that for the CDP, ellipse areas decreased as a function of the mean luminance and they were significantly larger at the two lowest mean luminances, 10 cd/m2 and 13 cd/m2, compared to the highest one, 25 cd/m2. For the CCP, the ellipses areas also decreased as a function of the mean luminance, but there was no significant difference between ellipses areas estimated at six stimulus mean luminances. The exponent of the decrease of ellipse areas as a function of stimulus mean luminance was steeper in the CDP than CCP. Further, reaction time increased linearly with the reciprocal of the length of the chromatic vectors varying along the four chromatic half-axes. It decreased as a function of stimulus mean luminance in the CDP but not in the CCP. The findings indicated that visual

  6. Prediction of feeling of subject on odor stimulation from physiological information

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, H.; Nishida, S. [Osaka Univ., Suita (Japan)] Tsutsumi, M. [Matsushita Electric Industrial Co. Ltd., Kadoma, Osaka (Japan)

    1997-10-20

    Some research groups studied how to evaluate the human olfaction objectively. But there was no attempt to evaluate objectively a subjectivity evoked by an odor stimulation. We tried to evaluate the feeling of subject, namely subjectivity evoked by the odor stimulation. In this study, we have measured an EEG activity of a subject who was stimulated by the odor and we have evaluated objectively the influence of the odor stimulation by a chaotic analysis and a frequency analysis. We could get the affection of odor stimulation even if the subject did not consciously feel the odor. The results showed that in the favorite odor stimulation the chaotic value of EEG data decreased slowly but it of the unfavorite odor stimulation dispersed. We could measure the change of the feeling of subject by the odor stimulation and we could predict the feeling of subject by several explanatory variates selected from physiological information. 11 refs., 9 figs., 2 tabs.

  7. Body odor based personality judgments: The effect of fragranced cosmetics

    Directory of Open Access Journals (Sweden)

    Agnieszka eSorokowska

    2016-04-01

    Full Text Available People can accurately assess various personality traits of others based on body odor alone. Previous studies have shown that correlations between odor ratings and self-assessed personality dimensions are evident for assessments of neuroticism and dominance. Here, we tested differences between assessments based on natural body odor alone, without the use of cosmetics and assessments based on the body odor of people who were allowed to use cosmetics following their daily routine. Sixty-seven female observers assessed samples of odors from 113 odor donors (each odor donor provided two samples – one with and one without cosmetic use; the donors provided their personality ratings, and the raters judged personality characteristics of the donors based on the provided odor samples. Correlations between observers’ ratings and self-rated neuroticism were stronger when raters assessed body odor in the natural body odor condition (natural BO condition; rs = .20 than in the cosmetics use condition (BO+cosmetics condition; rs = .15. Ratings of dominance significantly predicted self-assessed dominance in both conditions (rs = .34 for natural BO and rs = .21 for BO+cosmetics, whereas ratings of extraversion did not predict self-assessed extraversion in either condition. In addition, ratings of body odor attractiveness and pleasantness were significantly lower in natural BO condition than in BO+cosmetics condition, although the intensity of donors’ body odors was similar under both conditions. Our findings suggest that although olfaction seems to contribute to accurate first impression judgments of certain personality traits, cosmetic use can affect assessments of others based on body odor.

  8. Body Odor Based Personality Judgments: The Effect of Fragranced Cosmetics.

    Science.gov (United States)

    Sorokowska, Agnieszka; Sorokowski, Piotr; Havlíček, Jan

    2016-01-01

    People can accurately assess various personality traits of others based on body odor (BO) alone. Previous studies have shown that correlations between odor ratings and self-assessed personality dimensions are evident for assessments of neuroticism and dominance. Here, we tested differences between assessments based on natural body odor alone, without the use of cosmetics and assessments based on the body odor of people who were allowed to use cosmetics following their daily routine. Sixty-seven observers assessed samples of odors from 113 odor donors (each odor donor provided two samples - one with and one without cosmetic use); the donors provided their personality ratings, and the raters judged personality characteristics of the donors based on the provided odor samples. Correlations between observers' ratings and self-rated neuroticism were stronger when raters assessed body odor in the natural body odor condition (natural BO condition; r s = 0.20) than in the cosmetics use condition (BO+cosmetics condition; r s = 0.15). Ratings of dominance significantly predicted self-assessed dominance in both conditions (r s = 0.34 for natural BO and r s = 0.21 for BO+cosmetics), whereas ratings of extraversion did not predict self-assessed extraversion in either condition. In addition, ratings of body odor attractiveness and pleasantness were significantly lower in natural BO condition than in BO+cosmetics condition, although the intensity of donors' body odors was similar under both conditions. Our findings suggest that although olfaction seems to contribute to accurate first impression judgments of certain personality traits, cosmetic use can affect assessments of others based on body odor.

  9. Body Odor Based Personality Judgments: The Effect of Fragranced Cosmetics

    Science.gov (United States)

    Sorokowska, Agnieszka; Sorokowski, Piotr; Havlíček, Jan

    2016-01-01

    People can accurately assess various personality traits of others based on body odor (BO) alone. Previous studies have shown that correlations between odor ratings and self-assessed personality dimensions are evident for assessments of neuroticism and dominance. Here, we tested differences between assessments based on natural body odor alone, without the use of cosmetics and assessments based on the body odor of people who were allowed to use cosmetics following their daily routine. Sixty-seven observers assessed samples of odors from 113 odor donors (each odor donor provided two samples – one with and one without cosmetic use); the donors provided their personality ratings, and the raters judged personality characteristics of the donors based on the provided odor samples. Correlations between observers’ ratings and self-rated neuroticism were stronger when raters assessed body odor in the natural body odor condition (natural BO condition; rs = 0.20) than in the cosmetics use condition (BO+cosmetics condition; rs = 0.15). Ratings of dominance significantly predicted self-assessed dominance in both conditions (rs = 0.34 for natural BO and rs = 0.21 for BO+cosmetics), whereas ratings of extraversion did not predict self-assessed extraversion in either condition. In addition, ratings of body odor attractiveness and pleasantness were significantly lower in natural BO condition than in BO+cosmetics condition, although the intensity of donors’ body odors was similar under both conditions. Our findings suggest that although olfaction seems to contribute to accurate first impression judgments of certain personality traits, cosmetic use can affect assessments of others based on body odor. PMID:27148138

  10. Odorant-binding proteins OBP57d and OBP57e affect taste perception and host-plant preference in Drosophila sechellia.

    Directory of Open Access Journals (Sweden)

    Takashi Matsuo

    2007-05-01

    Full Text Available Despite its morphological similarity to the other species in the Drosophila melanogaster species complex, D. sechellia has evolved distinct physiological and behavioral adaptations to its host plant Morinda citrifolia, commonly known as Tahitian Noni. The odor of the ripe fruit of M. citrifolia originates from hexanoic and octanoic acid. D. sechellia is attracted to these two fatty acids, whereas the other species in the complex are repelled. Here, using interspecies hybrids between D. melanogaster deficiency mutants and D. sechellia, we showed that the Odorant-binding protein 57e (Obp57e gene is involved in the behavioral difference between the species. D. melanogaster knock-out flies for Obp57e and Obp57d showed altered behavioral responses to hexanoic acid and octanoic acid. Furthermore, the introduction of Obp57d and Obp57e from D. simulans and D. sechellia shifted the oviposition site preference of D. melanogaster Obp57d/e(KO flies to that of the original species, confirming the contribution of these genes to D. sechellia's specialization to M. citrifolia. Our finding of the genes involved in host-plant determination may lead to further understanding of mechanisms underlying taste perception, evolution of plant-herbivore interactions, and speciation.

  11. Pleasant and Unpleasant Odors Influence Hedonic Evaluations of Human Faces: An Event-Related Potential Study

    Science.gov (United States)

    Cook, Stephanie; Fallon, Nicholas; Wright, Hazel; Thomas, Anna; Giesbrecht, Timo; Field, Matt; Stancak, Andrej

    2015-01-01

    Odors can alter hedonic evaluations of human faces, but the neural mechanisms of such effects are poorly understood. The present study aimed to analyze the neural underpinning of odor-induced changes in evaluations of human faces in an odor-priming paradigm, using event-related potentials (ERPs). Healthy, young participants (N = 20) rated neutral faces presented after a 3 s pulse of a pleasant odor (jasmine), unpleasant odor (methylmercaptan), or no-odor control (clean air). Neutral faces presented in the pleasant odor condition were rated more pleasant than the same faces presented in the no-odor control condition, which in turn were rated more pleasant than faces in the unpleasant odor condition. Analysis of face-related potentials revealed four clusters of electrodes significantly affected by odor condition at specific time points during long-latency epochs (600−950 ms). In the 620−640 ms interval, two scalp-time clusters showed greater negative potential in the right parietal electrodes in response to faces in the pleasant odor condition, compared to those in the no-odor and unpleasant odor conditions. At 926 ms, face-related potentials showed greater positivity in response to faces in the pleasant and unpleasant odor conditions at the left and right lateral frontal-temporal electrodes, respectively. Our data shows that odor-induced shifts in evaluations of faces were associated with amplitude changes in the late (>600) and ultra-late (>900 ms) latency epochs. The observed amplitude changes during the ultra-late epoch are consistent with a left/right hemisphere bias towards pleasant/unpleasant odor effects. Odors alter evaluations of human faces, even when there is a temporal lag between presentation of odors and faces. Our results provide an initial understanding of the neural mechanisms underlying effects of odors on hedonic evaluations. PMID:26733843

  12. Pleasant and unpleasant odors influence hedonic evaluations of human faces: an event-related potential study.

    Directory of Open Access Journals (Sweden)

    Stephanie Jane Cook

    2015-12-01

    Full Text Available Odors can alter hedonic evaluations of human faces, but the neural mechanisms of such effects are poorly understood. The present study aimed to analyze the neural underpinning of odor-induced changes in evaluations of human faces in an odor-priming paradigm, using event-related potentials (ERPs. Healthy, young participants (N = 20 rated neutral faces presented after a three second pulse of a pleasant odor (jasmine, unpleasant odor (methylmercaptan, or no-odor control (clean air. Neutral faces presented in the pleasant odor condition were rated more pleasant than the same faces presented in the no-odor control condition, which in turn were rated more pleasant than faces in the unpleasant odor condition. Analysis of face-related potentials revealed four clusters of electrodes significantly affected by odor condition at specific time points during long-latency epochs (600−950 ms. In the 620−640 ms interval, two scalp-time clusters showed greater negative potential in the right parietal electrodes in response to faces in the pleasant odor condition, compared to those in the no-odor and unpleasant odor conditions. At 926 ms, face-related potentials showed greater positivity in response to faces in the pleasant and unpleasant odor conditions at the left and right lateral frontal-temporal electrodes, respectively. Our data shows that odor-induced shifts in evaluations of faces were associated with amplitude changes in the late (> 600 and ultra-late (> 900 ms latency epochs. The observed amplitude changes during the ultra-late epoch are consistent with a left/right hemisphere bias towards pleasant/unpleasant odor effects. Odors alter evaluations of human faces, even when there is a temporal lag between presentation of odors and faces. Our results provide an initial understanding of the neural mechanisms underlying effects of odors on hedonic evaluations.

  13. Detection and classification of natural odors with an in vivo bioelectronic nose.

    Science.gov (United States)

    Zhuang, Liujing; Guo, Tiantian; Cao, Duanxi; Ling, Liquan; Su, Kaiqi; Hu, Ning; Wang, Ping

    2015-05-15

    The mammalian olfactory system is recognized as one of the most effective chemosensing systems. We thus investigated the potential of utilizing the rat's olfactory system to detect odors. By chronically coupling multiple microelectrodes to olfactory bulb of behaving rats, we extract an array of mitral/tufted cells (M/Ts) which could generate odor-specific temporal patterns of neural discharge. We performed multidimensional analysis of recorded M/Ts, finding that natural odors released from different fruit lead to distinct odor response patterns. Thus an array of M/Ts carried sufficient information to discriminate odors. This novel brain-machine interface using rat's olfaction presents a promising method for odor detection and discrimination, and it is the first step towards in vivo bioelectronic nose equipped with biological olfaction and artificial devices.

  14. Mammalian Odor Information Recognition by Implanted Microsensor Array in vivo

    Science.gov (United States)

    Zhou, Jun; Dong, Qi; Zhuang, Liujing; Liu, Qingjun; Wang, Ping

    2011-09-01

    The mammalian olfactory system has an exquisite capacity to rapidly recognize and discriminate thousands of distinct odors in our environment. Our research group focus on reading information from olfactory bulb circuit of anethetized Sprague-Dawley rat and utilize artificial recognition system for odor discrimination. After being stimulated by three odors with concentration of 10 μM to rat nose, the response of mitral cells in olfactory bulb is recorded by eight channel microwire sensor array. In 20 sessions with 3 animals, we obtained 30 discriminated individual cells recordings. The average firing rates of the cells are Isoamyl acetate 26 Hz, Methoxybenzene 16 Hz, and Rose essential oil 11 Hz. By spike sorting, we detect peaks and analyze the interspike interval distribution. Further more, principal component analysis is applied to reduce the dimensionality of the data sets and classify the response.

  15. Odor coding in a disease-transmitting herbivorous insect, the Asian citrus psyllid.

    Science.gov (United States)

    Coutinho-Abreu, Iliano V; McInally, Shane; Forster, Lisa; Luck, Robert; Ray, Anandasankar

    2014-07-01

    Olfactory systems discriminate odorants very efficiently and herbivorous insects use them to find hosts in confounding and complex odor landscapes. The Asian citrus psyllid (ACP), Diaphorina citri, feeds on citrus flush and transmits Candidatus Liberibacter that causes citrus greening disease globally. Here, we perform a systematic analysis of odor detection in the ACP antenna using single-unit electrophysiology of rhinarial plate sensilla to a large panel of odorants from plants. We identify neurons that respond strongly to odorants found in the host citrus plants. Comparisons with the generalist yeast-feeding Drosophila melanogaster and specialist anthropophilic Anopheles gambiae reveal differences in odor-coding strategies for the citrus-seeking ACP. These findings provide a foundation for understanding host-odor coding in herbivorous insects.

  16. Multiple activities of insect repellents on odorant receptors in mosquitoes

    Science.gov (United States)

    Several lines of evidence suggest that insect repellent molecules reduce mosquito-host contacts by interacting with odorants and odorant receptors (ORs) ultimately affecting olfactory-driven behaviors. We describe the molecular effects of ten insect repellents and a pyrethroid insecticide with known...

  17. Orthogonal Design Study on Factors Affecting the Determination of Common Odors in Water Samples by Headspace Solid-Phase Microextraction Coupled to GC/MS.

    Science.gov (United States)

    Peng, Shifu; Ding, Zhen; Xia, Weiwen; Zheng, Hao; Xia, Yuting; Chen, Xiaodong

    2013-01-01

    Geosmin and 2-MIB are responsible for the majority of earthy and musty events related to the drinking water. These two odorants have extremely low odor threshold concentrations at ng L(-1) level in the water, so a simple and sensitive method for the analysis of such trace levels was developed by headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry. In this study, the orthogonal experiment design L32 (4(9)) was applied to arrange and optimize experimental conditions. The optimum was the following: temperatures of extraction and desorption, 65°C and 260°C, respectively; times of extraction and desorption, 30 min and 5 min, respectively; ionic strength, 25% (w/v); rotate-speed, 600 rpm; solution pH, 5.0. Under the optimized conditions, limits of detection (S/N = 3) were 0.04 and 0.13 ng L(-1) for geosmin and 2-MIB, respectively. Calculated calibration curves gave high levels of linearity with a correlation coefficient value of 0.9999 for them. Finally, the proposed method was applied to water samples, which were previously analyzed and confirmed to be free of target analytes. Besides, the proposal method was applied to test environmental water samples. The RSDs were 2.75%~3.80% and 4.35%~7.6% for geosmin and 2-MIB, respectively, and the recoveries were 91%~107% and 91%~104% for geosmin and 2-MIB, respectively.

  18. Orthogonal Design Study on Factors Affecting the Determination of Common Odors in Water Samples by Headspace Solid-Phase Microextraction Coupled to GC/MS

    Directory of Open Access Journals (Sweden)

    Shifu Peng

    2013-01-01

    Full Text Available Geosmin and 2-MIB are responsible for the majority of earthy and musty events related to the drinking water. These two odorants have extremely low odor threshold concentrations at ng L−1 level in the water, so a simple and sensitive method for the analysis of such trace levels was developed by headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry. In this study, the orthogonal experiment design L32 (49 was applied to arrange and optimize experimental conditions. The optimum was the following: temperatures of extraction and desorption, 65°C and 260°C, respectively; times of extraction and desorption, 30 min and 5 min, respectively; ionic strength, 25% (w/v; rotate-speed, 600 rpm; solution pH, 5.0. Under the optimized conditions, limits of detection (S/N=3 were 0.04 and 0.13 ng L−1 for geosmin and 2-MIB, respectively. Calculated calibration curves gave high levels of linearity with a correlation coefficient value of 0.9999 for them. Finally, the proposed method was applied to water samples, which were previously analyzed and confirmed to be free of target analytes. Besides, the proposal method was applied to test environmental water samples. The RSDs were 2.75%~3.80% and 4.35%~7.6% for geosmin and 2-MIB, respectively, and the recoveries were 91%~107% and 91%~104% for geosmin and 2-MIB, respectively.

  19. Distributed representation of social odors indicates parallel processing in the antennal lobe of ants.

    Science.gov (United States)

    Brandstaetter, Andreas Simon; Kleineidam, Christoph Johannes

    2011-11-01

    In colonies of eusocial Hymenoptera cooperation is organized through social odors, and particularly ants rely on a sophisticated odor communication system. Neuronal information about odors is represented in spatial activity patterns in the primary olfactory neuropile of the insect brain, the antennal lobe (AL), which is analog to the vertebrate olfactory bulb. The olfactory system is characterized by neuroanatomical compartmentalization, yet the functional significance of this organization is unclear. Using two-photon calcium imaging, we investigated the neuronal representation of multicomponent colony odors, which the ants assess to discriminate friends (nestmates) from foes (nonnestmates). In the carpenter ant Camponotus floridanus, colony odors elicited spatial activity patterns distributed across different AL compartments. Activity patterns in response to nestmate and nonnestmate colony odors were overlapping. This was expected since both consist of the same components at differing ratios. Colony odors change over time and the nervous system has to constantly adjust for this (template reformation). Measured activity patterns were variable, and variability was higher in response to repeated nestmate than to repeated nonnestmate colony odor stimulation. Variable activity patterns may indicate neuronal plasticity within the olfactory system, which is necessary for template reformation. Our results indicate that information about colony odors is processed in parallel in different neuroanatomical compartments, using the computational power of the whole AL network. Parallel processing might be advantageous, allowing reliable discrimination of highly complex social odors.

  20. Can common functional gene variants affect visual discrimination in metacontrast masking?

    Directory of Open Access Journals (Sweden)

    Margus Maksimov

    Full Text Available Mechanisms of visual perception should be robustly fast and provide veridical information about environmental objects in order to facilitate survival and successful coping. Because species-specific brain mechanisms for fast vision must have evolved under heavy pressure for efficiency, it has been held that different human individuals see the physical world in the same way and produce psychophysical functions of visual discrimination that are qualitatively the same. For many years, this assumption has been implicitly accepted in vision research studying extremely fast, basic visual processes, including studies of visual masking. However, in recent studies of metacontrast masking surprisingly robust individual differences in the qualitative aspects of subjects' performance have been found. As the basic species-specific visual functions very likely are based on universal brain mechanisms of vision, these differences probably are the outcome of variability in ontogenetic development (i.e., formation of idiosyncrasic skills of perception. Such developmental differences can be brought about by variants of genes that are differentially expressed in the course of CNS development. The objective of this study was to assess whether visual discrimination in metacontrast masking is related to three widely studied genetic polymorphisms implicated in brain function and used here as independent variables. The findings suggest no main effects of BDNF Val66Met, NRG1/rs6994992, or 5-HTTLPR polymorphisms on metacontrast performance, but several notable interactions of genetic variables with gender, stage of the sequence of experimental trials, perceptual strategies, and target/mask shape congruence were found. Thus, basic behavioral functions of fast vision may be influenced by common genetic variability. Also, when left uncontrolled, genetic factors may seriously confound variables in vision research using masking, obscure clear theoretical interpretation, lead to

  1. Cloning and expression profiling of odorant-binding proteins in the tarnished plant bug, Lygus lineolaris

    Science.gov (United States)

    In insects, the perception and discrimination of odorants requires the involvement of odorant binding proteins (OBPs). To gain a better molecular understanding of olfaction in the agronomic pest, Lygus lineolaris (tarnished plant bug), we used a transcriptomics-based approach to identify potential ...

  2. Rapid odor perception in rat olfactory bulb by microelectrode array

    Institute of Scientific and Technical Information of China (English)

    Jun ZHOU; Qi DONG; Liu-jing ZHUANG; Rong LI; Ping WANG

    2012-01-01

    Responses of 302 mitral/tufted (M/T) cells in the olfactory bulb were recorded from 42 anesthetized freely breathing rats using a 16-channel microwire electrode array.Saturated vapors of four pure chemicals,anisole,carvone,citral and isoamyl acetate were applied.After aligning spike trains to the iritial phase of the inhalation after odor onset,the responses of M/T cells showed transient temporal features including excitatory and inhibitory patterns.Both odor-evoked patterns indicated that mammals recognize odors within a short respiration cycle after odor stimulus.Due to the small amount of information received from a single cell,we pooled results from all responsive M/T cells to study the ensemble activity.The firing rates of the cell ensembles were computed over 100 ms bins and population vectors were constructed.The high dimension vectors were condensed into three dimensions for visualization using principal component analysis.The trajectories of both excitatory and inhibitory cell ensembles displayed strong dynamics during odor stimulation.The distances among cluster centers were enlarged compared to those of the resting state.Thus,we presumed that pictures of odor information sent to higher brain regions were depicted and odor discrimination was completed within the first breathing cycle.

  3. α7-Nicotinic acetylcholine receptor: role in early odor learning preference in mice.

    Directory of Open Access Journals (Sweden)

    Jennifer L Hellier

    Full Text Available Recently, we have shown that mice with decreased expression of α7-nicotinic acetylcholine receptors (α7 in the olfactory bulb were associated with a deficit in odor discrimination compared to wild-type mice. However, it is unknown if mice with decreased α7-receptor expression also show a deficit in early odor learning preference (ELP, an enhanced behavioral response to odors with attractive value observed in rats. In this study, we modified ELP methods performed in rats and implemented similar conditions in mice. From post-natal days 5-18, wild-type mice were stroked simultaneously with an odor presentation (conditioned odor for 90 s daily. Control mice were only stroked, exposed to odor, or neither. On the day of testing (P21, mice that were stroked in concert with a conditioned odor significantly investigated the conditioned odor compared to a novel odor, as observed similarly in rats. However, mice with a decrease in α7-receptor expression that were stroked during a conditioned odor did not show a behavioral response to that odorant. These results suggest that decreased α7-receptor expression has a role in associative learning, olfactory preference, and/or sensory processing deficits.

  4. Food's visually perceived fat content affects discrimination speed in an orthogonal spatial task.

    Science.gov (United States)

    Harrar, Vanessa; Toepel, Ulrike; Murray, Micah M; Spence, Charles

    2011-10-01

    Choosing what to eat is a complex activity for humans. Determining a food's pleasantness requires us to combine information about what is available at a given time with knowledge of the food's palatability, texture, fat content, and other nutritional information. It has been suggested that humans may have an implicit knowledge of a food's fat content based on its appearance; Toepel et al. (Neuroimage 44:967-974, 2009) reported visual-evoked potential modulations after participants viewed images of high-energy, high-fat food (HF), as compared to viewing low-fat food (LF). In the present study, we investigated whether there are any immediate behavioural consequences of these modulations for human performance. HF, LF, or non-food (NF) images were used to exogenously direct participants' attention to either the left or the right. Next, participants made speeded elevation discrimination responses (up vs. down) to visual targets presented either above or below the midline (and at one of three stimulus onset asynchronies: 150, 300, or 450 ms). Participants responded significantly more rapidly following the presentation of a HF image than following the presentation of either LF or NF images, despite the fact that the identity of the images was entirely task-irrelevant. Similar results were found when comparing response speeds following images of high-carbohydrate (HC) food items to low-carbohydrate (LC) food items. These results support the view that people rapidly process (i.e. within a few hundred milliseconds) the fat/carbohydrate/energy value or, perhaps more generally, the pleasantness of food. Potentially as a result of HF/HC food items being more pleasant and thus having a higher incentive value, it seems as though seeing these foods results in a response readiness, or an overall alerting effect, in the human brain.

  5. Spatial discrimination and visual discrimination

    DEFF Research Database (Denmark)

    Haagensen, Annika M. J.; Grand, Nanna; Klastrup, Signe

    2013-01-01

    in a visual discrimination test. The juvenile minipigs were able to learn the spatial hole-board discrimination test and showed improved working and reference memory during the learning phase. Performance in the memory phases was affected by the retention intervals, but the minipigs were able to remember...... the concept of the test in both memory phases. Working memory and reference memory were significantly improved in the last trials of the memory phases. In the visual discrimination test, the minipigs learned to discriminate between the three figures presented to them within 9-14 sessions. For the memory test......, all minipigs performed 9/12 correct choices or better. Juvenile Gottingen minipigs are able to learn to perform in a spatial hole-board discrimination test as well as in a visual discrimination test, showing an increase in performance over time. Both tests have considerable scope to assess learning...

  6. Cognitive performance of Göttingen minipigs is affected by diet in a spatial hole-board discrimination test

    DEFF Research Database (Denmark)

    Haagensen, Annika Maria Juul; Klein, Anders Bue; Ettrup, Anders

    2013-01-01

    Consumption of a high energy diet, containing high amounts of saturated fat and refined sugar has been associated with impairment of cognitive function in rodents and humans. We sought to contrast the effect of a high fat/cholesterol, low carbohydrate diet and a low fat, high carbohydrate....../sucrose diet, relative to a standard low fat, high carbohydrate minipig diet on spatial cognition with regards to working memory and reference memory in 24 male Göttingen minipigs performing in a spatial hole-board discrimination test. We found that both working memory and reference memory were impaired...... by both diets relative to a standard minipig diet high in carbohydrate, low in fat and sugar. The different diets did not impact levels of brain-derived neurotrophic factor in brain tissue and neither did they affect circulatory inflammation measured by concentrations of C-reactive protein and haptoglobin...

  7. Odor-cued taste avoidance: a simple and robust test of mouse olfaction.

    Science.gov (United States)

    Slotnick, Burton; Coppola, David M

    2015-05-01

    In odor-cued taste avoidance (OCTA), thirsty mice, offered either an odorized nonaversive fluid (S+) or an odorized aversive fluid (S-), quickly learn to use odor to avoid drinking the S-. Acquisition of both odor detection and odor discrimination tasks is very rapid with learning evidenced in most cases by either long response times or total avoidance on the second presentation of the S- stimulus. OCTA is perhaps one of the simplest conditioning procedures for assessing olfaction in mice; it requires only a test box, drinkometer circuit, and thirsty mice accustomed to drinking in the apparatus. Its advantages over the most commonly used alternatives, habituation-dishabituation, and the mouse dig test, are discussed.

  8. Olfactory discrimination of structurally similar alcohols by cockroaches.

    Science.gov (United States)

    Sakura, M; Okada, R; Mizunami, M

    2002-11-01

    The capability of the cockroach Periplaneta americana to discriminate odors of structurally similar aliphatic alcohols was studied by using an operant conditioning paradigm. Cockroaches were trained to discriminate three odors: one odor associated with sucrose solution (reward) and two odors associated with NaCl solution (non-reward). After training, their odor preferences were tested by counting the number of visits to each odor source. We tested the capability of cockroaches to discriminate (1) three normal aliphatic alcohols with different numbers of carbon (1-pentanol, 1-hexanol and 1-octanol), (2) three C6 aliphatic alcohols (1-hexanol, 2-hexanol and trans-2-hexen-1-ol), (3) binary mixtures of two of these three alcohols and their components, and (4) 1-hexanol solution of three different concentrations (1, 10 and 100 micro g micro l(-1)). Cockroaches exhibited higher preferences for the odors associated with reward in these tests, and we therefore conclude that cockroaches can discriminate these odors. However, discrimination of 1-hexanol and trans-2-hexen-1-ol and their binary mixture was imperfect, in that some statistical tests suggested significant level of discrimination but other tests did not. In addition, the cockroaches learned to associate a 1-hexanol solution of the highest or lowest concentration with sucrose reward but failed to learn to associate 1-hexanol of an intermediate concentration with reward.

  9. Coding odor identity and odor value in awake rodents.

    Science.gov (United States)

    Nunez-Parra, Alexia; Li, Anan; Restrepo, Diego

    2014-01-01

    In the last decade, drastic changes in the understanding of the role of the olfactory bulb and piriform cortex in odor detection have taken place through awake behaving recording in rodents. It is clear that odor responses in mitral and granule cells are strikingly different in the olfactory bulb of anesthetized versus awake animals. In addition, sniff recording has evidenced that mitral cell responses to odors during the sniff can convey information on the odor identity and sniff phase. Moreover, we review studies that show that the mitral cell conveys information on not only odor identity but also whether the odor is rewarded or not (odor value). Finally, we discuss how the substantial increase in awake behaving recording raises questions for future studies.

  10. The role of piriform associative connections in odor categorization.

    Science.gov (United States)

    Bao, Xiaojun; Raguet, Louise Lg; Cole, Sydni M; Howard, James D; Gottfried, Jay

    2016-04-28

    Distributed neural activity patterns are widely proposed to underlie object identification and categorization in the brain. In the olfactory domain, pattern-based representations of odor objects are encoded in piriform cortex. This region receives both afferent and associative inputs, though their relative contributions to odor perception are poorly understood. Here, we combined a placebo-controlled pharmacological fMRI paradigm with multivariate pattern analyses to test the role of associative connections in sustaining olfactory categorical representations. Administration of baclofen, a GABA(B) agonist known to attenuate piriform associative inputs, interfered with within-category pattern separation in piriform cortex, and the magnitude of this drug-induced change predicted perceptual alterations in fine-odor discrimination performance. Comparatively, baclofen reduced pattern separation between odor categories in orbitofrontal cortex, and impeded within-category generalization in hippocampus. Our findings suggest that odor categorization is a dynamic process concurrently engaging stimulus discrimination and generalization at different stages of olfactory information processing, and highlight the importance of associative networks in maintaining categorical boundaries.

  11. Enantioselective recognition of menthol by mouse odorant receptors.

    Science.gov (United States)

    Takai, Yoshiki; Touhara, Kazushige

    2015-01-01

    The olfactory system has a remarkable ability to detect and discriminate a vast variety of odorant molecules. In mammals, hundreds to thousands of odorant receptors (ORs) expressed in olfactory sensory neurons play an essential role in this discrimination. Odorants are recognized by ORs in a combinatorial fashion in which a single odorant activates a particular combination of receptors, leading to its perception as a particular aroma. It is well known that enantiomers emit different aromas in spite of exhibiting otherwise identical chemical properties. To elucidate the molecular basis for the difference, we recorded responses to l- and d-menthol in the mouse olfactory bulb and found that enantiomers elicited similar but overlapping and distinct receptor activation patterns. We then identified l-menthol-specific and d-menthol-biased receptors and performed detailed structure-activity relationship studies, revealing high stereoselectivity of the enantiospecific menthol receptor. The binding site on ORs appears to have evolved to distinguish subtle differences in very similar odorant structures.

  12. Destruction of central noradrenergic neurones with DSP4 impairs the acquisition of temporal discrimination but does not affect memory for duration in a delayed conditional discrimination task.

    Science.gov (United States)

    al-Zahrani, S S; al-Ruwaitea, A S; Ho, M Y; Bradshaw, C M; Szabadi, E

    1997-03-01

    This experiment examined the effect of destroying central noradrenergic neurones using the selective neurotoxin N-(2-chloroethyl)-n-ethyl-2-bromobenzylamine (DSP4) on the acquisition of a temporal discrimination and on memory for duration, using a delayed conditional discrimination task. In phase I, rats that had received systemic treatment with DSP4 and vehicle-treated control rats were trained in a series of discrete trials to press lever A following a 2-s presentation of a light stimulus, and lever B following an 8-s presentation of the same stimulus. Following stimulus offset, a response on a panel placed midway between the two levers was required to initiate lever presentation; a single response on either lever resulted in withdrawal of both levers and, in the case of a "correct" response, reinforcer delivery. Both groups acquired accurate discrimination, achieving 90% correct choices within 50 sessions; the DSP4-treated group acquired accurate performance more slowly than the control group. In phase II, delays were interposed between stimulus offset and lever presentation in 50% of the trials. In the absence of a delay, discriminative accuracy was lower in the DSP4-treated group than in the control group. Accuracy declined as a function of post-stimulus delay in both groups; both groups showed a delay-dependent bias towards responding on lever A ("choose-short" bias). Neither of these effects differed significantly between the two groups. The concentrations of noradrenaline in the parietal cortex and hippocampus were reduced by 90% and 89% in the DSP4-treated group, compared to the levels in the control group, but the levels of dopamine, 5-hydroxytryptamine and 5-hydroxyindoleacetic acid did not differ significantly between the groups. The results confirm the deleterious effect of DSP4 on the acquisition of temporal discrimination, but do not provide evidence for a role of the noradrenergic innervation of the hippocampus and neocortex in temporal working

  13. Identification of agonists for a group of human odorant receptors

    Directory of Open Access Journals (Sweden)

    Daniela eGonzalez-Kristeller

    2015-03-01

    Full Text Available Olfaction plays a critical role in several aspects of the human life. Odorants are detected by hundreds of odorant receptors (ORs which belong to the superfamily of G protein-coupled receptors. These receptors are expressed in the olfactory sensory neurons of the nose. The information provided by the activation of different combinations of ORs in the nose is transmitted to the brain, leading to odorant perception and emotional and behavioral responses. There are ~400 intact human ORs, and to date only a small percentage of these receptors (~10% have known agonists. The determination of the specificity of the human ORs will contribute to a better understanding of how odorants are discriminated by the olfactory system. In this work, we aimed to identify human specific ORs, that is, ORs that are present in humans but absent from other species, and their corresponding agonists. To do this, we first selected 22 OR gene sequences from the human genome with no counterparts in the mouse, rat or dog genomes. Then we used a heterologous expression system to screen a subset of these human ORs against a panel of odorants of biological relevance, including foodborne aroma volatiles. We found that different types of odorants are able to activate some of these previously uncharacterized human ORs.

  14. Expressing exogenous functional odorant receptors in cultured olfactory sensory neurons

    Directory of Open Access Journals (Sweden)

    Fomina Alla F

    2008-09-01

    Full Text Available Abstract Background Olfactory discrimination depends on the large numbers of odorant receptor genes and differential ligand-receptor signaling among neurons expressing different receptors. In this study, we describe an in vitro system that enables the expression of exogenous odorant receptors in cultured olfactory sensory neurons. Olfactory sensory neurons in the culture express characteristic signaling molecules and, therefore, provide a system to study receptor function within its intrinsic cellular environment. Results We demonstrate that cultured olfactory sensory neurons express endogenous odorant receptors. Lentiviral vector-mediated gene transfer enables successful ectopic expression of odorant receptors. We show that the ectopically expressed mouse I7 is functional in the cultured olfactory sensory neurons. When two different odorant receptors are ectopically expressed simultaneously, both receptor proteins co-localized in the same olfactory sensory neurons up to 10 days in vitro. Conclusion This culture technique provided an efficient method to culture olfactory sensory neurons whose morphology, molecular characteristics and maturation progression resembled those observed in vivo. Using this system, regulation of odorant receptor expression and its ligand specificity can be studied in its intrinsic cellular environment.

  15. Suppression of Background Odor Effect in Odor Sensing System Using Olfactory Adaptation Model

    Science.gov (United States)

    Ohba, Tsuneaki; Yamanaka, Takao

    In this study, a new method for suppressing the background odor effect is proposed. Since odor sensors response to background odors in addition to a target odor, it is difficult to detect the target odor information. In the conventional odor sensing systems, the effect of the background odors are compensated by subtracting the response to the background odors (the baseline response). Although this simple subtraction method is effective for constant background odors, it fails in the compensation for time-varying background odors. The proposed method for the background suppression is effective even for the time-varying background odors.

  16. Cognitive performance of Gottingen minipigs is affected by diet in a spatial hole-board discrimination test.

    Directory of Open Access Journals (Sweden)

    Annika Maria Juul Haagensen

    Full Text Available Consumption of a high energy diet, containing high amounts of saturated fat and refined sugar has been associated with impairment of cognitive function in rodents and humans. We sought to contrast the effect of a high fat/cholesterol, low carbohydrate diet and a low fat, high carbohydrate/sucrose diet, relative to a standard low fat, high carbohydrate minipig diet on spatial cognition with regards to working memory and reference memory in 24 male Göttingen minipigs performing in a spatial hole-board discrimination test. We found that both working memory and reference memory were impaired by both diets relative to a standard minipig diet high in carbohydrate, low in fat and sugar. The different diets did not impact levels of brain-derived neurotrophic factor in brain tissue and neither did they affect circulatory inflammation measured by concentrations of C-reactive protein and haptoglobin in serum. However, higher levels of triglycerides were observed for minipigs fed the diets with high fat/cholesterol, low carbohydrate and low fat, high carbohydrate/sucrose compared to minipigs fed a standard minipig diet. This might explain the observed impairments in spatial cognition. These findings suggest that high dietary intake of both fat and sugar may impair spatial cognition which could be relevant for mental functioning in humans.

  17. Adaptive adjustment of the generalization-discrimination balance in larval Drosophila.

    Science.gov (United States)

    Mishra, Dushyant; Louis, Matthieu; Gerber, Bertram

    2010-09-01

    Learnt predictive behavior faces a dilemma: predictive stimuli will never 'replay' exactly as during the learning event, requiring generalization. In turn, minute differences can become meaningful, prompting discrimination. To provide a study case for an adaptive adjustment of this generalization-discrimination balance, the authors ask whether Drosophila melanogaster larvae are able to either generalize or discriminate between two odors (1-octen-3-ol and 3-octanol), depending on the task. The authors find that after discriminatively rewarding one but not the other odor, larvae show conditioned preference for the rewarded odor. On the other hand, no odor specificity is observed after nondiscriminative training, even if the test involves a choice between both odors. Thus, for this odor pair at least, discrimination training is required to confer an odor-specific memory trace. This requires that there is at least some difference in processing between the two odors already at the beginning of the training. Therefore, as a default, there is a small yet salient difference in processing between 1-octen-3-ol and 3-octanol; this difference is ignored after nondiscriminative training (generalization), whereas it is accentuated by odor-specific reinforcement (discrimination). Given that, as the authors show, both faculties are lost in anosmic Or83b(1) mutants, this indicates an adaptive adjustment of the generalization-discrimination balance in larval Drosophila, taking place downstream of Or83b-expressing sensory neurons.

  18. Arc visualization of odor objects reveals experience-dependent ensemble sharpening, separation, and merging in anterior piriform cortex in adult rat.

    Science.gov (United States)

    Shakhawat, Amin Md; Harley, Carolyn W; Yuan, Qi

    2014-07-30

    Visualization using the immediate early gene Arc revealed sparser and more robust odor representations in the anterior piriform cortex of adult rats when odor was associated with water reward over 2-3 d. Rewarded odor "mixtures" resulted in rats responding to either component odor similarly, and, correspondingly, the odor representations became more similar as indexed by increased overlap in piriform Arc-expressing (Arc(+)) pyramidal neurons. The increased overlap was consistent with the rats' generalization from component odors. Discriminating among highly similar odor mixtures for reward led to increased differentiation of the neural representations as indexed by a reduction in overlap for piriform Arc(+) pyramidal neurons after training. Similar odor mixture discrimination also required more trials to criterion. The visible reduction in the overlap of odor representations indexes pattern separation. The Arc visualization of odor representations in the anterior piriform network suggests that odor objects are widely distributed representations and can be rapidly modified by reward training in adult rats. We suggest that dynamic changes such as those observed here in piriform odor encoding are at the heart of perceptual learning and reflect the continuing plastic nature of mature associative cortex as an outcome of successful problem solving.

  19. A Longitudinal Examination of Perceived Discrimination and Depressive Symptoms in Ethnic Minority Youth: The Roles of Attributional Style, Positive Ethnic/Racial Affect, and Emotional Reactivity

    Science.gov (United States)

    Stein, Gabriela L.; Supple, Andrew J.; Huq, Nadia; Dunbar, Angel S.; Prinstein, Mitchell J.

    2016-01-01

    Although perceived ethnic/racial discrimination is well established as a risk factor for depressive symptoms in ethnic minority youth, few studies have examined their longitudinal relationship over time. This study examined whether a negative attributional style, positive ethnic/racial affect, and emotional reactivity moderated the longitudinal…

  20. Fancy citrus, feel good: Positive judgment of citrus odor, but not the odor itself, is associated with elevated mood during experienced helplessness

    Directory of Open Access Journals (Sweden)

    Matthias eHoenen

    2016-02-01

    Full Text Available Aromatherapy claims that citrus essential oils exert mood lifting effects. Controlled studies, however, have yielded inconsistent results. Notably, studies so far did not control for odor pleasantness, although pleasantness is a critical determinant of emotional responses to odors. This study investigates mood lifting effects of d-(+-limonene, the most prominent substance in citrus essential oils, with respect to odor quality judgments.Negative mood was induced within 78 participants using a helplessness paradigm (unsolvable social discrimination task. During this task, participants were continuously (mean duration: 19.5 min exposed to d-(+-limonene (n = 25, vanillin (n = 26, or diethyl phthalate (n = 27. Participants described their mood (Self-Assessment-Manikin, basic emotion ratings and judged the odors’ quality (intensity, pleasantness, unpleasantness, familiarity prior to and following the helplessness induction. The participants were in a less positive mood after the helplessness induction (p < .001, irrespective of the odor condition. Still, the more pleasant the participants judged the odors, the less effective the helplessness induction was in reducing happiness (p = .019.The results show no odor specific mood lifting effect of d-(+-limonene, but indicate a positive effect of odor pleasantness on mood. The study highlights the necessity to evaluate odor judgments in aromatherapy research.

  1. Identifying key odorants from animal feeding operations

    Science.gov (United States)

    Odor emissions from animal agriculutre negatively impact air qualitly in surrounding communities. Current analytical practices are biased against agriculutral odorants and thus inadequate for odor quantification. The purpose of this study was to evaluate two different techniques ability to identify ...

  2. Memory for brief, widely spaced odor presentations in the rat.

    Science.gov (United States)

    Lovelace, C T; Slotnick, B M

    1995-04-01

    Rats trained on a series of 16 novel 2-odor discrimination tasks using a 10-s intertrial interval (ITI) rapidly improved in performance and made only 0-3 errors by the end of the test series. They were then tested on other novel pairs of odors, but with a 10- and a 30-min interval between trials. There was no decrement in performance accuracy in the longer ITI tests and, in most cases, criterion performance was achieved after making zero or 1 error after the first (information) trial. These results demonstrate that rats have the capacity to remember for at least 30 min whether a single brief presentation of a novel odor was followed by a reward.

  3. Perception of odors linked to precise timing in the olfactory system.

    Directory of Open Access Journals (Sweden)

    Michelle R Rebello

    2014-12-01

    Full Text Available While the timing of neuronal activity in the olfactory bulb (OB relative to sniffing has been the object of many studies, the behavioral relevance of timing information generated by patterned activation within the bulbar response has not been explored. Here we show, using sniff-triggered, dynamic, 2-D, optogenetic stimulation of mitral/tufted cells, that virtual odors that differ by as little as 13 ms are distinguishable by mice. Further, mice are capable of discriminating a virtual odor movie based on an optically imaged OB odor response versus the same virtual odor devoid of temporal dynamics-independently of the sniff-phase. Together with studies showing the behavioral relevance of graded glomerular responses and the response timing relative to odor sampling, these results imply that the mammalian olfactory system is capable of very high transient information transmission rates.

  4. Odorant normative data for use in olfactory memory experiments: Dimension selection and analysis of individual differences.

    Directory of Open Access Journals (Sweden)

    Andrew Gordon Moss

    2016-08-01

    Full Text Available The present study reports normative ratings for 200 food and non-food odors. One hundred participants rated odors across measures of verbalisability, perceived descriptive ability, context availability, pleasantness, irritability, intensity, familiarity, frequency, age of acquisition, and complexity. Analysis of the agreement between raters revealed that four dimensions, those of familiarity, intensity, pleasantness, and irritability, have the strongest utility as normative data. The ratings for the remaining dimensions exhibited reduced discriminability across the odor set and should therefore be used with caution. Indeed, these dimensions showed a larger difference between individuals in the ratings of the odors. Familiarity was shown to be related to pleasantness, and a non-linear relationship between pleasantness and intensity was observed which reflects greater intensity for odors that elicit a strong hedonic response. The suitability of these data for use in future olfactory study is considered, and effective implementation of the data for controlling stimuli is discussed.

  5. Muscarinic cholinergic neuromodulation reduces proactive interference between stored odor memories during associative learning in rats.

    Science.gov (United States)

    De Rosa, E; Hasselmo, M E

    2000-02-01

    Previous electrophysiological studies and computational modeling suggest the hypothesis that cholinergic neuromodulation may reduce olfactory associative interference during learning (M. E. Hasselmo, B. P. Anderson, & J. M. Bower, 1992; M. E. Hasselmo & J. M. Bower, 1993). These results provide behavioral evidence supporting this hypothesis. A simultaneous discrimination task required learning a baseline odor pair (A+B-) and then, under the influence of scopolamine, a novel odor pair (A-C+) with an overlapping component (A) versus a novel odor pair (D+E-) with no overlapping component. As predicted by the model, rats that received scopolamine (0.50 and 0.25 mg/kg) were more impaired at acquiring overlapping than nonoverlapping odor pairs relative to their performance under normal saline or methylscopolamine. These results support the prediction that the physiological effects of acetylcholine can reduce interference between stored odor memories during associative learning.

  6. Minimizing indoor odors from products

    NARCIS (Netherlands)

    Walpot, J.I.

    1996-01-01

    Regarding negative perceptions in indoor environments perceived odors are often mentio-ned as indicating factors. At TNO (Organisation for Applied Scientific Research in The Netherlands) a combination of methods is developed and used for the characterisation and quantification of indoor odor problem

  7. Odor from a chemical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Wray, T.K.

    1995-06-01

    Early odor-detection measurements categorized chemicals according to odor quality. Recent methods focus on the odor threshold, or the quantitative amount of a chemical in air that can be detected by the human sense of smell. Researchers characterize and quantify odor using an array of sensory and analytical procedures. Humans possess one of the dullest mammalian senses of smell; however, they can recognize about 10,000 distinct odors at concentrations ranging from less than 1 part per billion to several hundred thousand parts per million. Each time humans inhale, they chemically analyze microscopic pieces of the environment that make physical contact with the nerves in their noses. Individual molecules travel up the nose to a sheet of moist, mucus-bathed tissue that consists of about 5 million smell-sensing, olfactory neurons. After dissolving in the mucus, odor molecules ``float`` into appropriately shaped receptor pockets. A series of cellular reactions then transmit impulses to the limbic system, hippocampus and, finally, the neocortex. Odor detection is an important defense mechanism. The author presents the odor thresholds for selected organic compounds, and other hazardous chemicals.

  8. Dual activities of odorants on olfactory and nuclear hormone receptors.

    Science.gov (United States)

    Pick, Horst; Etter, Sylvain; Baud, Olivia; Schmauder, Ralf; Bordoli, Lorenza; Schwede, Torsten; Vogel, Horst

    2009-10-30

    We have screened an odorant compound library and discovered molecules acting as chemical signals that specifically activate both G-protein-coupled olfactory receptors (ORs) on the cell surface of olfactory sensory neurons and the human nuclear estrogen receptor alpha (ER) involved in transcriptional regulation of cellular differentiation and proliferation in a wide variety of tissues. Hence, these apparent dual active odorants induce distinct signal transduction pathways at different subcellular localizations, which affect both neuronal signaling, resulting in odor perception, and the ER-dependent transcriptional control of specific genes. We demonstrate these effects using fluorescence-based in vitro and cellular assays. Among these odorants, we have identified synthetic sandalwood compounds, an important class of molecules used in the fragrance industry. For one estrogenic odorant we have also identified the cognate OR. This prompted us to compare basic molecular recognition principles of odorants on the two structurally and apparent functionally non-related receptors using computational modeling in combination with functional assays. Faced with the increasing evidence that ORs may perform chemosensory functions in a number of tissues outside of the nasal olfactory epithelium, the unraveling of these molecular ligand-receptor interaction principles is of critical importance. In addition the evidence that certain olfactory sensory neurons naturally co-express ORs and ERs may provide a direct functional link between the olfactory and hormonal systems in humans. Our results are therefore useful for defining the structural and functional characteristics of ER-specific odorants and the role of odorant molecules in cellular processes other than olfaction.

  9. Chemical structure of odorants and perceptual similarity in ants.

    Science.gov (United States)

    Bos, Nick; d'Ettorre, Patrizia; Guerrieri, Fernando J

    2013-09-01

    Animals are often immersed in a chemical world consisting of mixtures of many compounds rather than of single substances, and they constantly face the challenge of extracting relevant information out of the chemical landscape. To this purpose, the ability to discriminate among different stimuli with different valence is essential, but it is also important to be able to generalise, i.e. to treat different but similar stimuli as equivalent, as natural variation does not necessarily affect stimulus valence. Animals can thus extract regularities in their environment and make predictions, for instance about distribution of food resources. We studied perceptual similarity of different plant odours by conditioning individual carpenter ants to one odour, and subsequently testing their response to another, structurally different odour. We found that asymmetry in generalisation, where ants generalise from odour A to B, but not from B to A, is dependent on both chain length and functional group. By conditioning ants to a binary mixture, and testing their reaction to the individual components of the mixture, we show that overshadowing, where parts of a mixture are learned better than others, is rare. Additionally, generalisation is dependent not only on the structural similarity of odorants, but also on their functional value, which might play a crucial role. Our results provide insight into how ants make sense of the complex chemical world around them, for example in a foraging context, and provide a basis with which to investigate the neural mechanisms behind perceptual similarity.

  10. Odor detection in Manduca sexta is optimized when odor stimuli are pulsed at a frequency matching the wing beat during flight.

    Directory of Open Access Journals (Sweden)

    Kevin C Daly

    Full Text Available Sensory systems sample the external world actively, within the context of self-motion induced disturbances. Mammals sample olfactory cues within the context of respiratory cycles and have adapted to process olfactory information within the time frame of a single sniff cycle. In plume tracking insects, it remains unknown whether olfactory processing is adapted to wing beating, which causes similar physical effects as sniffing. To explore this we first characterized the physical properties of our odor delivery system using hotwire anemometry and photo ionization detection, which confirmed that odor stimuli were temporally structured. Electroantennograms confirmed that pulse trains were tracked physiologically. Next, we quantified odor detection in moths in a series of psychophysical experiments to determine whether pulsing odor affected acuity. Moths were first conditioned to respond to a target odorant using Pavlovian olfactory conditioning. At 24 and 48 h after conditioning, moths were tested with a dilution series of the conditioned odor. On separate days odor was presented either continuously or as 20 Hz pulse trains to simulate wing beating effects. We varied pulse train duty cycle, olfactometer outflow velocity, pulsing method, and odor. Results of these studies, established that detection was enhanced when odors were pulsed. Higher velocity and briefer pulses also enhanced detection. Post hoc analysis indicated enhanced detection was the result of a significantly lower behavioral response to blank stimuli when presented as pulse trains. Since blank responses are a measure of false positive responses, this suggests that the olfactory system makes fewer errors (i.e. is more reliable when odors are experienced as pulse trains. We therefore postulate that the olfactory system of Manduca sexta may have evolved mechanisms to enhance odor detection during flight, where the effects of wing beating represent the norm. This system may even exploit

  11. Macroglomeruli for fruit odors change blend preference in Drosophila

    Science.gov (United States)

    Ibba, Irene; Angioy, Anna Maria; Hansson, Bill S.; Dekker, Teun

    2010-12-01

    The olfactory circuitry of Drosophila melanogaster is becoming increasingly clear. However, how olfactory processing translates into appropriate behavioral responses is still poorly understood. Using a sibling species approach, we tested how a perturbation in the olfactory circuitry affects odor preference. In a previous study, we found that the sibling species of D. melanogaster, the specialist D. sechellia, overrepresents a sensillum, ab3, the A neuron of which is sensitive to hexanoate esters, characteristic of the species' sole host, the Morinda citrifolia fruit. Concordantly, the corresponding glomerulus, DM2, is enlarged. In this study, we found that the ab3B neuron, the expansion of which was previously assumed to be pleiotropic and of no ecological significance, is in fact tuned to another morinda fruit volatile, 2-heptanone (HP). Axons of this neuron type arborize in a second enlarged glomerulus. In behavioral experiments we tested how this has affected the fly's odor preference. We demonstrate that D. sechellia has a reversed preference for the key ligands of these macroglomeruli, especially at high concentrations. Whereas D. melanogaster was repelled by high concentrations of these odors, D. sechellia was highly attracted. This was the case for odors presented singly, but more notably for blends thereof. Our study indicates that relatively simple changes, such as a shift in sensillar abundance, and concordant shifts in glomerular size, can distort the resulting olfactory code, and can lead to saltatory shifts in odor preference. D. sechellia has exploited this to align its olfactory preference with its ecological niche.

  12. Odor-based recognition of familiar and related conspecifics: a first test conducted on captive Humboldt penguins (Spheniscus humboldti.

    Directory of Open Access Journals (Sweden)

    Heather R Coffin

    Full Text Available Studies of kin recognition in birds have largely focused on parent-offspring recognition using auditory or visual discrimination. Recent studies indicate that birds use odors during social and familial interactions and possibly for mate choice, suggesting olfactory cues may mediate kin recognition as well. Here, we show that Humboldt penguins (Spheniscus humboldti, a natally philopatric species with lifetime monogamy, discriminate between familiar and unfamiliar non-kin odors (using prior association and between unfamiliar kin and non-kin odors (using phenotype matching. Penguins preferred familiar non-kin odors, which may be associated with the recognition of nest mates and colony mates and with locating burrows at night after foraging. In tests of kin recognition, penguins preferred unfamiliar non-kin odors. Penguins may have perceived non-kin odors as novel because they did not match the birds' recognition templates. Phenotype matching is likely the primary mechanism for kin recognition within the colony to avoid inbreeding. To our knowledge this is the first study to provide evidence of odor-based kin discrimination in a bird.

  13. Odor Absorbing Hydrocolloid Dressings for Direct Wound Contact.

    Science.gov (United States)

    Lipman, Roger D A; van Bavel, Davy

    2007-05-01

    Patients in institutional settings, such as hospitals and nursing homes, often have or acquire chronic wounds such as those resulting from venous insufficiency and pressure ulcers-these wounds can possess a very offensive odor. 1 The most direct way of avoiding or eliminating wound odor is to prevent or eradicate the infection responsible for it.Topical antibiotics, such as metronidazole gel (0.8 w/v) have proved to be quite effective, but can generate resistant organisms. Further, the action of metronidazole can be sluggish; often several days are needed for any infection to be resolved, and meanwhile the odor is still being generated.Thus, in practice, other methods such as charcoal-based dressings are often used with or with-out concomitant antibiotic therapy. Odor absorbing dressings have been marketed in one form or other for many years. During the past decades a number of charcoal based dressings have been introduced into the market. Some of the more current products are Actisorb ® Silver (Johnson & Johnson Medical Ltd, Gargrave, UK), CarboFlex ® (ConvaTec, Princeton, NJ), Carbonet ® (Smith and Nephew Abstract: Charcoal based odor-absorbing dressings for management of odoriferous chronic wounds have been marketed for many years. However, the presence of wound serum deactivates the charcoal and inhibits the adsorption of odor molecules. Charcoal dressings also gen-erally need adjunct fixation to hold them in place. A new series of hydrocolloid adhesives based on cyclodextrins has been developed to provide an alternative technology for the adsorption of chronic wound odors. Dressings incorporating this technology are suitable for direct wound contact. In presence of serum, superior odor absorption with these new materials in comparison with charcoal dressings has been demonstrated in vitro. These new dressings have significant fluid absorption potential, are self-adhesive, and require no additional fixa-tion. Some of the factors affecting performance of

  14. Odor-enriched environment rescues long-term social memory, but does not improve olfaction in social isolated adult mice.

    Science.gov (United States)

    Gusmão, Isabela D; Monteiro, Brisa M M; Cornélio, Guilherme O S; Fonseca, Cristina S; Moraes, Márcio F D; Pereira, Grace S

    2012-03-17

    Prolonged permanence of animals under social isolation (SI) arouses a variety of psychological symptoms like aggression, stress, anxiety and depression. However, short-term SI is commonly used to evaluate social memory. Interestingly, the social memory cannot be accessed with delays higher than 30min in SI mice. Our hypothesis is that SI with intermediate duration, like one week (1w), impairs the long-term storage of new social information (S-LTM), without affecting anxiety or other types of memories, because the SI compromises the olfactory function of the animal. Our results demonstrated that SI impaired S-LTM, without affecting other kinds of memory or anxiety. In addition, the SI increased the latency in the buried-food finding task, but did not affect the habituation or the discrimination of odors. Next, we postulated that if continuous input to the olfactory system is fundamental for the maintenance of the olfactory function and social memory persistence, isolated mice under odor-enriched environment (OEE) should behave like group-housed (GH) animals. In fact, the OEE prevented the S-LTM deficit imposed by the SI. However, OEE did not restore the SI mice olfaction to the GH mice level. Our results suggest that SI modulates olfaction and social memory persistence, probably, by independent mechanisms. We also showed for the first time that OEE rescued S-LTM in SI mice through a mechanism not necessarily involved with olfaction.

  15. Odorous and pungent attributes of mixed and unmixed odorants.

    Science.gov (United States)

    Cometto-Muñiz, J E; Hernández, S M

    1990-04-01

    In order to explore functional properties of the olfactory and common chemical senses as well as their relation to the total nasal sensation experienced, various concentrations of two pungent odorants were presented alone and in the presence of different backgrounds of the other irritant. Stimuli comprised formaldehyde (at 1.0, 3.5, 6.9, and 16.7 ppm), ammonia (at 210, 776, 1,172, and 1,716 ppm), and their 16 possible binary mixtures. Subjects were asked to estimate the total nasal perceived intensity, and then to assess the olfactory (odor) and common chemical (pungency) attributes of the evoked sensations. The results showed that stimulus-response functions for pungency are steeper than those for odor. Furthermore, odor was always hypoadditive in mixtures (i.e., mixtures were perceived as less intense than the sum of their components), whereas pungency was, mainly, additive, and even suggested hyperadditivity. Total perceived intensity of the stimuli, alone and in mixtures, followed the stimulus-response patterns for pungency, which, therefore, emerged as the dominating attribute used by subjects in scaling the explored range of concentrations. The relationship between total nasal perceived intensity of the mixtures and that of their components reflected hypoaddition, resembling the outcome for the odor attribute.

  16. Learning modulation of odor representations: new findings from Arc-indexed networks

    Directory of Open Access Journals (Sweden)

    Qi eYuan

    2014-12-01

    Full Text Available We first review our understanding of odor representations in rodent olfactory bulb and anterior piriform cortex. We then consider learning-induced representation changes. Finally we describe the perspective on network representations gained from examining Arc-indexed odor networks of awake rats. Arc-indexed networks are sparse and distributed, consistent with current views. However Arc provides representations of repeated odors. Arc-indexed repeated odor representations are quite variable. Sparse representations are assumed to be compact and reliable memory codes. Arc suggests this is not necessarily the case. The variability seen is consistent with electrophysiology in awake animals and may reflect top down-cortical modulation of context. Arc-indexing shows that distinct odors share larger than predicted neuron pools. These may be low-threshold neuronal subsets.Learning’s effect on Arc-indexed representations is to increase the stable or overlapping component of rewarded odor representations. This component can decrease for similar odors when their discrimination is rewarded. The learning effects seen are supported by electrophysiology, but mechanisms remain to be elucidated.

  17. The effects of odor and body posture on perceived duration

    NARCIS (Netherlands)

    Schreuder, E.; Hoeksma, M.R.; Smeets, M.A.M.; Semin, G.R.

    2014-01-01

    This study reports an examination of the internal clock model, according to which subjective time duration is influenced by attention and arousal state. In a time production task, we examine the hypothesis that an arousing odor and an upright body posture affect perceived duration. The experimental

  18. Odor Classification using Agent Technology

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2014-03-01

    Full Text Available In order to measure and classify odors, Quartz Crystal Microbalance (QCM can be used. In the present study, seven QCM sensors and three different odors are used. The system has been developed as a virtual organization of agents using an agent platform called PANGEA (Platform for Automatic coNstruction of orGanizations of intElligent Agents. This is a platform for developing open multi-agent systems, specifically those including organizational aspects. The main reason for the use of agents is the scalability of the platform, i.e. the way in which it models the services. The system models functionalities as services inside the agents, or as Service Oriented Approach (SOA architecture compliant services using Web Services. This way the adaptation of the odor classification systems with new algorithms, tools and classification techniques is allowed.

  19. CONTROLLING ODOROUS EMISSIONS FROM IRON FOUNDRIES

    Science.gov (United States)

    The report discusses the control of odorous emissions from iron foundries. he main process sources of odors in iron foundries are mold and core making, casting, and sand shakeout. he odors are usually caused by chemicals, which may be present as binders and other additives to the...

  20. Potent odorants characterize the aroma quality of leaves and stalks in raw and boiled celery.

    Science.gov (United States)

    Kurobayashi, Yoshiko; Kouno, Emi; Fujita, Akira; Morimitsu, Yasujiro; Kubota, Kikue

    2006-04-01

    The raw and boiled odors of celery leaves and stalks were investigated. Among 12 compounds identified as potent odorants, 3-n-butylphthalide 1, sedanenolide 2, and trans- and cis-sedanolides 3, 4 were assessed to be most contributive to the overall odor of celery. These three phthalides, (3E,5Z)-1,3,5-undecatriene, myrcene, and (E)-2-nonenal were common to both raw and boiled materials. Two compounds, ((Z)-3-hexenal and (Z)-3-hexenol), were dominant in raw materials and four compounds, (2-methylbutanoic acid, sotolon, beta-damascenone, and beta-ionone), were dominant in boiled materials. Sensory evaluations were performed on natural celery odor and a series of reconstructed model aromas by assigning each intensity ratings for a set of seven odor qualities which aptly describe the odors of raw and boiled celery. According to the evaluation results, six common components contributed to the moderate odor of raw celery, two components dominant in raw materials enhanced the raw celery character, and four components dominant in boiled materials reduced the raw celery character and enhanced the boiled celery character. It was clarified that boiling-induced changes in celery odor were not affected by the amounts of phthalides, but by thermally generated compounds such as sotolon, beta-damascenone, and beta-ionone, which reduce the "green spicy" note.

  1. Size determines antennal sensitivity and behavioral threshold to odors in bumblebee workers

    Science.gov (United States)

    Spaethe, Johannes; Brockmann, Axel; Halbig, Christine; Tautz, Jürgen

    2007-09-01

    The eusocial bumblebees exhibit pronounced size variation among workers of the same colony. Differently sized workers engage in different tasks (alloethism); large individuals are found to have a higher probability to leave the colony and search for food, whereas small workers tend to stay inside the nest and attend to nest duties. We investigated the effect of size variation on morphology and physiology of the peripheral olfactory system and the behavioral response thresholds to odors in workers of Bombus terrestris. Number and density of olfactory sensilla on the antennae correlate significantly with worker size. Consistent with these morphological changes, we found that antennal sensitivity to odors increases with body size. Antennae of large individuals show higher electroantennogram responses to a given odor concentration than those of smaller nestmates. This finding indicates that large antennae exhibit an increased capability to catch odor molecules and thus are more sensitive to odors than small antennae. We confirmed this prediction in a dual choice behavioral experiment showing that large workers indeed are able to respond correctly to much lower odor concentrations than small workers. Learning performance in these experiments did not differ between small and large bumblebees. Our results clearly show that, in the social bumblebees, variation in olfactory sensilla number due to size differences among workers strongly affects individual odor sensitivity. We speculate that superior odor sensitivity of large workers has favored size-related division of labor in bumblebee colonies.

  2. The swipe card model of odorant recognition.

    Science.gov (United States)

    Brookes, Jennifer C; Horsfield, Andrew P; Stoneham, A Marshall

    2012-11-12

    Just how we discriminate between the different odours we encounter is not completely understood yet. While obviously a matter involving biology, the core issue isa matter for physics: what microscopic interactions enable the receptors in our noses-small protein switches—to distinguish scent molecules? We survey what is and is not known about the physical processes that take place when we smell things, highlighting the difficulties in developing a full understanding of the mechanics of odorant recognition. The main current theories, discussed here, fall into two major groups. One class emphasises the scent molecule's shape, and is described informally as a "lock and key" mechanism. But there is another category, which we focus on and which we call "swipe card" theories:the molecular shape must be good enough, but the information that identifies the smell involves other factors. One clearly-defined "swipe card" mechanism that we discuss here is Turin's theory, in which inelastic electron tunnelling is used to discern olfactant vibration frequencies. This theory is explicitly quantal, since it requires the molecular vibrations to take in or give out energy only in discrete quanta. These ideas lead to obvious experimental tests and challenges. We describe the current theory in a form that takes into account molecular shape as well as olfactant vibrations. It emerges that this theory can explain many observations hard to reconcile in other ways. There are still some important gaps in a comprehensive physics-based description of the central steps in odorant recognition. We also discuss how far these ideas carry over to analogous processes involving other small biomolecules, like hormones, steroids and neurotransmitters. We conclude with a discussion of possible quantum behaviours in biology more generally, the case of olfaction being just one example. This paper is presented in honour of Prof. Marshall Stoneham who passed away unexpectedly during its writing.

  3. Modeling indoor odor-odorant concentrations and the relative humidity effect on odor perception at a water reclamation plant

    Science.gov (United States)

    Wang, Tingting; Sattayatewa, Chakkrid; Venkatesan, Dhesikan; Noll, Kenneth E.; Pagilla, Krishna R.; Moschandreas, Demetrios J.

    2011-12-01

    Models formulated to associate odors and odorants in many industrial and agricultural fields ignore the potential effect of relative humidity on odor perception, and are not validated. This study addresses literature limitations by formulating a model that includes relative humidity and by validating the model. The model employs measured paired values, n = 102, of indoor odors and odorants from freshly dewatered biosolids in a post-digestion dewatering building of a Water Reclamation Plant (WRP). A random sub-sample of n = 32 is used to validate the model by associating predicted vs. measured values ( R2 = 0.90). The model is validated again with a smaller independent database from a second WRP ( R2 = 0.85). Moreover this study asserts that reduction of hydrogen sulfide concentrations, conventionally used as a surrogate of sewage odors, to acceptable levels does not assure acceptable odor levels. It is concluded that: (1) The addition of relative humidity results in a stronger association between odors and odorants than the use of H 2S alone; (2) the two step model validation indicates that the model is not simply site-specific but can be applied to similar facilities; and (3) the model is a promising tool for designing odor and odorant control strategies, the ultimate goal of engineering studies.

  4. Genetic Discrimination

    Science.gov (United States)

    ... in Genetics Archive Regulation of Genetic Tests Genetic Discrimination Overview Genetic Information Nondiscrimination Act Genetic Discrimination and ... gov/employees/process.cfm Top of page Genetic Discrimination and Other Laws Bill Clinton's Executive Order Prohibiting ...

  5. Multivariate prediction of odor from pig production based on in-situ measurement of odorants

    Science.gov (United States)

    Hansen, Michael J.; Jonassen, Kristoffer E. N.; Løkke, Mette Marie; Adamsen, Anders Peter S.; Feilberg, Anders

    2016-06-01

    The aim of the present study was to estimate a prediction model for odor from pig production facilities based on measurements of odorants by Proton-Transfer-Reaction Mass spectrometry (PTR-MS). Odor measurements were performed at four different pig production facilities with and without odor abatement technologies using a newly developed mobile odor laboratory equipped with a PTR-MS for measuring odorants and an olfactometer for measuring the odor concentration by human panelists. A total of 115 odor measurements were carried out in the mobile laboratory and simultaneously air samples were collected in Nalophan bags and analyzed at accredited laboratories after 24 h. The dataset was divided into a calibration dataset containing 94 samples and a validation dataset containing 21 samples. The prediction model based on the measurements in the mobile laboratory was able to explain 74% of the variation in the odor concentration based on odorants, whereas the prediction models based on odor measurements with bag samples explained only 46-57%. This study is the first application of direct field olfactometry to livestock odor and emphasizes the importance of avoiding any bias from sample storage in studies of odor-odorant relationships. Application of the model on the validation dataset gave a high correlation between predicted and measured odor concentration (R2 = 0.77). Significant odorants in the prediction models include phenols and indoles. In conclusion, measurements of odorants on-site in pig production facilities is an alternative to dynamic olfactometry that can be applied for measuring odor from pig houses and the effects of odor abatement technologies.

  6. The "Sniffin' Kids" test--a 14-item odor identification test for children.

    Directory of Open Access Journals (Sweden)

    Valentin A Schriever

    Full Text Available Tools for measuring olfactory function in adults have been well established. Although studies have shown that olfactory impairment in children may occur as a consequence of a number of diseases or head trauma, until today no consensus on how to evaluate the sense of smell in children exists in Europe. Aim of the study was to develop a modified "Sniffin' Sticks" odor identification test, the "Sniffin' Kids" test for the use in children. In this study 537 children between 6-17 years of age were included. Fourteen odors, which were identified at a high rate by children, were selected from the "Sniffin' Sticks" 16-item odor identification test. Normative date for the 14-item "Sniffin' Kids" odor identification test was obtained. The test was validated by including a group of congenital anosmic children. Results show that the "Sniffin' Kids" test is able to discriminate between normosmia and anosmia with a cutoff value of >7 points on the odor identification test. In addition the test-retest reliability was investigated in a group of 31 healthy children and shown to be ρ = 0.44. With the 14-item odor identification "Sniffin' Kids" test we present a valid and reliable test for measuring olfactory function in children between ages 6-17 years.

  7. Housing conditions affect rat responses to two types of ambiguity in a reward-reward discrimination cognitive bias task.

    Science.gov (United States)

    Parker, Richard M A; Paul, Elizabeth S; Burman, Oliver H P; Browne, William J; Mendl, Michael

    2014-11-01

    Decision-making under ambiguity in cognitive bias tasks is a promising new indicator of affective valence in animals. Rat studies support the hypothesis that animals in a negative affective state evaluate ambiguous cues negatively. Prior automated operant go/go judgement bias tasks have involved training rats that an auditory cue of one frequency predicts a Reward and a cue of a different frequency predicts a Punisher (RP task), and then measuring whether ambiguous cues of intermediate frequency are judged as predicting reward ('optimism') or punishment ('pessimism'). We investigated whether an automated Reward-Reward (RR) task yielded similar results to, and was faster to train than, RP tasks. We also introduced a new ambiguity test (simultaneous presentation of the two training cues) alongside the standard single ambiguous cue test. Half of the rats experienced an unpredictable housing treatment (UHT) designed to induce a negative state. Control rats were relatively 'pessimistic', whilst UHT rats were quicker, but no less accurate, in their responses in the RR test, and showed less anxiety-like behaviour in independent tests. A possible reason for these findings is that rats adapted to and were stimulated by UHT, whilst control rats in a predictable environment were more sensitive to novelty and change. Responses in the new ambiguity test correlated positively with those in single ambiguous cue tests, and may provide a measure of attention bias. The RR task was quicker to train than previous automated RP tasks. Together, they could be used to disentangle how reward and punishment processes underpin affect-induced cognitive biases.

  8. Changes in the hydrocarbon proportions of colony odor and their consequences on nestmate recognition in social wasps.

    Directory of Open Access Journals (Sweden)

    Elena Costanzi

    Full Text Available In social insects, colonies have exclusive memberships and residents promptly detect and reject non-nestmates. Blends of epicuticular hydrocarbons communicate colony affiliation, but the question remains how social insects use the complex information in the blends to discriminate between nestmates and non-nestmates. To test this we altered colony odor by simulating interspecific nest usurpation. We split Polistes dominulus paper-wasp nests into two halves and assigned a half to the original foundress and the other half to a P. nimphus usurper for 4 days. We then removed foundresses and usurpers from nests and investigated whether emerging P. dominulus workers recognized their never-before-encountered mothers, usurpers and non-nestmates of the two species. Behavioral and chemical analyses of wasps and nests indicated that 1 foundresses marked their nests with their cuticular hydrocarbons; 2 usurpers overmarked foundress marks and 3 emerging workers learned colony odor from nests as the odor of the female that was last on nest. However, notwithstanding colony odor was usurper-biased in usurped nests, workers from these nests recognized their mothers, suggesting that there were pre-imaginal and/or genetically encoded components in colony-odor learning. Surprisingly, workers from usurped nests also erroneously tolerated P. nimphus non-nestmates, suggesting they could not tell odor differences between their P. nimphus usurpers and P. nimphus non-nestmates. Usurpers changed the odors of their nests quantitatively, because the two species had cuticular hydrocarbon profiles that differed only quantitatively. Possibly, P. dominulus workers were unable to detect differences between nestmate and non-nestmate P. nimphus because the concentration of some peaks in these wasps was beyond the range of workers' discriminatory abilities (as stated by Weber's law. Indeed, workers displayed the least discrimination abilities in the usurped nests where the relative

  9. Monitoring of odor nuisance in the tri-city agglomeration

    Science.gov (United States)

    Gebicki, Jacek; Dymerski, Tomasz; Namieśnik, Jacek

    2016-11-01

    The paper describes a principle of operation of odor nuisance monitoring network, which is being designed in the tri-city agglomeration. Moreover, it presents the preliminary results of an investigation on ambient air quality with respect to odour nuisance in a vicinity of the municipal landfill. The investigation was performed during spring-winter season using a prototype of electronic nose and the Nasal Ranger field olfactometers. The prototype was equipped with a set of six semiconductor sensors by FIGARO Co. and one PID-type sensor. The field olfactometers were used to determine mean concentration of odorants, which amounted from 2.2 to 30.2 ou/m3 depending on the place of measurement. In case of the investigation with the electronic nose prototype a classification of the ambient air samples with respect to the place of sampling was performed utilizing kNN algorithm supported with a cross-validation method. Correct classification of the ambient air samples was at the level of 66.7%. Performed investigation revealed that discrimination of the ambient air samples differing in concentration of odorants and place of origin was possible.

  10. Do ambient urban odors evoke basic emotions?

    Directory of Open Access Journals (Sweden)

    Sandra Theresia Weber-Glass

    2014-04-01

    Full Text Available Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman’s (Ekman et al., 1983 basic emotions happiness, surprise, anger, fear, sadness and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles / bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the skin conductance response and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles / bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

  11. Do ambient urban odors evoke basic emotions?

    Science.gov (United States)

    Glass, Sandra T; Lingg, Elisabeth; Heuberger, Eva

    2014-01-01

    Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman's (Ekman et al., 1983) basic emotions happiness, surprise, anger, fear, sadness, and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles/bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate, and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response (SCR) varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the SCR and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles/bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

  12. Plant odorants interfere with detection of sex pheromone signals by male Heliothis virescens

    Directory of Open Access Journals (Sweden)

    Pablo ePregitzer

    2012-10-01

    Full Text Available In many insects, mate finding relies on female-released sex pheromones, which have to be deciphered by the male olfactory system within an odorous background of plant volatiles present in the environment of a calling female. With respect to pheromone-mediated mate localization, plant odorants may be neutral, favorable or disturbing. Here we examined the impact of plant odorants on detection and coding of the major sex pheromone component, (Z-11-hexadecenal (Z11-16:Ald in the noctuid moth Heliothis virescens. By in vivo imaging the activity in the male antennal lobe, we monitored the interference at the level of olfactory sensory neurons (OSN to illuminate mixture interactions. The results show that stimulating the male antenna with Z11-16:Ald and distinct plant-related odorants simultaneously suppressed pheromone-evoked activity in the region of the macroglomerular complex (MGC, where Z11-16:Ald-specific OSNs terminate. Based on our previous findings that antennal detection of Z11-16:Ald involves an interplay of the pheromone binding protein HvirPBP2 and the pheromone receptor HR13, we asked if the plant odorants may interfere with any of the elements involved in pheromone detection. Using a competitive fluorescence binding assay, we found that the plant odorants neither bind to HvirPBP2 nor affect the binding of Z11-16:Ald to the protein. However, imaging experiments analyzing a cell line that expressed the receptor HR13 revealed that plant odorants significantly inhibited the Z11-16:Ald-evoked calcium responses. Together the results indicate that, plant odorants can interfere with the signaling process of the major sex pheromone component at the receptor level. Consequently, it can be assumed that plant odorants in the environment may reduce the firing activity of pheromone-specific OSNs in H. virescens and thus affect mate localization.

  13. Basic emotions evoked by odorants: comparison between autonomic responses and self-evaluation.

    Science.gov (United States)

    Alaoui-Ismaïli, O; Robin, O; Rada, H; Dittmar, A; Vernet-Maury, E

    1997-10-01

    The present study was designed to analyze the relationship between self-report and physiological expression of basic emotions (happiness, surprise, fear, sadness, disgust and anger) in response to odorants. 44 subjects inhaled five odorants: vanillin, menthol, eugenol, methyl methacrylate, and propionic acid. Six autonomic nervous systems (ANS) parameters were simultaneously recorded in real time and without interference: Skin Potential (SP), Skin Resistance (SR), Skin Temperature (ST), Skin Blood Flow (SBF), Instantaneous Respiratory Frequency (IRF) and Instantaneous Heart Rate (IHR). At the end of the recording, subjects were instructed i) to identify the odorants roughly II) to situate them on an 11-point hedonic scale from highly pleasant (0) to highly unpleasant (10); and iii) to define what type of basic emotion was evoked by each odorant. In this study, the expected affects were aroused in the subjects. Vanillin and menthol were rated pleasant, while methyl methacrylate and propionic acid were judged unpleasant. Eugenol was median in hedonic estimation. ANS evaluation (each autonomic pattern induced by an odorant was transcripted into a basic emotion) shows that pleasantly connoted odorants evoked mainly happiness and surprise, but that unpleasant ones induced mainly disgust and anger. Eugenol was associated with positive and negative affects. Comparison between conscious (verbal) and unconscious (ANS) emotions, reveals that these two estimations 1) were not significantly different as far as the two pleasant odorants were concerned, 2) showed a tendency to be significantly different for eugenol odorant which was variably scored on the hedonic axis, and 3) exhibited a significant difference for the two unpleasant odorants, for which the corresponding "verbal emotion" was mainly "disgust", while the most frequent ANS emotion was "anger". In conclusion, these results show quite a good correlation between verbal and ANS estimated basic emotions. The main

  14. Functional Characterization of Odorant Receptors

    Science.gov (United States)

    1994-02-07

    distinct patterns of neural activity ( Sicard and Holley, 1984). Decoding of these patterns is initiated in the olfactory bulb, the first synaptic relay in...flies in the bottom compartment of the tube demarcated by the 3-cm line are taken at 5-second intervals, starting with the 15-second time point . Thus...and Dodd, G. H. (1986) Olfactory adenylate cyclase of the rat: stimulation by odorants and inhibition by Ca>. Biochem. J. 240, 605- 607. Sicard , G

  15. Odor Landscapes in Turbulent Environments

    Science.gov (United States)

    Celani, Antonio; Villermaux, Emmanuel; Vergassola, Massimo

    2014-10-01

    The olfactory system of male moths is exquisitely sensitive to pheromones emitted by females and transported in the environment by atmospheric turbulence. Moths respond to minute amounts of pheromones, and their behavior is sensitive to the fine-scale structure of turbulent plumes where pheromone concentration is detectible. The signal of pheromone whiffs is qualitatively known to be intermittent, yet quantitative characterization of its statistical properties is lacking. This challenging fluid dynamics problem is also relevant for entomology, neurobiology, and the technological design of olfactory stimulators aimed at reproducing physiological odor signals in well-controlled laboratory conditions. Here, we develop a Lagrangian approach to the transport of pheromones by turbulent flows and exploit it to predict the statistics of odor detection during olfactory searches. The theory yields explicit probability distributions for the intensity and the duration of pheromone detections, as well as their spacing in time. Predictions are favorably tested by using numerical simulations, laboratory experiments, and field data for the atmospheric surface layer. The resulting signal of odor detections lends itself to implementation with state-of-the-art technologies and quantifies the amount and the type of information that male moths can exploit during olfactory searches.

  16. Radial localization of odors by human newborns.

    Science.gov (United States)

    Rieser, J; Yonas, A; Wikner, K

    1976-09-01

    To study sensitivity to radial location of an odor source, 20 human newborns, ranging from 16 to 130 hours of age, were presented with a small amount of ammonium hydroxide. The odor source was placed near the nose slightly to the left or right of midline, with its position randomized over repeated trails. Direction of headturn with respect to the odor location and diffuse motor activity were scored from the videotape recordings of the newborns' behavior. It was found that as a group, the newborns turned away from the odor source more frequently than they turned toward it. The tendency to turn away from the odor was stronger in infants who displayed less motor activity after the response. Newborns also exhibited a right bias in the direction of the head movements. It is concluded that a spatially appropriate avoidance response is present in the neonate and that the newborn is innately sensitive to the radial location of an odor.

  17. Exchanging ligand-binding specificity between a pair of mouse olfactory receptor paralogs reveals odorant recognition principles.

    Science.gov (United States)

    Baud, Olivia; Yuan, Shuguang; Veya, Luc; Filipek, Slawomir; Vogel, Horst; Pick, Horst

    2015-10-09

    A multi-gene family of ~1000 G protein-coupled olfactory receptors (ORs) constitutes the molecular basis of mammalian olfaction. Due to the lack of structural data its remarkable capacity to detect and discriminate thousands of odorants remains poorly understood on the structural level of the receptor. Using site-directed mutagenesis we transferred ligand specificity between two functionally related ORs and thereby revealed amino acid residues of central importance for odorant recognition and discrimination of the two receptors. By exchanging two of three residues, differing at equivalent positions of the putative odorant binding site between the mouse OR paralogs Olfr73 (mOR-EG) and Olfr74 (mOR-EV), we selectively changed ligand preference but remarkably also signaling activation strength in both ORs. Computer modeling proposed structural details at atomic resolution how the very same odorant molecule might interact with different contact residues to induce different functional responses in two related receptors. Our findings provide a mechanistic explanation of how the olfactory system distinguishes different molecular aspects of a given odorant molecule, and unravel important molecular details of the combinatorial encoding of odorant identity at the OR level.

  18. Odors: appetizing or satiating? Development of appetite during odor exposure over time

    NARCIS (Netherlands)

    Ramaekers, M.G.; Boesveldt, S.; Lakemond, C.M.M.; Boekel, van M.A.J.S.; Luning, P.A.

    2014-01-01

    Background: Exposure to palatable food odors influences appetite responses, either promoting or inhibiting food intake. Possibly, food odors are appetizing after a short exposure (of circa 1–3¿min), but become satiating over time (circa 10–20¿min). Objective: To investigate the effect of odor exposu

  19. Price Discrimination

    OpenAIRE

    Armstrong, Mark

    2008-01-01

    This paper surveys recent economic research on price discrimination, both in monopoly and oligopoly markets. Topics include static and dynamic forms of price discrimination, and both final and input markets are considered. Potential antitrust aspects of price discrimination are highlighted throughout the paper. The paper argues that the informational requirements to make accurate policy are very great, and with most forms of price discrimination a laissez-faire policy may be the best availabl...

  20. Fractal Based Analysis of the Influence of Odorants on Heart Activity

    Science.gov (United States)

    Namazi, Hamidreza; Kulish, Vladimir V.

    2016-12-01

    An important challenge in heart research is to make the relation between the features of external stimuli and heart activity. Olfactory stimulation is an important type of stimulation that affects the heart activity, which is mapped on Electrocardiogram (ECG) signal. Yet, no one has discovered any relation between the structures of olfactory stimuli and the ECG signal. This study investigates the relation between the structures of heart rate and the olfactory stimulus (odorant). We show that the complexity of the heart rate is coupled with the molecular complexity of the odorant, where more structurally complex odorant causes less fractal heart rate. Also, odorant having higher entropy causes the heart rate having lower approximate entropy. The method discussed here can be applied and investigated in case of patients with heart diseases as the rehabilitation purpose.

  1. Development of a sensory test method for odor measurement in a package headspace

    DEFF Research Database (Denmark)

    Reinbach, Helene Christine; Allesen-Holm, Bodil Helene; Kristoffersson, Lars

    2011-01-01

    The aim of the present study was to develop a sensory method to evaluate off-odors in a package headspace relative to a reference scale. Selection of panelists was performed with a questionnaire and with the Sniffin' stick test. A 1-butanol reference scale and three types of scales (a 15-cm line......, a color-graded brightness line scale and a color-graded brightness category scale) were compared. 1-butanol proved to be a reliable reference scale for the off-odor intensity in the package headspace. The type of scales did not affect the odor intensity ratings; however, the color-graded brightness line...... scale tended to give a greater accuracy of scored odor intensity. The color-graded brightness scale may strengthen the repeatability of the intensity measures due to the cross-modal support in the judgment processes. The method allows the conversion of intensity judgment of a package headspace...

  2. Comparison of the Attraction Index of Male and Female Drosophila. Melanogaster to Varying Odorant Substances

    Directory of Open Access Journals (Sweden)

    S. Abba

    2012-11-01

    Full Text Available This study aims at investigating the differences if any, in the olfactory discrematory ability of wild type drosophila and mutated Or83b type and also if these differences exists between male and females of both species. Insect and mammalian olfactory systems are strikingly similar. Therefore, Drosophila can be used as a simple model for olfaction. The olfactory system has evolved the capacity to recognize and discriminate an inordinate number of chemically distinct odors that signal the presence of food, predators, or mating partners. Most organisms including humans rely on their olfactory system to detect and analyze olfactory cues in the environment, cues that are subsequently utilized in the context of behavior. Several works have been done on the olfactory system of the insect drosophila, attraction of various strain of drosophila to different odors but no work has been done to investigate sexual differences in this attraction to odorants. In this research we try investigating differences in the sensitivity of the olfactory receptors of male and female drosophila by measuring their attraction index to odors (yeast. O83b mutants and ORR wild type flies were used. By behavioral analysis, using the attraction index as a measure of sensitivity of the olfactory receptors, we were able to show that the female flies have a higher attraction index to odorant than the males but this difference is not significant statistically as indicated by the p value.

  3. Water Treatment Technology - Taste, Odor & Color.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on taste, odor, and color provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: taste and odor determination, control of…

  4. Impaired odor perception in tank cleaners.

    Science.gov (United States)

    Ahlström, R; Berglund, B; Berglund, U; Lindvall, T; Wennberg, A

    1986-12-01

    The olfactory perception of 20 men (tank cleaners) exposed to petroleum products (while cleaning oil tanks) was examined. Office workers and watchmen were used as referents (N = 20 + 20). They were matched with regard to sex, age, and smoking habits. Odor detection thresholds and the perceived odor intensity of four odorous stimuli, pyridine, dimethyl disulfide (DMDS), n-butanol, and heating oil vapor (gas phase of heating oil heated to +40 degrees C), were determined. The results suggested that the tank cleaners had higher absolute odor thresholds for n-butanol and oil vapor than the referents. The psychophysical function of the tank cleaners and referents differed for all the tested substances in respect to odor intensity. The tank cleaners displayed an odor deficit analogous to the hearing loss known as "loudness recruitment," ie, normal perception of strong stimuli but impaired perception of weak stimuli. This odor deficit was therefore named "odor intensity recruitment" and seems, in tank cleaners, to be associated with occupational exposure to oil vapor.

  5. Evaluation of impaired fingertip texture discrimination and wrist position sense in patients affected by stroke: comparison of clinical and new quantitative measures.

    Science.gov (United States)

    Carey, Leeanne M; Matyas, Thomas A; Oke, Linda E

    2002-01-01

    Discriminative sensory loss is common following stroke but may not be adequately detected by routine clinical measures. Quantitative tests of texture discrimination and limb position sense have been recently developed. These tests provide reliable estimates of discrimination, differentiate impaired performance following stroke, and have standardized criteria of abnormality. The purpose of this study was to compare predictions of impairment based on current clinical measures with predictions based on these quantitative, standardized measures. Thirty-five patients who had strokes were tested on the new quantitative measures and clinical measures of texture discrimination and limb position sense. The findings indicated poor agreement between impairment defined using current clinical measures and statistically abnormal performance on the new quantitative, norm-referenced measures. The findings suggest that the quantitative tests may provide additional assessment information to supplement that of the existing clinical measures of texture discrimination and limb position sense. Further development of these new quantitative measures is indicated.

  6. The neurobiology of infant maternal odor learning

    Directory of Open Access Journals (Sweden)

    C. Raineki

    2010-10-01

    Full Text Available Infant rats must learn to identify their mother’s diet-dependent odor. Once learned, maternal odor controls pups’ approach to the mother, their social behavior and nipple attachment. Here we present a review of the research from four different laboratories, which suggests that neural and behavioral responses to the natural maternal odor and neonatal learned odors are similar. Together, these data indicate that pups have a unique learning circuit relying on the olfactory bulb for neural plasticity and on the hyperfunctioning noradrenergic locus coeruleus flooding the olfactory bulb with norepinephrine to support the neural changes. Another important factor making this system unique is the inability of the amygdala to become incorporated into the infant learning circuit. Thus, infant rats appear to be primed in early life to learn odors that will evoke approach responses supporting attachment to the caregiver.

  7. The Intensity of Human Body Odors and the MHC: Should We Expect a Link?

    Directory of Open Access Journals (Sweden)

    Claus Wedekind

    2006-01-01

    Full Text Available It is now well established that genes within the major histocompatibility complex (MHC somehow affect the production of body odors in several vertebrates, including humans. Here we discuss whether variation in the intensity of body odors may be influenced by the MHC. In order to examine this question, we have to control for MHC-linked odor perception on the smeller's side. Such a control is necessary because the perception of pleasantness and intensity seem to be confounded, and the causalities are still unsolved. It has previously been found that intense odors are scored as less pleasant if the signaler and the receiver are of MHC-dissimilar type, but not if they are of MHC similar type. We argue, and first data suggest, that an effect of the degree of MHC-heterozygosity and odor intensity is likely (MHC-homozygotes may normally smell more intense, while there is currently no strong argument for other possible links between the MHC and body odor intensity.

  8. Isoamyl alcohol odor promotes longevity and stress tolerance via DAF-16 in Caenorhabditis elegans.

    Science.gov (United States)

    Kurino, Chiho; Furuhashi, Tsubasa; Sudoh, Kaori; Sakamoto, Kazuichi

    2017-02-14

    The possibility that odor plays a role in lifespan regulation through effects on the nervous system is indicated by research on Caenorhabditis elegans. In fact, ablation of AWA and AWC, which are suggested as olfactory neurons, has been shown to extend lifespan via DAF-16, a homolog of FoxO. However, the effects of odor stimuli on the lifespan still remain unclear. Thus, we here aimed to clarify the effect of attractive and repulsive odors on longevity and stress tolerance in C. elegans and to analyze the pathways thereof. We used isoamyl alcohol as an attractive odor, and acetic acid as a repellent component, as identified by chemotaxis assay. We found that isoamyl alcohol stimulus promoted longevity in a DAF-16-dependent manner. On the other hand, acetic acid stimulus promoted thermotolerance through mechanisms independent of DAF-16. Above all, our results indicate that odor stimuli affect the lifespan and stress tolerance of C. elegans, with attractive and repulsive odors exerting their effects through different mechanisms, and that longevity is induced by both activation and inactivation of olfactory neurons.

  9. Enantioselectivity of the Musk Odor Sensation

    Institute of Scientific and Technical Information of China (English)

    G. Fráter; P. Kraft

    2005-01-01

    @@ 1Introduction Chiral recognition of substrates is one of the most characteristic phenomena of biological activity. And one of the most fundamental biological activities of chemical substances is their smell. In 1991, Linda Buck and Richard Axel[1] discovered a large multigene family that en codes odorant receptors, for which they were awarded the 2004 Nobel Prize in Medicine and Physiology. These odorant receptors are highly homologous,consist of ca. 320 amino acids, and show a heptahelical transmembrane structure as typical for G-protein-coupled receptors. In the human genome, 347 putative full-length olfactory receptor genes have been identified,which allow via characteristic activation patterns of the associated glomeruli the differentiation of more than 10 000 odorants. Since the odorant receptors are built from enantiomerically pure amino acids, they are themselves chiral. Consequently, one would expect a strong diastereomeric interaction, and enantiomeric pairs of odorants should thus differ significantly in both their odor character and their strengths or odor threshold.

  10. Effects of Odor on Emotion, with Implications

    Directory of Open Access Journals (Sweden)

    Mikiko eKadohisa

    2013-10-01

    Full Text Available The sense of smell is found widely in the animal kingdom. Human and animal studies show that odor perception is modulated by experience and/or physiological state (such as hunger, and that some odors can arouse emotion, and can lead to the recall of emotional memories. Further, odors can influence psychological and physiological states. Individual odorants are mapped via gene-specified receptors to corresponding glomeruli in the olfactory bulb, which directly projects to the piriform cortex and the amygdala without a thalamic relay. The odors to which a glomerulus responds reflect the chemical structure of the odorant. The piriform cortex and the amygdala both project to the orbitofrontal cortex which with the amygdala is involved in emotion and associative learning, and to the entorhinal/hippocampal system which is involved in long-term memory including episodic memory. Evidence that some odors can modulate emotion and cognition is described, and the possible implications for the treatment of psychological problems, for example in reducing the effects of stress, are considered.

  11. Odor mental imagery in non-experts in odors: a paradox?

    Directory of Open Access Journals (Sweden)

    Jean-Pierre eROYET

    2013-03-01

    Full Text Available In agreement with the theoretical framework stipulating that mental images arise from neural activity in early sensory cortices, the primary olfactory cortex (i.e., the piriform cortex, PC is activated when non-olfactory-experts try to generate odor mental images. This finding strongly contrasts with the allegation that it is typically impossible to mentally imagine odors. However, other neurophysiological or cognitive processes engaged in the endeavor of odor mental imagery such as sniffing, attention, expectation and cross-modal interactions involve the PC and could explain this paradox. To unambiguously study the odor mental imagery, we first argued the need to investigate odor experts who have learned to specifically reactivate olfactory percepts. We then assert the necessity to explore the network dedicated to this function by considering variations in both the activity level and the connection strength of the areas belonging to this network as a function of the level of expertise of the odor experts.

  12. Development Of An Electronic Nose For Environmental Monitoring: Detection Of Specific Environmentally Important Gases At Their Odor Detection Threshold Concentration

    Science.gov (United States)

    Dentoni, Licinia; Capelli, Laura; Sironi, Selena; Del Rosso, Renato; Centola, Paolo; Della Torre, Matteo; Demattè, Fabrizio

    2011-09-01

    The use of a sensor array is demonstrated to be an effective approach to evaluate hazardous odor (or gas) emissions from industrial sites1. Therefore the possibility to use electronic noses for the prolonged survey of odor emissions from industrial sites is of particular interest for environmental monitoring purposes2. At the Olfactometric Laboratory of the Politecnico di Milano, in collaboration with Sacmi Group, Imola, an innovative electronic nose for the continuous monitoring of environmental odors is being developed. The aim of this work is to show the laboratory tests conducted to evaluate the capability of the electronic nose to recognize some specific environmentally important gases at their odor detection threshold concentration. The laboratory studies up to now focused on ammonia and butyric acid, those being compounds that can typically be found in the emissions from waste treatment plants, that may cause health effects when they exceed a given concentration level. The laboratory tests proved the sensors to be sensitive towards the considered compounds and the system to be capable of discriminating between odorous or non-odorous air, with a detection limit comparable with the detection limit of human nose.

  13. Odor and odorous chemical emissions from animal buildings: part 1 - project overview, collection methods, and quality control

    Science.gov (United States)

    Livestock facilities have historically generated public concerns due to their emissions of odorous air and various chemical pollutants. Odor emission factors and identification of principal odorous chemicals are needed to better understand the problem. Applications of odor emission factors include i...

  14. Structural Discrimination

    DEFF Research Database (Denmark)

    Thorsen, Mira Skadegård

    In this article, I discuss structural discrimination, an underrepresented area of study in Danish discrimination and intercultural research. It is defined here as discursive and constitutive, and presented as a central element of my analytical approach. This notion is employed in the with which...

  15. Malaria-induced changes in host odors enhance mosquito attraction.

    Science.gov (United States)

    De Moraes, Consuelo M; Stanczyk, Nina M; Betz, Heike S; Pulido, Hannier; Sim, Derek G; Read, Andrew F; Mescher, Mark C

    2014-07-29

    Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analyses--using discriminant analysis of principal components and random forest approaches--revealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection.

  16. Olfaction Presentation System Using Odor Scanner and Odor-Emitting Apparatus Coupled with Chemical Capsules of Alginic Acid Polymer

    Science.gov (United States)

    Sakairi, Minoru; Nishimura, Ayako; Suzuki, Daisuke

    For the purpose of the application of odor to information technology, we have developed an odor-emitting apparatus coupled with chemical capsules made of alginic acid polymer. This apparatus consists of a chemical capsule cartridge including chemical capsules of odor ingredients, valves to control odor emission, and a temperature control unit. Different odors can be easily emitted by using the apparatus. We have developed an integrated system of vision, audio and olfactory information in which odor strength can be controlled coinciding with on-screen moving images based on analytical results from the odor scanner.

  17. Influence of background noise on the performance in the odor sensitivity task: effects of noise type and extraversion.

    Science.gov (United States)

    Seo, Han-Seok; Hähner, Antje; Gudziol, Volker; Scheibe, Mandy; Hummel, Thomas

    2012-10-01

    Recent research demonstrated that background noise relative to silence impaired subjects' performance in a cognitively driven odor discrimination test. The current study aimed to investigate whether the background noise can also modulate performance in an odor sensitivity task that is less cognitively loaded. Previous studies have shown that the effect of background noise on task performance can be different in relation to degree of extraversion and/or type of noise. Accordingly, we wanted to examine whether the influence of background noise on the odor sensitivity task can be altered as a function of the type of background noise (i.e., nonverbal vs. verbal noise) and the degree of extraversion (i.e., introvert vs. extrovert group). Subjects were asked to conduct an odor sensitivity task in the presence of either nonverbal noise (e.g., party sound) or verbal noise (e.g., audio book), or silence. Overall, the subjects' mean performance in the odor sensitivity task was not significantly different across three auditory conditions. However, with regard to the odor sensitivity task, a significant interaction emerged between the type of background noise and the degree of extraversion. Specifically, verbal noise relative to silence significantly impaired or improved the performance of the odor sensitivity task in the introvert or extrovert group, respectively; the differential effect of introversion/extraversion was not observed in the nonverbal noise-induced task performance. In conclusion, our findings provide new empirical evidence that type of background noise and degree of extraversion play an important role in modulating the effect of background noise on subjects' performance in an odor sensitivity task.

  18. Characterization and analysis of diesel exhaust odor

    Energy Technology Data Exchange (ETDEWEB)

    Partridge, P.A.; Shala, F.J.; Cernansky, N.P.; Suffet, I.H.

    1987-04-01

    An analytical method was developed to determine which compound or compounds in the oxygenated fraction of diesel exhaust were changing in intensity and number with respect to the odor correlation between human sensory panels and diesel exhaust samples as developed at Arthur D. Little, Inc. A sample fractionation with silica Sep-Pak cartridges and gas chromatography analysis procedures were developed to analyze exhaust odor samples. By use of a chromatographic computer profiling method, correlations were developed indicating a linear relation between log (odor intensity) and log (concentration) of specific character impact peaks (which may or may not be odorous themselves). Excellent correlations were obtained with the character impact peaks identified as benzaldehyde and a methylbenzaldehyde isomer in this study. Correlation coefficients of 0.97 and 0.90, respectively, were obtained for the sample set. 17 references, 5 figures, 2 tables.

  19. Selectivity of Odorant Receptors in Insects

    Science.gov (United States)

    2012-07-13

    repellents do not elicit evolutionary adaptive behaviors in mosquitoes , but rather disrupt the final stages of host attraction (Figure 1B). It is...Dickens, J. C. (2010). Insect repellents : mod- ulators of mosquito odorant receptor activity. PLoS ONE 5, e12138. doi: 10.1371/journal.pone. 0012138...Multiple activities of insect repellents on odorant receptors in mosquitoes . Med. Vet. Entomol. 25, 436–444. Bohbot, J. D., Jones, P. L., Wang, G

  20. Olfactory sensitivity and odor structure-activity relationships for aliphatic carboxylic acids in CD-1 mice.

    Science.gov (United States)

    Can Güven, Selçuk; Laska, Matthias

    2012-01-01

    Using a conditioning paradigm, the olfactory sensitivity of CD-1 mice for a homologous series of aliphatic n-carboxylic acids (ethanoic acid to n-octanoic acid) and several of their isomeric forms was investigated. With all 14 odorants, the animals significantly discriminated concentrations as low as 0.03 ppm (parts per million) from the solvent, and with four odorants the best-scoring animals even detected concentrations as low as 3 ppt (parts per trillion). Analysis of odor structure-activity relationships showed that the correlation between olfactory detection thresholds of the mice for the unbranched carboxylic acids and carbon chain length can best be described as a U-shaped function with the lowest threshold values at n-butanoic acid. A significant positive correlation between olfactory detection thresholds and carbon chain length of the carboxylic acids with their branching next to the functional carboxyl group was found. In contrast, no such correlation was found for carboxylic acids with their branching at the distal end of the carbon chain relative to the functional carboxyl group. Finally, a significant correlation was found between olfactory detection thresholds and the position of the branching of the carboxylic acids. Across-species comparisons suggest that mice are more sensitive for short-chained (C(2) to C(4)) aliphatic n-carboxylic acids than other mammalian species, but not for longer-chained ones (C(5) to C(8)). Further comparisons suggest that odor structure-activity relationships are both substance class- and species-specific.

  1. A model for discrimination freshness of shrimp

    Directory of Open Access Journals (Sweden)

    Linong Du

    2015-12-01

    Full Text Available The shrimp is popular for its nutrition and dainty, however, it is easy to decay, and its freshness degrades, so, it is important to assess its freshness. The shrimp gives off unpleasant odor with its freshness change, detecting its odor difference can evaluate its freshness. The feasibility of using electronic nose for evaluating the freshness of shrimp (Penaeus vanmamei is explored in this paper. The odor of shrimp, stored at 5 °C, was detected by the electronic nose. Combined with the sensory evaluation and TVBN, a model based on the electronic nose was constructed to evaluate the shrimp freshness. In principal components analysis, the first three principal components accounted for 86.97% of total variation, and they are used to establish a model to estimate the shrimp freshness with Fisher Liner Discriminant. The discriminant rates were 98.3% for 120 modeling sample data, and 91.7% for 36 testing sample data. The model could be easily used to evaluate the freshness of shrimp with better accuracy.

  2. Direct nuclear magnetic resonance observation of odorant binding to mouse odorant receptor MOR244-3.

    Science.gov (United States)

    Burger, Jessica L; Jeerage, Kavita M; Bruno, Thomas J

    2016-06-01

    Mammals are able to perceive and differentiate a great number of structurally diverse odorants through the odorant's interaction with odorant receptors (ORs), proteins found within the cell membrane of olfactory sensory neurons. The natural gas industry has used human olfactory sensitivity to sulfur compounds (thiols, sulfides, etc.) to increase the safety of fuel gas transport, storage, and use through the odorization of this product. In the United States, mixtures of sulfur compounds are used, but the major constituent of odorant packages is 2-methylpropane-2-thiol, also known as tert-butyl mercaptan. It has been fundamentally challenging to understand olfaction and odorization due to the low affinity of odorous ligands to the ORs and the difficulty in expressing a sufficient number of OR proteins. Here, we directly observed the binding of tert-butyl mercaptan and another odiferous compound, cis-cyclooctene, to mouse OR MOR244-3 on living cells by saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy. This effort lays the groundwork for resolving molecular mechanisms responsible for ligand binding and resulting signaling, which in turn will lead to a clearer understanding of odorant recognition and competition.

  3. Assessment of odor activity value coefficient and odor contribution based on binary interaction effects in waste disposal plant

    Science.gov (United States)

    Wu, Chuandong; Liu, Jiemin; Yan, Luchun; Chen, Haiying; Shao, Huiqi; Meng, Tian

    2015-02-01

    Odor activity value (OAV) has been widely used for the assessment of odor pollution from various sources. However, little attention has been paid to the extreme OAV variation and potential inaccuracies of odor contribution assessment caused by odor interaction effects. The objective of this study is to assess the odor interaction effect for precise assessment of odor contribution. In this paper, samples were collected from a food waste disposal plant, and analyzed by instrumental and olfactory method to conclude odorants' occurrence and OAV. Then odor activity value coefficient (γ) was first proposed to evaluate the type and the level of binary interaction effects based on determination of OAV variation. By multiplying OAV and γ, odor activity factor (OAF) was used to reflect the real OAV. Correlation between the sum of OAF and odor concentration reached 80.0 ± 5.7%, which was 10 times higher than the sum of OAV used before. Results showed that hydrogen sulfide contributed most (annual average 66.4 ± 15.8%) to odor pollution in the waste disposal plant. However, as odor intensity of samples in summer rising, odor contribution of trimethylamine increased to 48.3 ± 3.7% by the strong synergistic interaction effect, while odor contribution of phenol decreased to 0.1 ± 0.02% for the increasing antagonistic interaction effect.

  4. Release of drinking water contaminants and odor impacts caused by green building cross-linked polyethylene (PEX) plumbing systems.

    Science.gov (United States)

    Kelley, Keven M; Stenson, Alexandra C; Dey, Rajarashi; Whelton, Andrew J

    2014-12-15

    Green buildings are increasingly being plumbed with crosslinked polyethylene (PEX) potable water pipe. Tap water quality was investigated at a six month old plumbing system and chemical and odor quality impacts of six PEX pipe brands were examined. Eleven PEX related contaminants were found in the plumbing system; one regulated (toluene) and several unregulated: Antioxidant degradation products, resin solvents, initiator degradation products, or manufacturing aides. Water chemical and odor quality was monitored for new PEX-a, -b and -c pipes with (2 mg/L free chlorine) and without disinfectant over 30 days. Odor and total organic carbon (TOC) levels decreased for all pipes, but odor remained greater than the USA's Environmental Protection Agency's (USEPA) secondary maximum contaminant level. Odors were not attributed to known odorants ethyl-tert-butyl ether (ETBE) or methyl-tert-butyl ether (MTBE). Free chlorine caused odor levels for PEX-a1 pipe to increase from 26 to 75 threshold odor number (TON) on day 3 and affected the rate at which TOC changed for each brand over 30 days. As TOC decreased, the ultraviolet absorbance at 254 nm increased. Pipes consumed as much as 0.5 mg/L as Cl2 during each 3 day stagnation period. Sixteen organic chemicals were identified, including toluene, pyridine, methylene trichloroacetate and 2,4-di-tert-butylphenol. Some were also detected during the plumbing system field investigation. Six brands of PEX pipes sold in the USA and a PEX-a green building plumbing system impacted chemical and drinking water odor quality.

  5. [Odor sensing system and olfactory display].

    Science.gov (United States)

    Nakamoto, Takamichi

    2014-01-01

    In this review, an odor sensing system and an olfactory display are introduced into people in pharmacy. An odor sensing system consists of an array of sensors with partially overlapping specificities and pattern recognition technique. One of examples of odor sensing systems is a halitosis sensor which quantifies the mixture composition of three volatile sulfide compounds. A halitosis sensor was realized using a preconcentrator to raise sensitivity and an electrochemical sensor array to suppress the influence of humidity. Partial least squares (PLS) method was used to quantify the mixture composition. The experiment reveals that the sufficient accuracy was obtained. Moreover, the olfactory display, which present scents to human noses, is explained. A multi-component olfactory display enables the presentation of a variety of smells. The two types of multi-component olfactory display are described. The first one uses many solenoid valves with high speed switching. The valve ON frequency determines the concentration of the corresponding odor component. The latter one consists of miniaturized liquid pumps and a surface acoustic wave (SAW) atomizer. It enables the wearable olfactory display without smell persistence. Finally, the application of the olfactory display is demonstrated. Virtual ice cream shop with scents was made as a content of interactive art. People can enjoy harmony among vision, audition and olfaction. In conclusion, both odor sensing system and olfactory display can contribute to the field of human health care.

  6. Detection and Classification of Human Body Odor Using an Electronic Nose

    Directory of Open Access Journals (Sweden)

    Teerakiat Kerdcharoen

    2009-09-01

    Full Text Available An electronic nose (E-nose has been designed and equipped with software that can detect and classify human armpit body odor. An array of metal oxide sensors was used for detecting volatile organic compounds. The measurement circuit employs a voltage divider resistor to measure the sensitivity of each sensor. This E-nose was controlled by in-house developed software through a portable USB data acquisition card with a principle component analysis (PCA algorithm implemented for pattern recognition and classification. Because gas sensor sensitivity in the detection of armpit odor samples is affected by humidity, we propose a new method and algorithms combining hardware/software for the correction of the humidity noise. After the humidity correction, the E-nose showed the capability of detecting human body odor and distinguishing the body odors from two persons in a relative manner. The E-nose is still able to recognize people, even after application of deodorant. In conclusion, this is the first report of the application of an E-nose for armpit odor recognition.

  7. Chemical complexity of odors increases reliability of olfactory threshold testing.

    Science.gov (United States)

    Oleszkiewicz, Anna; Pellegrino, Robert; Pusch, Katharina; Margot, Celine; Hummel, Thomas

    2017-01-10

    Assessment of odor thresholds is a widely recognized method of measuring olfactory abilities in humans. To date no attempts have been made to assess whether chemical complexity of odors used can produce more reliable results. To this end, we performed two studies of repeated measures design with 121 healthy volunteers (age 19-62 years). In Study 1, we compared thresholds obtained from tests based on one odor presented in a pen-like odor dispensing device with three odors and six odors mixtures presented in glass containers. In study 2 we compared stimuli of one and three odors, both presented in glass containers. In both studies measurements were performed twice, separated by at least three days. Results indicate that the multiple odor mixtures produced more reliable threshold scores, as compared to thresholds based on a single substance.

  8. A fishy odor episode in a north China reservoir: occurrence, origin, and possible odor causing compounds.

    Science.gov (United States)

    Zhao, Yunyun; Yu, Jianwei; Su, Ming; An, Wei; Yang, Min

    2013-12-01

    A significant outbreak of fishy odor occurred in a reservoir located in Inner Mongolia, China, in the winter of 2011, and the odor rating, algal density and concentrations of some potential odorous compounds were monitored over a period of two months. The peak odor rating of the fishy odor was 7 according to flavor profile analysis. Among the dominant algal species (two diatom and one chrysophyte species) observed during the survey, the chrysophyte Dinobryon sp. was the most abundant species, with the peak density recorded at 88,520 cells/mL. Seven potential algal metabolites including heptanal, 2,4-heptadienal, 2,4-decadienal, nonanal, 2-octenal, 2,6-nonadienal and hexanal were detected. The principal component analysis result showed that n-hexanal, n-heptanal and 2,4-decadienal, possibly the metabolites of diatoms, and 2,4-heptadienal, possibly the metabolite of Dinobryon sp., might have contributed to the fishy odor episode. This study demonstrated that the fishy odor episode in this reservoir might be caused by the abnormal growth of chrysophytes and diatoms under the ice-cover.

  9. Single-unit activity in piriform cortex during slow-wave state is shaped by recent odor experience.

    Science.gov (United States)

    Wilson, Donald A

    2010-02-03

    Memory and its underlying neural plasticity play important roles in sensory discrimination and cortical pattern recognition in olfaction. Given the reported function of slow-wave sleep states in neocortical and hippocampal memory consolidation, we hypothesized that activity during slow-wave states within the piriform cortex may be shaped by recent olfactory experience. Rats were anesthetized with urethane and allowed to spontaneously shift between slow-wave and fast-wave states as recorded in local field potentials within the anterior piriform cortex. Single-unit activity of piriform cortical layer II/III neurons was recorded simultaneously. The results suggest that piriform cortical activity during slow-wave states is shaped by recent (several minutes) odor experience. The temporal structure of single-unit activity during slow waves was modified if the animal had been stimulated with an odor within the receptive field of that cell. If no odor had been delivered, the activity of the cell during slow-wave activity was stable across the two periods. The results demonstrate that piriform cortical activity during slow-wave state is shaped by recent odor experience, which could contribute to odor memory consolidation.

  10. Microbial survival and odor in laundry

    DEFF Research Database (Denmark)

    Jepsen, Signe Munk; Johansen, Charlotte; Stahnke, Louise Heller

    2001-01-01

    -were evaluated on cotton textile. A significant survival and transfer between textiles were found for all four test strains washed in E.U. and U.S. color detergents (without bleach), whereas no survival was observed in bleach-containing detergents. Gram-negative strains generally survived in greater numbers than...... Gram-positive strains. A greater survival was observed in U.S. detergents at U.S. conditions (30 degreesC, 12 min) than in E.U. detergents at E.U. conditions (40 degreesC, 30 min). The adhesion of odorants to cotton and polyester textiles during washing and drying was studied using six previously......, hydrophobic odorants [(Z)-4- heptenal, (E)-2-nonenal, and guaiacol] adhered more strongly to polyester than the acids. The odor formed by surviving skin microflora attached to textiles soiled with human sebum and sweat after laundering at 30 degreesC was studied by sensory evaluation and aroma extract...

  11. Unsaturated hydrocarbons with fruity and floral odors.

    Science.gov (United States)

    Anselmi, C; Centini, M; Fedeli, P; Paoli, M L; Sega, A; Scesa, C; Pelosi, P

    2000-04-01

    Hydrocarbons usually do not exhibit odors of interest or well-defined character. However, certain cyclic alkenes have been associated with typical and pleasant notes, such as fruity, green, and floral. One of the best known examples is represented by the isomeric megastigmatrienes, endowed with a pleasant smell of tropical fruits. From the structures of these odorants, 24 analogues and homologues, most of them cyclic alkenes, but including also some open-chain alkenes, have been synthesized to define structural parameters related to the characteristic odors of these compounds. The number and position of double bonds, the substitution on the ring, and the size of the ring are the variables taken into account. Most of the new compounds present a mainly fruity character, associated in several cases with floral and green notes, producing an overall sensation described as "tropical fruit".

  12. Ventilation requirements for control of occupancy odor and tobacco smoke odor: laboratory studies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cain, W.S.; Isseroff, R.; Leaderer, B.P.; Lipsitt, E.D.; Huey, R.J.; Perlman, D.; Bergland, L.G.; Dunn, J.D.

    1981-04-01

    Experiments on occupancy odor addressed the question of why required ventilation rate per occupant increased progressively with increases in the number of persons in a space. In order to investigate ventilation requirements under approximately ideal conditions, we constructed an aluminum-lined environmental chamber with excellent control over environmental conditions and a ventilation system that provided rapid and uniform mixing of air. Psychophysical experiments on occupancy odor explored 47 different combinations of occupancy density, temperature and humidity, and ventilation rate. The experiments collected judgements both from visitors, who smelled air from the chamber only once every few minutes, and from occupants, who remained in the chamber for an hour at a time. The judgements of visitors revealed that occupancy odor increased only gradually over time and rarely reached very high or objectionable levels. Judgements of occupants also revealed rather minor dissatisfaction. Only during combinations of high temperature and humidity did objectionability become more than a minor issue to either group. Experiments on cigarette smoking explored rates of 4, 8, and 16 cigarettes per hour under various environmental conditions and with ventilation rates as high as 68 cfm (34 L.s/sup -1/) per occupant. As soon as occupants lit cigarettes in the chamber, the odor level increased dramatically. At ventilation rates far greater than necessary to control occupancy odor, the odor from cigarette smoking remained quite intense. In general, the odor proved impossible to control adequately even with a ventilation rate of 68 cfm (34 L.s/sup -1/) per occupant (4 occupants) and even when only one occupant smoked at a time. As in the case of occupancy odor, a combination of high temperature and humidity exacerbated the odor problem.

  13. Sampling Odor Substances by Mist-Cyclone System

    Science.gov (United States)

    Matsubara, Osamu; Jiang, Zhiheng; Toyama, Shigeki

    2009-05-01

    Many techniques have been developed to measure odor substances. However most of those methods are based on using aquatic solutions(1),(2). Many odor substances specifically at low density situation, are difficult to dissolve into water. To absorb odor substances and obtain highest concentration solutions are key problems for olfactory systems. By blowing odor substances contained air mixture through mist of water and then separating the liquid from two-phases fluid with a cyclone unit a high concentration solution was obtained.

  14. Behavioral responses to mammalian blood odor and a blood odor component in four species of large carnivores.

    Directory of Open Access Journals (Sweden)

    Sara Nilsson

    Full Text Available Only little is known about whether single volatile compounds are as efficient in eliciting behavioral responses in animals as the whole complex mixture of a behaviorally relevant odor. Recent studies analysing the composition of volatiles in mammalian blood, an important prey-associated odor stimulus for predators, found the odorant trans-4,5-epoxy-(E-2-decenal to evoke a typical "metallic, blood-like" odor quality in humans. We therefore assessed the behavior of captive Asian wild dogs (Cuon alpinus, African wild dogs (Lycaon pictus, South American bush dogs (Speothos venaticus, and Siberian tigers (Panthera tigris altaica when presented with wooden logs that were impregnated either with mammalian blood or with the blood odor component trans-4,5-epoxy-(E-2-decenal, and compared it to their behavior towards a fruity odor (iso-pentyl acetate and a near-odorless solvent (diethyl phthalate as control. We found that all four species displayed significantly more interactions with the odorized wooden logs such as sniffing, licking, biting, pawing, and toying, when they were impregnated with the two prey-associated odors compared to the two non-prey-associated odors. Most importantly, no significant differences were found in the number of interactions with the wooden logs impregnated with mammalian blood and the blood odor component in any of the four species. Only one of the four species, the South American bush dogs, displayed a significant decrease in the number of interactions with the odorized logs across the five sessions performed per odor stimulus. Taken together, the results demonstrate that a single blood odor component can be as efficient in eliciting behavioral responses in large carnivores as the odor of real blood, suggesting that trans-4,5-epoxy-(E-2-decenal may be perceived by predators as a "character impact compound" of mammalian blood odor. Further, the results suggest that odorized wooden logs are a suitable manner of environmental

  15. The Swipe Card Model of Odorant Recognition 

    Directory of Open Access Journals (Sweden)

    Jennifer C. Brookes

    2012-11-01

    Full Text Available Just how we discriminate between the different odours we encounter is notcompletely understood yet. While obviously a matter involving biology, the core issue isa matter for physics: what microscopic interactions enable the receptors in our noses-smallprotein switches—to distinguish scent molecules? We survey what is and is not known aboutthe physical processes that take place when we smell things, highlighting the difficultiesin developing a full understanding of the mechanics of odorant recognition. The maincurrent theories, discussed here, fall into two major groups. One class emphasises thescent molecule's shape, and is described informally as a "lock and key" mechanism. Butthere is another category, which we focus on and which we call "swipe card" theories:the molecular shape must be good enough, but the information that identifies the smellinvolves other factors. One clearly-defined "swipe card" mechanism that we discuss hereis Turin's theory, in which inelastic electron tunnelling is used to discern olfactant vibrationfrequencies. This theory is explicitly quantal, since it requires the molecular vibrations totake in or give out energy only in discrete quanta. These ideas lead to obvious experimentaltests and challenges. We describe the current theory in a form that takes into accountmolecular shape as well as olfactant vibrations. It emerges that this theory can explainmany observations hard to reconcile in other ways. There are still some important gapsin a comprehensive physics-based description of the central steps in odorant recognition. We also discuss how far these ideas carry over to analogous processes involving other smallbiomolecules, like hormones, steroids and neurotransmitters. We conclude with a discussionof possible quantum behaviours in biology more generally, the case of olfaction being justone example. This paper is presented in honour of Prof. Marshall Stoneham who passedaway unexpectedly during its writing. 

  16. Odor management in petroleum refining units; Gerenciamento de odores em refinaria de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Gutierres, Ricardo; Evangelho, Mauro Rocha; Moreira, Andrea Cristina de Castro Araujo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). P e D de Energia e Desenvolvimento Sustentavel (PDEDS)

    2004-07-01

    Odor emissions can cause serious annoyance in the neighbourhood of the emissions sources related to industrial processes and effluent and wastewater treatments. Jointly with the industrial control for reducing the odor, the emissions monitoring becomes convenient for identification and quantification of compounds responsible for the odors. To reach this objective, they are proposed analytical and olfactometric methodologies. The analytical procedures are based on the application of methods of sampling and analysis in gas chromatography-mass spectrometry, accepted for environmental agencies. The olfactometric methodology is based on the use of procedures that consider the subjective manner with that the odors are felt and evaluated by the people. This work describes as these methodologies can be applied in petroleum refining units. (author)

  17. Predicting Odor Pleasantness from Odorant Structure: Pleasantness as a Reflection of the Physical World

    Science.gov (United States)

    2009-11-01

    dimentional space made of the first and second PCs. The 9 odorants used in Experiment 1(acetophenone, amyl acetate, diphenyl oxide, ethyl butyrate, eugenol ...ethyl butyrate, eugenol , guaiacol) are in further enlarged circles. C: For the 9 odorants, the correlation between explicit perceived similarity... Eugenol , Heptanal, Hexanoic acid, Hexanol1, Hexanol3, Indole, Methyl-iso-Borneol2, Methyl Quinolinepara, Octanol1, Octenol-1-3-OL, Phenyl Ethanol, Skatole

  18. Diagnostic and solutions for the odors problems in the waste water treatment plants in Monte Orgegia (Alicante) with olphactometry techniques; Diagnostico y soluciones a los problemas de olores en la E.D.A.R. de Monte Orgegia (Alicante) mediante tecnicas de olfatometria

    Energy Technology Data Exchange (ETDEWEB)

    Valor Herencia, I.; Cortada, C. [Labaqua, S.A., Alicante (Spain); Uribarri, E.; Suarez, C. [Haskoning, S.a., Madrid (Spain)

    1996-10-01

    The problem of odor nuisances affects our society more and more each day. There are many activities that generate bad odors, such as wastewater treatment plants, municipal waste treatment plants, industries, etc. These problems are difficult to solve as the solutions must be based on the knowledge of odor origin and intensity. Olfactometry techniques establish a relation between the origin of odors (generation and emission) and the nuisance caused in the surroundings (inmision). In this paper, a recent study for the identification of odor problems and the proposed of the solutions in a wastewater treatment plant in Alicante (Spain) using the olfactometry techniques is shown.

  19. Cross-cultural color-odor associations

    NARCIS (Netherlands)

    Levitan, C.A.; Ren, J.; Boesveldt, S.; Chan, J.; McKenzie, K.J.; Levin, J.A.; Leong, C.X.; Bosch, van den J.F.

    2014-01-01

    Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons (i.e.

  20. Turning tryptophanase into odor-generating biosensors.

    Science.gov (United States)

    Xu, Yaqin; Zhang, Zhuyuan; Ali, M Monsur; Sauder, Joanna; Deng, Xudong; Giang, Karen; Aguirre, Sergio D; Pelton, Robert; Li, Yingfu; Filipe, Carlos D M

    2014-03-01

    An odor-based sensor system that exploits the metabolic enzyme tryptophanase (TPase) as the key component is reported. This enzyme is able to convert an odorless substrate like S-methyl-L-cysteine or L-tryptophan into the odorous products methyl mercaptan or indole. To make a biosensor, TPase was biotinylated so that it could be coupled with a molecular recognition element, such as an antibody, to develop an ELISA-like assay. This method was used for the detection of an antibody present in nM concentrations by the human nose. TPase can also be combined with the enzyme pyridoxal kinase (PKase) for use in a coupled assay to detect adenosine 5'-triphosphate (ATP). When ATP is present in the low μM concentration range, the coupled enzymatic system generates an odor that is easily detectable by the human nose. Biotinylated TPase can be combined with various biotin-labeled molecular recognition elements, thereby enabling a broad range of applications for this odor-based reporting system.

  1. Assessment of Odor Annoying Impacts on Trade and Serving Centers Close to a Vegetable Oil Manufacturing Plant

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Monazzam

    2012-12-01

    Full Text Available The environmental odor pollution emitted from different sources has undesirable impacts on communities' health and welfare in a way that caused increasing public worry and complains around the world.Pars Vegetable Oil Processing Plant (PVOPP is located near populated residential areas in Tehran; hence, many people are exposed to the plant process annoying odor daily. In order to assess the odor annoying impacts on its nearby business centers a social survey has been applied.In the field area 200 questionnaires were intended to be filled out but 180 of them have been completed by the respondents (90%. Almost 98% of the respondents have perceived the odor from the outdoor source in their working places which is known as the industry by 78% of them. Among the respondents 42% of them have defined the odor as intolerable.Considering that industry has been recognized as the most important external parameter which affect the quality of working environments, the impact of this industrial unit on decreasing the quality level of working conditions is more obvious. The duration of presence in the working place and record of service are related to disorders in working activity and emotion and thus confirm the odor pollution impacts on the employees' efficiency.

  2. Eye-catching odors: olfaction elicits sustained gazing to faces and eyes in 4-month-old infants.

    Science.gov (United States)

    Durand, Karine; Baudouin, Jean-Yves; Lewkowicz, David J; Goubet, Nathalie; Schaal, Benoist

    2013-01-01

    This study investigated whether an odor can affect infants' attention to visually presented objects and whether it can selectively direct visual gaze at visual targets as a function of their meaning. Four-month-old infants (n = 48) were exposed to their mother's body odors while their visual exploration was recorded with an eye-movement tracking system. Two groups of infants, who were assigned to either an odor condition or a control condition, looked at a scene composed of still pictures of faces and cars. As expected, infants looked longer at the faces than at the cars but this spontaneous preference for faces was significantly enhanced in presence of the odor. As expected also, when looking at the face, the infants looked longer at the eyes than at any other facial regions, but, again, they looked at the eyes significantly longer in the presence of the odor. Thus, 4-month-old infants are sensitive to the contextual effects of odors while looking at faces. This suggests that early social attention to faces is mediated by visual as well as non-visual cues.

  3. Using odor cues to elicit a behavioral and hormonal response in zoo-housed African wild dogs.

    Science.gov (United States)

    Rafacz, Michelle L; Santymire, Rachel M

    2014-01-01

    Olfactory enrichment, like odor cues, can positively affect behavior, reproductive success, and stress physiology in zoo-housed species. Our goal was to determine if odor cues were enriching to the African wild dog (AWD; Lycaon pictus), a species with a complex social structure and a highly developed sense of smell. Our objectives were to: (1) examine changes in activity levels and stress hormone physiology in response to fecal odor cues from natural competitor and natural/unnatural prey species; and (2) determine whether these odor cues could function as effective enrichment for zoo-housed AWDs. Over a 6-month period, fecal samples were collected from two males (AWD 1: dominant, AWD 2: subordinate), fecal glucocorticoid metabolites (FGMs) were validated using an ACTH-challenge, and hormones were analyzed for FGMs by enzyme immunoassay. Behavioral observations were conducted using scan-sampling, and contact and proximity were recorded. AWDs were presented with three fecal odor cues: LION (competitor), CATTLE (unnatural prey), and GAZELLE (natural prey). Only the GAZELLE cue elicited an increase in activity (10.6%) in both individuals and increased positive social behaviors with higher frequencies of affiliative, submissive, and dominant behavior. AWD 1 demonstrated lower (P < 0.05) FGMs than AWD 2 both before and after all odor cues, and FGMs decreased (P = 0.08) in AWD 2 after all cues. We conclude that exposure to natural prey odor cues may be used as effective enrichment for AWDs, and that changes in stress hormone physiology in response to odor cues may be dependent on social rank in this species.

  4. The insular taste cortex contributes to odor quality coding

    Directory of Open Access Journals (Sweden)

    Maria G Veldhuizen

    2010-07-01

    Full Text Available Despite distinct peripheral and central pathways, stimulation of both the olfactory and the gustatory systems may give rise to the sensation of sweetness. Whether there is a common central mechanism producing sweet quality sensations or two discrete mechanisms associated independently with gustatory and olfactory stimuli is currently unknown. Here we used fMRI to determine whether odor sweetness is represented in the piriform olfactory cortex, which is thought to code odor quality, or in the insular taste cortex, which is thought to code taste quality. Fifteen participants sampled two concentrations of a pure sweet taste (sucrose, two sweet food odors (chocolate and strawberry, and two sweet floral odors (lilac and rose. Replicating prior work we found that olfactory stimulation activated the piriform, orbitofrontal and insular cortices. Of these regions, only the insula also responded to sweet taste. More importantly, the magnitude of the response to the food odors, but not to the non-food odors, in this region of insula was positively correlated with odor sweetness rating. These findings demonstrate that insular taste cortex contributes to odor quality coding by representing the taste-like aspects of food odors. Since the effect was specific to the food odors, and only food odors are experienced with taste, we suggest this common central mechanism develops as a function of experiencing flavors.

  5. Does odor and taste identification change during hyperemesis gravidarum?

    Directory of Open Access Journals (Sweden)

    Mehmet Yasar

    2016-02-01

    Full Text Available Aim To investigate a difference in odor and taste identification among pregnant women with hyperemesis gravidarum, those with healthy pregnancy and non-pregnant women. Methods This prospective, controlled study included 33 pregnant women with hyperemesis gravidarum, 33 healthy pregnant and 26 non-pregnant women. For all participants, rhinological examinations were performed. Odor and taste identification were performed by holding Sniffin Sticks test battery (Burghart, Wedel, Germany in all participants. Results There was a statistically significant difference in results of odor identification tests among the groups (p=0.031. Rose odor was selected as the most pleasant odor by the hyperemesis gravidarum group, 32 (96.9%. Orange odor was selected as the most pleasant odor by the healthy pregnant women, 33 (100% whereas the banana odor was selected as the most pleasant odor by the healthy non-pregnant women, 10 (38.4%. In taste identification tests, there was a significant difference in total taste scores among the groups (p=0.003. Conclusion It is obvious that there is a need to evaluate odor thresholds and other parameters by detailed studies on odor perception in the context of hyperemesis gravidarum.

  6. Increasing Explicit Sequence Knowledge by Odor Cueing during Sleep in Men but not Women.

    Science.gov (United States)

    Diekelmann, Susanne; Born, Jan; Rasch, Björn

    2016-01-01

    Sleep consolidates newly acquired memories. Beyond stabilizing memories, sleep is thought to reorganize memory representations such that invariant structures, statistical regularities and even new explicit knowledge are extracted. Whereas increasing evidence suggests that the stabilization of memories during sleep can be facilitated by cueing with learning-associated stimuli, the effect of cueing on memory reorganization is less well understood. Here we asked whether olfactory cueing during sleep enhances the generation of explicit knowledge about an implicitly learned procedural memory task. Subjects were trained on a serial reaction time task (SRTT) containing a hidden 12-element sequence in the presence of an odor. During subsequent sleep, half of the subjects were re-exposed to the odor during periods of slow wave sleep (SWS), while the other half received odorless vehicle. In the next morning, subjects were tested on their explicit knowledge about the underlying sequence in a free recall test and a generation task. Although odor cueing did not significantly affect overall explicit knowledge, differential effects were evident when analyzing male and female subjects separately. Explicit sequence knowledge, both in free recall and the generation task, was enhanced by odor cueing in men, whereas women showed no cueing effect. Procedural skill in the SRTT was not affected by cueing, neither in men nor in women. These findings suggest that olfactory memory reactivation can increase explicit knowledge about implicitly learned information, but only in men. Hormonal differences due to menstrual cycle phase and/or hormonal contraceptives might explain the lacking effect in women.

  7. NMDA receptors in mouse anterior piriform cortex initialize early odor preference learning and L-type calcium channels engage for long-term memory.

    Science.gov (United States)

    Mukherjee, Bandhan; Yuan, Qi

    2016-10-14

    The interactions of L-type calcium channels (LTCCs) and NMDA receptors (NMDARs) in memories are poorly understood. Here we investigated the specific roles of anterior piriform cortex (aPC) LTCCs and NMDARs in early odor preference memory in mice. Using calcium imaging in aPC slices, LTCC activation was shown to be dependent on NMDAR activation. Either D-APV (NMDAR antagonist) or nifedipine (LTCC antagonist) reduced somatic calcium transients in pyramidal cells evoked by lateral olfactory tract stimulation. However, nifedipine did not further reduce calcium in the presence of D-APV. In mice that underwent early odor preference training, blocking NMDARs in the aPC prevented short-term (3 hr) and long-term (24 hr) odor preference memory, and both memories were rescued when BayK-8644 (LTCC agonist) was co-infused. However, activating LTCCs in the absence of NMDARs resulted in loss of discrimination between the conditioned odor and a similar odor mixture at 3 hr. Elevated synaptic AMPAR expression at 3 hr was prevented by D-APV infusion but restored when LTCCs were directly activated, mirroring the behavioral outcomes. Blocking LTCCs prevented 24 hr memory and spared 3 hr memory. These results suggest that NMDARs mediate stimulus-specific encoding of odor memory while LTCCs mediate intracellular signaling leading to long-term memory.

  8. Infant rats can learn time intervals before the maturation of the striatum: evidence from odor fear conditioning

    Directory of Open Access Journals (Sweden)

    Julie eBoulanger Bertolus

    2014-05-01

    Full Text Available Interval timing refers to the ability to perceive, estimate and discriminate durations in the range of seconds to minutes. Very little is currently known about the ontogeny of interval timing throughout development. On the other hand, even though the neural circuit sustaining interval timing is a matter of debate, the striatum has been suggested to be an important component of the system and its maturation occurs around the third post-natal week in rats. The global aim of the present study was to investigate interval timing abilities at an age for which striatum is not yet mature. We used odor fear conditioning, as it can be applied to very young animals. In odor fear conditioning, an odor is presented to the animal and a mild footshock is delivered after a fixed interval. Adult rats have been shown to learn the temporal relationships between the odor and the shock after a few associations. The first aim of the present study was to assess the activity of the striatum during odor fear conditioning using 2-Deoxyglucose autoradiography during development in rats. The data showed that although fear learning was displayed at all tested ages, activation of the striatum was observed in adults but not in juvenile animals. Next, we assessed the presence of evidence of interval timing in ages before and after the inclusion of the striatum into the fear conditioning circuit. We used an experimental setup allowing the simultaneous recording of freezing and respiration that have been demonstrated to be sensitive to interval timing in adult rats. This enabled the detection of duration-related temporal patterns for freezing and/or respiration curves in infants as young as 12 days post-natal during odor-fear conditioning. This suggests that infants are able to encode time durations as well as and as quickly as adults while their striatum is not yet functional. Alternative networks possibly sustaining interval timing in infant rats are discussed.

  9. Peripubertal exposure to male chemosignals accelerates vaginal opening and induces male-directed odor preference in female mice

    Directory of Open Access Journals (Sweden)

    Mélanie eJouhanneau

    2015-03-01

    Full Text Available Reproductive physiology in female mouse is profoundly affected by male odor. A well-known effect of male odor is the acceleration of puberty onset in prepubertal female mice exposed to male urine. Whether peripubertal exposure to male odor also influences female sexual behavior in adulthood is poorly known. Recently, we reported that female mice exposed to male-soiled bedding showed advanced vaginal opening associated with early expression of male-directed odor preference in adulthood. The aim of the present study is to determine whether peripubertal exposure to male urinary chemosignals affects both occurrence of vaginal opening and attraction to male odor at older age in female mice. Therefore, we exposed female mice to (1R, 5S, 7R-3,4-dehydro-exo-brevicomin (DHB, 6-hydroxy-6-methyl-3-heptanone (HMH and (S-2-sec-butyl-4,5-dihydrothiazole (SBT, individually or in mixture, from postnatal day (PD 21 to PD38 and monitored the occurrence of vaginal opening. We measured then the time that the female mice spent sniffing male and female mouse urinary volatiles at PD45. As expected, peripubertal exposure to DHB, HMH or SBT accelerated vaginal opening in female mice. In addition, we showed that exposure to a mixture of these three compounds induced expression of male-directed odor preference at PD45, contrary to the single exposure to each of these molecules. In conclusion, the volatile compounds DHB, HMH and SBT in urine of male mice influence both occurrence of vaginal opening and adult expression of male-directed odor preference in female mice.

  10. Human Odorant Reception in the Common Bed Bug, Cimex lectularius.

    Science.gov (United States)

    Liu, Feng; Liu, Nannan

    2015-11-02

    The common bed bug Cimex lectularius is a temporary ectoparasite on humans and currently resurgent in many developed countries. The ability of bed bugs to detect human odorants in the environment is critical for their host-seeking behavior. This study deciphered the chemical basis of host detection by investigating the neuronal response of olfactory sensilla to 104 human odorants using single sensillum recording and characterized the electro-physiological responses of bed bug odorant receptors to human odorants with the Xenopus expression system. The results showed that the D type of olfactory sensilla play a predominant role in detecting the human odorants tested. Different human odorants elicited different neuronal responses with different firing frequencies and temporal dynamics. Particularly, aldehydes and alcohols are the most effective stimuli in triggering strong response while none of the carboxylic acids showed a strong stimulation. Functional characterization of two bed bug odorant receptors and co-receptors in response to human odorants revealed their specific responses to the aldehyde human odorants. Taken together, the findings of this study not only provide exciting new insights into the human odorant detection of bed bugs, but also offer valuable information for developing new reagents (attractants or repellents) for the bed bug control.

  11. Ventilation Requirements for Control of Occupancy Odor and Tobacco Smoke Odor: Laboratory Studies Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cain, W. S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Isseroff, R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leaderere, B. P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lipsitt, E. D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Huey, R. J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perlman, D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bergland, L. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dunn, J. D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1981-04-01

    A sensitive chemical analysis of the air in a building will characteristically reveal a large number of organic substances, many at concentrations too low to have discernible biological impact. If the concentrations of the chemicals increase, the first sign of their presence may occur via the sense of smell. The air may become odorous. In the general absence of any better or faster indicator, smell will serve as the principal means to decide whether the air in a room is acceptable. Accordingly, this modality has long figured directly or indirectly in the choice of ventilation rates. The cost of ventilation, on the average more than 25% of the operating cost of a building, increases proportionally with the cost of energy and therefore provides a strong incentive to search for energy efficiency. A previous report reviewed the literature relevant to odor perception, odor control, and ventilation (1). The report highlighted prospects for research that might point to ways to achieve both acceptable air quality and energy efficiency in ventilation. The present report provides an account of laboratory research stimulated by that review. The report focuses on ventilation requirements for occupancy odor (Part l) and tobacco smoke odor (Part 2), and offers some preliminary observations on how filtration may aid ventilation (Part 3).

  12. Fluctuation-Enhanced Sensing of Bacterium Odors

    CERN Document Server

    Chang, Hung-Chih; King, Maria D; Kwan, Chiman

    2009-01-01

    The goal of this paper is to explore the possibility to detect and identify bacteria by sensing their odor via fluctuation-enhanced sensing with commercial Taguchi sensors. The fluctuations of the electrical resistance during exposure to different bacterial odors, Escherichia coli and anthrax-surrogate Bacillus subtilis, have been measured and analyzed. In the present study, the simplest method, the measurement and analysis of power density spectra was used. The sensors were run in the normal heated and the sampling-and-hold working modes, respectively. The results indicate that Taguchi sensors used in these fluctuation-enhanced modes are effective tools of bacterium detection and identification even when they are utilizing only the power density spectrum of the stochastic sensor signal.

  13. Olfactory responsiveness to two odorous steroids in three species of nonhuman primates.

    Science.gov (United States)

    Laska, Matthias; Wieser, Alexandra; Hernandez Salazar, Laura Teresa

    2005-07-01

    Social communication by means of odor signals is widespread among mammals. In pigs, for example, the C19-steroids 5-alpha-androst-16-en-3-one and 5-alpha-androst-16-en-3-ol are secreted by the boar and induce the mating stance in the sow. In humans, the same substances have been shown to be compounds of body odor and are presumed to affect human behavior. Using an instrumental conditioning paradigm, we here show that squirrel monkeys, spider monkeys and pigtail macaques are able to detect androstenone at concentrations in the micromolar range and thus at concentrations at least as low as those reported in pigs and humans. All three species of nonhuman primates were considerably less sensitive to androstenol, which was detected at concentrations in the millimolar range. Additional tests, using a habituation-dishabituation paradigm, showed that none of the 10 animals tested per species was anosmic to the two odorous steroids. These results suggest that androstenone and androstenol may be involved in olfactory communication in the primate species tested and that the specific anosmia to these odorants found in approximately 30% of human subjects may be due to their reduced number of functional olfactory receptor genes compared with nonhuman primates.

  14. Investigation of Mechanisms Underlying Odor Recognition.

    Science.gov (United States)

    1984-02-01

    olfactory epithelium of the rat using a procedure similar to that used in .amphibian forms (e.g., Kubie & Moulton, 1979). The detailed description of most...distinct differences in responsiveness of the underlying receptor sheet depending upon the region stimulated (e.g., Kauer & Moulton, 1979; Kubie M...patterns of olfactory bulb neurons using odor stimulation of small nasal areas in the salamander. J. Physiol. (London), 1974, 243, 717-737. Kubie , J.S

  15. Quantitative method to determine the regional drinking water odorant regulation goals based on odor sensitivity distribution: illustrated using 2-MIB.

    Science.gov (United States)

    Yu, Jianwei; An, Wei; Cao, Nan; Yang, Min; Gu, Junong; Zhang, Dong; Lu, Ning

    2014-07-01

    Taste and odor (T/O) in drinking water often cause consumer complaints and are thus regulated in many countries. However, people in different regions may exhibit different sensitivities toward T/O. This study proposed a method to determine the regional drinking water odorant regulation goals (ORGs) based on the odor sensitivity distribution of the local population. The distribution of odor sensitivity to 2-methylisoborneol (2-MIB) by the local population in Beijing, China was revealed by using a normal distribution function/model to describe the odor complaint response to a 2-MIB episode in 2005, and a 2-MIB concentration of 12.9 ng/L and FPA (flavor profile analysis) intensity of 2.5 was found to be the critical point to cause odor complaints. Thus the Beijing ORG for 2-MIB was determined to be 12.9 ng/L. Based on the assumption that the local FPA panel can represent the local population in terms of sensitivity to odor, and that the critical FPA intensity causing odor complaints was 2.5, this study tried to determine the ORGs for seven other cities of China by performing FPA tests using an FPA panel from the corresponding city. ORG values between 12.9 and 31.6 ng/L were determined, showing that a unified ORG may not be suitable for drinking water odor regulations. This study presents a novel approach for setting drinking water odor regulations.

  16. Reef odor: a wake up call for navigation in reef fish larvae.

    Directory of Open Access Journals (Sweden)

    Claire B Paris

    Full Text Available The behavior of reef fish larvae, equipped with a complex toolbox of sensory apparatus, has become a central issue in understanding their transport in the ocean. In this study pelagic reef fish larvae were monitored using an unmanned open-ocean tracking device, the drifting in-situ chamber (DISC, deployed sequentially in oceanic waters and in reef-born odor plumes propagating offshore with the ebb flow. A total of 83 larvae of two taxonomic groups of the families Pomacentridae and Apogonidae were observed in the two water masses around One Tree Island, southern Great Barrier Reef. The study provides the first in-situ evidence that pelagic reef fish larvae discriminate reef odor and respond by changing their swimming speed and direction. It concludes that reef fish larvae smell the presence of coral reefs from several kilometers offshore and this odor is a primary component of their navigational system and activates other directional sensory cues. The two families expressed differences in their response that could be adapted to maintain a position close to the reef. In particular, damselfish larvae embedded in the odor plume detected the location of the reef crest and swam westward and parallel to shore on both sides of the island. This study underlines the critical importance of in situ Lagrangian observations to provide unique information on larval fish behavioral decisions. From an ecological perspective the central role of olfactory signals in marine population connectivity raises concerns about the effects of pollution and acidification of oceans, which can alter chemical cues and olfactory responses.

  17. Thresholds for odor and nasal pungency.

    Science.gov (United States)

    Cometto-Muñiz, J E; Cain, W S

    1990-11-01

    Detection thresholds were measured repeatedly for 11 chemicals in normosmic and anosmic subjects. The stimuli comprised the first eight members of the series of n-aliphatic alcohols, phenyl ethyl alcohol, pyridine, and menthol. Results showed that anosmics could detect, via pungency, all but phenyl ethyl alcohol reliably. In the aliphatic series, both odor and pungency thresholds declined with chain length in a way that implied dependence of both in part on phase distribution in the mucosa. Odor thresholds, however, declined more rapidly than pungency thresholds: the ratio of anosmics threshold/normosmics threshold increased from 23 for methanol to 10,000 for 1-octanol. The outcome of a scaling experiment employing normosmic subjects indicated that, with the exception of methanol and ethanol, pungency arose when perceived intensity reached a narrowly tuned criterion level. When thresholds were expressed as percentages of saturated vapor, an index of thermodynamic activity, thereby accounting for differences in solubility and in phase distribution in the mucosa among the various stimuli, both odor and pungency thresholds depicted a striking constancy across stimuli.

  18. Odor Memory Stability after Reinnervation of the Olfactory Bulb

    Science.gov (United States)

    Blanco-Hernández, Eduardo; Valle-Leija, Pablo; Zomosa-Signoret, Viviana; Drucker-Colín, René; Vidaltamayo, Román

    2012-01-01

    The olfactory system, particularly the olfactory epithelium, presents a unique opportunity to study the regenerative capabilities of the brain, because of its ability to recover after damage. In this study, we ablated olfactory sensory neurons with methimazole and followed the anatomical and functional recovery of circuits expressing genetic markers for I7 and M72 receptors (M72-IRES-tau-LacZ and I7-IRES-tau-GFP). Our results show that 45 days after methimazole-induced lesion, axonal projections to the bulb of M72 and I7 populations are largely reestablished. Furthermore, regenerated glomeruli are re-formed within the same areas as those of control, unexposed mice. This anatomical regeneration correlates with functional recovery of a previously learned odorant-discrimination task, dependent on the cognate ligands for M72 and I7. Following regeneration, mice also recover innate responsiveness to TMT and urine. Our findings show that regeneration of neuronal circuits in the olfactory system can be achieved with remarkable precision and underscore the importance of glomerular organization to evoke memory traces stored in the brain. PMID:23071557

  19. Odor memory stability after reinnervation of the olfactory bulb.

    Directory of Open Access Journals (Sweden)

    Eduardo Blanco-Hernández

    Full Text Available The olfactory system, particularly the olfactory epithelium, presents a unique opportunity to study the regenerative capabilities of the brain, because of its ability to recover after damage. In this study, we ablated olfactory sensory neurons with methimazole and followed the anatomical and functional recovery of circuits expressing genetic markers for I7 and M72 receptors (M72-IRES-tau-LacZ and I7-IRES-tau-GFP. Our results show that 45 days after methimazole-induced lesion, axonal projections to the bulb of M72 and I7 populations are largely reestablished. Furthermore, regenerated glomeruli are re-formed within the same areas as those of control, unexposed mice. This anatomical regeneration correlates with functional recovery of a previously learned odorant-discrimination task, dependent on the cognate ligands for M72 and I7. Following regeneration, mice also recover innate responsiveness to TMT and urine. Our findings show that regeneration of neuronal circuits in the olfactory system can be achieved with remarkable precision and underscore the importance of glomerular organization to evoke memory traces stored in the brain.

  20. Modeling the Effects of Person Group Factors on Discrimination

    Science.gov (United States)

    Humphry, Stephen M.

    2010-01-01

    Discrimination has traditionally been parameterized for items but not other empirical factors. Consequently, if person factors affect discrimination they cause misfit. However, by explicitly formulating the relationship between discrimination and the unit of a metric, it is possible to parameterize discrimination for person groups. This article…

  1. AN ODORANT-BINDING PROTEIN INVOLVED IN PERCEPTION OF HOST PLANT ODORANTS IN LOCUST Locusta migratoria.

    Science.gov (United States)

    Li, Jia; Zhang, Long; Wang, Xiaoqi

    2016-04-01

    Locusts, Locusta migratoria (Orthoptera: Acrididae), are extremely destructive agricultural pests, but very little is known of their molecular aspects of perception to host plant odorants including related odorant-binding proteins (OBPs), though several OBPs have been identified in locust. To elucidate the function of LmigOBP1, the first OBP identified from locust, RNA interference was employed in this study to silence LmigOBP1, which was achieved by injection of dsRNA targeting LmigOBP1 into the hemolymph of male nymphs. Compared with LmigOBP1 normal nymphs, LmigOBP1 knockdown nymphs significantly decreased food (maize leaf, Zea mays) consumption and electro-antennography responses to five maize leaf volatiles, ((Z)-3-hexenol, linalool, nonanal, decanal, and (Z)-3-hexenyl acetate). These suggest that LmigOBP1 is involved in perception of host plant odorants.

  2. Human Odorant Reception in the Common Bed Bug, Cimex lectularius

    OpenAIRE

    Feng Liu; Nannan Liu

    2015-01-01

    The common bed bug Cimex lectularius is a temporary ectoparasite on humans and currently resurgent in many developed countries. The ability of bed bugs to detect human odorants in the environment is critical for their host-seeking behavior. This study deciphered the chemical basis of host detection by investigating the neuronal response of olfactory sensilla to 104 human odorants using single sensillum recording and characterized the electro-physiological responses of bed bug odorant receptor...

  3. Olfactory systems and neural circuits that modulate predator odor fear.

    Science.gov (United States)

    Takahashi, Lorey K

    2014-01-01

    When prey animals detect the odor of a predator a constellation of fear-related autonomic, endocrine, and behavioral responses rapidly occur to facilitate survival. How olfactory sensory systems process predator odor and channel that information to specific brain circuits is a fundamental issue that is not clearly understood. However, research in the last 15 years has begun to identify some of the essential features of the sensory detection systems and brain structures that underlie predator odor fear. For instance, the main (MOS) and accessory olfactory systems (AOS) detect predator odors and different types of predator odors are sensed by specific receptors located in either the MOS or AOS. However, complex predator chemosignals may be processed by both the MOS and AOS, which complicate our understanding of the specific neural circuits connected directly and indirectly from the MOS and AOS to activate the physiological and behavioral components of unconditioned and conditioned fear. Studies indicate that brain structures including the dorsal periaqueductal gray (DPAG), paraventricular nucleus (PVN) of the hypothalamus, and the medial amygdala (MeA) appear to be broadly involved in predator odor induced autonomic activity and hypothalamic-pituitary-adrenal (HPA) stress hormone secretion. The MeA also plays a key role in predator odor unconditioned fear behavior and retrieval of contextual fear memory associated with prior predator odor experiences. Other neural structures including the bed nucleus of the stria terminalis and the ventral hippocampus (VHC) appear prominently involved in predator odor fear behavior. The basolateral amygdala (BLA), medial hypothalamic nuclei, and medial prefrontal cortex (mPFC) are also activated by some but not all predator odors. Future research that characterizes how distinct predator odors are uniquely processed in olfactory systems and neural circuits will provide significant insights into the differences of how diverse predator

  4. Composition of key offensive odorants released from fresh food materials

    Science.gov (United States)

    Kim, Ki-Hyun; Kim, Yong-Hyun

    2014-06-01

    A refrigerator loaded with a variety of foods without sealed packaging can create quite an olfactory nuisance, and it may come as a surprise that fresh foods emit unpleasant odorants just as those that are decaying. To learn more about nuisance sources in our daily lives, we measured a list of 22 compounds designated as the key offensive odorants (e.g., reduced sulfur, nitrogenous, volatile fatty acid (VFA), and carbonyls) from nine types of common food items consumed in S. Korea: raw beef, raw fish, spam, yolks and albumin of boiled eggs (analyzed separately), milk, cheese, onions, and strawberries. The odor intensity (OI) of each food item was computed initially with the aid of previously used empirical equations. This indicates that the malodor properties of target foods tend to be governed by a few key odorants such as VFA, S, and N compounds. The extent of odorant mixing of a given food was then evaluated by exploring the correlation between the human olfaction (e.g., dilution-to-threshold (D/T) ratio) and the odor potential determined indirectly (instrumentally) such as odor activity value (OAV) or sum of odor intensity (SOI). The overall results of our study confirm the existence of malodorant compounds released from common food items and their contribution to their odor characteristics to a certain degree.

  5. Molecular determinants of odorant receptor function in insects

    Indian Academy of Sciences (India)

    Anandasankar Ray; Wynand Van Der Goes Van Naters; John R Carlson

    2014-09-01

    The olfactory system of Drosophila melanogaster provides a powerful model to study molecular and cellular mechanisms underlying function of a sensory system. In the 1970s Siddiqi and colleagues pioneered the application of genetics to olfactory research and isolated several mutant Drosophila with odorant-specific defects in olfactory behaviour, suggesting that odorants are detected differentially by the olfactory system. Since then basic principles of olfactory system function and development have emerged using Drosophila as a model. Nearly four decades later we can add computational methods to further our understanding of how specific odorants are detected by receptors. Using a comparative approach we identify two categories of short amino acid sequence motifs: ones that are conserved family-wide predominantly in the C-terminal half of most receptors, and ones that are present in receptors that detect a specific odorant, 4-methylphenol, found predominantly in the N-terminal half. The odorant-specific sequence motifs are predictors of phenol detection in Anopheles gambiae and other insects, suggesting they are likely to participate in odorant binding. Conversely, the family-wide motifs are expected to participate in shared functions across all receptors and a mutation in the most conserved motif leads to a reduction in odor response. These findings lay a foundation for investigating functional domains within odorant receptors that can lead to a molecular understanding of odor detection.

  6. Analysis of Key Odorants in Roasted Green Tea

    Science.gov (United States)

    Mizukami, Yuzo; Sawai, Yusuke; Yamaguchi, Yuichi

    This research aims to identify key odorants in roasted green tea. The aroma extract dilution analysis revealed 25 odor-active peaks with the flavor dilution factors of ≥ 16. We identified 2-ethyl-3,5-dimethylpyrazine as the most important odorant in roasted green tea with the highest flavor dilution factor of 4096. In addition, tetramethylpyrazine, 2,3-diethyl-5- methylpyrazine were also detected as potent odorants with the high flavor dilution factors. These three alkylpyrazines would be key contributors to aroma of roasted green tea.

  7. Odor and odorous chemical emissions from dairy and swine facilities: Part 5-Simultaneous chemical and sensory analysis with Gas Chromatography - Mass Spectrometry - Olfactometry

    Science.gov (United States)

    Simultaneous chemical and sensory analyses using gas chromatography-mass spectrometry-olfactometry (GC-MS-O) for air samples collected at barn exhaust fans were used for quantification and ranking of odor impact of target odorous gases. Fifteen target odorous VOCs (odorants) were selected. Air sampl...

  8. Orientation of larval and juvenile horseshoe crabs Limulus polyphemus to visual cues: Effects of chemical odors

    Directory of Open Access Journals (Sweden)

    Julie M. MEDINA, Richard A. TANKERSLEY

    2010-10-01

    Full Text Available Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that (1 larval and juvenile crabs can detect and respond to visual targets and (2 the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30-330o was tested in a circular arena containing water that either lacked estuarine chemical cues (offshore water or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles > 60°. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis [Current Zoology 56 (5: 618–633, 2010].

  9. Postnatal odorant exposure induces peripheral olfactory plasticity at the cellular level.

    Science.gov (United States)

    Cadiou, Hervé; Aoudé, Imad; Tazir, Bassim; Molinas, Adrien; Fenech, Claire; Meunier, Nicolas; Grosmaitre, Xavier

    2014-04-01

    Mammalian olfactory sensory neurons (OSNs) form the primary elements of the olfactory system. Inserted in the olfactory mucosa lining of the nasal cavity, they are exposed to the environment and their lifespan is brief. Several reports say that OSNs are regularly regenerated during the entire life and that odorant environment affects the olfactory epithelium. However, little is known about the impact of the odorant environment on OSNs at the cellular level and more precisely in the context of early postnatal olfactory exposure. Here we exposed MOR23-green fluorescent protein (GFP) and M71-GFP mice to lyral or acetophenone, ligands for MOR23 or M71, respectively. Daily postnatal exposure to lyral induces plasticity in the population of OSNs expressing MOR23. Their density decreases after odorant exposure, whereas the amount of MOR23 mRNA and protein remain stable in the whole epithelium. Meanwhile, quantitative PCR indicates that each MOR23 neuron has higher levels of olfactory receptor transcripts and also expresses more CNGA2 and phosphodiesterase 1C, fundamental olfactory transduction pathway proteins. Transcript levels return to baseline after 4 weeks recovery. Patch-clamp recordings reveal that exposed MOR23 neurons respond to lyral with higher sensitivity and broader dynamic range while the responses' kinetics were faster. These effects are specific to the odorant-receptor pair lyral-MOR23: there was no effect of acetophenone on MOR23 neurons and no effect of acetophenone and lyral on the M71 population. Together, our results clearly demonstrate that OSNs undergo specific anatomical, molecular, and functional adaptation when chronically exposed to odorants in the early stage of life.

  10. A sensory 3-D map of the odor description space derived from a comparison of numeric odor profile databases

    OpenAIRE

    Zarzo Castelló, Manuel

    2015-01-01

    Many authors have proposed different schemes of odor classification, which are useful to aid the complex task of describing smells. However, reaching a consensus on a particular classification seems difficult because our psychophysical space of odor description is a continuum and is not clustered into well-defined categories. An alternative approach is to describe the perceptual space of odors as a low-dimensional coordinate system. This idea was first proposed by Crocker and Henderson in 192...

  11. Fighting discrimination.

    Science.gov (United States)

    Wientjens, Wim; Cairns, Douglas

    2012-10-01

    In the fight against discrimination, the IDF launched the first ever International Charter of Rights and Responsibilities of People with Diabetes in 2011: a balance between rights and duties to optimize health and quality of life, to enable as normal a life as possible and to reduce/eliminate the barriers which deny realization of full potential as members of society. It is extremely frustrating to suffer blanket bans and many examples exist, including insurance, driving licenses, getting a job, keeping a job and family affairs. In this article, an example is given of how pilots with insulin treated diabetes are allowed to fly by taking the responsibility of using special blood glucose monitoring protocols. At this time the systems in the countries allowing flying for pilots with insulin treated diabetes are applauded, particularly the USA for private flying, and Canada for commercial flying. Encouraging developments may be underway in the UK for commercial flying and, if this materializes, could be used as an example for other aviation authorities to help adopt similar protocols. However, new restrictions implemented by the new European Aviation Authority take existing privileges away for National Private Pilot Licence holders with insulin treated diabetes in the UK.

  12. An odor timer in milk? Synchrony in the odor of milk effluvium and neonatal chemosensation in the mouse.

    Directory of Open Access Journals (Sweden)

    Syrina Al Aïn

    Full Text Available Mammalian newborns exhibit avid responsiveness to odor compounds emanating from conspecific milk. Milk is however developmentally heterogeneous in composition as a function of both evolved constraints and offspring demand. The present study aimed to verify whether milk odor attractivity for neonates is equally distributed along lactation in Mus musculus (Balb-c strain. Therefore, we exposed pups varying in age to milk samples collected from females in different lactational stages. The pups were assayed at postnatal days 2 (P2, 6 (P6 and 15 (P15 in a series of paired-choice tests opposing either murine milk and a blank (water, or two samples of milk collected in different stages of lactation [lactation days 2 (L2, 6 (L6, and 15 L15]. Pups of any age were able to detect, and were attracted to, the odor of the different milk. When milk from different lactational stages were simultaneously presented, P2 pups oriented for a similar duration to the odors of L2 and of L6 milk, but significantly less to the odor of L15 milk. Next, P6 pups roamed equivalently over L2 and L6 milk odors, but still less over the odor of L15 milk. Finally, P15 pups explored as much L15 milk odor as the odors of both L2 and L6 milk. This developmental shift in milk attractivity is discussed in terms of changing chemosensory properties of milk and of shifting chemosensory abilities/experience of pups.

  13. Face adaptation improves gender discrimination.

    Science.gov (United States)

    Yang, Hua; Shen, Jianhong; Chen, Juan; Fang, Fang

    2011-01-01

    Adaptation to a visual pattern can alter the sensitivities of neuronal populations encoding the pattern. However, the functional roles of adaptation, especially in high-level vision, are still equivocal. In the present study, we performed three experiments to investigate if face gender adaptation could affect gender discrimination. Experiments 1 and 2 revealed that adapting to a male/female face could selectively enhance discrimination for male/female faces. Experiment 3 showed that the discrimination enhancement induced by face adaptation could transfer across a substantial change in three-dimensional face viewpoint. These results provide further evidence suggesting that, similar to low-level vision, adaptation in high-level vision could calibrate the visual system to current inputs of complex shapes (i.e. face) and improve discrimination at the adapted characteristic.

  14. Numerical simulation of airway dimension effects on airflow patterns and odorant deposition patterns in the rat nasal cavity.

    Directory of Open Access Journals (Sweden)

    Zehong Wei

    Full Text Available The sense of smell is largely dependent on the airflow and odorant transport in the nasal cavity, which in turn depends on the anatomical structure of the nose. In order to evaluate the effect of airway dimension on rat nasal airflow patterns and odorant deposition patterns, we constructed two 3-dimensional, anatomically accurate models of the left nasal cavity of a Sprague-Dawley rat: one was based on high-resolution MRI images with relatively narrow airways and the other was based on artificially-widening airways of the MRI images by referencing the section images with relatively wide airways. Airflow and odorant transport, in the two models, were determined using the method of computational fluid dynamics with finite volume method. The results demonstrated that an increase of 34 µm in nasal airway dimension significantly decreased the average velocity in the whole nasal cavity by about 10% and in the olfactory region by about 12% and increased the volumetric flow into the olfactory region by about 3%. Odorant deposition was affected to a larger extent, especially in the olfactory region, where the maximum odorant deposition difference reached one order of magnitude. The results suggest that a more accurate nasal cavity model is necessary in order to more precisely study the olfactory function of the nose when using the rat.

  15. Parallel olfactory processing in the honey bee brain: odor learning and generalization under selective lesion of a projection neuron tract

    Directory of Open Access Journals (Sweden)

    Julie eCarcaud

    2016-01-01

    Full Text Available The function of parallel neural processing is a fundamental problem in Neuroscience, as it is found across sensory modalities and evolutionary lineages, from insects to humans. Recently, parallel processing has attracted increased attention in the olfactory domain, with the demonstration in both insects and mammals that different populations of second-order neurons encode and/or process odorant information differently. Among insects, Hymenoptera present a striking olfactory system with a clear neural dichotomy from the periphery to higher-order centers, based on two main tracts of second-order (projection neurons: the medial and lateral antennal lobe tracts (m-ALT and l-ALT. To unravel the functional role of these two pathways, we combined specific lesions of the m-ALT tract with behavioral experiments, using the classical conditioning of the proboscis extension response (PER conditioning. Lesioned and intact bees had to learn to associate an odorant (1-nonanol with sucrose. Then the bees were subjected to a generalization procedure with a range of odorants differing in terms of their carbon chain length or functional group. We show that m-ALT lesion strongly affects acquisition of an odor-sucrose association. However, lesioned bees that still learned the association showed a normal gradient of decreasing generalization responses to increasingly dissimilar odorants. Generalization responses could be predicted to some extent by in vivo calcium imaging recordings of l-ALT neurons. The m-ALT pathway therefore seems necessary for normal classical olfactory conditioning performance.

  16. Parallel Olfactory Processing in the Honey Bee Brain: Odor Learning and Generalization under Selective Lesion of a Projection Neuron Tract.

    Science.gov (United States)

    Carcaud, Julie; Giurfa, Martin; Sandoz, Jean Christophe

    2015-01-01

    The function of parallel neural processing is a fundamental problem in Neuroscience, as it is found across sensory modalities and evolutionary lineages, from insects to humans. Recently, parallel processing has attracted increased attention in the olfactory domain, with the demonstration in both insects and mammals that different populations of second-order neurons encode and/or process odorant information differently. Among insects, Hymenoptera present a striking olfactory system with a clear neural dichotomy from the periphery to higher-order centers, based on two main tracts of second-order (projection) neurons: the medial and lateral antennal lobe tracts (m-ALT and l-ALT). To unravel the functional role of these two pathways, we combined specific lesions of the m-ALT tract with behavioral experiments, using the classical conditioning of the proboscis extension response (PER conditioning). Lesioned and intact bees had to learn to associate an odorant (1-nonanol) with sucrose. Then the bees were subjected to a generalization procedure with a range of odorants differing in terms of their carbon chain length or functional group. We show that m-ALT lesion strongly affects acquisition of an odor-sucrose association. However, lesioned bees that still learned the association showed a normal gradient of decreasing generalization responses to increasingly dissimilar odorants. Generalization responses could be predicted to some extent by in vivo calcium imaging recordings of l-ALT neurons. The m-ALT pathway therefore seems necessary for normal classical olfactory conditioning performance.

  17. Animal-to-Animal Variation in Odor Preference and Neural Representation of Odors

    Science.gov (United States)

    Honegger, Kyle; Smith, Matthew; Turner, Glenn; de Bivort, Benjamin

    Across any population of animals, individuals exhibit diverse behaviors and reactions to sensory stimuli like tastes and odors. While idiosyncratic behavior is ubiquitous, its biological basis is poorly understood. In this talk, I will present evidence that individual fruit flies (Drosophila melanogaster) display idiosyncratic olfactory behaviors and discuss our ongoing efforts to map these behavioral differences to variation in neural circuits. Using a high-throughput, single-fly assay for odor preference, we have demonstrated that highly inbred flies display substantial animal-to-animal variability, beyond that expected from experimental error, and that these preferences persist over days. Using in vivo two-photon calcium imaging, we are beginning to examine the idiosyncrasy of neural coding in the fly olfactory pathway and find that the odor responses of individual processing channels in the antennal lobe can vary substantially from fly to fly. These results imply that individual differences in neural coding may be used to predict the idiosyncratic behavior of an individual - a hypothesis we are currently testing by imaging neural activity from flies after measuring their odor preferences.

  18. Factor analysis of olfactory responses in Drosophila melanogaster enhancer-trap lines as a method for ascertaining common reception components for different odorants.

    Science.gov (United States)

    Martin, Fernando; Kim, Min-Su; Hovemann, Bernard; Alcorta, Esther

    2002-01-01

    Olfactory information is transmitted to the brain using combinatorial receptor codes; consequently, a single reception element can be activated by different odorants. Several methods have been applied to describe from a functional point of view those odorants sharing olfactory reception components. A genetic approach in Drosophila melanogaster used correlation between behavioral responses to different odorants for deducing common olfactory pathway-genes. A factor analysis applied to behavioral responses to five odorants of 27 antennal enhancer-trap lines revealed three components, explaining 82.1% of the total observed variance. A first factor affects simultaneously the response to ethyl acetate, propionaldehyde, and acetone. A second factor was related to responses to ethyl acetate, ethyl alcohol, and acetone, and, finally, the third factor associates responses to acetic acid and ethyl acetate. They contribute by 35.1%, 36.9%, and 28%, respectively, to the explained variance.

  19. Discrimination and Anti-discrimination in Denmark

    DEFF Research Database (Denmark)

    Olsen, Tore Vincents

    The purpose of this report is to describe and analyse Danish anti-discrimination legislation and the debate about discrimination in Denmark in order to identify present and future legal challenges. The main focus is the implementation of the EU anti-discrimination directives in Danish law...

  20. An individual and a sex odor signature in kittiwakes? Study of the semiochemical composition of preen secretion and preen down feathers

    Science.gov (United States)

    Leclaire, Sarah; Merkling, Thomas; Raynaud, C.; Giacinti, Géraldine; Bessiere, J.-M.; Hatch, Scott A.; Danchin, Etienne

    2011-01-01

    The importance of olfaction in birds' social behavior has long been denied. Avian chemical signaling has thus been relatively unexplored. The black-legged kittiwake provides a particularly appropriate model for investigating this topic. Kittiwakes preferentially mate with genetically dissimilar individuals, but the cues used to assess genetic characteristics remain unknown. As in other vertebrates, their body odors may carry individual and sexual signatures thus potentially reliably signaling individual genetic makeup. Here, we test whether body odors in preen gland secretion and preen down feathers in kittiwakes may provide a sex and an individual signature. Using gas chromatography and mass spectrometry, we found that male and female odors differ quantitatively, suggesting that scent may be one of the multiple cues used by birds to discriminate between sexes. We further detected an individual signature in the volatile and nonvolatile fractions of preen secretion and preen down feathers. These results suggest that kittiwake body odor may function as a signal associated with mate recognition. It further suggests that preen odor might broadcast the genetic makeup of individuals, and could be used in mate choice to assess the genetic compatibility of potential mates.

  1. Odors as triggering and worsening factors for migraine in men

    Directory of Open Access Journals (Sweden)

    A M Lima

    2011-01-01

    Full Text Available OBJECTIVE: To assess the role of odors in triggering or worsening migraine in men. METHOD: Ninety-eight male migraineurs from the general population were assessed individually through questionnaires. Environmental factors relating to their migraine were reported, with special focus on the role of odors. RESULTS: Odors were the second most frequent triggering factor for migraine attacks (48%, behind stressful situations (59%. Likewise, odors were the second most frequent worsening factor (73%, just behind excessive light (74%. Thirty-three individuals (33.4% stated that odors were both triggering and worsening factors for their migraine attacks. Perfume, cigarette smoke and cleaning products were the most frequent migraine-related odors reported by these male migraineurs. CONCLUSION: This was the first study to assess the role of odors in migraine exclusively in men. There was a high degree of odor-related migraine among these men, thus suggesting that patient education could alert such individuals to gender-related factors, since different triggering and worsening factors have been reported by males and females.

  2. Odorant-stimulated phosphoinositide signaling in mammalian olfactory receptor neurons

    Science.gov (United States)

    Klasen, K.; Corey, E.A.; Kuck, F.; Wetzel, C.H.; Hatt, H.; Ache, B.W.

    2009-01-01

    Recent evidence has revived interest in the idea that phosphoinositides (PIs) may play a role in signal transduction in mammalian olfactory receptor neurons (ORNs). To provide direct evidence that odorants indeed activate PI signaling in ORNs, we used adenoviral vectors carrying two different fluorescently tagged probes, the pleckstrin homology (PH) domains of phospholipase Cδ1 (PLCδ1) and the general receptor of phosphoinositides (GRP1), to monitor PI activity in the dendritic knobs of ORNs in vivo. Odorants mobilized PI(4,5)P2/IP3 and PI(3,4,5)P3, the substrates and products of PLC and PI3K. We then measured odorant activation of PLC and PI3K in olfactory ciliary-enriched membranes in vitro using a phospholipid overlay assay and ELISAs. Odorants activated both PLC and PI3K in the olfactory cilia within 2 sec of odorant stimulation. Odorant-dependent activation of PLC and PI3K in the olfactory epithelium could be blocked by enzyme-specific inhibitors. Odorants activated PLC and PI3K with partially overlapping specificity. These results provide direct evidence that odorants indeed activate PI signaling in mammalian ORNs in a manner that is consistent with the idea that PI signaling plays a role in olfactory transduction. PMID:19781634

  3. Odor from pig production: its relation to diet

    NARCIS (Netherlands)

    Dinh Phung, Le P.D.

    2006-01-01

    Keywords.Odor, Pigs, Diet, Manure, Protein, Amino Acids, Fermentable carbohydratesOdor from pig manure creates a serious nuisance for people li

  4. Characterization and dispersion modeling of odors from a piggery facility.

    Science.gov (United States)

    Karageorgos, Petros; Latos, Manolis; Mpasiakos, Christos; Chalarakis, Elefterios; Dimitrakakis, Emmanuel; Daskalakis, Charis; Psillakis, Elefteria; Lazaridis, Mihalis; Kalogerakis, Nicolas

    2010-01-01

    Piggeries are known for their nuisance odors, creating problems for workers and nearby residents. Chemical substances that contribute to these odors include sulfurous organic compounds, hydrogen sulfide, phenols and indoles, ammonia, volatile amines, and volatile fatty acids. In this work, daily mean concentrations of ammonia (NH3) and hydrogen sulfide (H2S) were measured by hand-held devices. Measurements were taken in several places within the facility (farrowing to finishing rooms). Hydrogen sulfide concentration was found to be 40 to 50 times higher than the human odor threshold value in the nursery and fattening room, resulting in strong nuisance odors. Ammonia concentrations ranged from 2 to 18 mL m(-3) and also contributed to the total odor nuisance. Emission data from various chambers of the pig farm were used with the dispersion model AERMOD to determine the odor nuisance caused due to the presence of H2S and NH3 to receptors at various distances from the facility. Because just a few seconds of exposure can cause an odor nuisance, a "peak-to-mean" ratio was used to predict the maximum odor concentrations. Several scenarios were examined using the modified AERMOD program, taking into account the complex terrain around the pig farm.

  5. HDAC I inhibition in the dorsal and ventral hippocampus differentially modulates predator-odor fear learning and generalization

    Directory of Open Access Journals (Sweden)

    Robin K Yuan

    2015-09-01

    Full Text Available Although predator odors are ethologically relevant stimuli for rodents, the molecular pathways and contribution of some brain regions involved remain elusive. Inhibition of histone deacetylases (HDACs in the dorsal hippocampus has been shown to enhance shock-induced contextual fear learning, but it is unknown if HDACs have differential effects along the dorso-ventral hippocampal axis during predator odor fear learning. We injected MS-275, a class I HDAC inhibitor, bilaterally in the dorsal or ventral hippocampus of mice and found that it had no effects on innate anxiety in either region. We then assessed the effects of MS-275 at different stages of fear learning along the longitudinal hippocampal axis. Animals were injected with MS-275 or vehicle after context pre-exposure (pre-conditioning injections, when a representation of the context is first formed, or after exposure to coyote urine (post-conditioning injections, when the context becomes associated with predator odor. When MS-275 was administered after context pre-exposure, dorsally injected animals showed enhanced fear in the training context but were able to discriminate it from a neutral environment. Conversely, ventrally injected animals did not display enhanced learning in the training context but generalized the fear response to a neutral context. However, when MS-275 was administered after conditioning, there were no differences between MS-275 or vehicle control groups in either the dorsal or ventral hippocampus. Surprisingly, all groups displayed generalization to a neutral context, suggesting that predator odor exposure followed by the restraint necessary for the injections leads to fear generalization. These results may elucidate distinct functions of the dorsal and ventral hippocampus in predator odor-induced fear conditioning as well as some of the molecular mechanisms underlying fear generalization.

  6. Odor-Induced Neuronal Rhythms in the Olfactory Bulb Are Profoundly Modified in ob/ob Obese Mice

    Science.gov (United States)

    Chelminski, Yan; Magnan, Christophe; Luquet, Serge H.; Everard, Amandine; Meunier, Nicolas; Gurden, Hirac; Martin, Claire

    2017-01-01

    Leptin, the product of the Ob(Lep) gene, is a peptide hormone that plays a major role in maintaining the balance between food intake and energy expenditure. In the brain, leptin receptors are expressed by hypothalamic cells but also in the olfactory bulb, the first central structure coding for odors, suggesting a precise function of this hormone in odor-evoked activities. Although olfaction plays a key role in feeding behavior, the ability of the olfactory bulb to integrate the energy-related signal leptin is still missing. Therefore, we studied the fate of odor-induced activity in the olfactory bulb in the genetic context of leptin deficiency using the obese ob/ob mice. By means of an odor discrimination task with concomitant local field potential recordings, we showed that ob/ob mice perform better than wild-type (WT) mice in the early stage of the task. This behavioral gain of function was associated in parallel with profound changes in neuronal oscillations in the olfactory bulb. The distribution of the peaks in the gamma frequency range was shifted toward higher frequencies in ob/ob mice compared to WT mice before learning. More notably, beta oscillatory activity, which has been shown previously to be correlated with olfactory discrimination learning, was longer and stronger in expert ob/ob mice after learning. Since oscillations in the olfactory bulb emerge from mitral to granule cell interactions, our results suggest that cellular dynamics in the olfactory bulb are deeply modified in ob/ob mice in the context of olfactory learning.

  7. Odor tracking in sharks is reduced under future ocean acidification conditions.

    Science.gov (United States)

    Dixson, Danielle L; Jennings, Ashley R; Atema, Jelle; Munday, Philip L

    2015-04-01

    Recent studies show that ocean acidification impairs sensory functions and alters the behavior of teleost fishes. If sharks and other elasmobranchs are similarly affected, this could have significant consequences for marine ecosystems globally. Here, we show that projected future CO2 levels impair odor tracking behavior of the smooth dogfish (Mustelus canis). Adult M. canis were held for 5 days in a current-day control (405 ± 26 μatm) and mid (741 ± 22 μatm) or high CO2 (1064 ± 17 μatm) treatments consistent with the projections for the year 2100 on a 'business as usual' scenario. Both control and mid CO2 -treated individuals maintained normal odor tracking behavior, whereas high CO2 -treated sharks significantly avoided the odor cues indicative of food. Control sharks spent >60% of their time in the water stream containing the food stimulus, but this value fell below 15% in high CO2 -treated sharks. In addition, sharks treated under mid and high CO2 conditions reduced attack behavior compared to the control individuals. Our findings show that shark feeding could be affected by changes in seawater chemistry projected for the end of this century. Understanding the effects of ocean acidification on critical behaviors, such as prey tracking in large predators, can help determine the potential impacts of future ocean acidification on ecosystem function.

  8. Emissions of sulfur-containing odorants, ammonia, and methane from pig slurry

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Adamsen, Anders Peter S.; Nørgaard, Jan Værum

    2010-01-01

    Supplementation of benzoic acid to pig diets reduces the pH of urine and may thereby affect emissions of ammonia and other gases from slurry, including sulfur-containing compounds that are expected to play a role in odor emission. Over a period of 112 d, we investigated hydrogen sulfide (H2S...... from the slurry of the control treatment, which came from pigs fed according to Danish recommendations for amino acids and minerals. The emission patterns of volatile S compounds suggested an intense cycling between pools of organic S in the slurries, with urinary sulfate as the main source. Diet...... and benzoic acid treatments, which caused a significant increase in emissions of especially MT, but also of DMDS. In conclusion, addition of 2% benzoic acid to pig diets effectively reduced ammonia volatilization, but interactions with dietary S may increase odor problems....

  9. Nuisance Odors: Is there a Concern - 12340

    Energy Technology Data Exchange (ETDEWEB)

    Brounstein, Robert A. [TerranearPMC, Los Alamos New Mexico 87544 (United States)

    2012-07-01

    Nuisance odors are generally thought of as just being annoying or unpleasant and not causing any physiological harm to our internal organs or other biologic systems. Yet during an excavation of buried animal remains, field workers experienced a multitude of symptoms that are associated with exposures to toxic materials. An examination of the decomposition process revealed that there is a potential off-gassing of a number of common, yet harmful chemicals including ammonia, mercaptans, hydrogen sulfide, butyric acid and phenol. In addition, other compounds, that have limited information such as established health data and occupational exposure limits, were also potential contaminants-of-concern. While a variety of monitoring and sampling techniques were used to assess worker exposures, all results indicated non-detectable airborne concentrations. Nevertheless, workers were experiencing such symptoms as nausea and headaches. As such, protective measures were necessary for field personnel to continue work while having confidence that the project was instituting sincere steps to ensure their health and safety. Researching the possible reasons for the causes of workers exhibiting adverse health effects from nuisance odors revealed that such exposures initiate electrochemical pathways, starting from the olfactory bulb to the brain, followed by a transfer of information to such biologic systems as the hypothalamus and pituitary gland. These systems, in turn, secrete hormones that cause a number of involuntary reactions; many of which are observed as typical adverse health effects, when in fact, they are merely reactions caused by the brain's memory; most likely created from previous experiences to unpleasant odors. The concern then focuses of how the Occupational Safety and Health community shall respond to such workplace exposures. Future work in this area may need to focus on the viability of current occupational exposure limits and the possibility of revising these

  10. The odorant receptor repertoire of teleost fish

    Directory of Open Access Journals (Sweden)

    Alioto Tyler S

    2005-12-01

    Full Text Available Abstract Background Vertebrate odorant receptors comprise three types of G protein-coupled receptors: the OR, V1R and V2R receptors. The OR superfamily contains over 1,000 genes in some mammalian species, representing the largest gene superfamily in the mammalian genome. Results To facilitate an informed analysis of OR gene phylogeny, we identified the complete set of 143 OR genes in the zebrafish genome, as well as the OR repertoires in two pufferfish species, fugu (44 genes and tetraodon (42 genes. Although the genomes analyzed here contain fewer genes than in mammalian species, the teleost OR genes can be grouped into a larger number of major clades, representing greater overall OR diversity in the fish. Conclusion Based on the phylogeny of fish and mammalian repertoires, we propose a model for OR gene evolution in which different ancestral OR genes or gene families were selectively lost or expanded in different vertebrate lineages. In addition, our calculations of the ratios of non-synonymous to synonymous codon substitutions among more recently expanding OR subgroups in zebrafish implicate residues that may be involved in odorant binding.

  11. A Sensory 3D Map of the Odor Description Space Derived from a Comparison of Numeric Odor Profile Databases.

    Science.gov (United States)

    Zarzo, Manuel

    2015-06-01

    Many authors have proposed different schemes of odor classification, which are useful to aid the complex task of describing smells. However, reaching a consensus on a particular classification seems difficult because our psychophysical space of odor description is a continuum and is not clustered into well-defined categories. An alternative approach is to describe the perceptual space of odors as a low-dimensional coordinate system. This idea was first proposed by Crocker and Henderson in 1927, who suggested using numeric profiles based on 4 dimensions: "fragrant," "acid," "burnt," and "caprylic." In the present work, the odor profiles of 144 aroma chemicals were compared by means of statistical regression with comparable numeric odor profiles obtained from 2 databases, enabling a plausible interpretation of the 4 dimensions. Based on the results and taking into account comparable 2D sensory maps of odor descriptors from the literature, a 3D sensory map (odor cube) has been drawn up to improve understanding of the similarities and dissimilarities of the odor descriptors most frequently used in fragrance chemistry.

  12. The context of discrimination: workplace conditions, institutional environments, and sex and race discrimination charges.

    Science.gov (United States)

    Hirsh, C Elizabeth; Kornrich, Sabino

    2008-03-01

    This article explores the organizational conditions under which discrimination charges occur. Drawing on structural and organizational theories of the workplace, the authors demonstrate how organizational conditions affect workers' and regulatory agents' understandings of unlawful discrimination. Using a national sample of work establishments, matched to discrimination-charge data obtained from the Equal Employment Opportunity Commission (EEOC), the authors examine how characteristics of the workplace and institutional environment affect variation in the incidence of workers' charges of sex and race discrimination and in the subset of discrimination claims that are verified by EEOC investigators. The findings indicate that workplace conditions, including size, composition, and minority management, affect workers' charges as well as verified claims; the latter are also affected by institutional factors, such as affirmative action requirements, subsidiary status, and industrial sector. These results suggest that internal workplace conditions affect both workers' and regulatory agents' interpretations of potentially discriminatory experiences, while institutional conditions matter only for regulatory agents' interpretations of those events.

  13. Increasing explicit sequence knowledge by odor cueing during sleep in men but not women

    Directory of Open Access Journals (Sweden)

    Susanne eDiekelmann

    2016-04-01

    Full Text Available Sleep consolidates newly acquired memories. Beyond stabilizing memories, sleep is thought to reorganize memory representations such that invariant structures, statistical regularities and even new explicit knowledge are extracted. Whereas increasing evidence suggests that the stabilization of memories during sleep can be facilitated by cueing with learning-associated stimuli, the effect of cueing on memory reorganization is less well understood. Here we asked whether olfactory cueing during sleep enhances the generation of explicit knowledge about an implicitly learned procedural memory task. Subjects were trained on a serial reaction time task (SRTT containing a hidden 12-element sequence in the presence of an odor. During subsequent sleep, half of the subjects were re-exposed to the odor during periods of slow wave sleep (SWS, while the other half received odorless vehicle. In the next morning, subjects were tested on their explicit knowledge about the underlying sequence in a free recall test and a generation task. Although odor cueing did not significantly affect overall explicit knowledge, differential effects were evident when analyzing male and female subjects separately. Explicit sequence knowledge, both in free recall and the generation task, was enhanced by odor cueing in men, whereas women showed no cueing effect. Procedural skill in the SRTT was not affected by cueing, neither in men nor in women. These findings suggest that olfactory memory reactivation can increase explicit knowledge about implicitly learned information, but only in men. Hormonal differences due to menstrual cycle phase and/or hormonal contraceptives might explain the lacking effect in women.

  14. The Badness of Discrimination

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2006-01-01

    The most blatant forms of discrimination are morally outrageous and very obviously so; but the nature and boundaries of discrimination are more controversial, and it is not clear whether all forms of discrimination are morally bad; nor is it clear why objectionable cases of discrimination are bad...

  15. Socially-Tolerable Discrimination

    OpenAIRE

    J. Atsu Amegashie

    2008-01-01

    History is replete with overt discrimination of various forms. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race or gender is much less acceptable. Why? I develop a simple model of conflict which is driven by either racial (gender) discrimination or generational discrimination (i.e., young versus old). I show that there exist parameters of the model where racial (gender) di...

  16. Research on Odor Interaction between Aldehyde Compounds via a Partial Differential Equation (PDE Model

    Directory of Open Access Journals (Sweden)

    LuchunYan

    2015-01-01

    Full Text Available In order to explore the odor interaction of binary odor mixtures, a series of odor intensity evaluation tests were performed using both individual components and binary mixtures of aldehydes. Based on the linear relation between the logarithm of odor activity value and odor intensity of individual substances, the relationship between concentrations of individual constituents and their joint odor intensity was investigated by employing a partial differential equation (PDE model. The obtained results showed that the binary odor interaction was mainly influenced by the mixing ratio of two constituents, but not the concentration level of an odor sample. Besides, an extended PDE model was also proposed on the basis of the above experiments. Through a series of odor intensity matching tests for several different binary odor mixtures, the extended PDE model was proved effective at odor intensity prediction. Furthermore, odorants of the same chemical group and similar odor type exhibited similar characteristics in the binary odor interaction. The overall results suggested that the PDE model is a more interpretable way of demonstrating the odor interactions of binary odor mixtures.

  17. Smelling shapes: crossmodal correspondences between odors and shapes.

    Science.gov (United States)

    Hanson-Vaux, Grant; Crisinel, Anne-Sylvie; Spence, Charles

    2013-02-01

    Crossmodal correspondences between odors and visual stimuli-particularly colors-are well-established in the literature, but there is a paucity of research involving visual shape correspondences. Crossmodal associations between 20 odors (a selection of those commonly found in wine) and visual shape stimuli ("kiki"/"bouba" forms-Köhler W. 1929. Gestalt psychology. New York: Liveright.) were investigated in a sample of 25 participants (mean age of 21 years). The odors were rated along a form scale anchored by 2 shapes, as well as several descriptive adjective scales. Two of the odors were found to be significantly associated with an angular shape (lemon and pepper) and two others with a rounded shape (raspberry and vanilla). Principal component analysis indicated that the hedonic value and intensity of odors are important in this crossmodal association, with more unpleasant and intense smells associated with more angular forms. These results are discussed in terms of their practical applications, such as in the use of bottle, logo, or label shape by marketers of perfume and wine to convey the prominent notes through congruent odor-shape pairing. In conclusion, these results support the existence of widespread crossmodal associations (or correspondences) between odors and visual shape stimuli.

  18. Regulatory Features for Odorant Receptor Genes in the Mouse Genome.

    Science.gov (United States)

    Degl'Innocenti, Andrea; D'Errico, Anna

    2017-01-01

    The odorant receptor genes, seven transmembrane receptor genes constituting the vastest mammalian gene multifamily, are expressed monogenically and monoallelicaly in each sensory neuron in the olfactory epithelium. This characteristic, often referred to as the one neuron-one receptor rule, is driven by mostly uncharacterized molecular dynamics, generally named odorant receptor gene choice. Much attention has been paid by the scientific community to the identification of sequences regulating the expression of odorant receptor genes within their loci, where related genes are usually arranged in genomic clusters. A number of studies identified transcription factor binding sites on odorant receptor promoter sequences. Similar binding sites were also found on a number of enhancers that regulate in cis their transcription, but have been proposed to form interchromosomal networks. Odorant receptor gene choice seems to occur via the local removal of strongly repressive epigenetic markings, put in place during the maturation of the sensory neuron on each odorant receptor locus. Here we review the fast-changing state of art for the study of regulatory features for odorant receptor genes.

  19. Inhibitory Odorant Signaling in Mammalian Olfactory Receptor Neurons

    Science.gov (United States)

    Corey, Elizabeth A.; Brunert, Daniela; Klasen, Katharina; Ache, Barry W.

    2010-01-01

    Odorants inhibit as well as excite olfactory receptor neurons (ORNs) in many species of animals. Cyclic nucleotide-dependent activation of canonical mammalian ORNs is well established but it is still unclear how odorants inhibit these cells. Here we further implicate phosphoinositide-3-kinase (PI3K), an indispensable element of PI signaling in many cellular processes, in olfactory transduction in rodent ORNs. We show that odorants rapidly and transiently activate PI3K in the olfactory cilia and in the olfactory epithelium in vitro. We implicate known G-protein–coupled isoforms of PI3K and show that they modulate not only the magnitude but also the onset kinetics of the electrophysiological response of ORNs to complex odorants. Finally, we show that the ability of a single odorant to inhibit another can be PI3K dependent. Our collective results provide compelling support for the idea that PI3K-dependent signaling mediates inhibitory odorant input to mammalian ORNs and at least in part contributes to the mixture suppression typically seen in the response of ORNs to complex natural odorants. PMID:20032232

  20. Multidimensional representation of odors in the human olfactory cortex.

    Science.gov (United States)

    Fournel, A; Ferdenzi, C; Sezille, C; Rouby, C; Bensafi, M

    2016-06-01

    What is known as an odor object is an integrated representation constructed from physical features, and perceptual attributes mainly mediated by the olfactory and trigeminal systems. The aim of the present study was to comprehend how this multidimensional representation is organized, by deciphering how similarities in the physical, olfactory and trigeminal perceptual spaces of odors are represented in the human brain. To achieve this aim, we combined psychophysics, functional MRI and multivariate representational similarity analysis. Participants were asked to smell odors diffused by an fMRI-compatible olfactometer and to rate each smell along olfactory dimensions (pleasantness, intensity, familiarity and edibility) and trigeminal dimensions (irritation, coolness, warmth and pain). An event-related design was implemented, presenting different odorants. Results revealed that (i) pairwise odorant similarities in anterior piriform cortex (PC) activity correlated with pairwise odorant similarities in chemical properties (P physical, olfactory and trigeminal features is based on specific fine processing of similarities between odorous stimuli in a distributed manner in the olfactory system. Hum Brain Mapp 37:2161-2172, 2016. © 2016 Wiley Periodicals, Inc.

  1. Metabolic and Sensory Influences on Odor Sensitivity in Humans.

    Science.gov (United States)

    Ramaekers, Marielle G; Verhoef, Alard; Gort, Gerrit; Luning, Pieternel A; Boesveldt, Sanne

    2016-02-01

    Our olfactory sense plays an important role in eating behavior by modulating our food preferences and intake. However, hunger or satiety may also influence how we perceive odors. Albeit speculative, contradictory results found in the past may have resulted from confounding by type of meal that participants ate to induce satiety. We aimed to investigate the influence of hunger state on olfactory sensitivity, comparing hunger to satiety using 2 different types of lunch to control for sensory-specific satiety. Odor detection thresholds were measured in 2 groups of participants (39 per group, 18-40 years), under 3 conditions: when hungry (twice), after a sweet lunch, and after a savory lunch. One group had their detection thresholds tested for a sweet odor, whereas in the other group, sensitivity to a savory odor was measured. Differences in olfactory sensitivity conditions were analyzed using linear mixed models. Participants had higher scores on the odor sensitivity task in a hungry versus satiated state (P = 0.001). Within the satiated condition, there was no effect of type of lunch on odor sensitivity. In conclusion, hunger slightly enhances sensitivity to food odors, but did not significantly depend on the type of food participants ate, suggesting no clear influence of sensory-specific satiety.

  2. Effects of visual priming on taste-odor interaction.

    Directory of Open Access Journals (Sweden)

    Marije van Beilen

    Full Text Available Little is known about the influence of visual characteristics other than colour on flavor perception, and the complex interactions between more than two sensory modalities. This study focused on the effects of recognizability of visual (texture information on flavor perception of odorized sweet beverages. Participants rated the perceived sweetness of odorized sucrose solutions in the presence or absence of either a congruent or incongruent visual context. Odors were qualitatively reminiscent of sweet foods (strawberry and caramel or not (savoury. Visual context was either an image of the same sweet foods (figurative context or a visual texture derived from this product (non-figurative context. Textures were created using a texture synthesis method that preserved perceived food qualities while removing object information. Odor-taste combinations were rated sweeter within a figurative than a non-figurative context. This behaviour was exhibited for all odor-taste combinations, even in trials without images, indicating sustained priming by figurative visual context. A non-figurative context showed a transient sweetening effect. Sweetness was generally enhanced most by the strawberry odor. We conclude that the degree of recognizability of visual information (figurative versus non-figurative, influences flavor perception differently. Our results suggest that this visual context priming is mediated by separate sustained and transient processes that are differently evoked by figurative and non-figurative visual contexts. These components operate independent of the congruency of the image-odor-taste combinations.

  3. Generalization mediates sensitivity to complex odor features in the honeybee.

    Directory of Open Access Journals (Sweden)

    Geraldine A Wright

    Full Text Available Animals use odors as signals for mate, kin, and food recognition, a strategy which appears ubiquitous and successful despite the high intrinsic variability of naturally-occurring odor quantities. Stimulus generalization, or the ability to decide that two objects, though readily distinguishable, are similar enough to afford the same consequence, could help animals adjust to variation in odor signals without losing sensitivity to key inter-stimulus differences. The present study was designed to investigate whether an animal's ability to generalize learned associations to novel odors can be influenced by the nature of the associated outcome. We use a classical conditioning paradigm for studying olfactory learning in honeybees to show that honeybees conditioned on either a fixed- or variable-proportion binary odor mixture generalize learned responses to novel proportions of the same mixture even when inter-odor differences are substantial. We also show that the resulting olfactory generalization gradients depend critically on both the nature of the stimulus-reward paradigm and the intrinsic variability of the conditioned stimulus. The reward dependency we observe must be cognitive rather than perceptual in nature, and we argue that outcome-dependent generalization is necessary for maintaining sensitivity to inter-odor differences in complex olfactory scenes.

  4. Odors eliciting fear: a conditioning approach to Idiopathic Environmental Intolerances.

    Science.gov (United States)

    Leer, Arne; Smeets, Monique A M; Bulsing, Patricia J; van den Hout, Marcel A

    2011-06-01

    Patients suffering from Idiopathic Environmental Intolerances (IEI) report health symptoms, referable to multiple organ systems, which are triggered by harmless odors and therefore medically unexplainable. In line with previous research that predominantly points towards psychological explanations, the present study tests the hypothesis that IEI symptoms result from learning via classical conditioning of odors to fear. A differential conditioning paradigm was employed. Hedonically different odors were compared on ease of fear acquisition. Conditioned stimuli (CSs) were Dimethyl Sulfide (unpleasant) and peach (pleasant). The unconditioned stimulus (US) was an electrical shock. During acquisition one odor (CS+) was followed by shock, while the other odor (CS-) was not. Next, fear extinction was tested by presenting both CS+ and CS- without US. Electrodermal response, odor evaluation, and sniffing behavior were monitored. Results showed successful fear conditioning irrespective of hedonic character as evidenced by electrodermal response. Acquired fear did not extinguish. There was no evidence of evaluative conditioning taking place, as CS evaluation did not change during fear acquisition. Early avoidance of the CS+, as deduced from odor inhalation measures, was demonstrated, but did not sustain during the entire acquisition phase. This study suggests that a fear conditioning account of IEI is only partially satisfactory.

  5. Experiencing discrimination increases risk taking.

    Science.gov (United States)

    Jamieson, Jeremy P; Koslov, Katrina; Nock, Matthew K; Mendes, Wendy Berry

    2013-02-01

    Prior research has revealed racial disparities in health outcomes and health-compromising behaviors, such as smoking and drug abuse. It has been suggested that discrimination contributes to such disparities, but the mechanisms through which this might occur are not well understood. In the research reported here, we examined whether the experience of discrimination affects acute physiological stress responses and increases risk-taking behavior. Black and White participants each received rejecting feedback from partners who were either of their own race (in-group rejection) or of a different race (out-group rejection, which could be interpreted as discrimination). Physiological (cardiovascular and neuroendocrine) changes, cognition (memory and attentional bias), affect, and risk-taking behavior were assessed. Significant participant race × partner race interactions were observed. Cross-race rejection, compared with same-race rejection, was associated with lower levels of cortisol, increased cardiac output, decreased vascular resistance, greater anger, increased attentional bias, and more risk-taking behavior. These data suggest that perceived discrimination is associated with distinct profiles of physiological reactivity, affect, cognitive processing, and risk taking, implicating direct and indirect pathways to health disparities.

  6. The Conformational Behaviour of the Odorant Dihydrocarveol

    Science.gov (United States)

    Loru, Donatella; Jarman, Natasha; Sanz, M. Eugenia

    2016-06-01

    The odorant dihydrocarveol (C10H18O) has been investigated in the gas phase using a 2-8 GHz chirped-pulse Fourier transform microwave spectrometer. Dihydrocarveol was purchased as a mixture of n-, iso-, neo-, and neoiso- isomers. The sample was placed in a bespoke heating nozzle at about 85°C and seeded in Ne at 5 bar. Three conformers were observed and their rotational constants were determined. By comparing the experimental rotational constants with those calculated ab initio the three conformers were identified as belonging to n-dihydrocarveol. In all three conformers the isopropenyl group is in equatorial position with respect to the six-membered ring, and the OH group maintains the same configuration. The conformers differ in the orientation of the isopropenyl group.

  7. Primary odorants of naturally soiled laundry

    DEFF Research Database (Denmark)

    Jepsen, Signe Munk; Münch, Petra; Stahnke, Marie Louise Heller;

    2000-01-01

    Odorants still attached to laundry soiled with human axillary sweat and sebum, after a mild washing procedure, were extracted and analysed by aroma extract dilution analysis. Esters (ethyl-2-methylpropanoate and ethylbutanoate), ketones (1-hexen-3-one and 1-octen-3-one) and, in particular......, on the other hand, effectively removed during wash. The influence of lipase activity on the odour profile was investigated by analysing selected sets of textile swatches, sampled from the right/left axillary of male runners, washed in the presence/absence of lipase. The swatches were examined by a sensory...... ranking analysis prior to the analytical odour analysis. Swatches selected for the subsequent odour analysis possessed greater odour intensity, when washed in the presence of lipase than the corresponding swatches washed in the absence of lipase. The aroma extract dilution analysis revealed that generally...

  8. Neurons and circuits for odor processing in the piriform cortex.

    Science.gov (United States)

    Bekkers, John M; Suzuki, Norimitsu

    2013-07-01

    Increased understanding of the early stages of olfaction has lead to a renewed interest in the higher brain regions responsible for forming unified 'odor images' from the chemical components detected by the nose. The piriform cortex, which is one of the first cortical destinations of olfactory information in mammals, is a primitive paleocortex that is critical for the synthetic perception of odors. Here we review recent work that examines the cellular neurophysiology of the piriform cortex. Exciting new findings have revealed how the neurons and circuits of the piriform cortex process odor information, demonstrating that, despite its superficial simplicity, the piriform cortex is a remarkably subtle and intricate neural circuit.

  9. Analysis of Five Earthy-Musty Odorants in Environmental Water by HS-SPME/GC-MS

    Directory of Open Access Journals (Sweden)

    Zhen Ding

    2014-01-01

    Full Text Available The pressing issue of earthy and musty odor compounds in natural waters, which can affect the organoleptic properties of drinking water, makes it a public health concern. A simple and sensitive method for simultaneous analysis of five odorants in environmental water was developed by headspace solid-phase microextraction (HS-SPME coupled to chromatography-mass spectrometry (GC-MS, including geosmin (GSM and 2-methylisoborneol (2-MIB, as well as dimethyl trisulfide (DMTS, β-cyclocitral, and β-ionone. Based on the simple modification of original magnetic stirrer purchased from CORNING (USA, the five target compounds can be separated within 23 min, and the calibration curves show good linearity with a correlation coefficient above 0.999 (levels = 5. The limits of detection (LOD are all below 1.3 ng L−1, and the relative standard deviation (%RSD is between 4.4% and 9.9% (n = 7 and recoveries of the analytes from water samples are between 86.2% and 112.3%. In addition, the storage time experiment indicated that the concentrations did not change significantly for GSM and 2-MIB if they were stored in canonical environment. In conclusion, the method in this study could be applied for monitoring these five odorants in natural waters.

  10. New Look at odorization levels for propane gas. [Ethyl mercaptan; thiophane; equilibrium K values

    Energy Technology Data Exchange (ETDEWEB)

    Whisman, M.L.; Goetzinger, J.W.; Cotton, F.O.; Brinkman, D.W.; Thompson, C.J.

    1977-09-01

    Nearly 4,000 persons participated in a study to evaluate three odorant systems in four test modes and at 24 different test sites. Participants included trained panels, untrained ERDA employees, and several thousand untrained volunteer evaluators. The classical testing technique and three modified test modes were used to represent a spectrum of conditions that would define the effect of environmental familiarity and mental distractions upon olfactory responses to LP-gas. Significant efforts were directed toward determination of odorant levels that not only can be detected but also will be detected. The study showed that in addition to defects of the nasal anatomy, psychological factors also affect olfactory responses, and that unfamiliarity with a given environment as well as anxieties or mental distractions can produce reduced awareness to odorants intended to warn individuals of the presence of LP-gas. A second part of the study involved a laboratory determination of equilibrium K-values for both ethyl mercaptan and thiophane at three temperatures. Novel sample handling and gas chromatographic techniques provided reproducible results which were in close agreement with theoretical predictions. (28 tables, 29 tables)

  11. A specific area of olfactory cortex involved in stress hormone responses to predator odors

    Science.gov (United States)

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

    2016-01-01

    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 behavioral changes as well as a surge in blood stress hormones that mobilizes multiple body systems to escape impending danger1,2. 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 that induces stress hormone responses to volatile predator odors. Using monosynaptic and polysynaptic viral tracers, we found that multiple olfactory cortical areas transmit signals to hypothalamic CRH (corticotropin releasing hormone) 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 odors. Chemogenetic stimulation of AmPir activated CRH neurons and induced an increase in blood stress hormone, mimicking an instinctive fear response. Moreover, chemogenetic silencing of AmPir markedly reduced the stress hormone response to predator odors without affecting a fear behavior. These findings suggest that AmPir, a small area comprising olfactory cortex, plays a key role in the hormonal component of the instinctive fear response to volatile predator scents. PMID:27001694

  12. Molecular cloning, expression profile, odorant affinity, and stability of two odorant-binding proteins in Macrocentrus cingulum Brischke (Hymenoptera: Braconidae).

    Science.gov (United States)

    Ahmed, Tofael; Zhang, Tiantao; Wang, Zhenying; He, Kanglai; Bai, Shuxiong

    2017-02-01

    The polyembryonic endoparasitoid wasp Macrocentrus cingulum Brischke (Hymenoptera: Braconidae) is deployed successfully as a biocontrol agent for corn pest insects from the Lepidopteran genus Ostrinia in Europe and throughout Asia, including Japan, Korea, and China. The odorants are recognized, bound, and solubilized by odorant-binding protein (OBP) in the initial biochemical recognition steps in olfaction that transport them across the sensillum lymph to initiate behavioral response. In the present study, we examine the odorant-binding effects on thermal stability of McinOBP2, McinOBP3, and their mutant form that lacks the third disulfide bonds. Real-time PCR experiments indicate that these two are expressed mainly in adult antennae, with expression levels differing by sex. Odorant-binding affinities of aldehydes, terpenoids, and aliphatic alcohols were measured with circular dichroism spectroscopy based on changes in the thermal stability of the proteins upon their affinities to odorants. The obtained results reveal higher affinity of trans-caryophelle, farnesene, and cis-3-Hexen-1-ol exhibits to both wild and mutant McinOBP2 and McinOBP3. Although conformational flexibility of the mutants and shape of binding cavity make differences in odorant affinity between the wild-type and mutant, it suggested that lacking the third disulfide bond in mutant proteins may have chance to incorrect folded structures that reduced the affinity to these odorants. In addition, CD spectra clearly indicate proteins enriched with α-helical content.

  13. The specter of discrimination: Fear of interpersonal racial discrimination among adolescents in Chicago.

    Science.gov (United States)

    Herda, Daniel

    2016-01-01

    This analysis examines fear of interpersonal racial discrimination among Black, Hispanic, and White adolescents. The extent and correlates of these concerns are examined using survey data from the Project for Human Development in Chicago Neighborhoods. Borrowing from the fear-of-crime literature, the contact hypothesis, and group threat theory, several hypotheses are developed linking discrimination fear to direct personal experience with discrimination, indirect or vicarious experience, and environmental signals of discrimination. Results show that about half of Blacks and Hispanics have feared discrimination in the past year. Multivariate results indicate that fear is most likely if one has experienced victimization first-hand and when one's parent is affected by discrimination. Further, a larger presence neighborhood outgroups produces greater fear. Overall, discrimination fear constitutes an additional obstacle for minority adolescents as they transition to adulthood. The phenomenon warrants increased scholarly attention and represents a fruitful avenue for future research.

  14. AMisfit Theory of Spontaneous Conscious Odor Perception (MITSCOP: reflections on the role and function of odor memory in everyday life.

    Directory of Open Access Journals (Sweden)

    Egon P Köster

    2014-02-01

    Full Text Available Our senses have developed as an answer to the world we live in (Gibson, 1966 and so have the forms of memory that accompany them. All senses serve different purposes and do so in different ways. In vision, where orientation and object recognition are important, memory is strongly linked to identification. In olfaction, the guardian of vital functions such as breathing and food ingestion, perhaps the most important (and least noticed and researched role of odor memory is to help us not to notice the well-known odors or flavors in our everyday surroundings, but to react immediately to the unexpected ones. At the same time it provides us with a feeling of safety when our expectancies are met. All this happens without any smelling intention or conscious knowledge of our expectations. Identification by odor naming is not involved in this and people are notoriously bad at it. Odors are usually best identified via the episodic memory of the situation in which they once occurred. Spontaneous conscious odor perception normally only occurs in situations where attention is demanded, either because the inhaled air or the food smell is particularly good or particularly bad and people search for its source or because people want to actively enjoy the healthiness and pleasantness of their surroundings or food. Odor memory is concerned with novelty detection rather than with recollection of odors. In this paper, these points are illustrated with experimental results and their consequences for doing ecologically valid odor memory research are drawn. Furthermore, suggestions for ecologically valid research on everyday odor memory and some illustrative examples are given.

  15. Combinatorial activation and repression by seven transcription factors specify Drosophila odorant receptor expression.

    Directory of Open Access Journals (Sweden)

    Shadi Jafari

    Full Text Available The mechanism that specifies olfactory sensory neurons to express only one odorant receptor (OR from a large repertoire is critical for odor discrimination but poorly understood. Here, we describe the first comprehensive analysis of OR expression regulation in Drosophila. A systematic, RNAi-mediated knock down of most of the predicted transcription factors identified an essential function of acj6, E93, Fer1, onecut, sim, xbp1, and zf30c in the regulation of more than 30 ORs. These regulatory factors are differentially expressed in antennal sensory neuron classes and specifically required for the adult expression of ORs. A systematic analysis reveals not only that combinations of these seven factors are necessary for receptor gene expression but also a prominent role for transcriptional repression in preventing ectopic receptor expression. Such regulation is supported by bioinformatics and OR promoter analyses, which uncovered a common promoter structure with distal repressive and proximal activating regions. Thus, our data provide insight into how combinatorial activation and repression can allow a small number of transcription factors to specify a large repertoire of neuron classes in the olfactory system.

  16. Gender Discrimination in English

    Institute of Scientific and Technical Information of China (English)

    廖敏慧

    2014-01-01

    Gender discrimination in language is usually defined as discrimination based on sex, especially discrimination against women. With the rise of women’s liberation movement in the 1960s and 1970s, and the improvement of women’s social status in recent years, gender discrimination in English attracts more and more attention. Based on previous studies, this thesis first dis⁃cusses the manifestations of gender discrimination in English vocabulary and address terms, then analyzes the factors of gender dis⁃crimination in English from social and cultural perspectives, finally puts forward some methods that are good for avoiding or elim⁃inating gender discrimination in English.

  17. Proteomic analysis of pig (Sus scrofa olfactory soluble proteome reveals O-GlcNAcylation of secreted odorant-binding proteins

    Directory of Open Access Journals (Sweden)

    Patricia eNAGNAN-LE MEILLOUR

    2014-12-01

    Full Text Available The diversity of olfactory binding proteins (OBPs is a key point to understand their role in molecular olfaction. Since only few different sequences were characterized in each mammalian species, they have been considered as passive carriers of odors and pheromones. We have explored the soluble proteome of pig nasal mucus, taking benefit of the powerful tools of proteomics. Combining two-dimensional electrophoresis, mass spectrometry and western-blot with specific antibodies, our analyses revealed for the first time that the pig nasal mucus is mainly composed of secreted OBP isoforms, some of them being potentially modified by O-GlcNAcylation. An ortholog gene of the glycosyltransferase responsible of the O-GlcNAc linking on extracellular proteins in Drosophila and Mouse (EOGT was amplified from tissues of pigs of different ages and sex. The sequence was used in a phylogenetic analysis, which evidenced conservation of EOGT in insect and mammalian models studied in molecular olfaction. Extracellular O-GlcNAcylation of secreted OBPs could finely modulate their binding specificities to odors and pheromones. This constitutes a new mechanism for extracellular signaling by OBPs, suggesting that they act as the first step of odor discrimination.

  18. Individual odor differences and their social functions in insects.

    Science.gov (United States)

    Barrows, E M; Bell, W J; Michener, C D

    1975-01-01

    The evolution of individual or subgroup differences in odors of halictine bees is suggested from possible widespread intraspecific variation in pheromones. An important result of such variation may be maintenance of genetic polymorphisms; in nesting Hymenoptera odor differences may also facilitate individual nest recognition. In Lasioglosum zephyrum males habituate to odors of different females and perhaps thus save time by not trying to copulate with nonreceptive individuals. Guards (females) at nest entrances distinguish their few nestmates (other females) from other conspecific individuals by odors, seemingly pheromones. Duration of the habituation in L. zephyrum is at least an hour (perhaps much more) for males in relation to females and 6 or 7 days for guards in relation to nestmates. Studies of pheromones should take into consideration the possibility of pheromonal polymorphism in any species and the likelihood that it may be significant from biological and practical viewpoints. PMID:1058498

  19. Evaluation of γ-radiation on green tea odor volatiles

    Science.gov (United States)

    Fanaro, G. B.; Duarte, R. C.; Araújo, M. M.; Purgatto, E.; Villavicencio, A. L. C. H.

    2011-01-01

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  20. Evaluation of {gamma}-radiation on green tea odor volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, G.B., E-mail: gbfanaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Duarte, R.C., E-mail: renatocduarte@yahoo.com.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Araujo, M.M., E-mail: mmozeika@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Purgatto, E., E-mail: epurgatt@usp.b [Universidade de Sao Paulo-Faculdade de Ciencias Farmaceuticas, FCF/USP, Departamento de Alimentos e Nutricao Experimental, Av. Prof. Lineu Prestes, 580 Bloco 14, 05508-900, Sao Paulo, SP (Brazil); Villavicencio, A.L.C.H., E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil)

    2011-01-15

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  1. Hazardous Odor Recognition by CMAC Based Neural Networks

    Directory of Open Access Journals (Sweden)

    Bekir Karlık

    2009-09-01

    Full Text Available Electronic noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. Artificial neural networks (ANNs have been used to analyze complex data and to recognize patterns, and have shown promising results in recognition of volatile compounds and odors in electronic nose applications. When an ANN is combined with a sensor array, the number of detectable chemicals is generally greater than the number of unique sensor types. The odor sensing system should be extended to new areas since its standard style where the output pattern from multiple sensors with partially overlapped specificity is recognized by a neural network or multivariate analysis. This paper describes the design, implementation and performance evaluations of the application developed for hazardous odor recognition using Cerebellar Model Articulation Controller (CMAC based neural networks.

  2. Hazardous Odor Recognition by CMAC Based Neural Networks.

    Science.gov (United States)

    Bucak, Ihsan Ömür; Karlık, Bekir

    2009-01-01

    Electronic noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. Artificial neural networks (ANNs) have been used to analyze complex data and to recognize patterns, and have shown promising results in recognition of volatile compounds and odors in electronic nose applications. When an ANN is combined with a sensor array, the number of detectable chemicals is generally greater than the number of unique sensor types. The odor sensing system should be extended to new areas since its standard style where the output pattern from multiple sensors with partially overlapped specificity is recognized by a neural network or multivariate analysis. This paper describes the design, implementation and performance evaluations of the application developed for hazardous odor recognition using Cerebellar Model Articulation Controller (CMAC) based neural networks.

  3. Labour Market Performance Effects of Discrimination and Loss of Skill

    DEFF Research Database (Denmark)

    Larsen, Birthe; Waisman, Gisela

    We examine the impact of discrimination on labour market performance when workers are subject to a risk of losing skills during the experience of unemployment. Within a search and matching model, we show that all natives and immigrants are affected by discrimination. Discrimination in one sector...

  4. Simultaneous removal of multiple odorants from source water suffering from septic and musty odors: Verification in a full-scale water treatment plant with ozonation.

    Science.gov (United States)

    Guo, Qingyuan; Yang, Kai; Yu, Jianwei; Wang, Chunmiao; Wen, Xiaodong; Zhang, Liping; Yang, Min; Xia, Ping; Zhang, Dong

    2016-09-01

    Ozonation is known to be very effective in the removal of odorants from source water. However, it is not known if ozonation is effective in the removal of multiple odorants causing different types of odors. In this study, the removal performance for odors and odorants were evaluated in a Water Treatment Plant (WTP), which was equipped with coagulation, sedimentation, ozonation, biological activated carbon (BAC) filtration, sand filtration, and chlorination in succession and located in the downstream of the Huangpu (HP) River, over the period from April, 2014 to April, 2015. Flavor profile analysis (FPA) results showed that the source water was constantly associated with septic and musty odors. Geosmin and 2-MIB, with an average OAV of 4.54 and 1.38, respectively, were the major odorants for musty odor, while bis(2-chloroisopropyl) ether, DEDS and DMDS with an average OAV of 2.35, 1.65 and 0.78, respectively, might be responsible for the septic odor. While the musty odor could be removed effectively through the combination of ozonation and BAC, the septic odor and associated odorants required further treatment with sand filtration and chlorination for complete removal. It is clear that the advanced treatment process was effective for the treatment of source water containing complicated odorants. It should be noted that the sedimentation process needs careful management because release of odorants may occur during the treatment. The result of this study will be helpful for the mitigation of odors in WTP using source waters suffering from complicated odor problems.

  5. A circuit supporting concentration-invariant odor perception in Drosophila

    Directory of Open Access Journals (Sweden)

    Asahina Kenta

    2009-01-01

    Full Text Available Abstract Background Most odors are perceived to have the same quality over a large concentration range, but the neural mechanisms that permit concentration-invariant olfactory perception are unknown. In larvae of the vinegar fly Drosophila melanogaster, odors are sensed by an array of 25 odorant receptors expressed in 21 olfactory sensory neurons (OSNs. We investigated how subsets of larval OSNs with overlapping but distinct response properties cooperate to mediate perception of a given odorant across a range of concentrations. Results Using calcium imaging, we found that ethyl butyrate, an ester perceived by humans as fruity, activated three OSNs with response thresholds that varied across three orders of magnitude. Whereas wild-type larvae were strongly attracted by this odor across a 500-fold range of concentration, individuals with only a single functional OSN showed attraction across a narrower concentration range corresponding to the sensitivity of each ethyl butyrate-tuned OSN. To clarify how the information carried by different OSNs is integrated by the olfactory system, we characterized the response properties of local inhibitory interneurons and projection neurons in the antennal lobe. Local interneurons only responded to high ethyl butyrate concentrations upon summed activation of at least two OSNs. Projection neurons showed a reduced response to odors when summed input from two OSNs impinged on the circuit compared to when there was only a single functional OSN. Conclusions Our results show that increasing odor concentrations induce progressive activation of concentration-tuned olfactory sensory neurons and concomitant recruitment of inhibitory local interneurons. We propose that the interplay of combinatorial OSN input and local interneuron activation allows animals to remain sensitive to odors across a large range of stimulus intensities.

  6. Wild western lowland gorillas signal selectively using odor.

    Directory of Open Access Journals (Sweden)

    Michelle Klailova

    Full Text Available Mammals communicate socially through visual, auditory and chemical signals. The chemical sense is the oldest sense and is shared by all organisms including bacteria. Despite mounting evidence for social chemo-signaling in humans, the extent to which it modulates behavior is debated and can benefit from comparative models of closely related hominoids. The use of odor cues in wild ape social communication has been only rarely explored. Apart from one study on wild chimpanzee sniffing, our understanding is limited to anecdotes. We present the first study of wild gorilla chemo-communication and the first analysis of olfactory signaling in relation to arousal levels and odor strength in wild apes. If gorilla scent is used as a signaling mechanism instead of only a sign of arousal or stress, odor emission should be context specific and capable of variation as a function of the relationships between the emitter and perceiver(s. Measured through a human pungency scale, we determined the factors that predicted extreme levels of silverback odor for one wild western lowland gorilla (Gorilla gorilla gorilla group silverback. Extreme silverback odor was predicted by the presence and intensity of inter-unit interactions, silverback anger, distress and long-calling auditory rates, and the absence of close proximity between the silverback and mother of the youngest infant. Odor strength also varied according to the focal silverback's strategic responses during high intensity inter-unit interactions. Silverbacks appear to use odor as a modifiable form of communication; where odor acts as a highly flexible, context dependent signaling mechanism to group members and extra-group units. The importance of olfaction to ape social communication may be especially pertinent in Central African forests where limited visibility may necessitate increased reliance on other senses.

  7. Synaptic clusters function as odor operators in the olfactory bulb

    OpenAIRE

    Migliore, Michele; Cavarretta, Francesco; Marasco, Addolorata; Tulumello, Eleonora; Michael L Hines; Shepherd, Gordon M.

    2015-01-01

    How the olfactory bulb organizes and processes odor inputs through fundamental operations of its microcircuits is still controversial. To reveal these operations we hypothesize that one of the key mechanisms underlying odor coding is the interaction among spatially restricted and well-defined clusters of potentiated mitral–granule cell synapses. These experimentally observed clusters selectively gate the propagation of neuronal activity within the olfactory bulb and extensively contribute to ...

  8. Unsupervised Linear Discriminant Analysis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An algorithm for unsupervised linear discriminant analysis was presented. Optimal unsupervised discriminant vectors are obtained through maximizing covariance of all samples and minimizing covariance of local k-nearest neighbor samples. The experimental results show our algorithm is effective.

  9. Airline Price Discrimination

    OpenAIRE

    Stacey, Brian

    2015-01-01

    Price discrimination enjoys a long history in the airline industry. Borenstein (1989) discusses price discrimination through frequent flyer programs from 1985 as related to the Piedmont-US Air merger, price discrimination strategies have grown in size and scope since then. From Saturday stay over requirements to varying costs based on time of purchase, the airline industry is uniquely situated to enjoy the fruits of price discrimination.

  10. Differential Electrophysiological Responses to Odorant Isotopologues in Drosophilid Antennae123

    Science.gov (United States)

    Drimyli, Efstathia; Gaitanidis, Alexandros; Maniati, Klio; Turin, Luca

    2016-01-01

    Abstract Olfaction presents the ultimate challenge to molecular recognition as thousands of molecules have to be recognized by far fewer olfactory receptors. We have presented evidence that Drosophila readily distinguish odorants based on their molecular vibrations using a battery of behavioral assays suggesting engagement of a molecular vibration-sensing component. Here we interrogate electrophysiologically the antennae of four Drosophilids and demonstrate conserved differential response amplitudes to aldehydes, alcohols, ketones, nitriles, and their deuterated isotopologues. Certain deuterated odorants evoked larger electroantennogram (EAG) amplitudes, while the response to the normal odorant was elevated in others. Significantly, benzonitrile isotopologues were not distinguishable as predicted. This suggests that isotopologue-specific EAG amplitudes result from differential activation of specific olfactory receptors. In support of this, odorants with as few as two deuteria evoke distinct EAG amplitudes from their normal isotopologues, and this is independent of the size of the deuterated molecule. Importantly, we find no evidence that these isotopologue-specific amplitudes depend on perireceptor mechanisms or other pertinent physical property of the deuterated odorants. Rather, our results strongly suggest that Drosophilid olfactory receptors are activated by molecular vibrations differentiating similarly sized and shaped odorants in vivo, yielding sufficient differential information to drive behavioral choices. PMID:27351023

  11. Variable selection based cotton bollworm odor spectroscopic detection

    Science.gov (United States)

    Lü, Chengxu; Gai, Shasha; Luo, Min; Zhao, Bo

    2016-10-01

    Aiming at rapid automatic pest detection based efficient and targeting pesticide application and shooting the trouble of reflectance spectral signal covered and attenuated by the solid plant, the possibility of near infrared spectroscopy (NIRS) detection on cotton bollworm odor is studied. Three cotton bollworm odor samples and 3 blank air gas samples were prepared. Different concentrations of cotton bollworm odor were prepared by mixing the above gas samples, resulting a calibration group of 62 samples and a validation group of 31 samples. Spectral collection system includes light source, optical fiber, sample chamber, spectrometer. Spectra were pretreated by baseline correction, modeled with partial least squares (PLS), and optimized by genetic algorithm (GA) and competitive adaptive reweighted sampling (CARS). Minor counts differences are found among spectra of different cotton bollworm odor concentrations. PLS model of all the variables was built presenting RMSEV of 14 and RV2 of 0.89, its theory basis is insect volatilizes specific odor, including pheromone and allelochemics, which are used for intra-specific and inter-specific communication and could be detected by NIR spectroscopy. 28 sensitive variables are selected by GA, presenting the model performance of RMSEV of 14 and RV2 of 0.90. Comparably, 8 sensitive variables are selected by CARS, presenting the model performance of RMSEV of 13 and RV2 of 0.92. CARS model employs only 1.5% variables presenting smaller error than that of all variable. Odor gas based NIR technique shows the potential for cotton bollworm detection.

  12. Mixed Odor Classification for QCM Sensor Data by Neural Network

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2012-09-01

    Full Text Available Normal 0 21 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Compared with metal oxide semiconductor gas sensors, quarts crystal microbalance (QCM sensors are sensitive for odors. Using an array of QCM sensors, we measure mixed odors and classify them into an original odor class beforemixing based on neural networks. For simplicity we consider the case that two kinds of odor are mixed since more than two becomes too complex to analyze the classification results. We have used eight sensors and four kinds of odor are used as the original odors. The neural network used here is a conventional layered neural network. The classification is acceptable although the perfect classification could not been achieved.

  13. Mixed Odor Classification for QCM Sensor Data by Neural Network

    Directory of Open Access Journals (Sweden)

    Hiroyuki NAKAZUMI

    2013-07-01

    Full Text Available Normal 0 21 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Compared with metal oxide semiconductor gas sensors, quarts crystal microbalance (QCM sensors are sensitive for odors. Using an array of QCM sensors, we measure mixed odors and classify them into an original odor class before mixing based on neural networks. For simplicity we consider the case that two kinds of odor are mixed since more than two becomes too complex to analyze the classification results. We have used eight sensors and four kinds of odor are used as the original odors. The neural network used here is a conventional layered neural network. The classification is acceptable although the perfect classification could not been achieved.

  14. Investigations on the Aroma of Cocoa Pulp (Theobroma cacao L.) and Its Influence on the Odor of Fermented Cocoa Beans.

    Science.gov (United States)

    Chetschik, Irene; Kneubühl, Markus; Chatelain, Karin; Schlüter, Ansgar; Bernath, Konrad; Hühn, Tilo

    2017-03-29

    The odor-active constituents of cocoa pulp have been analyzed by aroma extract dilution analysis (AEDA) for the first time. Pulps of three different cocoa varieties have been investigated. The variety CCN51 showed low flavor intensities, in terms of flavor dilution (FD) factors, in comparison to varieties FSV41 and UF564, for which floral and fruity notes were detected in higher intensities. To gain first insights on a molecular level of how the cocoa pulp odorants affected the odor quality of cocoa beans during fermentation, quantitative measurements of selected aroma compounds were conducted in pulp and bean at different time points of the fermentation. The results showed significantly higher concentrations of 2-phenylethanol and 3-methylbutyl acetate in pulp than in the bean during the different time steps of the fermentation, whereas the reverse could be observed for the odorants linalool and 2-methoxyphenol. The findings of this study constitute a basis for further investigations on the aroma formation of cocoa during fermentation.

  15. Off-odor compounds produced in cork by isolated bacteria and fungi: a gas chromatography-mass spectrometry and gas chromatography-olfactometry study.

    Science.gov (United States)

    Prat, Chantal; Trias, Rosalia; Culleré, Laura; Escudero, Ana; Anticó, Enriqueta; Bañeras, Lluís

    2009-08-26

    The risk of development of specific olfactory profiles in cork was evaluated after inoculation of cork granules and agglomerated and natural cork stoppers with isolated bacteria and fungi. The highest incidence of off-odor development was found in assays when fungi were inoculated. Cork granules with musty-earthy, musty-earthy-TCA, and vegetative deviations were inspected by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Sixteen odor zones were clearly recognized in the GC-O analyses. Among these, octanal, 2-methoxy-3,5-dimethylpyrazine (MDMP), Z-2-nonenal, 2-methylisoborneol, 2,4,6-trichloroanisole (TCA), geosmin, and guaiacol were the most significant odorants and helped in the discrimination of sensory deviations. Only TCA and guaiacol were detected above their respective detection limits by HS-SPME-GC-MS. The fungi Cryptococcus sp. isolate F020, Rhodotorula sp. isolate F025, Penicillium glabrum isolate F001, and Pennicillium variabile F003A and the bacterium Pseudomonas jessenii isolate A1 were found to produce TCA to a greater extent. Additionally, 13 of 38 isolated microorganisms (2 bacteria and 11 fungi) proved able to produce unpleasant musty-earthy or vegetative odors that were not related to a significant TCA accumulation.

  16. Discriminately Decreasing Discriminability with Learned Image Filters

    CERN Document Server

    Whitehill, Jacob

    2011-01-01

    In machine learning and computer vision, input images are often filtered to increase data discriminability. In some situations, however, one may wish to purposely decrease discriminability of one classification task (a "distractor" task), while simultaneously preserving information relevant to another (the task-of-interest): For example, it may be important to mask the identity of persons contained in face images before submitting them to a crowdsourcing site (e.g., Mechanical Turk) when labeling them for certain facial attributes. Another example is inter-dataset generalization: when training on a dataset with a particular covariance structure among multiple attributes, it may be useful to suppress one attribute while preserving another so that a trained classifier does not learn spurious correlations between attributes. In this paper we present an algorithm that finds optimal filters to give high discriminability to one task while simultaneously giving low discriminability to a distractor task. We present r...

  17. Flammability, Odor, and Offgassing Requirements and Test Procedures for Materials in Environments That Support Combustion

    Science.gov (United States)

    1988-05-01

    Methone (dl) 2 ul in 333 ml Pungent Formic acid 25 ml of 90% solution in 500 ml Putrid Methyl disulfide (Methyl dithiomethane) 1 ul in 10,000 ml (4...pool shall not participate on the panel if their sense of smell is affected in any manner such as by recent smoking, ingestion of highly flavored foods...or exposure to pungent vapors. (10) At least one of the seven odors shall be presented to the panel as a standard for verifying the ability to

  18. Odor recognition and segmentation by coupled olfactory bulb and cortical networks

    CERN Document Server

    Li, Z; Li, Zhaoping; Hertz, John

    1999-01-01

    We present a model of a coupled system of the olfactory bulb and cortex. Odor inputs to the epithelium are transformed to oscillatory bulbar activities. The cortex recognizes the odor by resonating to the bulbar oscillating pattern when the amplitude and phase patterns from the bulb match an odor memory stored in the intracortical synapses. We assume a cortical structure which transforms the odor information in the oscillatory pattern to a slow DC feedback signal to the bulb. This feedback suppresses the bulbar response to the pre-existing odor, allowing subsequent odor objects to be segmented out for recognition.

  19. Odors bias time perception in visual and auditory modalities

    Directory of Open Access Journals (Sweden)

    Zhenzhu eYue

    2016-04-01

    Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

  20. Fetal alcohol exposure leads to abnormal olfactory bulb development and impaired odor discrimination in adult mice

    NARCIS (Netherlands)

    K.G. Akers (Katherine); S.A. Kushner (Steven); A.T. Leslie (Ana); L. Clarke (Laura); D. van der Kooy (Derek); J.P. Lerch (Jason); P.W. Frankland (Paul)

    2011-01-01

    textabstractBackground: Children whose mothers consumed alcohol during pregnancy exhibit widespread brain abnormalities and a complex array of behavioral disturbances. Here, we used a mouse model of fetal alcohol exposure to investigate relationships between brain abnormalities and specific behavior

  1. Associative Encoding in Posterior Piriform Cortex during Odor Discrimination and Reversal Learning

    OpenAIRE

    Calu, Donna J.; Roesch, Matthew R.; Stalnaker, Thomas A; Schoenbaum, Geoffrey

    2006-01-01

    Recent proposals have conceptualized piriform cortex as an association cortex, capable of integrating incoming olfactory information with descending input from higher order associative regions such as orbitofrontal cortex and basolateral amygdala (ABL). If true, encoding in piriform cortex should reflect associative features prominent in these areas during associative learning involving olfactory cues. We recently reported that neurons in anterior piriform cortex (APC) in rats exhibited signi...

  2. Full evaporation dynamic headspace and gas chromatography-mass spectrometry for uniform enrichment of odor compounds in aqueous samples.

    Science.gov (United States)

    Ochiai, Nobuo; Sasamoto, Kikuo; Hoffmann, Andreas; Okanoya, Kazunori

    2012-06-01

    A method for analysis of a wide range of odor compounds in aqueous samples at sub-ng mL⁻¹ to μg mL⁻¹ levels was developed by full evaporation dynamic headspace (FEDHS) and gas chromatography-mass spectrometry (GC-MS). Compared to conventional DHS and headspace solid phase microextraction (HS-SPME), FEDHS provides more uniform enrichment over the entire polarity range for odor compounds in aqueous samples. FEDHS at 80°C using 3 L of purge gas allows complete vaporization of 100 μL of an aqueous sample, and trapping and drying it in an adsorbent packed tube, while providing high recoveries (85-103%) of the 18 model odor compounds (water solubility at 25°C: log0.54-5.65 mg L⁻¹, vapor pressure at 25°C: 0.011-3.2 mm Hg) and leaving most of the low volatile matrix behind. The FEDHS-GC-MS method showed good linearity (r²>0.9909) and high sensitivity (limit of detection: 0.21-5.2 ng mL⁻¹) for the model compounds even with the scan mode in the conventional MS. The feasibility and benefit of the method was demonstrated with analyses of key odor compounds including hydrophilic and less volatile characteristics in beverages (whiskey and green tea). In a single malt whiskey sample, phenolic compounds including vanillin could be determined in the range of 0.92-5.1 μg mL⁻¹ (RSD<7.4%, n=6). For a Japanese green tea sample, 48 compounds including 19 potent odorants were positively identified from only 100 μL of sample. Heat-induced artifact formation for potent odorants was also examined and the proposed method does not affect the additional formation of thermally generated compounds. Eighteen compounds including 12 potent odorants (e.g. coumarin, furaneol, indole, maltol, and pyrazine congeners) were determined in the range of 0.21-110 ng mL⁻¹ (RSD<10%, n=6).

  3. A unique memory process modulated by emotion underpins successful odor recognition and episodic retrieval in humans

    Directory of Open Access Journals (Sweden)

    Anne-Lise eSaive

    2014-06-01

    Full Text Available We behaviorally explore the link between olfaction, emotion and memory by testing the hypothesis that the emotion carried by odors facilitates the memory of specific unique events. To investigate this idea, we used a novel behavioral approach inspired by a paradigm developed by our team to study episodic memory in a controlled and as ecological as possible way in humans. The participants freely explored three unique and rich laboratory episodes; each episode consisted of three unfamiliar odors (What positioned at three specific locations (Where within a visual context (Which context. During the retrieval test, which occurred 24 to 72 hours after the encoding, odors were used to trigger the retrieval of the complex episodes. The participants were proficient in recognizing the target odors among distractors and retrieving the visuospatial context in which they were encountered. The episodic nature of the task generated high and stable memory performances, which were accompanied by faster responses and slower and deeper breathing. Successful odor recognition and episodic memory were not related to differences in odor investigation at encoding. However, memory performances were influenced by the emotional content of the odors, regardless of odor valence, with both pleasant and unpleasant odors generating higher recognition and episodic retrieval than neutral odors. Finally, the present study also suggested that when the binding between the odors and the spatio-contextual features of the episode was successful, the odor recognition and the episodic retrieval collapsed into a unique memory process that began as soon as the participants smelled the odors.

  4. Odor identity influences tracking of temporally patterned plumes in Drosophila

    Directory of Open Access Journals (Sweden)

    Frye Mark A

    2011-06-01

    Full Text Available Abstract Background Turbulent fluid landscapes impose temporal patterning upon chemical signals, and the dynamical neuronal responses to patterned input vary across the olfactory receptor repertoire in flies, moths, and locusts. Sensory transformations exhibit low pass filtering that ultimately results in perceptual fusion of temporally transient sensory signals. For example, humans perceive a sufficiently fast flickering light as continuous, but the frequency threshold at which this fusion occurs varies with wavelength. Although the summed frequency sensitivity of the fly antenna has been examined to a considerable extent, it is unknown how intermittent odor signals are integrated to influence plume tracking behavior independent of wind cues, and whether temporal fusion for behavioral tracking might vary according to the odor encountered. Results Here we have adopted a virtual reality flight simulator to study the dynamics of plume tracking under different experimental conditions. Flies tethered in a magnetic field actively track continuous (non-intermittent plumes of vinegar, banana, or ethyl butyrate with equal precision. However, pulsing these plumes at varying frequency reveals that the threshold rate, above which flies track the plume as if it were continuous, is unique for each odorant tested. Thus, the capability of a fly to navigate an intermittent plume depends on the particular odorant being tracked during flight. Finally, we measured antennal field potential responses to an intermittent plume, found that receptor dynamics track the temporal pattern of the odor stimulus and therefore do not limit the observed behavioral temporal fusion limits. Conclusions This study explores the flies' ability to track odor plumes that are temporally intermittent. We were surprised to find that the perceptual critical fusion limit, determined behaviorally, is strongly dependent on odor identity. Antennal field potential recordings indicate that

  5. Cancer odor in the blood of ovarian cancer patients: a retrospective study of detection by dogs during treatment, 3 and 6 months afterward

    OpenAIRE

    Horvath, György; Andersson, Håkan; Nemes, Szilárd

    2013-01-01

    Background In recent decades it has been noted that trained dogs can detect specific odor molecules emitted by cancer cells. We have shown that the same odor can also be detected in the patient’s blood with high sensitivity and specificity by trained dogs. In the present study, we examined how the ability of dogs to detect this smell was affected by treatment to reduce tumor burden, including surgery and five courses of chemotherapy. Methods In Series I, one drop of plasma from each of 42 ova...

  6. Investigating a persistent odor at an aircraft seat manufacturer.

    Science.gov (United States)

    Broadwater, Kendra; de Perio, Marie A; Roberts, Jennifer; Burton, Nancy C; Lemons, Angela R; Green, Brett J; Brueck, Scott E

    2016-10-01

    An aircraft seat manufacturing company requested a NIOSH health hazard evaluation to help identify a strong odor that had persisted throughout the facility for over a year. Employees reported experiencing health effects thought to be related to the odor. We collected and analyzed area air samples for volatile organic compounds, endotoxin, bacterial and fungal metagenome, and metalworking fluid aerosol. Bulk metalworking fluid samples were analyzed for endotoxin, bacterial and fungal metagenome, and viable bacteria and fungus. We also evaluated the building ventilation systems and water diversion systems. Employees underwent confidential medical interviews about work practices, medical history, and health concerns. Based on our analyses, the odor was likely 2-methoxy-3,5-dimethylpyrazine. This pyrazine was found in air samples across the facility and originated from bacteria in the metalworking fluid. We did not identify bacteria known to produce the compound but bacteria from the same Proteobacteria order were found as well as bacteria from orders known to produce other pyrazines. Chemical and biological contaminants and odors could have contributed to health symptoms reported by employees, but it is likely that the symptoms were caused by several factors. We provided several recommendations to eliminate the odor including washing and disinfecting the metalworking machines and metalworking fluid recycling equipment, discarding all used metalworking fluid, instituting a metalworking fluid maintenance program at the site, and physically isolating the metalworking department from other departments.

  7. Nanocellulose-Zeolite Composite Films for Odor Elimination.

    Science.gov (United States)

    Keshavarzi, Neda; Mashayekhy Rad, Farshid; Mace, Amber; Ansari, Farhan; Akhtar, Farid; Nilsson, Ulrika; Berglund, Lars; Bergström, Lennart

    2015-07-08

    Free standing and strong odor-removing composite films of cellulose nanofibrils (CNF) with a high content of nanoporous zeolite adsorbents have been colloidally processed. Thermogravimetric desorption analysis (TGA) and infrared spectroscopy combined with computational simulations showed that commercially available silicalite-1 and ZSM-5 have a high affinity and uptake of volatile odors like ethanethiol and propanethiol, also in the presence of water. The simulations showed that propanethiol has a higher affinity, up to 16%, to the two zeolites compared with ethanethiol. Highly flexible and strong free-standing zeolite-CNF films with an adsorbent loading of 89 w/w% have been produced by Ca-induced gelation and vacuum filtration. The CNF-network controls the strength of the composite films and 100 μm thick zeolite-CNF films with a CNF content of less than 10 vol % displayed a tensile strength approaching 10 MPa. Headspace solid phase microextraction (SPME) coupled to gas chromatography-mass spectroscopy (GC/MS) analysis showed that the CNF-zeolite films can eliminate the volatile thiol-based odors to concentrations below the detection ability of the human olfactory system. Odor removing zeolite-cellulose nanofibril films could enable improved transport and storage of fruits and vegetables rich in odors, for example, onion and the tasty but foul-smelling South-East Asian Durian fruit.

  8. Inhibitory effect of luteolin on the odorant-induced cAMP level in HEK293 cells expressing the olfactory receptor.

    Science.gov (United States)

    Yoon, Yeo Cho; Hwang, Jin-Teak; Sung, Mi-Jeong; Wang, Shuaiyu; Munkhtugs, Davaatseren; Rhyu, Mee-Ra; Park, Jae-Ho

    2012-01-01

    Luteolin is a flavonoid in many fruits and vegetables. Although luteolin has important biological functions, including antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities, little is known about the functions of luteolin in the olfactory system. Various odorants can be detected and distinguished by using several molecular processes, including the binding of odorants to odorant receptors, activation of adenylyl cyclase (AC), changes of cyclic adenosine monophosphate (cAMP) and Ca(2+) levels in olfactory sensory neurons, as well as changes in membrane potentials and the transmission of electric signals to the brain. Because AC-cAMP signal transduction plays a pivotal role in the olfactory system, we evaluated the effects of luteolin on the AC-cAMP pathway that had been stimulated by the odorant eugenol. We demonstrated that eugenol caused an upregulation of the cAMP level and the phosphorylation of phosphokinase A (PKA, a downstream target of cAMP) in human embryonic kidney 293 (HEK293) cells expressing the murine eugenol receptor. This upregulation significantly decreased in the presence of luteolin, suggesting that luteolin inhibited the odorant-induced production of cAMP and affected the downstream phosphorylation of PKA.

  9. The cleaning method selected for new PEX pipe installation can affect short-term drinking water quality.

    Science.gov (United States)

    Kelley, Keven M; Stenson, Alexandra C; Cooley, Racheal; Dey, Rajarashi; Whelton, Andrew J

    2015-12-01

    The influence of four different cleaning methods used for newly installed polyethylene (PEX) pipes on chemical and odor quality was determined. Bench-scale testing of two PEX (type b) pipe brands showed that the California Plumbing Code PEX installation method does not maximize total organic carbon (TOC) removal. TOC concentration and threshold odor number values significantly varied between two pipe brands. Different cleaning methods impacted carbon release, odor, as well the level of drinking water odorant ethyl tert-butyl ether. Both pipes caused odor values up to eight times greater than the US federal drinking water odor limit. Unique to this project was that organic chemicals released by PEX pipe were affected by pipe brand, fill/empty cycle frequency, and the pipe cleaning method selected by the installer.

  10. A 3D Analysis of Flight Behavior of Anopheles gambiae sensu stricto Malaria Mosquitoes in Response to Human Odor and Heat

    NARCIS (Netherlands)

    Spitzen, J.; Spoor, C.W.; Grieco, F.; Braak, ter C.J.F.; Beeuwkes, J.; Brugge, van S.P.; Kranenbarg, S.; Noldus, L.; Leeuwen, van J.L.; Takken, W.

    2013-01-01

    Female mosquitoes use odor and heat as cues to navigate to a suitable landing site on their blood host. The way these cues affect flight behavior and modulate anemotactic responses, however, is poorly understood. We studied in-flight behavioral responses of females of the nocturnal malaria mosquito

  11. Research of Frequency Discriminator on Frequency Lock Loops

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Frequency lock loops (FLL) discriminating algorithms for direct-sequence spread-spectrum are discussed. The existing algorithms can't solve the problem of data bit reversal during one pre-detection integral period. And when the initial frequency offset is large, the frequency discriminator can't work normally. To solve these problems, a new FLL discriminating algorithm is introduced. The least-squares discriminator is used in this new algorithm. As the least-squares discriminator has a short process unit period, the corresponding frequency discriminating range is large. And the data bit reversal just influence one process unit period, so the least-squares discriminated result will not be affected. Compared with traditional frequency discriminator, the least-squares algorithm can effectively solve the problem of data bit reversal and can endure larger initial frequency offset.

  12. Labour Market Performance Effects of Discrimination and Loss of Skill

    DEFF Research Database (Denmark)

    Larsen, Birthe; Waisman, Gisela

    We examine the impact of discrimination on labour market performance when workers are subject to a risk of losing skills during an unemployment experience. Within a search and matching framework, we show that both natives and immigrants are affected by discrimination. Discrimination in one sector...... has positive spill-overs, inducing employment to increase in the other sector and the effect on labour market performance therefore depends on whether discrimination is present in only one sector or in both sectors. Discrimination may induce workers to train more or less than natives after having lost...... their skills, dependent upon which sector there is discrimination. Net output tends to the be most negatively affected by discrimination among high-skilled workers....

  13. Labor Market Performance Effects of Discrimination and Loss of Skill

    DEFF Research Database (Denmark)

    Larsen, Birthe; Waisman, Gisela

    2016-01-01

    We examine the impact of discrimination on labor market performance when workers are subject to a risk of losing skills during an unemployment experience. Within a search and matching framework, we show that both natives and immigrants are affected by discrimination. Discrimination in one sector...... has positive spillovers, inducing employment to increase in the other sector and the effect on labor market performance therefore depends on whether discrimination is present in only one sector or in both. Discrimination may induce workers to train more or less than natives after having lost...... their skills, dependent upon in which sector there is discrimination. Net output tends to be most negatively affected by discrimination among high-skilled workers. (JEL J15, J31, J61, J64, J71)...

  14. Multi-Sensor Integration to Map Odor Distribution for the Detection of Chemical Sources

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    2016-07-01

    Full Text Available This paper addresses the problem of mapping odor distribution derived from a chemical source using multi-sensor integration and reasoning system design. Odor localization is the problem of finding the source of an odor or other volatile chemical. Most localization methods require a mobile vehicle to follow an odor plume along its entire path, which is time consuming and may be especially difficult in a cluttered environment. To solve both of the above challenges, this paper proposes a novel algorithm that combines data from odor and anemometer sensors, and combine sensors’ data at different positions. Initially, a multi-sensor integration method, together with the path of airflow was used to map the pattern of odor particle movement. Then, more sensors are introduced at specific regions to determine the probable location of the odor source. Finally, the results of odor source location simulation and a real experiment are presented.

  15. Evaluation of the active odorants in Amontillado sherry wines during the aging process.

    Science.gov (United States)

    Moyano, Lourdes; Zea, Luis; Moreno, Jose A; Medina, Manuel

    2010-06-09

    Odor compounds in Amontillado sherry white wine obtained by means of biological aging first and oxidative aging second in American oak casks were determined by gas chromatography-olfactometry. Sniffing revealed fruity, fatty, chemical, spicy, vegetable, floral and empyreumatic odors, the first being the most common. Olfactometric intensity was assessed on a four-point scale. Most changes were detected during the first years of the oxidative aging step. Ethyl isobutanoate, ethyl butanoate, ethyl octanoate, and eugenol were the strongest odor compounds detected by sniffing in wines. The odor spectrum values for all active odorants were calculated in relation to ethyl octanoate, this compound being the most potent odorant. On the basis of olfactometric intensities and odor spectrum values, ethyl octanoate, ethyl butanoate, eugenol, ethyl isobutanoate, and sotolon can be deemed the main group of potent odorants in Amontillado wines. These compounds maintained similar relative contributions to the aroma profile during the oxidative aging step.

  16. Low Pass Filter Model for Chemical Sensors in Response to Gases and Odors

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Iskandarani

    2012-01-01

    Full Text Available Design and Modeling multi-gap sensing odor system for the objectives of odor recognition, classification and correlation are carried out. The model illustrates the low pass functionality of the multi-gap sensor acting as a filter for odors. Problem statement: Odor filtering is an important issue in today's world. In addition knowing the original material that an odor belongs to even after being mixed with others is also of vital importance. In addition measuring quality of mixed odors in terms of their affinity and belonging to a specific category or is critical. Approach: Mathematical modeling using low pass filter is carried out. Results: Clear evidence of ability to filter components of an odor mixture as the multi-gap sensor is acting as a filter. Conclusion: The ability to custom design chemical sensors to indicate the presence of various odors.

  17. Odor impact of volatiles emitted from marijuana, cocaine, heroin and their surrogate scents

    Directory of Open Access Journals (Sweden)

    Somchai Rice

    2015-12-01

    Full Text Available Volatile compounds emitted into headspace from illicit street drugs have been identified, but until now odor impact of these compounds have not been reported. Data in support of identification of these compounds and their odor impact to human nose are presented. In addition, data is reported on odor detection thresholds for canines highlighting differences with human ODTs and needs to address gaps in knowledge. New data presented here include: (1 compound identification, (2 gas chromatography (GC column retention times, (3 mass spectral data, (4 odor descriptors from 2 databases, (5 human odor detection thresholds from 2 databases, (6 calculated odor activity values, and (7 subsequent ranking of compounds by concentration and ranking of compounds by odor impact (reported as calculated odor activity values. For further interpretation and discussion, see Rice and Koziel [1] and Rice [2].

  18. Electronic Nose Odor Classification with Advanced Decision Tree Structures

    Directory of Open Access Journals (Sweden)

    S. Guney

    2013-09-01

    Full Text Available Electronic nose (e-nose is an electronic device which can measure chemical compounds in air and consequently classify different odors. In this paper, an e-nose device consisting of 8 different gas sensors was designed and constructed. Using this device, 104 different experiments involving 11 different odor classes (moth, angelica root, rose, mint, polis, lemon, rotten egg, egg, garlic, grass, and acetone were performed. The main contribution of this paper is the finding that using the chemical domain knowledge it is possible to train an accurate odor classification system. The domain knowledge about chemical compounds is represented by a decision tree whose nodes are composed of classifiers such as Support Vector Machines and k-Nearest Neighbor. The overall accuracy achieved with the proposed algorithm and the constructed e-nose device was 97.18 %. Training and testing data sets used in this paper are published online.

  19. Epac Activation Initiates Associative Odor Preference Memories in the Rat Pup

    Science.gov (United States)

    Grimes, Matthew T.; Powell, Maria; Gutierrez, Sandra Mohammed; Darby-King, Andrea; Harley, Carolyn W.; McLean, John H.

    2015-01-01

    Here we examine the role of the exchange protein directly activated by cAMP (Epac) in ß-adrenergic-dependent associative odor preference learning in rat pups. Bulbar Epac agonist (8-pCPT-2-O-Me-cAMP, or 8-pCPT) infusions, paired with odor, initiated preference learning, which was selective for the paired odor. Interestingly, pairing odor with Epac…

  20. Carrion odor and cattle grazing: Evidence for plant defense by carrion odor.

    Science.gov (United States)

    Lev-Yadun, Simcha; Gutman, Mario

    2013-11-01

    Recently, it has been proposed on theoretical grounds that carrion odor from flowers may not only attract pollinators, but also repel mammalian herbivores. Two grazing experiments involving 16 to 26 cattle heads per year, one for eight years (1982-1989) and the other for seven (1994-2000), in a region with no large carnivores that could influence cattle behavior, show that cattle avoid areas where dead cattle have recently been dumped. They grazed much less in these unfenced plots that were used to dump dead cattle each year. In the first experiment, with an area of ca. 20,000 m(2) per head, the average grass biomass at the end of the season was 124.6 gr/m(2) for the regular grazing area, whereas it was 236.5 gr/m(2) for the carcass dumping area. In the second experiment, with a higher stocking level, with ca. 9,000 m(2) per head, the average grass biomass at the end of the season was 61.7 gr/m(2) for the regular grazing area, and 153.7 gr/m(2) for the carcass dumping area. These significant differences existed throughout the 15 y of the experiments. We propose that these results are clear evidence of necrophobia in cattle, a character that might defend them from both pathogenic microbes and predators. This in turn demonstrates that carrion odor, primarily used by plants to attract pollinators, can simultaneously defend plants from herbivory by mammals as proposed.

  1. Isolation and analysis of odorous components in swine manure.

    Science.gov (United States)

    Yasuhara, A; Fuwa, K

    1983-12-23

    Systematic procedures are described for the isolation and extraction of odorous components in swine faeces, urine and rotten mixtures of swine faeces and urine. Samples were frozen and subjected to vacuum distillation in the frozen state. The distillate was continuously extracted with diethyl ether. The residue was extracted with diethyl ether and the extract was subjected to vacuum distillation. The former extract and the latter distillate were combined and concentrated. Recovery by these procedures was considered. Odorous compounds isolated were analyzed by gas chromatography and gas chromatography-mass spectrometry.

  2. Odor threshold prediction by means of the Monte Carlo method.

    Science.gov (United States)

    Toropov, Andrey A; Toropova, Alla P; Cappellini, Luigi; Benfenati, Emilio; Davoli, Enrico

    2016-11-01

    A large set of organic compounds (n=906) has been used as a basis to build up a model for the odor threshold (mg/m(3)). The statistical characteristics of the best model are the following: n=523, r(2)=0.647, RMSE=1.18 (training set); n=191, r(2)=0.610, RMSE=1.03, (calibration set); and n=192, r(2)=0.686, RMSE=1.06 (validation set). A mechanistic interpretation of the model is presented as the lists of statistical promoters of the increase and decrease in the odor threshold.

  3. Identification of Bacteria by Patterns Generated from Odor Spectra

    CERN Document Server

    Chang, Hung-Chih; King, Maria D; Kwan, Chiman

    2009-01-01

    We use the power density spectra obtained by fluctuation-enhanced sensing of bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) to generate new, highly distinguishable, types of patterns based on the average slope of the spectra in different frequency ranges. Such plots can be considered as "fingerprints" of bacterial odors. Three different ways of pattern generation are tested, including a simple binary version. The obtained patterns are simple enough to identify the situation by the naked eye without a pattern recognizer.

  4. Retronasal odor concentration coding in glomeruli of the rat olfactory bulb

    Directory of Open Access Journals (Sweden)

    ShreeHari eGautam

    2014-10-01

    Full Text Available The mammalian olfactory system processes odorants presented orthonasally (inhalation through the nose and also retronasally (exhalation, enabling identification of both external as well as internal objects during food consumption. There are distinct differences between ortho- and retronasal air flow patterns, psychophysics, multimodal integration and glomerular responses. Recent work indicates that rats can also detect odors retronasally, that rats can associate retronasal odors with tastes, and that their olfactory bulbs (OBs can respond to retronasal odorants but differently than to orthonasal odors. To further characterize retronasal OB input activity patterns, experiments here focus on determining the effects of odorant concentration on glomerular activity by monitoring calcium activity in the dorsal OB of rats using a dextran-conjugated calcium-sensitive dye in vivo. Results showed reliable concentration-response curves that differed between odorants, and recruitment of additional glomeruli, as odorant concentration increases. We found evidence of different concentration-response functions between glomeruli, that in turn depended on odor. Further, the relation between dynamics and concentration differed remarkably among retronasal odorants. These dynamics are suggested to reduce the odor map ambiguity based on response amplitude. Elucidating the coding of retronasal odor intensity is fundamental to the understanding of feeding behavior and the neural basis of flavor. These data further establish and refine the rodent model of flavor neuroscience.

  5. Retronasal odor concentration coding in glomeruli of the rat olfactory bulb

    Science.gov (United States)

    Gautam, Shree Hari; Short, Shaina M.; Verhagen, Justus V.

    2014-01-01

    The mammalian olfactory system processes odorants presented orthonasally (inhalation through the nose) and also retronasally (exhalation), enabling identification of both external as well as internal objects during food consumption. There are distinct differences between ortho- and retronasal air flow patterns, psychophysics, multimodal integration, and glomerular responses. Recent work indicates that rats can also detect odors retronasally, that rats can associate retronasal odors with tastes, and that their olfactory bulbs (OBs) can respond to retronasal odorants but differently than to orthonasal odors. To further characterize retronasal OB input activity patterns, experiments here focus on determining the effects of odor concentration on glomerular activity by monitoring calcium activity in the dorsal OB of rats using a dextran-conjugated calcium-sensitive dye in vivo. Results showed reliable concentration-response curves that differed between odorants, and recruitment of additional glomeruli, as odor concentration increased. We found evidence of different concentration-response functions between glomeruli, that in turn depended on odor. Further, the relation between dynamics and concentration differed remarkably among retronasal odorants. These dynamics are suggested to reduce the odor map ambiguity based on response amplitude. Elucidating the coding of retronasal odor intensity is fundamental to the understanding of feeding behavior and the neural basis of flavor. These data further establish and refine the rodent model of flavor neuroscience. PMID:25386123

  6. The Enantioselectivity of Odor Sensation: Some Examples for Undergraduate Chemistry Courses

    Science.gov (United States)

    Kraft, Philip; Mannschreck, Albrecht

    2010-01-01

    This article discusses seven chiral odorants that demonstrate the enantioselectivity of odor sensation: carvone, Celery Ketone, camphor, Florhydral, 3-methyl-3-sulfanylhexan-1-ol, muscone, and methyl jasmonate. After a general introduction of the odorant-receptor interaction and the combinatorial code of olfaction, the olfactory properties of the…

  7. High and low roads to odor valence? A choice response-time study.

    Science.gov (United States)

    Olofsson, Jonas K; Bowman, Nicholas E; Gottfried, Jay A

    2013-10-01

    Valence and edibility are two important features of olfactory perception, but it remains unclear how they are read out from an olfactory input. For a given odor object (e.g., the smell of rose or garlic), does perceptual identification of that object necessarily precede retrieval of information about its valence and edibility, or alternatively, are these processes independent? In the present study, we studied rapid, binary perceptual decisions regarding odor detection, object identity, valence, and edibility for a set of common odors. We found that decisions regarding odor-object identity were faster than decisions regarding odor valence or edibility, but slower than detection. Mediation analysis revealed that odor valence and edibility decision response times were predicted by a model in which odor-object identity served as a mediator along the perceptual pathway from detection to both valence and edibility. According to this model, odor valence is determined through both a "low road" that bypasses odor objects and a "high road" that utilizes odor-object information. Edibility evaluations are constrained to processing via the high road. The results outline a novel causal framework that explains how major perceptual features might be rapidly extracted from odors through engagement of odor objects early in the processing stream.

  8. DESIGN MANUAL: ODOR AND CORROSION CONTROL IN SANITARY SEWERAGE SYSTEMS AND TREATMENT PLANTS

    Science.gov (United States)

    Wastewater is known to the public for its potential to create odor nuisance. Sometimes it is the odors escaping from sewer manholes that cause complaints; more commonly, the odor source is a wastewater treatment facility. Yet there are wastewater treatment facilities that are fr...

  9. Dummies versus air puffs: efficient stimulus delivery for low-volatile odors.

    Science.gov (United States)

    Brandstaetter, Andreas Simon; Rössler, Wolfgang; Kleineidam, Christoph Johannes

    2010-05-01

    Aiming to unravel how animals perceive odors, a variety of neurophysiological techniques are used today. For olfactory stimulation, odors are commonly incorporated into a constant airstream that carries odor molecules to the receptor organ (air-delivered stimulation). Such odor delivery works well for odors of high volatility (naturally effective over long distances) but less or not at all for low-volatile odors (usually only received at short range). We developed a new odor stimulation technique especially suited for low-volatile odors and compared it with conventional air-delivered stimulation using 2 neurophysiological approaches. Odor-loaded dummies were moved into close vicinity of the receptor organs on the antenna of the Florida carpenter ant Camponotus floridanus (dummy-delivered stimulation). Neuronal activity was monitored either at receptor neuron level using electroantennography or in the first olfactory neuropile, the antennal lobes, using calcium imaging. We tested 3 odors of different volatility: C. floridanus' highly volatile alarm pheromone undecane, its low-volatile trail pheromone nerolic acid, and an even less volatile, behaviorally active C23 alkene, cis-9-tricosene. For low-volatile odors, dummy-delivered stimulation was particularly efficient. We conclude that dummy-delivered stimulation is advantageous compared to the commonly used air-delivered stimulation when studying an animal's detection and processing of low-volatile odors.

  10. Self-Ratings of Olfactory Function Reflect Odor Annoyance Rather than Olfactory Acuity

    DEFF Research Database (Denmark)

    Knaapila, Antti; Tuorila, Hely; Kyvik, Kirsten;

    2008-01-01

    Kingdom rated their sense of smell and annoyance caused by ambient smells (e.g., smells of foods) using seven categories, and performed odor identification and evaluation task for six scratch-and-sniff odor stimuli. RESULTS:: The self-rating of olfactory function correlated with the self-rating of odor...

  11. Reduced pleasant touch appraisal in the presence of a disgusting odor.

    Directory of Open Access Journals (Sweden)

    Ilona Croy

    Full Text Available OBJECTIVES: Odors are powerful emotional stimuli influencing mood, attention and behavior. Here we examined if odors change the perception of pleasant touch. In line with the warning function of the olfactory system, we proposed that especially unpleasant odors will reduce touch pleasantness, presumably through a disgust-related mechanism. METHODS: Forty-five healthy participants (mean age 23.3 +/- 3years SD, 24 females were presented to slow (3 cm/s and fast (30 cm/s brush stroking delivered by a robot to the forearm. Touch pleasantness under the influence of an unpleasant odor (Civette, smelling like feces and an intensity matched pleasant odor (Rose was compared to an odorless control condition. In a pilot study with 30 participants (mean age 25.9 +/-6 years, 21 females, the odors were matched according to their intensity, and we studied the influence of disgust sensitivity on the perception of 4 different odor qualities. RESULTS: The unpleasant odor decreased touch pleasantness for both stroking velocities compared to the odorless control (p<0.005 whereas the rose odor did not change touch pleasantness significantly. Disgust sensitivity was correlated with the modulation of touch pleasantness. The pilot study revealed a significant correlation between disgust sensitivity and the perception of the unpleasant odor qualities (r = -0.56; p = 0.007, but not with any of the other odors. CONCLUSION: Unpleasant odors are powerful in modulating touch pleasantness, and disgust might be a moderating variable.

  12. Bench and full-scale studies for odor control from lime stabilized biosolids: the effect of mixing on odor generation.

    Science.gov (United States)

    Krach, Kenneth R; Li, Baikun; Burns, Benjamin R; Mangus, Jessica; Butler, Howard G; Cole, Charles

    2008-09-01

    Lime stabilization is a means to raise the pH of biosolids to meet specific pathogen requirements. Along with controlling the microbial growth, lime stabilization reduces the potential for offensive odors. Lime stabilized biosolids can be beneficially used as a soil amendment and also for land reclamation. However, if biosolids are not properly incorporated with the lime, there is a potential for microbial growth, which consequently leads to the emanation of offensive odors and growth of pathogens. Proper mixing was found to be an important factor for the reduction of offensive odors in biosolids treatment. To better understand the effects of mixing on odorous products, bench-scale and full-scale tests were conducted to assess the lime stabilization process and investigate mixing quality at a wastewater treatment plant to help reduce odors associated with known odorants. The results of 4-week laboratory bench-scale tests showed that mixing had the largest effect on odor. The hedonic tone test of the control samples with poor mixing showed a hedonic tone of -2.9 initially and then dropped to -7.3 on Day 29. The hedonic tone of the 3.5%, 7%, and 10% lime mixed biosolids had similar hedonic tones (-2.8 to -2.5) on Day 1 and slightly fluctuated over time and ended at -1.6 to -2.7 on Day 29, which was less odorous than the controls. The control sample with poor mixing showed a rapid pH drop from 12.1 on Day 1 to 8.4 on Day 7. The pH of the control sample was considerably lower than the mixed samples and ended up on Day 28 with a pH of 8.0. The pH of the 7% and 10% samples were relatively stable throughout the 4-week period with a pH still higher than 12 on Day 28. The biosolids with better mixing had a less offensive odor and weaker odor strength than the controls collected at the plant with poor mixing. The lime stabilization process in the wastewater treatment plant was modified in a full-scale study by prolonging the mixing time. The samples collected from the

  13. INTERSECTIONAL DISCRIMINATION AGAINST CHILDREN

    DEFF Research Database (Denmark)

    Ravnbøl, Camilla Ida

    This paper adds a perspective to existing research on child protection by engaging in a debate on intersectional discrimination and its relationship to child protection. The paper has a twofold objective, (1) to further establish intersectionality as a concept to address discrimination against ch...... children, and (2) to illustrate the importance of addressing intersectionality within rights-based programmes of child protection....

  14. Flash-Type Discrimination

    Science.gov (United States)

    Koshak, William J.

    2010-01-01

    This viewgraph presentation describes the significant progress made in the flash-type discrimination algorithm development. The contents include: 1) Highlights of Progress for GLM-R3 Flash-Type discrimination Algorithm Development; 2) Maximum Group Area (MGA) Data; 3) Retrieval Errors from Simulations; and 4) Preliminary Global-scale Retrieval.

  15. Gestão de odores: fundamentos do Nariz Eletrônico Odor management: fundamentals of Electronic Nose

    Directory of Open Access Journals (Sweden)

    Henrique de Melo Lisboa

    2009-03-01

    Full Text Available Narizes Eletrônicos têm sido desenvolvidos para detecção automática e classificação de odores, vapores e gases. São instrumentos capazes de medir a concentração ou intensidade odorante de modo similar a um olfatômetro, mas sem as limitações inerentes ao uso de painéis humanos, o que é altamente desejável. Um Nariz Eletrônico é geralmente composto por um sistema de sensores químicos e um sistema eletrônico associado à inteligência artificial para reconhecimento. Têm sido aplicados em muitas áreas, tais como análise de alimentos, controles ambientais e diagnósticos médicos. Do ponto de vista ambiental, sistemas de Narizes Eletrônicos vêm sendo usados para monitorar a qualidade do ar, detectar fontes e quantificar emissões odorantes. Este artigo pretende apresentar os fundamentos dos Narizes Eletrônicos.Electronic noses have been developed for automatic detection and classification of odors, vapors and gases. They are instruments capable to identify odors as the human nose does, and measure the odor concentration or intensity according to similar metrics as an olfactometer, but without the inherent limitations of human panels. An Electronic Nose is generally composed of a matrix of chemical sensors and computer based system for odor recognition and classification. It has been applied in many areas, such as food quality analysis, explosives detection, environmental monitoring and medical diagnosis. In the ambient environment, systems of Electronic Noses have been used to monitor the quality of air and to detect and quantify odor sources and emissions. This article intends to present the fundamentals and main characteristics of Electronic Noses.

  16. Selectivity of odorant-binding proteins from the southern house mosquito tested against physiologically relevant ligands

    Directory of Open Access Journals (Sweden)

    Jiao eYin

    2015-02-01

    Full Text Available As opposed to humans, insects rely heavily on an acute olfactory system for survival and reproduction. Two major types of olfactory proteins, namely, odorant-binding proteins (OBPs and odorant receptors (ORs, may contribute to the selectivity and sensitivity of the insects’ olfactory system. Here, we aimed at addressing the question whether OBPs highly enriched in the antennae of the southern house mosquito, Culex quinquefasciatus, contribute at least in part to the selective reception of physiologically relevant compounds. Using a fluorescence reporter and a panel of 34 compounds, including oviposition attractants, human-derived attractants, and repellents, we measured binding affinities of CquiOBP1, CquiOBP2, and CquiOBP5. Based on dissociation constants, we surmised that CquiOBP2 is a carrier for the oviposition attractant skatole, whereas CquiOBP1 and CquiOBP5 might transport the oviposition pheromone MOP, a human-derived attractant nonanal, and the insect repellent picardin. Binding of these three ligands to CquiOBP1 was further analyzed by examining the influence of pH on apparent affinity as well as by docking these three ligands into CquiOBP1. Our findings suggest that CquiOBP1 might discriminate MOP from nonanal/picaridin on the basis of the midpoint transition of a pH-dependence conformational change, and that MOP is better accommodated in the binding cavity than the other two ligands. These findings, along with previous experimental evidence suggesting that CquiOBP1 does not detect nonanal in vivo, suggest that OBP selectivity may not be clearly manifested in their dissociation constants.

  17. The Mouse Solitary Odorant Receptor Gene Promoters as Models for the Study of Odorant Receptor Gene Choice.

    Directory of Open Access Journals (Sweden)

    Andrea Degl'Innocenti

    Full Text Available In vertebrates, several anatomical regions located within the nasal cavity mediate olfaction. Among these, the main olfactory epithelium detects most conventional odorants. Olfactory sensory neurons, provided with cilia exposed to the air, detect volatile chemicals via an extremely large family of seven-transmembrane chemoreceptors named odorant receptors. Their genes are expressed in a monogenic and monoallelic fashion: a single allele of a single odorant receptor gene is transcribed in a given mature neuron, through a still uncharacterized molecular mechanism known as odorant receptor gene choice.Odorant receptor genes are typically arranged in genomic clusters, but a few are isolated (we call them solitary from the others within a region broader than 1 Mb upstream and downstream with respect to their transcript's coordinates. The study of clustered genes is problematic, because of redundancy and ambiguities in their regulatory elements: we propose to use the solitary genes as simplified models to understand odorant receptor gene choice.Here we define number and identity of the solitary genes in the mouse genome (C57BL/6J, and assess the conservation of the solitary status in some mammalian orthologs. Furthermore, we locate their putative promoters, predict their homeodomain binding sites (commonly present in the promoters of odorant receptor genes and compare candidate promoter sequences with those of wild-caught mice. We also provide expression data from histological sections.In the mouse genome there are eight intact solitary genes: Olfr19 (M12, Olfr49, Olfr266, Olfr267, Olfr370, Olfr371, Olfr466, Olfr1402; five are conserved as solitary in rat. These genes are all expressed in the main olfactory epithelium of three-day-old mice. The C57BL/6J candidate promoter of Olfr370 has considerably varied compared to its wild-type counterpart. Within the putative promoter for Olfr266 a homeodomain binding site is predicted. As a whole, our findings

  18. Nasal pungency and odor of homologous aldehydes and carboxylic acids.

    Science.gov (United States)

    Cometto-Muñiz, J E; Cain, W S; Abraham, M H

    1998-01-01

    Airborne substances can stimulate both the olfactory and the trigeminal nerve in the nose, giving rise to odor and pungent (irritant) sensations, respectively. Nose, eye, and throat irritation constitute common adverse effects in indoor environments. We measured odor and nasal pungency thresholds for homologous aliphatic aldehydes (butanal through octanal) and carboxylic acids (formic, acetic, butanoic, hexanoic, and octanoic). Nasal pungency was measured in subjects lacking olfaction (i.e., anosmics) to avoid odor biases. Similar to other homologous series, odor and pungency thresholds declined (i.e., sensory potency increased) with increasing carbon chain length. A previously derived quantitative structure-activity relationship (QSAR) based on solvation energies predicted all nasal pungency thresholds, except for acetic acid, implying that a key step in the mechanism for threshold pungency involves transfer of the inhaled substance from the vapor phase to the receptive biological phase. In contrast, acetic acid - with a pungency threshold lower than predicted - is likely to produce threshold pungency through direct chemical reaction with the mucosa. Both in the series studied here and in those studied previously, we reach a member at longer chain-lengths beyond which pungency fades. The evidence suggests a biological cut-off, presumably based upon molecular size, across the various series.

  19. Topological reorganization of odor representations in the olfactory bulb.

    Directory of Open Access Journals (Sweden)

    Emre Yaksi

    2007-07-01

    Full Text Available Odors are initially represented in the olfactory bulb (OB by patterns of sensory input across the array of glomeruli. Although activated glomeruli are often widely distributed, glomeruli responding to stimuli sharing molecular features tend to be loosely clustered and thus establish a fractured chemotopic map. Neuronal circuits in the OB transform glomerular patterns of sensory input into spatiotemporal patterns of output activity and thereby extract information about a stimulus. It is, however, unknown whether the chemotopic spatial organization of glomerular inputs is maintained during these computations. To explore this issue, we measured spatiotemporal patterns of odor-evoked activity across thousands of individual neurons in the zebrafish OB by temporally deconvolved two-photon Ca(2+ imaging. Mitral cells and interneurons were distinguished by transgenic markers and exhibited different response selectivities. Shortly after response onset, activity patterns exhibited foci of activity associated with certain chemical features throughout all layers. During the subsequent few hundred milliseconds, however, MC activity was locally sparsened within the initial foci in an odor-specific manner. As a consequence, chemotopic maps disappeared and activity patterns became more informative about precise odor identity. Hence, chemotopic maps of glomerular input activity are initially transmitted to OB outputs, but not maintained during pattern processing. Nevertheless, transient chemotopic maps may support neuronal computations by establishing important synaptic interactions within the circuit. These results provide insights into the functional topology of neural activity patterns and its potential role in circuit function.

  20. VOCs and odors: key factors in selecting `green` building materials?

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, C. [Steven Winter Associates Inc., Norwalk, CT and Washington DC (United States)

    1998-12-01

    The current state of knowledge available for selecting building materials on the basis of emissions of volatile organic compounds (VOCs) and odors is reviewed. The significance of VOCs and odors in building materials is related to their role in influencing indoor air quality. As far as toxicity is concerned, many of the VOCs detected in indoor air are relatively inert when considered singly. They are not however, unimportant because in actual fact they are invariably found in mixtures some of which can be toxic. Although knowledge of VOCs is incomplete, it is important to specify ozone-resistant polymeric building products, i.e. those that are chemically stable and inert to oxidation. In addition to VOCs, attention should also be focused on semi-volatile organic compounds (SVOCs) since they are even more persistent than VOCs and tend to offgas for prolonged periods of time. Similarly, it is reasonable to specify low-odor materials. Inclusion of issues related to complex indoor chemistry, less volatile emissions, in addition to VOCs and odor, should in time result in expanded choices of building materials that promote indoor air quality. 16 refs.,2 tabs.

  1. Odors and Air Pollution: A Bibliography with Abstracts.

    Science.gov (United States)

    Environmental Protection Agency, Research Triangle Park, NC. Office of Air Programs.

    The annotated bibliography presents a compilation of abstracts which deal with odors as they relate to air pollution. The abstracts are arranged within the following categories: Emission sources; Control methods; Measurement methods; Air quality measurements; Atmospheric interaction; Basic science and technology; Effects-human health;…

  2. Key Odorants of Lazur, a Polish Mold-Ripened Cheese.

    Science.gov (United States)

    Majcher, Małgorzata A; Myszka, Kamila; Gracka, Anna; Grygier, Anna; Jeleń, Henryk H

    2017-02-15

    Application of gas chromatography-olfactometry (GC-O) carried out on the volatile fraction isolated by solvent-assisted flavor evaporation (SAFE) and solid phase microextraction (SPME) from Lazur mold-ripened cheese revealed 17 odor-active compounds. The highest flavor dilution factor (FD) has been obtained for methanethiol (2048) with a burnt odor note and for 2(3)-methylbutanoic acid (2048) with a cheesy, pungent odor. Further quantitation of the 15 most aroma-active compounds allowed for calculation of their odor activity values (OAV). The highest OAVs were obtained for methanethiol (500), 3(2)-methylbutanoic acid (321), 3-(methylthio)propanal (210), 2,3-butanedione (65), dimethyl trisulfide (22), butanoic acid (20), 1-octen-3-ol (18), (Z)-4-heptenal (14), dimethyl disulfide (14), dimethyl sulfide (13), phenylacetaldehyde (6), 2-ethyl-3,5-dimethylpyrazine (5), and acetic acid (4). An aroma recombination experiment showed slight differences in the perception of cheesy/sweaty and moldy/musty notes. To verify the influence of methyl ketones on the aroma profile of mold-ripened cheese, recombinant has been additionally supplemented with 2-pentanone, 2-heptanone, and 2-nonanone in concentrations determined in Lazur cheese. The aroma profile remained unchanged, which would suggest that methyl ketones, in this particular cheese, do not play a significant role in the formation of aroma.

  3. Development of an odorant emission model for sewage treatment works.

    Science.gov (United States)

    Gostelow, P; Parsons, S A; Cobb, J

    2001-01-01

    In the field of odour assessment, much attention has been paid to the measurement of odour concentration. Whilst the concentration of an odour at a receptor is a useful indicator of annoyance, the concentration at the source tells only half the story. The emission rate - the product of odour concentration and air flow rate - is required to appreciate the significance of odour sources. Knowledge of emission rates allows odour sources to be ranked in terms of significance and facilitates appropriate selection and design of odour control units. The emission rate is also a key input for atmospheric dispersion models. Given the increasing importance of odour to sewage treatment works operators, there is a clear need for predictive methods for odour emission rates. Theory suggests that the emission of odorants from sewage to air is controlled by mass transfer resistances in both the gas and liquid phase. These are in turn controlled by odorant and emission source characteristics. The required odorant characteristics are largely known, and mass transfer from many different types of emission sources have been studied. Sewage treatment processes can be described by one or more of six characteristic emission sources, these being quiescent surfaces, channels, weirs and drop structures, diffused aeration, surface aeration and flow over media. This paper describes the development of odorant mass transfer models for these characteristic emission types. The models have been applied in the form of spreadsheet models to the prediction of H2S emissions and the results compared with commercial VOC emission models.

  4. Endogenous Nuclear RNAi Mediates Behavioral Adaptation to Odor

    DEFF Research Database (Denmark)

    Juang, Bi-Tzen; Gu, Chen; Starnes, Linda;

    2013-01-01

    Most eukaryotic cells express small regulatory RNAs. The purpose of one class, the somatic endogenous siRNAs (endo-siRNAs), remains unclear. Here, we show that the endo-siRNA pathway promotes odor adaptation in C. elegans AWC olfactory neurons. In adaptation, the nuclear Argonaute NRDE-3, which...

  5. Field sampling method for quantifying odorants in humid environments

    Science.gov (United States)

    Most air quality studies in agricultural environments typically use thermal desorption analysis for quantifying volatile organic compounds (VOC) associated with odor. Carbon molecular sieves (CMS) are popular sorbent materials used in these studies. However, there is little information on the effe...

  6. Odor supported place cell model and goal navigation in rodents

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Tamosiunaite, Minija; Ainge, James;

    2008-01-01

    Experiments with rodents demonstrate that visual cues play an important role in the control of hippocampal place cells and spatial navigation. Nevertheless, rats may also rely on auditory, olfactory and somatosensory stimuli for orientation. It is also known that rats can track odors or self...

  7. FET frequency discriminator

    Science.gov (United States)

    Mawhinney, F. D.

    1982-03-01

    The FET Frequency Discriminator is an experimental microwave frequency discriminator developed for use in a specialized set-on VCO frequency memory system. Additional development and evaluation work has been done during this program to more fully determine the applicability of the FET frequency discriminator as a low-cost, expendable receiver front-end for both surveillance and ECM systems. Various methods for adjusting the frequency-to-voltage characteristic of the discriminator as well as the effects of detector characteristics and ambient temperature changes were evaluated. A number of discriminators for use in the 7- to 11-GHz and the 11to 18-GHz bands were fabricated and tested. Interim breadboard and final packaged models were either delivered or installed in developmental frequency systems. The major limitations and deficiencies of the FET frequency discriminator that were reviewed during the program include the effects of temperature, input power level variations, nonlinearity, and component repeatability. Additional effort will be required to advance the developmental status of the FET frequency discriminator to the level necessary for inclusion in low-cost receiver systems, but the basic simplicity of the approach continues to show much promise.

  8. Recruits of the stingless bee Scaptotrigona pectoralis learn food odors from the nest atmosphere

    Science.gov (United States)

    Reichle, Christian; Jarau, Stefan; Aguilar, Ingrid; Ayasse, Manfred

    2010-05-01

    The ability to learn food odors inside the nest and to associate them with food sources in the field is of essential importance for the recruitment of nestmates in social bees. We investigated odor learning by workers within the hive and the influence of these odors on their food choice in the field in the stingless bee Scaptotrigona pectoralis. During the experiments, recruited bees had to choose between two feeders, one with an odor that was present inside the nest during the recruitment process, and one with an unknown odor. In all experiments with different odor combinations (linalool/phenylacetaldehyde, geraniol/eugenol) a significant majority of bees visited the feeder with the odor they had experienced in their nest ( χ 2-tests; p < 0.05). By contrast, the bees showed no preference for one of two feeders when they were either baited with the same odor (linalool) or contained no odor. Our results clearly show that naïve workers of S. pectoralis can learn the odor of a food source during the recruitment process from the nest atmosphere and that their subsequent food search in the field is influenced by the learned odor.

  9. Complex odor from plants under attack: herbivore's enemies react to the whole, not its parts.

    Directory of Open Access Journals (Sweden)

    Michiel van Wijk

    Full Text Available BACKGROUND: Insect herbivory induces plant odors that attract herbivores' natural enemies. Assuming this attraction emerges from individual compounds, genetic control over odor emission of crops may provide a rationale for manipulating the distribution of predators used for pest control. However, studies on odor perception in vertebrates and invertebrates suggest that olfactory information processing of mixtures results in odor percepts that are a synthetic whole and not a set of components that could function as recognizable individual attractants. Here, we ask if predators respond to herbivore-induced attractants in odor mixtures or to odor mixture as a whole. METHODOLOGY/PRINCIPAL FINDINGS: We studied a system consisting of Lima bean, the herbivorous mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. We found that four herbivore-induced bean volatiles are not attractive in pure form while a fifth, methyl salicylate (MeSA, is. Several reduced mixtures deficient in one component compared to the full spider-mite induced blend were not attractive despite the presence of MeSA indicating that the predators cannot detect this component in these odor mixtures. A mixture of all five HIPV is most attractive, when offered together with the non-induced odor of Lima bean. Odors that elicit no response in their pure form were essential components of the attractive mixture. CONCLUSIONS/SIGNIFICANCE: We conclude that the predatory mites perceive odors as a synthetic whole and that the hypothesis that predatory mites recognize attractive HIPV in odor mixtures is unsupported.

  10. The Major Histocompatibility Complex and Perfumers' Descriptions of Human Body Odors

    Directory of Open Access Journals (Sweden)

    Claus Wedekind

    2007-04-01

    Full Text Available The MHC (major histocompatibility complex is a group of genes that play a crucial role in immune recognition and in tolerance of tissue grafting. The MHC has also been found to influence body odors, body odor preferences, and mate choice in mice and humans. Here we test whether verbal descriptions of human body odors can be linked to the MHC. We asked 45 male students to live as odor neutral as possible for two consecutive days and to wear a T-shirt during the nights. The odors of these T-shirts were then described by five evaluators: two professional perfumers and three laymen. One of the perfumers was able to describe the T-shirt odors in such a way that some of the allelic specificity of the MHC was significantly revealed (after Bonferroni correction for multiple testing. This shows that, although difficult, some people are able to describe MHC-correlated body odor components.

  11. Sampling the Body Odor of Primates: Cotton Swabs Sample Semivolatiles Rather Than Volatiles.

    Science.gov (United States)

    Birkemeyer, Claudia S; Thomsen, Ruth; Jänig, Susann; Kücklich, Marlen; Slama, Anna; Weiß, Brigitte M; Widdig, Anja

    2016-07-01

    We assessed the suitability of a frequently used sampling method employing cotton swabs for collecting animal body odor for gas chromatography-mass spectrometry (GC-MS) analysis of volatile organic compounds (VOCs). Our method validation showed that both sampling material and sampling protocols affect the outcome of the analyses. Thus, among the tested protocols swabs of pure viscose baked before use and extracted with hexane had the least blank interferences in GC-MS analysis. Most critical for the recovery of VOCs was the handling time: the significant recovery losses of volatiles experienced with this sampling procedure suggest that a rapid processing of such samples is required. In a second part, we used swab sampling to sample the body odor of rhesus macaques (Macaca mulatta), which lack scent glands. First results after GC-MS analysis of the samples collected from these nonhuman primates emphasize that proper analytical performance is an indispensable prerequisite for successful automated data evaluation of the complex GC-MS profiles. Moreover, the retention times and the nature of the identified chemical compounds in our samples suggest that the use of swabs is generally more appropriate for collecting semivolatile rather than VOCs.

  12. Androstenol--a steroid derived odor activates the hypothalamus in women.

    Directory of Open Access Journals (Sweden)

    Ivanka Savic

    Full Text Available BACKGROUND: Whether pheromone signaling exists in humans is still a matter of intense discussion. In the present study we tested if smelling of Androstenol, a steroid produced by the human body and reported to affect human behavior, may elicit cerebral activation. A further issue was to evaluate whether the pattern of activation resembles the pattern of common odors. METHODOLOGY: PET measurements of regional cerebral blood flow (rCBF were conducted in 16 healthy heterosexual women during passive smelling of Androstenol, four ordinary odors (OO, and odorless air (the base line condition. PRINCIPAL FINDINGS: Smelling Androstenol caused activation of a portion of the hypothalamus, which according to animal data mediates the pheromone triggered mating behavior. Smelling of OO, on the other hand, engaged only the classical olfactory regions (the piriform cortex, lateral amygdala, anterior insular and anterior cingulate cortex. CONCLUSIONS: The observed pattern of activation is very similar to the pattern previously detected with 4,16-androstadien-3-one in heterosexual females. It suggests that several compounds released by human body may activate cerebral networks involved in human reproduction.

  13. Determination of the threshold odor concentration of main odorants in essential oils using gas chromatography-olfactometry incremental dilution technique.

    Science.gov (United States)

    Benzo, Maurizio; Gilardoni, Gianluca; Gandini, Carlo; Caccialanza, Gabriele; Vita Finzi, Paola; Vidari, Giovanni; Abdo, Susana; Layedra, Patricia

    2007-05-25

    An essential oil, obtained by steam distillation of Clinopodium tomentosum (Kunth) Govaerts (Lamiaceae), collected in Ecuador, was analyzed by gas chromatography-olfactometry (GC-O) and GC-MS techniques. To our knowledge, the composition of this essential oil is described here for the first time, both from the chemical and olfactometric viewpoints. A preliminary analysis by GC-MS and using Kovats' retention indexes, lead to characterize and quantify the oil constituents, while GC-O was then applied for the identification of the main odorants. By the incremental dilution method (AEDA, CHARM Analysis), applied to the GC-O technique, the flavor dilution (FD) chromatogram was obtained. In order to calculate the TOC values of the main odorants, the relationship between the odorant concentration at the sniffing port and that one in the injected solution was established. This relationship was calculated by comparing the injected amount with the TOC value of a reference compound (limonene), obtained by dynamic dilution olfactometry. A good agreement was found between calculated and measured TOC values of few odorants.

  14. Psychology of fragrance use: perception of individual odor and perfume blends reveals a mechanism for idiosyncratic effects on fragrance choice.

    Science.gov (United States)

    Lenochová, Pavlína; Vohnoutová, Pavla; Roberts, S Craig; Oberzaucher, Elisabeth; Grammer, Karl; Havlíček, Jan

    2012-01-01

    Cross-culturally, fragrances are used to modulate body odor, but the psychology of fragrance choice has been largely overlooked. The prevalent view is that fragrances mask an individual's body odor and improve its pleasantness. In two experiments, we found positive effects of perfume on body odor perception. Importantly, however, this was modulated by significant interactions with individual odor donors. Fragrances thus appear to interact with body odor, creating an individually-specific odor mixture. In a third experiment, the odor mixture of an individual's body odor and their preferred perfume was perceived as more pleasant than a blend of the same body odor with a randomly-allocated perfume, even when there was no difference in pleasantness between the perfumes. This indicates that fragrance use extends beyond simple masking effects and that people choose perfumes that interact well with their own odor. Our results provide an explanation for the highly individual nature of perfume choice.

  15. 大学生的气味词分类——基于语义相似性和知觉相似性的探讨%Undergraduates' Classification of Odor Terms:A Study Based on Semantic and Imagined Similarity

    Institute of Scientific and Technical Information of China (English)

    王娟; 沈树华; 张积家

    2011-01-01

    The world is suffused with various odors which are closely related to people's life. Odors are not only non-ignorable in love scene and interpersonal communication but also irreplaceable to be as effective retrieval in criminal cues scouting. It also affects people's physical and psychological health tremendously. However, few studies have focused on odor cognitions: it still lacks a uniform standard for classification of odor and basic odor categories has not been formed yet. Most of the previous studies investigated odors or odor categories based on semantics and perception. They focused on classification of specific odor or odor term clustering rather than getting the semantic space of odor or odor terms and summarization of standards of smell term clustering. Most studies highlighted the properties of odor presentation or culture's influence on classification rather than the discovery of inner mechanism of classification. The aims of the recent study were to explore standards of odor terms classification and mechanisms of interaction of odor concepts and to observe concept organization under Chinese culture to reveal how Chinese construct concept of odor terms.Ninety college students including 40 males and SO females were enrolled in the recent study. In Experiment 1, participants were asked to classify 60 daily odor-terms on the basis of semantic similarity. In Experiment 2, participants were instructed to imagine the odors of the 60 odor terms and classify them on the basis of imagined similarity. Data were analyzed with Multi-Dimensional Scaling and Hierarchical clustering program in SPSS 13.0.The results of Experiment 1 showed that semantic space of the 60 odor terms contains two dimensions: (1) food related/not food related, (2) artificiality objects/natural objects. Sixty odor terms were classified into 2 groups including food related odors and not food related odors with 6 sub-groups: (1) fruit, (2) food and man-made drinks, (3) meal and condiment, (4

  16. Volatile compounds and odor preferences of ground beef added with garlic and red wine, and irradiated with charcoal pack

    Science.gov (United States)

    Lee, Kyung Haeng; Yun, Hyejeong; Lee, Ju Woon; Ahn, Dong Uk; Lee, Eun Joo; Jo, Cheorun

    2012-08-01

    Irradiation is the most efficient non-thermal technology for improving hygienic quality and extending the shelf-life of food products. One of the adverse effects of food irradiation, however, is off-flavor production, which significantly affects the sensory preferences for certain foods. In this study, garlic (5%, w/w) and red wine (1:1, w/w) were added to ground beef to increase the radiation sensitivity of pathogens and improve meat odor/flavor. Samples were irradiated at 0 or 5 kGy in the presence of charcoal pack. SPME-GC-MS analysis was performed to measure the changes in the volatile compounds and sensory characteristics of the samples. The amount of total volatile compounds produced from ground beef was greater when the sample was irradiated. When garlic and red wine were added to the ground beef, the amount of volatile compounds significantly increased, and the amount of volatile compounds increased even further after irradiation. However, when the samples were irradiated with charcoal pack, the amount of volatile compounds decreased significantly. Sensory evaluation indicated that charcoal pack significantly increased the odor preferences for both irradiated and non-irradiated ground beef added with garlic. These results indicated that addition of charcoal pack to ground beef could reduce off-odor problems induced by irradiation, and this effect was consistent even when certain additives such as garlic and red wine were added.

  17. Diurnal odor, ammonia, hydrogen sulfide, and carbon dioxide emission profiles of confined swine grower/finisher rooms.

    Science.gov (United States)

    Sun, Gang; Guo, Huiqing; Peterson, Jonathan; Predicala, Bernardo; Laguë, Claude

    2008-11-01

    The objective of this study was to obtain diurnal variation profiles of odor and gas (ammonia [NH3], hydrogen sulfide [H2S], carbon dioxide [CO2]) concentrations and emission rate (OGCER) from confined swine grower/ finisher rooms under three typical weather conditions (warm, mild, and cold weather) in a year. Two grower/ finisher rooms, one with a fully slatted floor and the other with partially slatted floors, were measured for 2 consecutive days under each weather condition. The results revealed that the diurnal OGCER in the room with a fully slatted floor was 9.2-39.4% higher than that with a partially slatted floor; however, no significant differences in the diurnal OGCER were found between these two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odor concentrations and emissions in February (p > 0.05). The OGCER variations presented different diurnal patterns as affected by time of day, season, type of floor, ventilation rate, animal growth cycles, in-house manure storage, and weather conditions. Significant diurnal fluctuations in the OGCER (except for the odor concentrations and H2S emissions) were observed in August (p dispersion modeling to decrease the great incertitude of setback determination using randomly measured data.

  18. Anatomical and molecular consequences of Unilateral Naris Closure on two populations of olfactory sensory neurons expressing defined odorant receptors.

    Science.gov (United States)

    Molinas, Adrien; Aoudé, Imad; Soubeyre, Vanessa; Tazir, Bassim; Cadiou, Hervé; Grosmaitre, Xavier

    2016-07-28

    Mammalian olfactory sensory neurons (OSNs), the primary elements of the olfactory system, are located in the olfactory epithelium lining the nasal cavity. Exposed to the environment, their lifespan is short. Consequently, OSNs are regularly regenerated and several reports show that activity strongly modulates their development and regeneration: the peripheral olfactory system can adjust to the amount of stimulus through compensatory mechanisms. Unilateral naris occlusion (UNO) was frequently used to investigate this mechanism at the entire epithelium level. However, there is little data regarding the effects of UNO at the cellular level, especially on individual neuronal populations expressing a defined odorant receptor. Here, using UNO during the first three postnatal weeks, we analyzed the anatomical and molecular consequences of sensory deprivation in OSNs populations expressing the MOR23 and M71 receptors. The density of MOR23-expressing neurons is decreased in the closed side while UNO does not affect the density of M71-expressing neurons. Using Real Time qPCR on isolated neurons, we observed that UNO modulates the transcript levels for transduction pathway proteins (odorant receptors, CNGA2, PDE1c). The transcripts modulated by UNO will differ between populations depending on the receptor expressed. These results suggest that sensory deprivation will have different effects on different OSNs' populations. As a consequence, early experience will shape the functional properties of OSNs differently depending on the type of odorant receptor they express.

  19. Effects of harmonic roving on pitch discrimination

    DEFF Research Database (Denmark)

    Santurette, Sébastien; de Kérangal, Mathilde le Gal; Joshi, Suyash Narendra

    2015-01-01

    Performance in pitch discrimination tasks is limited by variability intrinsic to listeners which may arise from peripheral auditory coding limitations or more central noise sources. Perceptual limitations may be characterized by measuring an observer’s change in performance when introducting...... external noise in the physical stimulus (Lu and Dosher, 2008). The present study used this approach to attempt to quantify the “internal noise” involved in pitch coding of harmonic complex tones by estimating the amount of harmonic roving required to impair pitch discrimination performance. It remains...... a matter of debate whether pitch perception of natural complex sounds mostly relies on either spectral excitation-based information or temporal periodicity information. Comparing the way internal noise affects the internal representations of such information to how it affects pitch discrimination...

  20. C-terminus Methionene Specifically Involved in Binding Corn Odorants to Odorant Binding Protein4 in Macrocentrus cingulum

    Science.gov (United States)

    Ahmed, Tofael; Zhang, Tiantao; Wang, Zhenying; He, Kanglai; Bai, Shuxiong

    2017-01-01

    The soluble carrier proteins, OBPs carry odor components through sensilium lymph to specific receptors within the antennal sensilla to trigger behavioral responses. Herein, McinOBP4 was characterized from the Macrocentrus cingulum, which is the specialist parasitic insect of Ostrinia furnacalis for better understanding of olfactory recognition mechanism of this wasp. The classical odorant binding protein McinOBP4 showed good binding affinity to corn green leaf volatiles. RT-qPCR results showed that the McinOBP4 was primarily expressed in male and female wasp antennae, with transcripts levels differing by sex. Fluorescence assays indicate that, McinOBP4 binds corn green leaf volatiles including terpenoides and aliphatic alcohols as well as aldehydes with good affinity. We have also conducted series of binding assay with first mutant (M1), which lacked the last 8 residues and a second mutant (M2), with Met119 replaced by Leucine (Leu119). In the acidic conditions, affinity N-phenylnaphthylamine (1-NPN) to McinOBP4 and M1 were substantially decreased, but increase in basic condition with no significant differences. The lack of C-terminus showed reduced affinity to terpenoides and aliphatic alcohols as well as aldehydes compounds of corn odorants. The mutant M2 with Met119 showed significant reduction in binding affinity to tested odorants, it indicating that Met119 forming hydrophobic chain with the odorants functional group to binding. This finding provides detailed insight of chemosensory function of McinOBP4 in M. cingulum and help to develop low release agents that attract of this wasp to improve ecologically-friendly pest management strategy. PMID:28228732

  1. Disruption of adult neurogenesis in the olfactory bulb affects social interaction but not maternal behavior

    Directory of Open Access Journals (Sweden)

    Claudia E Feierstein

    2010-12-01

    Full Text Available Adult-born neurons arrive to the olfactory bulb and integrate into the existing circuit throughout life. Despite the prevalence of this phenomenon, its functional impact is still poorly understood. Recent studies point to the importance of newly generated neurons to olfactory learning and memory. Adult neurogenesis is regulated by a variety of factors, notably by instances related to reproductive behavior, such as exposure to mating partners, pregnancy and lactation, and exposure to offspring. To study the contribution of olfactory neurogenesis to maternal behavior and social recognition, here we selectively disrupted olfactory bulb neurogenesis using focal irradiation of the subventricular zone in adult female mice. We show that reduction of olfactory neurogenesis results in an abnormal social interaction pattern with male, but not female, conspecifics; we suggest that this effect could result from inability to detect or discriminate male odors and could therefore have implications for the recognition of potential mating partners. Disruption of olfactory bulb neurogenesis, however, neither impaired maternal-related behaviors, nor did it affect the ability of mothers to discriminate their own progeny from others.

  2. The mouthparts enriched odorant binding protein 11 of the alfalfa plant bug Adelphocoris lineolatus displays a preferential binding behaviour to host plant secondary metabolites

    Directory of Open Access Journals (Sweden)

    Liang eSun

    2016-06-01

    Full Text Available Odorant binding proteins (OBPs are proposed to be directly required for odorant discrimination and represent potential interesting targets for pest control. In the notoriously agricultural pest Adelphocoris lineolatus, our previous functional investigation of highly expressed antennal OBPs clearly supported this viewpoint, whereas the findings of the current study by characterizing of AlinOBP11 rather indicated that OBP in hemipterous plant bugs might fulfill a different and tantalizing physiological role. The phylogenetic analysis uncovered that AlinOBP11 together with several homologous bug OBP proteins are potential orthologs, implying they could exhibit a conserved function. Next, the results of expression profiles solidly showed that AlinOBP11 was predominantly expressed at adult mouthparts, the most important gustatory organ of Hemiptera mirid bug. Finally, a rigorously selective binding profile was observed in the fluorescence competitive binding assay, in which recombinant AlinOBP11 displayed much stronger binding abilities to non-volatile secondary metabolite compounds than the volatile odorants. These results reflect that AlinOBP11, even its orthologous proteins across bug species, could be associated with a distinctively conserved physiological role such as a crucial carrier for non-volatiles host secondary metabolites in gustatory system.

  3. Contribution of the cholinergic basal forebrain to proactive interference from stored odor memories during associative learning in rats.

    Science.gov (United States)

    De Rosa, E; Hasselmo, M E; Baxter, M G

    2001-04-01

    E. De Rosa and M. E. Hasselmo (2000) demonstrated that 0.25 mg/kg scopolamine (SCOP) selectively increased proactive interference (PI) from stored odor memories during learning. In the present study, rats with bilateral cholinergic lesions limited to the horizontal limb of the diagonal band of Broca, made with 192 IgG-saporin, were not impaired in acquiring the same olfactory discrimination task relative to control rats. Rats with bilateral 192 IgG-saporin lesions to all basal forebrain cholinergic nuclei (BF) also showed no impairment in acquisition of this task. However, the BF-saporin rats were hypersensitive to oxotremorine-induced hypothermia and demonstrated an increased sensitivity to PI following a low dose of SCOP (0.125 mg/kg) relative to control rats. The results suggest that weaker cholinergic modulation after cholinergic BF lesions makes the system more sensitive to PI during blockade of the remaining cholinergic elements.

  4. Associations of racial discrimination and parental discrimination coping messages with African American adolescent racial identity.

    Science.gov (United States)

    Richardson, Bridget L; Macon, Tamarie A; Mustafaa, Faheemah N; Bogan, Erin D; Cole-Lewis, Yasmin; Chavous, Tabbye M

    2015-06-01

    Research links racial identity to important developmental outcomes among African American adolescents, but less is known about the contextual experiences that shape youths' racial identity. In a sample of 491 African American adolescents (48% female), associations of youth-reported experiences of racial discrimination and parental messages about preparation for racial bias with adolescents' later racial identity were examined. Cluster analysis resulted in four profiles of adolescents varying in reported frequency of racial discrimination from teachers and peers at school and frequency of parental racial discrimination coping messages during adolescents' 8th grade year. Boys were disproportionately over-represented in the cluster of youth experiencing more frequent discrimination but receiving fewer parental discrimination coping messages, relative to the overall sample. Also examined were clusters of adolescents' 11th grade racial identity attitudes about the importance of race (centrality), personal group affect (private regard), and perceptions of societal beliefs about African Americans (public regard). Girls and boys did not differ in their representation in racial identity clusters, but 8th grade discrimination/parent messages clusters were associated with 11th grade racial identity cluster membership, and these associations varied across gender groups. Boys experiencing more frequent discrimination but fewer parental coping messages were over-represented in the racial identity cluster characterized by low centrality, low private regard, and average public regard. The findings suggest that adolescents who experience racial discrimination but receive fewer parental supports for negotiating and coping with discrimination may be at heightened risk for internalizing stigmatizing experiences. Also, the findings suggest the need to consider the context of gender in adolescents' racial discrimination and parental racial socialization.

  5. Structure-odor relationships of linalool, linalyl acetate and their corresponding oxygenated derivatives

    Science.gov (United States)

    Elsharif, Shaimaa; Banerjee, Ashutosh; Buettner, Andrea

    2015-10-01

    Linalool 1 is an odorant that is commonly perceived as having a pleasant odor, but is also known to elicit physiological effects such as inducing calmness and enhancing sleep. However, no comprehensive studies are at hand to show which structural features are responsible for these prominent effects. Therefore, a total of six oxygenated derivatives were synthesized from both 1 and linalyl acetate 2, and were tested for their odor qualities and relative odor thresholds (OTs) in air. Linalool was found to be the most potent odorant among the investigated compounds, with an average OT of 3.2 ng/L, while the 8-hydroxylinalool derivative was the least odorous compound with an OT of 160 ng/L; 8-carboxylinalool was found to be odorless. The odorant 8-oxolinalyl acetate, which has very similar odor properties to linalool, was the most potent odorant besides linalool, exhibiting an OT of 5.9 ng/L. By comparison, 8-carboxylinalyl acetate had a similar OT (6.1 ng/L) as its corresponding 8-oxo derivative but exhibited divergent odor properties (fatty, greasy, musty). Overall, oxygenation on carbon 8 had a substantial effect on the aroma profiles of structural derivatives of linalool and linalyl acetate.

  6. Odorous compounds in municipal wastewater effluent and potable water reuse systems.

    Science.gov (United States)

    Agus, Eva; Lim, Mong Hoo; Zhang, Lifeng; Sedlak, David L

    2011-11-01

    The presence of effluent-derived compounds with low odor thresholds can compromise the aesthetics of drinking water. The potent odorants 2,4,6-trichloroanisole and geosmin dominated the profile of odorous compounds in wastewater effluent with concentrations up to 2 orders of magnitude above their threshold values. Additional odorous compounds (e.g., vanillin, methylnaphthalenes, 2-pyrrolidone) also were identified in wastewater effluent by gas chromatography coupled with mass-spectrometry and olfactometry detection. Full-scale advanced treatment plants equipped with reverse osmosis membranes decreased odorant concentrations considerably, but several compounds were still present at concentrations above their odor thresholds after treatment. Other advanced treatment processes, including ozonation followed by biological activated carbon and UV/H(2)O(2) also removed effluent-derived odorants. However, no single treatment technology alone was able to reduce all odorant concentrations below their odor threshold values. To avoid the presence of odorous compounds in drinking water derived from wastewater effluent, it is necessary to apply multiple barriers during advanced treatment or to dilute wastewater effluent with water from other sources.

  7. Structure-odor relationships of linalool, linalyl acetate and their corresponding oxygenated derivatives

    Directory of Open Access Journals (Sweden)

    Shaimaa eElsharif

    2015-10-01

    Full Text Available Linalool 1 is an odorant that is commonly perceived as having a pleasant odor, but is also known to elicit physiological effects such as inducing calmness and enhancing sleep. However, no comprehensive studies are at hand to show which structural features are responsible for these prominent effects. Therefore, a total of six oxygenated derivatives were synthesized from both 1 and linalyl acetate 2, and were tested for their odor qualities and relative odor thresholds (OTs in air. Linalool was found to be the most potent odorant among the investigated compounds, with an average OT of 3.2 ng/L, while the 8-hydroxylinalool derivative was the least odorous compound with an OT of 160 ng/L; 8-carboxylinalool was found to be odorless. The odorant 8-oxolinalyl acetate, which has very similar odor properties to linalool, was the most potent odorant besides linalool, exhibiting an OT of 5.9 ng/L. By comparison, 8-carboxylinalyl acetate had a similar OT (6.1 ng/L as its corresponding 8-oxo derivative but exhibited divergent odor properties (fatty, greasy, musty. Overall, oxygenation on carbon 8 had a substantial effect on the aroma profiles of structural derivatives of linalool and linalyl acetate.

  8. An assessment of detection canine alerts using flowers that release methyl benzoate, the cocaine odorant, and an evaluation of their behavior in terms of the VOCs produced.

    Science.gov (United States)

    Cerreta, Michelle M; Furton, Kenneth G

    2015-06-01

    In recent years, the high frequency of illicit substance abuse reported in the United States has made the development of efficient and rapid detection methods important. Biological detectors, such as canines (Canis familiaris), are valuable tools for rapid, on-site identification of illicit substances. However, research indicates that in many cases canines do not alert to the contraband, but rather to the volatile organic compounds (VOCs) that are released from the contraband, referred to as the "active odor." In 2013, canine accuracy and reliability were challenged in the Supreme Court case, State of Florida v. Jardines. In this case, it was stated that if a canine alerts to the active odor, and not the contraband, the canine's accuracy and selectivity could be questioned, since many of these compounds have been found in common household products. Specifically, methyl benzoate, the active odor of cocaine, has been found to be the most abundant compound produced by snapdragon flowers. Therefore, the purpose of this study is to evaluate the odor profiles of various species of snapdragon flowers to assess how significantly methyl benzoate contributes to the total VOC profile or fragrance that is produced. Particularly, this study examines the VOCs released from newly grown snapdragon flowers and determines its potential at eliciting a false alert from specially trained detection canines. The ability of detection canines to differentiate between cocaine and snapdragon flowers was determined in order to validate the field accuracy and discrimination power of these detectors. An optimized method using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to test the different types and abundances of compounds generated from snapdragon flowers at various stages throughout the plants' life cycle. The results indicate that although methyl benzoate is present in the odor profile of snapdragon flowers, other

  9. Nasal pungency, odor, and eye irritation thresholds for homologous acetates.

    Science.gov (United States)

    Cometto-Muñiz, J E; Cain, W S

    1991-08-01

    We measured detection thresholds for nasal pungency (in anosmics), odor (in normosmics) and eye irritation employing a homologous series of acetates: methyl through octyl acetate, decyl and dodecyl acetate. All anosmics reliably detected the series up to heptyl acetate. Only the anosmics without smell since birth (congenital) reliably detected octyl acetate, and only one congenital anosmic detected decyl and dodecyl acetate. Anosmics who lost smell from head trauma proved to be selectively less sensitive. As expected, odor thresholds lay well below pungency thresholds. Eye irritation thresholds for selected acetates came close to nasal pungency thresholds. All three types of thresholds decreased logarithmically with carbon chain length, as previously seen with homologous alcohols and as seen in narcotic and toxic phenomena. Results imply that nasal pungency for these stimuli rests upon a physical, rather than chemical, interaction with susceptible mucosal structures. When expressed as thermodynamic activity, nasal pungency thresholds remain remarkably constant within and across the homologous series of acetates and alcohols.

  10. Recent Developments in the Chemistry of Woody Odorants

    Institute of Scientific and Technical Information of China (English)

    Andreas Goeke

    2005-01-01

    @@ 1Introduction Woody odorants constitute an important olfactory family in perfumery[1]. Essential wood oils, traditionally being obtained by steam distillation of plant materials, are extensively being used in a variety of perfumes.Patchouli oil (e. g. in "Gentlemen", Givenchy), vetiver oil ("Vetiver", J. P. Guerlain) and cedar wood oil ("Déclaration", Cartier) are classics in this field. On the other hand, many terpenic hydrocarbons which are perse not particularly useful as perfume ingredients, have been functionalized in order to obtain more sophisticated scents. Javanol(R), Belambre(R), Ysamber K(R) and Ambrocenide(R) (prepared from pinene, camphor,logifolene and cedrene) are the names of potent and recently commercialized wood odorants. However, due to variable qualities of the natural starting materials, it has been an important task in fragrance research to find inexpensive but fully synthetic alternatives which, in light of the complexity of the structures, remains challenging. See Fig. 1.

  11. Ozone Treatment of Animal Manure for Odor Control

    Directory of Open Access Journals (Sweden)

    Fahad N. Alkoaik

    2009-01-01

    Full Text Available Problem statement: The effectiveness of ozone in reducing odor emission from liquid animal manure was evaluated under batch and continuous treatment operations. Results: The results indicated that the use of ozone for the treatment of animal manure proved to be effective in reducing the odor offensiveness. A minimum 3.4 level out of 10 (66% reduction was achieved in the continuous operation; while a minimum of 3.1 (69% reduction was achieved in the batch operation. Increasing the level of ozone (O3 increased the level of offensiveness which was attributed to the presence of intermediate products due to the interaction between ozone and hydrogen sulfide and methylamine. Conclusion: The cost analysis indicated that the treatment is economical as a ton of manure could be treated at a cost of $ 0.23.

  12. Insect Repellents: Modulators of Mosquito Odorant Receptor Activity

    Science.gov (United States)

    2010-08-01

    molecular pathways through allosteric regulation of various proteins including proteases [39,40], the cannabinoid receptor 1 (CB1) [41], the a7 nicotinic...41. Price MR, Baillie GL, Thomas A, Stevenson LA, Easson M, et al. (2005) Allosteric modulation of the cannabinoid CB1 receptor . Mol Pharmacol 68...Insect Repellents: Modulators of Mosquito Odorant Receptor Activity Jonathan D. Bohbot, Joseph C. Dickens* Invasive Insect Biocontrol and Behavior

  13. Romantic love modulates women's identification of men's body odors.

    Science.gov (United States)

    Lundström, Johan N; Jones-Gotman, Marilyn

    2009-02-01

    Romantic love is one of our most potent and powerful emotions, but very little is known with respect to the hormonal and psychological mechanisms in play. Romantic love is thought to help intimate partners stay committed to each other and two mechanisms have been proposed to mediate this commitment: increased attention towards one's partner or deflected attention away from other potential partners. Both mechanisms find support in the literature. We explored the potential influence of each of these mechanisms by assessing women's ability to identify (ID) body odors originating from their boyfriend, a same-sex friend, and an opposite-sex friend and the relationship between this ability and the degree of romantic love expressed towards their boyfriend. We hypothesized that an increase in attention towards one's partner would render a positive correlation between ID of a boyfriend's body odor and degree of romantic love; conversely, we hypothesized that attention deflected away from other potential partners would render a negative correlation between ID of an opposite-sex friend's body odor and degree of romantic love for the boyfriend. Our results supported the deflection theory as we found a negative correlation between the degree of romantic love for the subjects' boyfriends and their ability to ID the body odor of an opposite-sex friend but not of their boyfriend or same-sex friend. Our results indicate that romantic love deflects attention away from potential new partners rather than towards the present partner. These changes are likely mediated by circulating neuropeptides and a testable model is suggested.

  14. Fluorescence properties of porcine odorant binding protein Trp 16 residue

    Energy Technology Data Exchange (ETDEWEB)

    Albani, Jihad Rene, E-mail: Jihad-Rene.Albani@univ-lille1.f [Laboratoire de Biophysique Moleculaire, Universite des Sciences et Technologies de Lille, F-59655 Villeneuve d' Ascq Cedex (France)

    2010-11-15

    Summary: The present work deals with fluorescence studies of adult porcine odorant binding protein at pH=7.5. At this pH, the protein is a dimer, each monomer contains one tryptophan residue. Our results show that tryptophan residue displays significant motions and emits with three fluorescence lifetimes. Decay associated spectra showed that the three lifetime's components emanate from sub-structures surrounded by the same microenvironment.

  15. Odor identification and Alzheimer disease biomarkers in clinically normal elderly

    Science.gov (United States)

    Growdon, Matthew E.; Schultz, Aaron P.; Dagley, Alexander S.; Amariglio, Rebecca E.; Hedden, Trey; Rentz, Dorene M.; Johnson, Keith A.; Sperling, Reisa A.; Albers, Mark W.

    2015-01-01

    Objectives: Our objective was to investigate cross-sectional associations between odor identification ability and imaging biomarkers of neurodegeneration and amyloid deposition in clinically normal (CN) elderly individuals, specifically testing the hypothesis that there may be an interaction between amyloid deposition and neurodegeneration in predicting odor identification dysfunction. Methods: Data were collected on 215 CN participants from the Harvard Aging Brain Study. Measurements included the 40-item University of Pennsylvania Smell Identification Test and neuropsychological testing, hippocampal volume (HV) and entorhinal cortex (EC) thickness from MRI, and amyloid burden using Pittsburgh compound B (PiB) PET. A linear regression model with backward elimination (p < 0.05 retention) evaluated the cross-sectional association between the University of Pennsylvania Smell Identification Test and amyloid burden, HV, and EC thickness, assessing for effect modification by PiB status. Covariates included age, sex, premorbid intelligence, APOE ε4 carrier status, and Boston Naming Test. Results: In unadjusted univariate analyses, worse olfaction was associated with decreased HV (p < 0.001), thinner EC (p = 0.003), worse episodic memory (p = 0.03), and marginally associated with greater amyloid burden (binary PiB status, p = 0.06). In the multivariate model, thinner EC in PiB-positive individuals (interaction term) was associated with worse olfaction (p = 0.02). Conclusions: In CN elderly, worse odor identification was associated with markers of neurodegeneration. Furthermore, individuals with elevated cortical amyloid and thinner EC exhibited worse odor identification, elucidating the potential contribution of olfactory testing to detect preclinical AD in CN individuals. PMID:25934852

  16. Identification and origin of odorous sulfur compounds in cooked ham

    OpenAIRE

    Thomas, Caroline; Mercier, Frederic; Tournayre, Pascal; Martin, Jean-Luc; Berdagué, Jean-Louis

    2014-01-01

    The aim of this work was to identify and gain further knowledge on the origin of sulfur compounds present in the volatile fraction of cooked ham, and on their role in the aroma of this product. To this end, we performed analyses by one- and two-dimensional gas chromatography coupled with mass spectrometry, and olfactometry. Among the odorant sulfur compounds identified, three furans present in trace amounts proved to have very intense odours responsible for the "meaty, cooked ham" notes of th...

  17. Gaschromatographic evaluation of the odor intensity of Diesel exhausts

    Energy Technology Data Exchange (ETDEWEB)

    Knuth, H.W.; Oelert, H.H.; Zajontz, J.

    1977-03-01

    To establish an absolute method for the odor evaluation of Diesel exhausts olfactometric threshhold data are correlated with gaschromatographic results from a two column operation providing a high number of chemical informations. Single and multiple linear regression calculations for the experiments on two Diesel engines give several satisfying correlations especially for the overall paraffin distribution that could also be obtained by more simple analytical procedures.

  18. Attention to odor modulates thalamocortical connectivity in the human brain.

    Science.gov (United States)

    Plailly, Jane; Howard, James D; Gitelman, Darren R; Gottfried, Jay A

    2008-05-14

    It is widely assumed that the thalamus is functionally irrelevant for the sense of smell. Although animal studies suggest that the mediodorsal (MD) thalamus links primary olfactory (piriform) cortex to olfactory neocortical projection sites in orbitofrontal cortex (OFC), this transthalamic route is regarded to be inconsequential, particularly compared with a direct monosynaptic pathway linking piriform cortex and OFC. In this study, we combined functional magnetic resonance imaging with novel effective connectivity techniques to measure attention-dependent network coherence within direct (nonthalamic) and indirect (transthalamic) olfactory pathways. Human subjects were presented with (or without) an odor and with (or without) a tone, while selectively attending to either modality. Attention to odor significantly modulated neural coupling within the indirect pathway, strengthening MD thalamus-OFC connectivity. Critically, these effects were modality specific (odor > tone attention), directionally sensitive (forward > backward connections), and selective to route (indirect > direct pathway). Our findings support the idea that the human transthalamic pathway is an active modulatory target of olfactory attention. The results imply that olfaction, like all other sensory modalities, requires a thalamic relay, if only to consciously analyze a smell.

  19. Construction of odor representations by olfactory bulb microcircuits.

    Science.gov (United States)

    Cleland, Thomas A

    2014-01-01

    Like other sensory systems, the olfactory system transduces specific features of the external environment and must construct an organized sensory representation from these highly fragmented inputs. As with these other systems, this representation is not accurate per se, but is constructed for utility, and emphasizes certain, presumably useful, features over others. I here describe the cellular and circuit mechanisms of the peripheral olfactory system that underlie this process of sensory construction, emphasizing the distinct architectures and properties of the two prominent computational layers in the olfactory bulb. Notably, while the olfactory system solves essentially similar conceptual problems to other sensory systems, such as contrast enhancement, activity normalization, and extending dynamic range, its peculiarities often require qualitatively different computational algorithms than are deployed in other sensory modalities. In particular, the olfactory modality is intrinsically high dimensional, and lacks a simple, externally defined basis analogous to wavelength or pitch on which elemental odor stimuli can be quantitatively compared. Accordingly, the quantitative similarities of the receptive fields of different odorant receptors (ORs) vary according to the statistics of the odor environment. To resolve these unusual challenges, the olfactory bulb appears to utilize unique nontopographical computations and intrinsic learning mechanisms to perform the necessary high-dimensional, similarity-dependent computations. In sum, the early olfactory system implements a coordinated set of early sensory transformations directly analogous to those in other sensory systems, but accomplishes these with unique circuit architectures adapted to the properties of the olfactory modality.

  20. Analgesia Is Enhanced by Providing Information regarding Good Outcomes Associated with an Odor: Placebo Effects in Aromatherapy?

    Directory of Open Access Journals (Sweden)

    Yuri Masaoka

    2013-01-01

    Full Text Available No previous report has described whether information regarding an odor used in aromatherapy has placebo effects. We investigated whether placebo analgesia was engendered by verbal information regarding the analgesic effects of an odor. Twelve of 24 subjects were provided with the information that a lavender odor would reduce pain (informed, whereas the other 12 subjects were not (not-informed. Concurrent with respiration recording, the subjects were administered a lavender-odor or no-odor treatment during application of painful stimulation to the forefinger. The subjects reported their experience of pain and its unpleasantness on a visual analogue scale after the painful stimulation. The lavender-odor treatment significantly alleviated pain and unpleasantness compared with the no-odor treatment in the informed (P<0.01 and not-informed groups (P<0.05. The no-odor treatment in the informed group significantly alleviated pain and unpleasantness compared with both the no-odor and lavender-odor treatments in the not-informed group (P<0.05. Rapid and shallow breathing induced by the painful stimulation became slow and deep during the lavender-odor and no-odor treatments in both groups. Information regarding a lavender odor, the lavender odor itself, and slower breathing contributed to reduced perceptions of pain and unpleasantness during painful stimulation, suggesting that placebo effects significantly contribute to analgesia in aromatherapy.

  1. Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization

    Energy Technology Data Exchange (ETDEWEB)

    Chennubhotla, Chakra [University of Pittsburgh School of Medicine, Pittsburgh PA; Castro, Jason [Bates College

    2013-01-01

    In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain un- clear. Here, we use non-negative matrix factorization (NMF) - a dimensionality reduction technique - to uncover structure in a panel of odor profiles, with each odor defined as a point in multi-dimensional descriptor space. The properties of NMF are favorable for the analysis of such lexical and perceptual data, and lead to a high-dimensional account of odor space. We further provide evidence that odor di- mensions apply categorically. That is, odor space is not occupied homogenously, but rather in a discrete and intrinsically clustered manner. We discuss the potential implications of these results for the neural coding of odors, as well as for developing classifiers on larger datasets that may be useful for predicting perceptual qualities from chemical structures.

  2. Activated charcoal and baking soda to reduce odor associated with extensive blistering disorders

    Directory of Open Access Journals (Sweden)

    Chakravarthi Arun

    2008-01-01

    Full Text Available Background: Skin disease leading to extensive blistering and loss of skin is associated with a characteristic smell. Odor can cause physiologic disturbances such as increase in heart rate and respiratory rate. It can also cause nausea and vomiting and is disturbing to bystanders. Aims: To test odor reducing capability of activated charcoal. Methods: In this blinded experimental study we used putrefied amniotic membrane to produce odor and studied the effectiveness of activated charcoal and soda-bi-carbonate to reduce odor. Results: Statistical analysis with Kruskal Wall′s Chi Square Test and Man Whitney U test showed significant reduction of odor using activated charcoal by itself or along with soda-bi-carbonate. Conclusion: We recommend the usage of activated charcoal with/without soda bicarbonate as an inexpensive practical measure to reduce foul odor associated with extensive skin loss.

  3. Coding Odorant Concentration through Activation Timing between the Medial and Lateral Olfactory Bulb

    Directory of Open Access Journals (Sweden)

    Zhishang Zhou

    2012-11-01

    Full Text Available In mammals, each olfactory bulb (OB contains a pair of mirror-symmetric glomerular maps organized to reflect odorant receptor identity. The functional implication of maintaining these symmetric medial-lateral maps within each OB remains unclear. Here, using in vivo multielectrode recordings to simultaneously detect odorant-induced activity across the entire OB, we reveal a timing difference in the odorant-evoked onset latencies between the medial and lateral halves. Interestingly, the latencies in the medial and lateral OB decreased at different rates as odorant concentration increased, causing the timing difference between them to also diminish. As a result, output neurons in the medial and lateral OB fired with greater synchrony at higher odorant concentrations. Thus, we propose that temporal differences in activity between the medial and lateral OB can dynamically code odorant concentration, which is subsequently decoded in the olfactory cortex through the integration of synchronous action potentials.

  4. Insect odorant receptors are molecular targets of the insect repellent DEET.

    Science.gov (United States)

    Ditzen, Mathias; Pellegrino, Maurizio; Vosshall, Leslie B

    2008-03-28

    DEET (N,N-diethyl-meta-toluamide) is the world's most widely used topical insect repellent, with broad effectiveness against most insects. Its mechanism of action and molecular target remain unknown. Here, we show that DEET blocks electrophysiological responses of olfactory sensory neurons to attractive odors in Anopheles gambiae and Drosophila melanogaster. DEET inhibits behavioral attraction to food odors in Drosophila, and this inhibition requires the highly conserved olfactory co-receptor OR83b. DEET inhibits odor-evoked currents mediated by the insect odorant receptor complex, comprising a ligand-binding subunit and OR83b. We conclude that DEET masks host odor by inhibiting subsets of heteromeric insect odorant receptors that require the OR83b co-receptor. The identification of candidate molecular targets for the action of DEET may aid in the design of safer and more effective insect repellents.

  5. The Role of Odor-Evoked Memory in Psychological and Physiological Health

    Directory of Open Access Journals (Sweden)

    Rachel S. Herz

    2016-07-01

    Full Text Available This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

  6. The Role of Odor-Evoked Memory in Psychological and Physiological Health

    Science.gov (United States)

    Herz, Rachel S.

    2016-01-01

    This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing. PMID:27447673

  7. Identification of Odorant-Receptor Interactions by Global Mapping of the Human Odorome

    DEFF Research Database (Denmark)

    Audouze, Karine Marie Laure; Tromelin, Anne; Le Bon, Anne Marie;

    2014-01-01

    The human olfactory system recognizes a broad spectrum of odorants using approximately 400 different olfactory receptors ( hORs). Although significant improvements of heterologous expression systems used to study interactions between ORs and odorant molecules have been made, screening the olfactory...... repertoire of hORs remains a tremendous challenge. We therefore developed a chemical systems level approach based on protein-protein association network to investigate novel hOR-odorant relationships. Using this new approach, we proposed and validated new bioactivities for odorant molecules and OR2W1, OR51E1...... between odorants and the cannabinoid receptor 1 (CB1) and the peroxisome proliferator-activated receptor gamma ( PPAR gamma). Overall, these results illustrate the potential of integrative systems chemical biology to explore the impact of odorant molecules on human health, i.e. human odorome....

  8. Studies on the key odorants formed by roasting of wild mango seeds (Irvingia gabonensis).

    Science.gov (United States)

    Tairu, A O; Hofmann, T; Schieberle, P

    2000-06-01

    Application of the aroma extract dilution analysis on a concentrate of volatiles obtained by solvent extraction and high vacuum distillation from roasted seeds (180 degrees C; 15 min) of wild mango (Irvingia gabonensis) revealed 32 odor-active compounds with flavor dilution (FD) factors ranging from 8 (low odor activity) to 2048 (high odor activity). The identification experiments based on the use of reference odorants revealed methional (cooked potato-like) followed by 2-acetyl-1-pyrroline (roasty, popcorn-like), butan-2,3-dione, pentan-2,3-dione, 2-ethyl-3,5-dimethylpyrazine, and 2,3-diethyl-5-methylpyrazine as the key aroma compounds among the 27 odorants identified. All odorants are reported for the first time as components of roasted wild mango seeds.

  9. Projection neurons in Drosophila antennal lobes signal the acceleration of odor concentrations.

    Science.gov (United States)

    Kim, Anmo J; Lazar, Aurel A; Slutskiy, Yevgeniy B

    2015-05-14

    Temporal experience of odor gradients is important in spatial orientation of animals. The fruit fly Drosophila melanogaster exhibits robust odor-guided behaviors in an odor gradient field. In order to investigate how early olfactory circuits process temporal variation of olfactory stimuli, we subjected flies to precisely defined odor concentration waveforms and examined spike patterns of olfactory sensory neurons (OSNs) and projection neurons (PNs). We found a significant temporal transformation between OSN and PN spike patterns, manifested by the PN output strongly signaling the OSN spike rate and its rate of change. A simple two-dimensional model admitting the OSN spike rate and its rate of change as inputs closely predicted the PN output. When cascaded with the rate-of-change encoding by OSNs, PNs primarily signal the acceleration and the rate of change of dynamic odor stimuli to higher brain centers, thereby enabling animals to reliably respond to the onsets of odor concentrations.

  10. Species discrimination among three kinds of puffer fish using an electronic nose combined with olfactory sensory evaluation.

    Science.gov (United States)

    Zhang, Meixiu; Wang, Xichang; Liu, Yuan; Xu, Xinglian; Zhou, Guanghong

    2012-01-01

    Species discrimination among three kinds of puffer fish, Takifugu obscurus, Takifugu flavidus and Takifugu rubripes, was conducted using an electronic nose combined with olfactory sensory evaluation. All data were treated by multivariate data processing based on principal component analysis (PCA) and discriminant factor analysis (DFA). The results showed the discriminant model by PCA method and DFA method. Using PCA and DFA, it was shown that the electronic nose was able to reasonably distinguish between each of the eleven puffer fish groups, with a discrimination index of 85. The olfactory sensory evaluation was undertaken in accordance to Sensory analysis-Methodology-Initiation and training of assessors in the detection and recognition of odors (BS ISO 5496-2006), and the results showed that the evaluation was able to identify puffer fish samples according to their species, geographical origin and age. Results from this analysis demonstrate that the E-nose can be used to complement the discrimination of odors by sensory evaluation from the three species of puffer fish studied here.

  11. Species Discrimination among Three Kinds of Puffer Fish Using an Electronic Nose Combined with Olfactory Sensory Evaluation

    Directory of Open Access Journals (Sweden)

    Guanghong Zhou

    2012-09-01

    Full Text Available Species discrimination among three kinds of puffer fish, Takifugu obscurus, Takifugu flavidus and Takifugu rubripes, was conducted using an electronic nose combined with olfactory sensory evaluation. All data were treated by multivariate data processing based on principal component analysis (PCA and discriminant factor analysis (DFA. The results showed the discriminant model by PCA method and DFA method. Using PCA and DFA, it was shown that the electronic nose was able to reasonably distinguish between each of the eleven puffer fish groups, with a discrimination index of 85. The olfactory sensory evaluation was undertaken in accordance to Sensory analysis—Methodology—Initiation and training of assessors in the detection and recognition of odors (BS ISO 5496-2006, and the results showed that the evaluation was able to identify puffer fish samples according to their species, geographical origin and age. Results from this analysis demonstrate that the E-nose can be used to complement the discrimination of odors by sensory evaluation from the three species of puffer fish studied here.

  12. Liking and wanting pleasant odors: different effects of repetitive exposure in men and women

    OpenAIRE

    Chantal eTriscoli; Ilona eCroy; Håkan eOlausson; Uta eSailer

    2014-01-01

    Odors can enrich the perception of our environment and are commonly used to attract people in marketing situations. However, the perception of an odor changes over repetitions. This study investigated whether repetitive exposition to olfactory stimuli leads to a change in the perceived pleasantness (“liking”) or in the wish to be further exposed to the same olfactory stimulus (“wanting”), and whether these two mechanisms show gender differences. Three different pleasant odors were each repeat...

  13. Analysis of particle-borne odorants emitted from concentrated animal feeding operations.

    Science.gov (United States)

    Yang, Xufei; Lorjaroenphon, Yaowapa; Cadwallader, Keith R; Wang, Xinlei; Zhang, Yuanhui; Lee, Jongmin

    2014-08-15

    Airborne particles are known to serve as a carrier of odors emanating from concentrated animal feeding operations (CAFOs). However, limited quantitative data about particle-borne odorants preclude an accurate assessment of the role of particles in odor transport. This study collected total suspended particulates (TSP) and PM10 (particles with aerodynamic diameter smaller than 10 μm) at the air exhaust of eight types of CAFOs (swine: farrowing, gestation, weaning, and finishing; poultry: manure-belt layer hen, tom turkey, chicken broiler, and cage-free layer hen; in total 20 animal buildings) in multiple seasons, and examined the variability in particle odorant composition with animal operation type, season, and particle size. Fifty-seven non-sulfur-containing odorants were identified and quantitated, including carbonyls, alcohols, acids, phenols, and nitrogen-containing compounds. They in total accounted for 2.19±1.52% TSP and 4.97±3.25% PM10 mass. Acetic acid and ethanol were most abundant but less odor-contributing than phenylacetic acid, indole, dodecanoic acid, and (E,E)-2,4-decadienal, as determined by odor activity value. Particle odorant composition varied significantly with animal operation type, season, and particle size. The TSP and PM10 samples from swine gestation buildings, for example, showed distinctly different odorant compositions than those from tom turkey buildings. The summer TSP and PM10 samples contained in general lower concentrations of short-chain fatty acids but higher concentrations of long-chain fatty acids, aldehydes, and short-chain alcohols than the winter samples. Compared to TSP, PM10 samples from different types of CAFOs shared a more similar odorant composition, contained higher odorant concentrations per mass of particles, and accounted for on average 53.2% of the odor strength of their corresponding TSP samples.

  14. GC-MS analysis of off-odor volatiles from irradiated pork

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The main compounds of off-odor volatiles from irradiated refrigerated vacuum-packaged pork were analyzed by gas chromatograph/mass spectrometer (GC-MS). The analytical results showed that the main compounds of off-odor volatiles were dimethyl disulfide, dimethyl sulfide, dimethyl trisulfide, S-methyl thioacetate, and methanethiol. It was proved that the off-odor volatile came from irradiated S-containing amino acid and thiamin.

  15. Dispersion modeling to compare alternative technologies for odor remediation at swine facilities.

    Science.gov (United States)

    Schiffman, Susan S; Graham, Brevick G; Williams, C Mike

    2008-09-01

    The effectiveness of 18 alternative technologies for reducing odor dispersion at and beyond the boundary of swine facilities was assessed in conjunction with an initiative sponsored through agreements between the Attorney General of North Carolina and Smithfield Foods, Premium Standard Farms, and Frontline Farmers. The trajectory and spatial distribution of odor emitted at each facility were modeled at 200 and 400 m downwind from each site under two meteorological conditions (daytime and nighttime) using a Eulerian-Lagrangian model. To predict the dispersion of odor downwind, the geographical area containing the odorant sources at each facility was partitioned into 10-m2 grids on the basis of satellite photographs and architectural drawings. Relative odorant concentrations were assigned to each grid point on the basis of intensity measurements made by the trained odor panel at each facility using a 9-point rating scale. The results of the modeling indicated that odor did not extend significantly beyond 400 m downwind of any of the test sites during the daytime when the layer of air above the earth's surface is usually turbulent. However, modeling indicated that odor from all full-scale farms extended beyond 400 m onto neighboring property in the evenings when deep surface cooling through long-wave radiation to space produces a stable (nocturnal) boundary layer. The results also indicated that swine housing, independent of waste management type, plays a significant role in odor downwind, as do odor sources of moderate to moderately high intensity that emanate from a large surface area such as a lagoon. Human odor assessments were utilized for modeling rather than instrument measurements of volatile organic compounds (VOCs), hydrogen sulfide, ammonia, or particulates less than 10 microm in diameter (PM10) because these physical measurements obtained simultaneously with human panel ratings were not found to accurately predict human odor intensity in the field.

  16. Longitudinal Changes in Familiarity, Free and Cued Odor Identification, and Edibility Judgments for Odors in Aging Individuals.

    Science.gov (United States)

    Wehling, Eike I; Lundervold, Astri J; Nordin, Steven; Wollschlaeger, Daniel

    2016-02-01

    This longitudinal study investigated changes in olfaction as assessed by a set of tasks requiring different aspects of semantic information in normal aging individuals. Using 16 odorous items from a standardized olfactory test, the Scandinavian Odor Identification Test, 107 middle aged and older adults were assessed up to three times over a period of 6.5 years, requesting them to rate familiarity and edibility for each odorous item before identifying it with or without presenting verbal cues. Using linear mixed models, the longitudinal analyses revealed significant correlations between all olfactory measures. Furthermore, we found an almost parallel age-related decline in all olfactory tasks, although free identification performance indicated a trend toward faster decline with age. Women showed less decline compared with men, in particular for edibility judgments. The results corroborate earlier cross-sectional findings showing significant correlations between the olfactory tasks. In the present study of healthy middle-aged and older adults, we found a parallel longitudinal decline across different tests of olfaction.

  17. Family scents: developmental changes in the perception of kin body odor?

    Science.gov (United States)

    Ferdenzi, Camille; Schaal, Benoist; Roberts, S Craig

    2010-08-01

    There is increasing evidence that human body odors are involved in adaptive behaviors, such as parental attachment in infants or partner choice in adults. The aim of the present study was to investigate changes in body-odor perception around puberty, a period largely ignored for odor-mediated behavioral changes, despite major changes in social needs and in odor emission and perception. Nine families with two children (8 pre-pubertal, aged 7-10, and 10 pubertal, aged 11-18) evaluated body odors of family members and unfamiliar individuals for pleasantness, intensity, and masculinity, and performed a recognition task. The hypothesized emergence of a parent-child mutual aversion for the odor of opposite-sex family members at puberty was not found, contradicting one of the few studies on the topic (Weisfeld et al., J. Exp. Child Psychol. 85:279-295, 2003). However, some developmental changes were observed, including reduced aversion for odor of the same-sex parent, and increased ability of adults, compared to children, to recognize odor of family members. Sex and personality (depressive and aggressive traits) also significantly influenced odor judgments. Further research with larger samples is needed to investigate the poorly explored issue of how olfactory perception of self and family members develops, and how it could correlate with normal reorganizations in social interactions at adolescence.

  18. Olfactory aversive conditioning alters olfactory bulb mitral/tufted cell glomerular odor responses

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    2012-03-01

    Full Text Available The anatomical organization of receptor neuron input into the olfactory bulb (OB allows odor information to be transformed into an odorant-specific spatial map of mitral/tufted cell glomerular activity at the upper level of the olfactory bulb. In other sensory systems, neuronal representations of stimuli can be reorganized or enhanced following learning. While the mammalian OB has been shown to undergo experience-dependent plasticity at the glomerular level, it is still unclear if similar representational change occurs within mitral/tufted cell glomerular odor representations following learning. To address this, odorant-evoked glomerular activity patterns were imaged in mice expressing a GFP-based calcium indicator (GCaMP2 in OB mitral/tufted cells. Glomerular odor responses were imaged before and after olfactory associative conditioning to aversive foot shock. Following conditioning, we found no overall reorganization of the glomerular representation. Training, however, did significantly alter the amplitudes of individual glomeruli within the representation in mice in which the odor was presented together with foot shock. Further, the specific pairing of foot shock with odor presentations lead to increased responses primarily in initially weakly activated glomeruli. Overall, these results suggest that associative conditioning can enhance the initial representation of odors within the olfactory bulb by enhancing responses to the learned odor in some glomeruli.

  19. Identification of odorous compounds in reclaimed water using FPA combined with sensory GC-MS

    Institute of Scientific and Technical Information of China (English)

    Zhiming Yan; Yu Zhang; Jianwei Yu; Hongying Yuan; Min Yang

    2011-01-01

    Odorous compounds in the influent of a reclaimed water treatment plant (RWTP),consisting of coagulation,sedimentation,continuous micro-filtration (CMF),and chlorination in succession,in a north China city,were identified by combining flavor profile analysis (FPA) with sensory gas chromatograph-mass spectrometry (GC-MS).The sewery/swampy/septic odor with an odor intensity of 6.4 was found to be the major odor group in the RWTP influent,and the existence of well-known odorant including dimethyl disulfide,dimethyl trisulfide,indole and skatole were confirmed using GC-MS.The result of a spiking test showed that the intensity (3.6) of the sewery/swampy/septic odor caused by these four chemicals contributed to over 50% of the odor intensity of the influent.The FPA intensity for sewery/swampy/septic odor in the RWTP effluent was 3.8,showing that the treatment process was not efficient for the removal of odorants,particularly indole and skatole.

  20. Development of sulfur- and nitrogen- free hydrogen odorants - An important step toward a safe hydrogen society -

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, N.; Oshikawa, K.; Hasegawa, H. [Toyota Motor Corporation, 1 Toyota-cho, Toyota, Aichi, 471-8751, (Japan); Le Lay, M.; Iwase, M. [Toyota Motor Europe NV/SA, Hoge Wei 33, 1930, Zaventem, (Belgium); Braun, N.A.; Eilers, J. [Symrise GmbH and Co. KG, Muehlenfeldstrasse 1, D-37603 Holzminden, (Germany); Walz, A. [Linde AG, Gas Division, Seitnerstrasse 70, 80249 Hollriegelskreuth, (Germany); Vogt, M. [Umicore AG and Co. KG, Rodenbacher Chaussee 4 P.O. Box 3151, 63403 Hanau-Wolfgang, (Germany); Herr, M. [ET Energy Technology GmbH, Eugen-Saenger-Ring 4, 85649 Brunnthal-Nord, (Germany)

    2006-07-01

    We have developed four sulfur-free and nitrogen-free odorants, which can be effectively used to odorize hydrogen. The odors were described through an olfactory test as alarming, strange, and chemical, giving sense of danger to the person who smells the odor. The safety of the material has been assessed and has been shown to be safe for usage. Testing the stability of odorized hydrogen in 80 MPa pressurized state, it was shown for a period of 13 weeks that the odorant retained its warning odor. Using the odorized hydrogen, FC duration test at 0.2 A/cm{sup 2} was carried out for over 900 h without significant decrease in performance or the detectable degradation of MEA. The outlet of the fuel cell had no warning odor, suggesting deodorization on the catalyst. Use of activated charcoal as an adsorbent showed that the deodorization could be effectively carried out, ensuring that normal operation conditions are not perceived as a hydrogen leakage. (authors)

  1. Identification of Odorant-Receptor Interactions by Global Mapping of the Human Odorome

    DEFF Research Database (Denmark)

    Audouze, Karine Marie Laure; Tromelin, Anne; Le Bon, Anne Marie

    2014-01-01

    between odorants and the cannabinoid receptor 1 (CB1) and the peroxisome proliferator-activated receptor gamma ( PPAR gamma). Overall, these results illustrate the potential of integrative systems chemical biology to explore the impact of odorant molecules on human health, i.e. human odorome.......The human olfactory system recognizes a broad spectrum of odorants using approximately 400 different olfactory receptors ( hORs). Although significant improvements of heterologous expression systems used to study interactions between ORs and odorant molecules have been made, screening the olfactory...

  2. Experience shapes our odor perception but depends on the initial perceptual processing of the stimulus.

    Science.gov (United States)

    Sinding, Charlotte; Coureaud, Gérard; Bervialle, Boris; Martin, Christophe; Schaal, Benoist; Thomas-Danguin, Thierry

    2015-07-01

    The questions of whether configural and elemental perceptions are competitive or exclusive perceptual processes and whether they rely on independent or dependent mechanisms are poorly understood. To examine these questions, we modified perceptual experience through preexposure to mixed or single odors and measured the resulting variation in the levels of configural and elemental perception of target odor mixtures. We used target mixtures that were spontaneously processed in a configural or an elemental manner. The AB binary mixture spontaneously involved the configural perception of a pineapple odor, whereas component A smelled like strawberry and component B smelled like caramel. The CD mixture produced the elemental perceptions of banana (C) and smoky (D) odors. Perceptual experience was manipulated through repeated exposure to either a mixture (AB or CD) or the components (A and B or C and D). The odor typicality rating data recorded after exposure revealed different influences of experience on odor mixtures and single-component perception, depending both on the type of exposure (components or mixture) and the mixture's initial perceptual property (configural or elemental). Although preexposure to A and B decreased the pineapple typicality of the configural AB mixture, preexposure to AB did not modify its odor quality. In contrast, preexposure to the CD elemental mixture induced a quality transfer between the components. These results emphasize the relative plasticity of odor mixture perception, which is prone to experience-induced modulations but depends on the stimulus's initial perceptual properties, suggesting that configural and elemental forms of odor mixture perception rely on rather independent processes.

  3. Sex Discrimination in Coaching.

    Science.gov (United States)

    Dessem, Lawrence

    1980-01-01

    Even in situations in which the underpayment of girls' coaches is due to the sex of the students coached rather than to the sex of the coaches, the coaches and the girls coached are victims of unlawful discrimination. Available from Harvard Women's Law Journal, Harvard Law School, Cambridge, MA 02138. (Author/IRT)

  4. Discrimination. Opposing Viewpoints Series.

    Science.gov (United States)

    Williams, Mary E., Ed.

    Books in the Opposing Viewpoints series challenge readers to question their own opinions and assumptions. By reading carefully balanced views, readers confront new ideas on the topic of interest. The Civil Rights Act of 1964, which prohibited job discrimination based on age, race, religion, gender, or national origin, provided the groundwork for…

  5. Education and Gender Discrimination

    Science.gov (United States)

    Sumi, V. S.

    2012-01-01

    This paper discusses the status of women education in present education system and some measures to overcome the lags existing. Discrimination against girls and women in the developing world is a devastating reality. It results in millions of individual tragedies, which add up to lost potential for entire countries. Gender bias in education is an…

  6. Color measurement and discrimination

    Science.gov (United States)

    Wandell, B. A.

    1985-01-01

    Theories of color measurement attempt to provide a quantative means for predicting whether two lights will be discriminable to an average observer. All color measurement theories can be characterized as follows: suppose lights a and b evoke responses from three color channels characterized as vectors, v(a) and v(b); the vector difference v(a) - v(b) corresponds to a set of channel responses that would be generated by some real light, call it *. According to theory a and b will be discriminable when * is detectable. A detailed development and test of the classic color measurement approach are reported. In the absence of a luminance component in the test stimuli, a and b, the theory holds well. In the presence of a luminance component, the theory is clearly false. When a luminance component is present discrimination judgements depend largely on whether the lights being discriminated fall in separate, categorical regions of color space. The results suggest that sensory estimation of surface color uses different methods, and the choice of method depends upon properties of the image. When there is significant luminance variation a categorical method is used, while in the absence of significant luminance variation judgments are continuous and consistant with the measurement approach.

  7. Aptitude Tests and Discrimination

    Science.gov (United States)

    Coupland, D. E.

    1970-01-01

    Explains why in the United States the feeling is increasing that much of the aptitude testing now being done discriminates against minority group members seeking employment. Skeptical of eliminating the discriminatory aspects of testing, the article raises the question of eliminating testing itself. (DM)

  8. Immunological self, nonself discrimination

    DEFF Research Database (Denmark)

    Guillet, J G; Lai, M Z; Briner, T J

    1987-01-01

    The ability of immunodominant peptides derived from several antigen systems to compete with each other for T cell activation was studied. Only peptides restricted by a given transplantation antigen are mutually competitive. There is a correlation between haplotype restriction, ability to bind to ...... that provides a basis for explaining self, nonself discrimination as well as alloreactivity....

  9. Discrimination Learning in Children

    Science.gov (United States)

    Ochocki, Thomas E.; And Others

    1975-01-01

    Examined the learning performance of 192 fourth-, fifth-, and sixth-grade children on either a two or four choice simultaneous color discrimination task. Compared the use of verbal reinforcement and/or punishment, under conditions of either complete or incomplete instructions. (Author/SDH)

  10. Discrimination and its Effects.

    Science.gov (United States)

    Thomas, Clarence

    1983-01-01

    Reviews challenges facing Black professionals committed to further promoting civil rights. Focuses on the Federal government role, particularly regarding racial discrimination in employment. Warns against the acceptance of orthodoxies, and calls for new action and the exercising of intellectual freedom. (KH)

  11. Prenatal exposure to vanilla or alcohol induces crawling after these odors in the neonate rat: The role of mu and kappa opioid receptor systems.

    Science.gov (United States)

    Gaztañaga, Mirari; Aranda-Fernández, P Ezequiel; Chotro, M Gabriela

    2015-09-01

    Rat fetuses can perceive chemosensory stimuli derived from their mother's diet, and they may learn about those stimuli. In previous studies we have observed that prenatal exposure to alcohol during the last days of gestation increases the acceptance and liking of an alcohol flavor in infant and adolescent rats. While these results were not found after prenatal exposure to vanilla, cineole or anise, suggesting that the pharmacological properties of alcohol, mediated by the opioid system, underlie the effects observed with this drug. Considering that other studies report enhanced acceptance of non-alcohol flavors experienced prenatally when subjects were tested before infancy, we explore the possibility of observing similar results if testing 1-day old rats exposed prenatally to vanilla. Using an "odor-induced crawling" testing procedure, it was observed that neonates exposed prenatally to vanilla or alcohol crawl for a longer distance towards the experienced odor than to other odors or than control pups. Blocking mu, but not kappa opioid receptors, reduced the attraction of vanilla odor to neonates exposed to vanilla in utero, while the response to alcohol in pups exposed prenatally to this drug was affected by both antagonists. Results confirm that exposure to a non-alcohol odor enhances postnatal responses to it, observable soon after birth, while also suggesting that the mu opioid receptor system plays an important role in generating this effect. The results also imply that with alcohol exposure, the prenatal opioid system is wholly involved, which could explain the longer retention of the enhanced attraction to alcohol following prenatal experience with the drug.

  12. Composition of agarose substrate affects behavioral output of Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi Aristomenis Apostolopoulou

    2014-01-01

    Full Text Available In the last decade the Drosophila larva has evolved into a simple model organism offering the opportunity to integrate molecular genetics with systems neuroscience. This led to a detailed understanding of the functional neuronal networks for a number of sensory functions and behaviors including olfaction, vision, gustation and learning and memory. Typically, behavioral assays in use exploit simple Petri dish setups with either agarose or agar as a substrate. However, neither the quality nor the concentration of the substrate is generally standardized across these experiments and there is no data available on how larval behavior is affected by such different substrates. Here, we have investigated the effects of different agarose concentrations on several larval behaviors. We demonstrate that agarose concentration is an important parameter, which affects all behaviors tested: preference, feeding, learning and locomotion. Larvae can discriminate between different agarose concentrations, they feed differently on them, they can learn to associate an agarose concentration with an odor stimulus and crawl faster on a substrate of higher agarose concentration. Additionally, we have investigated the effect of agarose concentration on three quinine based behaviors: preference, feeding and learning. We show that in all cases examined the behavioral output changes in an agarose concentration-dependent manner. Our results suggest that comparisons between experiments performed on substrates differing in agarose concentration should be done with caution. It should be taken into consideration that the agarose concentration can affect the behavioral output and thereby the experimental outcomes per se potentially due to an increased escape response on more rigid substrates.

  13. Examining Workplace Discrimination in a Discrimination-Free Environment

    OpenAIRE

    Braxton, Shawn Lamont

    2010-01-01

    Examining Workplace Discrimination in a Discrimination-Free Environment Shawn L. Braxton Abstract The purpose of this study is to explore how racial and gender discrimination is reproduced in concrete workplace settings even when anti-discrimination policies are present, and to understand the various reactions utilized by those who commonly experience it. I have selected a particular medical center, henceforth referred to by a pseudonym, â The Bliley Medical Centerâ as my case ...

  14. The relative merits of discriminating and non-discriminating dosemeters

    DEFF Research Database (Denmark)

    Marshal, T. O.; Christensen, Palle; Julius, H. W.;

    1986-01-01

    The need for discriminating and non-discriminating personal dosemeters in the field of radiological protection is examined. The ability of various types of dosemeter to meet these needs is also discussed. It is concluded that there is a need for discriminating dosemeters but in the majority of ca...

  15. 29 CFR 825.702 - Interaction with Federal and State anti-discrimination laws.

    Science.gov (United States)

    2010-07-01

    ... Pregnancy Discrimination Act, an employer should provide the same benefits for women who are pregnant as the... 29 Labor 3 2010-07-01 2010-07-01 false Interaction with Federal and State anti-discrimination laws... Federal and State anti-discrimination laws. (a) Nothing in FMLA modifies or affects any Federal or...

  16. Rapid decision-making with side-specific perceptual discrimination in ants.

    Directory of Open Access Journals (Sweden)

    Nathalie Stroeymeyt

    Full Text Available BACKGROUND: Timely decision making is crucial for survival and reproduction. Organisms often face a speed-accuracy trade-off, as fully informed, accurate decisions require time-consuming gathering and treatment of information. Optimal strategies for decision-making should therefore vary depending on the context. In mammals, there is mounting evidence that multiple systems of perceptual discrimination based on different neural circuits emphasize either fast responses or accurate treatment of stimuli depending on the context. METHODOLOGY/PRINCIPAL FINDINGS: We used the ant Camponotus aethiops to test the prediction that fast information processing achieved through direct neural pathways should be favored in situations where quick reactions are adaptive. Social insects discriminate readily between harmless group-members and dangerous strangers using easily accessible cuticular hydrocarbons as nestmate recognition cues. We show that i tethered ants display rapid aggressive reactions upon presentation of non-nestmate odor (120 to 160 ms; ii ants' aggressiveness towards non-nestmates can be specifically reduced by exposure to non-nestmate odor only, showing that social interactions are not required to alter responses towards non-nestmates; iii decision-making by ants does not require information transfer between brain hemispheres, but relies on side-specific decision rules. CONCLUSIONS/SIGNIFICANCE: Our results strongly suggest that first-order olfactory processing centers (up to the antennal lobes are likely to play a key role in ant nestmate recognition. We hypothesize that the coarse level of discrimination achieved in the antennal lobes early in odor processing provides enough information to determine appropriate behavioral responses towards non-nestmates. This asks for a reappraisal of the mechanisms underlying social recognition in insects.

  17. Employment Age Discrimination on Women

    Institute of Scientific and Technical Information of China (English)

    黄捧

    2015-01-01

    Employment age discrimination against women is not an unusual phenomenon in China.Through describing the present situation and negative effect of this phenomenon,this paper claims laws are very important weapon to eliminate age discrimination against women.

  18. Characteristics of electroencephalographic responses induced by a pleasant and an unpleasant odor.

    Science.gov (United States)

    Kim, Yeon-Kyu; Watanuki, Shigeki

    2003-11-01

    More than sensory stimuli, odorous stimuli were employed to facilitate the evocation of emotional responses in the present study. The odor-stimulated emotion was evaluated by investigating specific features of encephalographic (EEG) responses produced thereof. In this study, the concentrations of the same odor were altered; viz., the changes in odor-induced emotional level were compared with the concurrently monitored EEG response features. In addition, we performed the mental task to evoke the arousal state of the brain and investigated the resemblance of response characteristics of the resting state to the post-mental task resting state. Subjects having no abnormalities in the sense of smell included 12 male undergraduate and graduate students (age range: 22-26 years). Experiment I involved 2 types of odors that induced favorable odorous stimuli (pleasant induction); test-solutions were either diluted 150 (easily perceptible odorous sensation) or 500 (slightly perceptible odorous stimuli) times. Experiment II had 2 types of odors that evoked unfavorable odorous stimuli (unpleasant induction), and test-solutions with dilution rates similar to those of pleasant induction were prepared. Odorless distilled water was used as the control in both experiments. From results of rating the odorous stimuli of our compounds used, the candidates were respectively found to be appropriate in inducing the pleasant and unpleasant smell sensations. The analyses of EEG responses on inducing pleasant and unpleasant smell sensations revealed that the EEG activities of the left frontal region were enhanced. This finding may establish the hypothesis of a relationship prevailing between the positive approach-related emotion evoked by the visual sensation and the left hemisphere (Davidson, 1992; Tomarken et al., 1989). In other words, it can be interpreted that the negative withdrawal-related emotion may be associated with activities of the right hemisphere. However, this hypothesis may

  19. Perceptual processing strategy and exposure influence the perception of odor mixtures.

    Science.gov (United States)

    Le Berre, Elodie; Thomas-Danguin, Thierry; Béno, Noëlle; Coureaud, Gérard; Etiévant, Patrick; Prescott, John

    2008-02-01

    In flavor perception, both experience with the components of odor/taste mixtures and the cognitive strategy used to examine the interactions between the components influence the overall mixture perception. However, the effect of these factors on odor mixtures perception has never been studied. The present study aimed at evaluating whether 1) previous exposure to the odorants included in a mixture or 2) the synthetic or analytic strategy engaged during odorants mixture evaluation determines odor representation. Blending mixtures, in which subjects perceived a unique quality distinct from those of components, were chosen in order to induce a priori synthetic perception. In the first part, we checked whether the chosen mixtures presented blending properties for our subjects. In the second part, 3 groups of participants were either exposed to the odorants contributing to blending mixtures with a "pineapple" or a "red cordial" odor or nonexposed. In a following task, half of each group was assigned to a synthetic or an analytical task. The synthetic task consisted of rating how typical (i.e., representative) of the target odor name (pineapple or red cordial) were the mixtures and each of their components. The analytical task consisted of evaluating these stimuli on several scales labeled with the target odor name and odor descriptors of the components. Previous exposure to mixture components was found to decrease mixture typicality but only for the pineapple blending mixture. Likewise, subjects engaged in an analytical task rated both blending mixtures as less typical than did subjects engaged in a synthetic task. This study supports a conclusion that odor mixtures can be perceived either analytically or synthetically according to the cognitive strategy engaged.

  20. Ligands for pheromone-sensing neurons are not conformationally activated odorant binding proteins.

    Directory of Open Access Journals (Sweden)

    Carolina Gomez-Diaz

    Full Text Available Pheromones form an essential chemical language of intraspecific communication in many animals. How olfactory systems recognize pheromonal signals with both sensitivity and specificity is not well understood. An important in vivo paradigm for this process is the detection mechanism of the sex pheromone (Z-11-octadecenyl acetate (cis-vaccenyl acetate [cVA] in Drosophila melanogaster. cVA-evoked neuronal activation requires a secreted odorant binding protein, LUSH, the CD36-related transmembrane protein SNMP, and the odorant receptor OR67d. Crystallographic analysis has revealed that cVA-bound LUSH is conformationally distinct from apo (unliganded LUSH. Recombinantly expressed mutant versions of LUSH predicted to enhance or diminish these structural changes produce corresponding alterations in spontaneous and/or cVA-evoked activity when infused into olfactory sensilla, leading to a model in which the ligand for pheromone receptors is not free cVA, but LUSH that is "conformationally activated" upon cVA binding. Here we present evidence that contradicts this model. First, we demonstrate that the same LUSH mutants expressed transgenically affect neither basal nor pheromone-evoked activity. Second, we compare the structures of apo LUSH, cVA/LUSH, and complexes of LUSH with non-pheromonal ligands and find no conformational property of cVA/LUSH that can explain its proposed unique activated state. Finally, we show that high concentrations of cVA can induce neuronal activity in the absence of LUSH, but not SNMP or OR67d. Our findings are not consistent with the model that the cVA/LUSH complex acts as the pheromone ligand, and suggest that pheromone molecules alone directly activate neuronal receptors.

  1. Discrimination and psychological distress: does Whiteness matter for Arab Americans?

    Science.gov (United States)

    Abdulrahim, Sawsan; James, Sherman A; Yamout, Rouham; Baker, Wayne

    2012-12-01

    The white racial category in the U.S. encompasses persons who have Arab ancestry. Arab Americans, however, have always occupied a precarious position in relationship to Whiteness. This study examined differences in reporting racial/ethnic discrimination among Arab Americans. It also investigated whether and how the association between discrimination and psychological distress varies by characteristics that capture an Arab American's proximity to/distance from Whiteness. We used data from the Detroit Arab American Study (2003; n = 1016), which includes measures of discrimination and the Kessler-10 scale of psychological distress. A series of logistic regression models were specified to test the discrimination-psychological distress association, stratified by five measures that capture Whiteness--subjective racial identification, religion, skin color, ethnic centrality, and residence in the ethnic enclave. Discrimination was more frequently reported by Muslim Arab Americans, those who racially identify as non-white, and who live in the ethnic enclave. Conversely, the association between discrimination and psychological distress was stronger for Christian Arab Americans, those who racially identify as white, who have dark skin color, and who live outside the ethnic enclave. Even though Arab Americans who occupy an identity location close to Whiteness are less subjected to discrimination, they are more negatively affected by it. The findings illuminate the complex pathways through which discrimination associates with psychological distress among 'white' immigrants. Further research on discrimination and health among Arab Americans can help unpack the white racial category and deconstruct Whiteness.

  2. Polarization discrimination between repeater false-target and radar target

    Institute of Scientific and Technical Information of China (English)

    SHI LongFei; WANG XueSong; XIAO ShunPing

    2009-01-01

    High fidelity repeater false-target badly affects a radar system's detecting, tracking, and data processing. It is an available approach of confronting false-target for radar that discriminates firstly and then eliminates. Whereas for the technique progress about the repeater false-target jam, it is more and more difficult to discriminate this jam in the time-domain, frequency-domain, or space-domain. The technique using polarization information to discriminate the target and false-target is discussed in this paper. With the difference that false-target signal vector's polarization ratio is fixed and target echo signal vector's polarization ratio is variational along with radar transmission signal's polarization, we transform the discrimination problem to beeline distinguish problem in the 2-dim complex space. The distributing characteristic expression of the false-target discrimination statistic is constructed, with which the discrimination ratio of false-target is analyzed. For the target case, the decomposed model of target scattering matrix and the concept of distinguish quantity are proposed. Then, the discrimination ratio of target can be forecasted according to target distinguish quantity. Thus, the performance of discrimination method has been analyzed integrally. The simulation results demonstrate the method in this paper is effective on the discrimination of target and false-target.

  3. Workplace Discrimination: An Additional Stressor for Internationally Educated Nurses.

    Science.gov (United States)

    Baptiste, Maria M

    2015-08-18

    Discrimination against internationally educated nurses (IENs) remains a seldom-explored topic in the United States. Yet, the literature describing experiences of IENs indicates that some do experience workplace discrimination as an additional workplace stressor. IENs view this discrimination as an obstacle to career advancement and professional recognition. Consequences of workplace discrimination affect IENs' physical and psychological well being, the quality of patient care, and healthcare organizational costs. In anticipation of future nursing shortages, understanding and minimizing workplace discrimination will benefit nurses, patients, and healthcare organizations. In this article the author addresses motivation and challenges associated with international nurse migration and immigration, relates these challenges to Roy's theoretical framework, describes workplace discrimination, and reviews both consequences of and evidence for workplace discrimination. Next, she considers the significance of this discrimination for healthcare agencies, and approaches for decreasing stress for IENs during their transition process. She concludes that workplace discrimination has a negative, multifaceted effect on both professional nursing and healthcare organizations. Support measures developed to promote mutual respect among all nurses are presented.

  4. Transgender Discrimination and the Law

    Science.gov (United States)

    Trotter, Richard

    2010-01-01

    An emerging area of law is developing regarding sex/gender identity discrimination, also referred to as transgender discrimination, as distinguished from discrimination based on sexual orientation. A transgendered individual is defined as "a person who has a gender-identity disorder which is a persistent discomfort about one?s assigned sex or…

  5. Price Discrimination: A Classroom Experiment

    Science.gov (United States)

    Aguiló, Paula; Sard, Maria; Tugores, Maria

    2016-01-01

    In this article, the authors describe a classroom experiment aimed at familiarizing students with different types of price discrimination (first-, second-, and third-degree price discrimination). During the experiment, the students were asked to decide what tariffs to set as monopolists for each of the price discrimination scenarios under…

  6. Price Discrimination: Lessons for Consumers.

    Science.gov (United States)

    Maynes, E. Scott

    1990-01-01

    Explains price and product discrimination, showing how intelligent consumers can achieve increased purchasing power of their income and discusses how consumer educators can explain this discrimination. Evaluates the pros and cons of price/product discrimination from the social viewpoint. (Author/JOW)

  7. Fate of key odorants in Sauternes wines through aging.

    Science.gov (United States)

    Bailly, Sabine; Jerkovic, Vesna; Meurée, Ariane; Timmermans, Aurore; Collin, Sonia

    2009-09-23

    Recent work has revealed the importance of polyfunctional thiols in young Sauternes wines, but very little is yet known about the fate of such compounds during aging in the bottle. In this study, two Sauternes wines were investigated by gas chromatography-olfactometry (GC-O) aroma extract dilution analysis (AEDA), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-pulsed flame photometric detector (GC-PFPD) after XAD 2 and thiol-specific extractions. Most polyfunctional thiols (3-sulfanylpropyl acetate, 2-sulfanylethyl acetate, 3-methyl-3-sulfanylbutanal, etc.) proved to be completely degraded after 2 years of bottle aging in a cellar. Only 3-sulfanylhexan-1-ol was still found in aged samples at concentrations above its threshold value. Most other key odorants found in the young noble rot wine were still detected 5-6 years after harvest: varietal aroma (alpha-terpineol), sotolon, fermentation alcohols (3-methylbutan-1-ol and 2-phenylethanol) and esters (ethyl butyrate, isobutyrate, hexanoate, and isovalerate), and oak maturation-related compounds (guaiacol, vanillin, eugenol, beta-damascenone, trans-non-2-enal, beta-methyl-gamma-octalactone, gamma-nonalactone, and furaneol), as well as three newly identified aromas exhibiting interesting cake, honey-like, and dried apricot odors: homofuraneol, theaspirane, and gamma-decalactone. Interestingly, abhexon, never mentioned in sweet wines before, was found to be synthesized during bottle aging. An optimized extraction method allowed us to quantify this honey/spicy compound at levels close to its threshold value (up to 7 microg/L after 5-6 years), thus suggesting a key role of this strong odorant in old Sauternes wines.

  8. Malaria infected mosquitoes express enhanced attraction to human odor.

    Directory of Open Access Journals (Sweden)

    Renate C Smallegange

    Full Text Available There is much evidence that some pathogens manipulate the behaviour of their mosquito hosts to enhance pathogen transmission. However, it is unknown whether this phenomenon exists in the interaction of Anopheles gambiae sensu stricto with the malaria parasite, Plasmodium falciparum--one of the most important interactions in the context of humanity, with malaria causing over 200 million human cases and over 770 thousand deaths each year. Here we demonstrate, for the first time, that infection with P. falciparum causes alterations in behavioural responses to host-derived olfactory stimuli in host-seeking female An. gambiae s.s. mosquitoes. In behavioural experiments we showed that P. falciparum-infected An. gambiae mosquitoes were significantly more attracted to human odors than uninfected mosquitoes. Both P. falciparum-infected and uninfected mosquitoes landed significantly more on a substrate emanating human skin odor compared to a clean substrate. However, significantly more infected mosquitoes landed and probed on a substrate emanating human skin odor than uninfected mosquitoes. This is the first demonstration of a change of An. gambiae behaviour in response to olfactory stimuli caused by infection with P. falciparum. The results of our study provide vital information that could be used to provide better predictions of how malaria is transmitted from human being to human being by An. gambiae s.s. females. Additionally, it highlights the urgent need to investigate this interaction further to determine the olfactory mechanisms that underlie the differential behavioural responses. In doing so, new attractive compounds could be identified which could be used to develop improved mosquito traps for surveillance or trapping programmes that may even specifically target P. falciparum-infected An. gambiae s.s. females.

  9. Optimal time discrimination

    OpenAIRE

    Coşkun, Filiz; Sayalı, Zeynep Ceyda; Gürbüz, Emine; Balcı, Fuat

    2015-01-01

    Optimal Time Discrimination Journal: Quarterly Journal of Experimental Psychology Manuscript ID: QJE-STD 14-039.R1 Manuscript Type: Standard Article Date Submitted by the Author: n/a Complete List of Authors: Çoskun, Filiz; Koç University, Psychology Sayalı Ungerer, Zeynep; Koç University, Psychology Gürbüz, Emine; Koç University, Psychology Balcı, Fuat; Koç University, Psychology Keywords: Decision making, Interval Timing, Optimality, Response Times, Temporal ...

  10. [Comment on] Statistical discrimination

    Science.gov (United States)

    Chinn, Douglas

    In the December 8, 1981, issue of Eos, a news item reported the conclusion of a National Research Council study that sexual discrimination against women with Ph.D.'s exists in the field of geophysics. Basically, the item reported that even when allowances are made for motherhood the percentage of female Ph.D.'s holding high university and corporate positions is significantly lower than the percentage of male Ph.D.'s holding the same types of positions. The sexual discrimination conclusion, based only on these statistics, assumes that there are no basic psychological differences between men and women that might cause different populations in the employment group studied. Therefore, the reasoning goes, after taking into account possible effects from differences related to anatomy, such as women stopping their careers in order to bear and raise children, the statistical distributions of positions held by male and female Ph.D.'s ought to be very similar to one another. Any significant differences between the distributions must be caused primarily by sexual discrimination.

  11. Discrimination in lexical decision

    Science.gov (United States)

    Feldman, Laurie Beth; Ramscar, Michael; Hendrix, Peter; Baayen, R. Harald

    2017-01-01

    In this study we present a novel set of discrimination-based indicators of language processing derived from Naive Discriminative Learning (ndl) theory. We compare the effectiveness of these new measures with classical lexical-distributional measures—in particular, frequency counts and form similarity measures—to predict lexical decision latencies when a complete morphological segmentation of masked primes is or is not possible. Data derive from a re-analysis of a large subset of decision latencies from the English Lexicon Project, as well as from the results of two new masked priming studies. Results demonstrate the superiority of discrimination-based predictors over lexical-distributional predictors alone, across both the simple and primed lexical decision tasks. Comparable priming after masked corner and cornea type primes, across two experiments, fails to support early obligatory segmentation into morphemes as predicted by the morpho-orthographic account of reading. Results fit well with ndl theory, which, in conformity with Word and Paradigm theory, rejects the morpheme as a relevant unit of analysis. Furthermore, results indicate that readers with greater spelling proficiency and larger vocabularies make better use of orthographic priors and handle lexical competition more efficiently. PMID:28235015

  12. Workplace discrimination and cancer.

    Science.gov (United States)

    McKenna, Maureen A; Fabian, Ellen; Hurley, Jessica E; McMahon, Brian T; West, Steven L

    2007-01-01

    Data from the Equal Employment Opportunity Commission (EEOC) Integrated Mission System database were analyzed with specific reference to allegations of workplace discrimination filed by individuals with cancer under ADA Title One. These 6,832 allegations, filed between July 27, 1992 and September 30, 2003, were compared to 167,798 allegations from a general disability population on the following dimensions: type of workplace discrimination; demographic characteristics of the charging parties (CPs); the industry designation, location, and size of employers; and the outcome or resolution of EEOC investigations. Results showed allegations derived from CPs with cancer were more likely than those in the general disability population to include issues involving discharge, terms and conditions of employment, lay-off, wages, and demotion. Compared to the general disability group, CPs with cancer were more likely to be female, older, and White. Allegations derived from CPs with cancer were also more likely to be filed against smaller employers (15-100 workers) or those in service industries. Finally, the resolution of allegations by CPs with cancer were more likely to be meritorious than those filed from the general disability population; that is, actual discrimination is more likely to have occurred.

  13. Fluorescence competition assay for the assessment of green leaf volatiles and trans-β-farnesene bound to three odorant-binding proteins in the wheat aphid Sitobion avenae (Fabricius).

    Science.gov (United States)

    Zhong, Tao; Yin, Jiao; Deng, Sisi; Li, Kebin; Cao, Yazhong

    2012-06-01

    Odorant-binding proteins (OBPs) are important parts of insect olfactory systems, and sensitive olfaction is vital for phytophagous insects in host foraging. Electrophysiological studies are helpful in understanding olfactory sensing in Sitobion avenae (Hemiptera: Aphididae), but the functions of odorant-binding proteins in this insect are poorly understood. In this study, we used fluorescence competition assays to measure the binding specificities of SaveOBPs. The results showed that both SaveOBP2 and SaveOBP3 were superior to SaveOBP7 in binding green leaf volatiles. It was unexpected that SaveOBP7 bound trans-β-farnesene strongly, which was known as alarm pheromone of this species. Host volatiles were recognized much more easily by SaveOBP2, and the observed binding activity of SaveOBP2 equaled for tested green leaf volatiles. Our results imply that SaveOBP7 might play a more important role in aphid alarm pheromone discrimination.

  14. Characterization of a Deswapped Triple Mutant Bovine Odorant Binding Protein

    Directory of Open Access Journals (Sweden)

    Roberto Favilla

    2011-04-01

    Full Text Available The stability and functionality of GCC-bOBP, a monomeric triple mutant of bovine odorant binding protein, was investigated, in the presence of denaturant and in acidic pH conditions, by both protein and 1-aminoanthracene ligand fluorescence measurements, and compared to that of both bovine and porcine wild type homologues. Complete reversibility of unfolding was observed, though refolding was characterized by hysteresis. Molecular dynamics simulations, performed to detect possible structural changes of the monomeric scaffold related to the presence of the ligand, pointed out the stability of the β-barrel lipocalin scaffold.

  15. Correlation between Odor Concentration and Volatile Organic Compounds (VOC) Composition of Environmental Tobacco Smoke (ETS).

    Science.gov (United States)

    Noguchi, Miyuki; Tanaka, Saya; Watanabe, Kaede; Yamasaki, Akihiro

    2016-10-09

    We examined the correlation between the odor concentration and the chemical composition of environmental tobacco smoke (ETS). Three types of ETS samples were prepared: secondhand smoke (SHS), thirdhand smoke (THS), and field ETS samples from an outside smoking area. The odor concentrations of the ETS, SHS, and THS samples were determined by the triangle-odor-bag method, and the chemical compositions were determined by proton transfer mass spectrometry. The odor concentration of the SHS samples was three or four orders of magnitude higher than that of the field ETS samples, and three orders of magnitude higher than that of the THS samples. The concentration ratios of the constituent chemicals in THS to those in SHS were about 10(-4), corresponding to the ratio of the odor concentration. The concentration ratios of the constituent chemicals in the field ETS samples were much lower than the ratios of the odor concentrations. This suggests that the main contributing components to the odor of the field ETS samples are different from those in SHS and THS. The main contributors of the odor in the field ETS samples could be acetaldehyde, acetonitrile, acetic acid, and other unknown components with a mass-to-charge ratio (m/z) of 39 and 43.

  16. Attractiveness of binary blends of floral odorant compounds to moths in Florida, USA

    Science.gov (United States)

    Evaluation of combinations of flower odor compounds in the field revealed several chemicals that were attractive or co-attractive with phenylacetaldehyde (PAA) to pest noctuid and pyralid moths. A number of moth species responded positively to PAA. The floral odorants cis-jasmone, linalool, benzyl...

  17. Physiological and behavioral responses in Drosophila melanogaster to odorants present at different plant maturation stages.

    Science.gov (United States)

    Versace, Elisabetta; Eriksson, Anna; Rocchi, Federico; Castellan, Irene; Sgadò, Paola; Haase, Albrecht

    2016-09-01

    The fruit fly Drosophila melanogaster feeds and oviposits on fermented fruit, hence its physiological and behavioral responses are expected to be tuned to odorants abundant during later stages of fruit maturation. We used a population of about two-hundred isogenic lines of D. melanogaster to assay physiological responses (electroantennograms (EAG)) and behavioral correlates (preferences and choice ratio) to odorants found at different stages of fruit maturation. We quantified electrophysiological and behavioral responses of D. melanogaster for the leaf compound β-cyclocitral, as well as responses to odorants mainly associated with later fruit maturation stages. Electrophysiological and behavioral responses were modulated by the odorant dose. For the leaf compound we observed a steep dose-response curve in both EAG and behavioral data and shallower curves for odorants associated with later stages of maturation. Our data show the connection between sensory and behavioral responses and are consistent with the specialization of D. melanogaster on fermented fruit and avoidance of high doses of compounds associated with earlier stages of maturation. Odor preferences were modulated in a non-additive way when flies were presented with two alternative odorants, and combinations of odorants elicited higher responses than single compounds.

  18. Environmental Effects Exceed Genetic Effects on Perceived Intensity and Pleasantness of Several Odors

    DEFF Research Database (Denmark)

    Knaapila, Antti; Tuorila, Hely; Silventoinen, Karri

    2008-01-01

    and pleasantness of cinnamon, chocolate, turpentine, and isovaleric acid (sweaty) odors by quantitative genetic modeling of odor rating data from 856 twin individuals (including 83 complete monozygotic and 275 dizygotic twin pairs) aged 10-60 years (44% males and 56% females) from Australia, Denmark, and Finland...

  19. A machine learning approach for the identification of odorant binding proteins from sequence-derived properties

    Directory of Open Access Journals (Sweden)

    Suganthan PN

    2007-09-01

    Full Text Available Abstract Background Odorant binding proteins (OBPs are believed to shuttle odorants from the environment to the underlying odorant receptors, for which they could potentially serve as odorant presenters. Although several sequence based search methods have been exploited for protein family prediction, less effort has been devoted to the prediction of OBPs from sequence data and this area is more challenging due to poor sequence identity between these proteins. Results In this paper, we propose a new algorithm that uses Regularized Least Squares Classifier (RLSC in conjunction with multiple physicochemical properties of amino acids to predict odorant-binding proteins. The algorithm was applied to the dataset derived from Pfam and GenDiS database and we obtained overall prediction accuracy of 97.7% (94.5% and 98.4% for positive and negative classes respectively. Conclusion Our study suggests that RLSC is potentially useful for predicting the odorant binding proteins from sequence-derived properties irrespective of sequence similarity. Our method predicts 92.8% of 56 odorant binding proteins non-homologous to any protein in the swissprot database and 97.1% of the 414 independent dataset proteins, suggesting the usefulness of RLSC method for facilitating the prediction of odorant binding proteins from sequence information.

  20. Analysis of odorant receptor protein function in the yellow fever mosquito, aedes aegypti

    Science.gov (United States)

    Odorant receptors (ORs) in insects are ligand-gated ion channels comprised of two subunits: a variable receptor and an obligatory co-receptor (Orco). This protein receptor complex of unknown stoichiometry interacts with an odor molecule leading to changes in permeability of the sensory dendrite, th...

  1. Identification of Odorant-Receptor Interactions by Global Mapping of the Human Odorome

    DEFF Research Database (Denmark)

    Audouze, Karine Marie Laure; Tromelin, Anne; Le Bon, Anne Marie;

    2014-01-01

    between odorants and the cannabinoid receptor 1 (CB1) and the peroxisome proliferator-activated receptor gamma ( PPAR gamma). Overall, these results illustrate the potential of integrative systems chemical biology to explore the impact of odorant molecules on human health, i.e. human odorome....

  2. Olfactory processing and odor specificity: a meta-analysis of menstrual cycle variation in olfactory sensitivity

    Directory of Open Access Journals (Sweden)

    Martinec Nováková Lenka

    2014-12-01

    Full Text Available Cycle-correlated variation in olfactory threshold, with women becoming more sensitive to odors mid-cycle, is somewhat supported by the literature but the evidence is not entirely consistent, with several studies finding no, or mixed, effects. It has been argued that cyclic shifts in olfactory threshold might be limited to odors relevant to the mating context.

  3. Parallel odor processing by two anatomically distinct olfactory bulb target structures.

    Directory of Open Access Journals (Sweden)

    Colleen A Payton

    Full Text Available The olfactory cortex encompasses several anatomically distinct regions each hypothesized to provide differential representation and processing of specific odors. Studies exploring whether or not the diversity of olfactory bulb input to olfactory cortices has functional meaning, however, are lacking. Here we tested whether two anatomically major olfactory cortical structures, the olfactory tubercle (OT and piriform cortex (PCX, differ in their neural representation and processing dynamics of a small set of diverse odors by performing in vivo extracellular recordings from the OT and PCX of anesthetized mice. We found a wealth of similarities between structures, including odor-evoked response magnitudes, breadth of odor tuning, and odor-evoked firing latencies. In contrast, only few differences between structures were found, including spontaneous activity rates and odor signal-to-noise ratios. These results suggest that despite major anatomical differences in innervation by olfactory bulb mitral/tufted cells, the basic features of odor representation and processing, at least within this limited odor set, are similar within the OT and PCX. We predict that the olfactory code follows a distributed processing stream in transmitting behaviorally and perceptually-relevant information from low-level stations.

  4. Retronasal odor of dried bonito stock induces umami taste and improves the palatability of saltiness.

    Science.gov (United States)

    Manabe, Mariko; Ishizaki, Sanae; Yamagishi, Umi; Yoshioka, Tatsuhito; Oginome, Nozomu

    2014-09-01

    A traditional Japanese umami-rich stock, dried bonito stock, was reported to improve the palatability of a low-salt diet due to its characteristic aroma. Two pathways are available for the presentation of odors: the orthonasal and retronasal pathways. Aroma is perceived through the orthonasal pathway. In contrast, retronasal application of odors is thought to evoke different sensations from the orthonasal pathway, which is typically perceived as taste and modifies taste. Therefore, the effect of retronasal odor on salt-reduction might be different from that of aroma, that is, orthonasal odor. Thus, the effects of the retronasal odor of dried bonito stock on the enhancement and improvement of palatability upon salt reduction were examined using sensory evaluation. Moreover, the contributions to flavor expression and palatability of dried bonito stock were also investigated. Although the retronasal odor of dried bonito did not enhance saltiness, it improved the palatability of saltiness. In the presence of no tastants except 0.68% NaCl, a content 15% less than that of Japanese traditional soup, the retronasal odor of dried bonito generated umami, enhanced the suitability for dried bonito stock, and increased palatability. This indicates that the retronasal odor of dried bonito stock could improve the palatability of a salt-reduced diet. These findings can be applied to the development of new seasonings for improving the palatability of salt-reduced foods.

  5. Prenatal Alcohol Exposure Selectively Enhances Young Adult Perceived Pleasantness of Alcohol Odors

    Science.gov (United States)

    Hannigan, John H.; Chiodo, Lisa M.; Sokol, Robert J.; Janisse, James; Delaney-Black, Virginia

    2015-01-01

    Prenatal Alcohol Exposure (PAE) can lead to life-long neurobehavioral and social problems that can include a greater likelihood of early use and/or abuse of alcohol compared to older teens and young adults without PAE. Basic research in animals demonstrates that PAE influences later postnatal responses to chemosensory cues (i.e., odor & taste) associated with alcohol. We hypothesized that PAE would be related to poorer abilities to identify odors of alcohol-containing beverages, and would alter perceived alcohol odor intensity and pleasantness. To address this hypothesis we examined responses to alcohol and other odors in a small sample of young adults with detailed prenatal histories of exposure to alcohol and other drugs. The key finding from our controlled analyses is that higher levels of PAE were related to higher relative ratings of pleasantness for alcohol odors. As far as we are aware, this is the first published study to report the influence of PAE on responses to alcohol beverage odors in young adults. These findings are consistent with the hypothesis that positive associations (i.e., “pleasantness”) to the chemosensory properties of alcohol (i.e., odor) are acquired prenatally and are retained for many years despite myriad interceding postnatal experiences. Alternate hypotheses may also be supported by the results. There are potential implications of altered alcohol odor responses for understanding individual differences in initiation of drinking, and alcohol seeking and high-risk alcohol-related behaviors in young adults. PMID:25600468

  6. Odor-induced recall of emotional memories in PTSD-Review and new paradigm for research

    NARCIS (Netherlands)

    Daniels, Judith K.; Vermetten, Eric

    2016-01-01

    It is clinically well known that olfactory intrusions in PTSD can be a disabling phenomena due to the involuntary recall of odor memories. Odorants can trigger involuntary recall of emotional memories as well have the potential to help diminishing emotional arousal as grounding stimuli. Despite majo

  7. Neonatal Responsiveness to the Odor of Amniotic and Lacteal Fluids: A Test of Perinatal Chemosensory Continuity.

    Science.gov (United States)

    Marlier, Luc; Schaal, Benoist; Soussignan, Robert

    1998-01-01

    Studied head-orientation response of breast-feeding neonates in paired-choice odor tests. Found that 2-day olds detected amniotic fluid and colostrum, treating them as similar sensorily and/or hedonically. Four-day olds exhibited a preference for breast milk. Three-day olds oriented longer toward the odor of their own amniotic fluid than alien…

  8. Internal Representation and Memory Formation of Odor Preference Based on Oscillatory Activities in a Terrestrial Slug

    Science.gov (United States)

    Sekiguchi, Tatsuhiko; Furudate, Hiroyuki; Kimura, Tetsuya

    2010-01-01

    The terrestrial slug "Limax" exhibits a highly developed ability to learn odors with a small nervous system. When a fluorescent dye, Lucifer Yellow (LY), is injected into the slug's body cavity after odor-taste associative conditioning, a group of neurons in the procerebral (PC) lobe, an olfactory center of the slug, is labeled by LY. We examined…

  9. Sparse distributed representation of odors in a large-scale olfactory bulb circuit.

    Directory of Open Access Journals (Sweden)

    Yuguo Yu

    Full Text Available In the olfactory bulb, lateral inhibition mediated by granule cells has been suggested to modulate the timing of mitral cell firing, thereby shaping the representation of input odorants. Current experimental techniques, however, do not enable a clear study of how the mitral-granule cell network sculpts odor inputs to represent odor information spatially and temporally. To address this critical step in the neural basis of odor recognition, we built a biophysical network model of mitral and granule cells, corresponding to 1/100th of the real system in the rat, and used direct experimental imaging data of glomeruli activated by various odors. The model allows the systematic investigation and generation of testable hypotheses of the functional mechanisms underlying odor representation in the olfactory bulb circuit. Specifically, we demonstrate that lateral inhibition emerges within the olfactory bulb network through recurrent dendrodendritic synapses when constrained by a range of balanced excitatory and inhibitory conductances. We find that the spatio-temporal dynamics of lateral inhibition plays a critical role in building the glomerular-related cell clusters observed in experiments, through the modulation of synaptic weights during odor training. Lateral inhibition also mediates the development of sparse and synchronized spiking patterns of mitral cells related to odor inputs within the network, with the frequency of these synchronized spiking patterns also modulated by the sniff cycle.

  10. Olfactory tubercle stimulation alters odor preference behavior and recruits forebrain reward and motivational centers

    Directory of Open Access Journals (Sweden)

    Brynn J FitzGerald

    2014-03-01

    Full Text Available Rodents show robust behavioral responses to odors, including strong preferences or aversions for certain odors. The neural mechanisms underlying the effects of odors on these behaviors in animals are not well understood. Here, we provide an initial proof-of-concept study into the role of the olfactory tubercle (OT, a structure with known anatomical connectivity with both brain reward and olfactory structures, in regulating odor-motivated behaviors. We implanted c57bl/6 male mice with an ipsilateral bipolar electrode into the OT to administer electric current and thereby yield gross activation of the OT. We confirmed that electrical stimulation of the OT was rewarding, with mice frequently self-administering stimulation on a fixed ratio schedule. In a separate experiment, mice were presented with either fox urine or peanut odors in a three-chamber preference test. In absence of OT stimulation, significant preference for the peanut odor chamber was observed which was abolished in the presence of OT stimulation. Perhaps providing a foundation for this modulation in behavior, we found that OT stimulation significantly increased the number of c-Fos positive neurons in not only the OT, but also in forebrain structures essential to motivated behaviors, including the nucleus accumbens and lateral septum. The present results support the notion that the OT is integral to the display of motivated behavior and possesses the capacity to modulate odor hedonics either by directly altering odor processing or perhaps by indirect actions on brain reward and motivation structures.

  11. Ethnic discrimination and health: the relationship between experienced ethnic discrimination and multiple health domains in Norway's rural Sami population

    Directory of Open Access Journals (Sweden)

    Ketil Lenert Hansen

    2015-02-01

    Full Text Available Objective: Self-reported ethnic discrimination has been associated with a range of health outcomes. This study builds on previous efforts to investigate the prevalence of self-reported ethnic discrimination in the indigenous (Sami population, and how such discrimination may be associated with key health indicators. Study design: The study relies on data from the 2003/2004 (n=4,389 population-based study of adults (aged 36–79 years in 24 rural municipalities of Central and North Norway (the SAMINOR study. Self-reported ethnic discrimination was measured using the question: “Have you ever experienced discrimination due to your ethnic background?” Health indicators included questions regarding cardiovascular disease, diabetes, chronic muscle pain, metabolic syndrome and obesity. Logistic regression was applied to examine the relationship between self-reported ethnic discrimination and health outcomes. Results: The study finds that for Sami people living in minority areas, self-reported ethnic discrimination is associated with all the negative health indicators included in the study. Conclusion: We conclude that ethnic discrimination affects a wide range of health outcomes. Our findings highlight the importance of ensuring freedom from discrimination for the Sami people of Norway.

  12. Attracting, trapping and killing disease-transmitting mosquitoes using odor-baited stations - The Ifakara Odor-Baited Stations

    Directory of Open Access Journals (Sweden)

    John Alex N

    2010-03-01

    Full Text Available Abstract Background To accelerate efforts towards control and possibly elimination of mosquito-borne diseases such as malaria and lymphatic filariasis, optimally located outdoor interventions could be used to complement existing intradomicilliary vector control methods such as house spraying with insecticides and insecticidal bednets. Methods We describe a new odor-baited station for trapping, contaminating and killing disease-transmitting mosquitoes. This device, named the 'Ifakara Odor-baited Station' (Ifakara OBS, is a 4 m3 hut-shaped canvas box with seven openings, two of which may be fitted with interception traps to catch exiting mosquitoes. It is baited with synthetic human odors and may be augmented with contaminants including toxic insecticides or biological agents. Results In field trials where panels of fabric were soaked in 1% pirimiphos-methyl solution and suspended inside the Ifakara OBS, at least 73.6% of Anopheles arabiensis, 78.7% of Culex and 60% of Mansonia mosquitoes sampled while exiting the OBS, died within 24 hours. When used simply as a trap and evaluated against two existing outdoor traps, Ifakara Tent trap and Mosquito Magnet-X®, the OBS proved more efficacious than the Ifakara Tent trap in catching all mosquito species found (P ®, it was equally efficacious in catching An. arabiensis (P = 0.969, but was less efficacious against Culex (P Mansonia species (P Conclusion The Ifakara OBS is efficacious against disease-carrying mosquitoes including the malaria vector, An. arabiensis and Culicine vectors of filarial worms and arboviruses. It can be used simultaneously as a trap and as a contamination or killing station, meaning most mosquitoes which escape trapping would leave when already contaminated and die shortly afterwards. This technique has potential to complement current vector control methods, by targeting mosquitoes in places other than human dwellings, but its effectiveness in the field will require cheap, long

  13. Determination of the odor threshold concentrations of chlorobrominated anisoles in water.

    Science.gov (United States)

    Diaz, Alfredo; Fabrellas, Cristina; Ventura, Francesc; Galceran, M Teresa

    2005-01-26

    Trihalophenols, which are drinking water disinfection byproducts (DBPs) formed by chlorination or chloramination practices, can be biomethylated into trihalogenated anisoles. These latter compounds have traditionally been suspected of causing odor episodes in drinking water around the world. The odor threshold concentration (OTC) of mixed chlorobrominated anisoles, which were previously synthesized, was determined by flavor profile analysis (FPA) performed by an experienced panel trained to identify odors and tastes in water. The odor threshold amount (OTA) was evaluated by using a gas chromatograph equipped with olfactometry (GC-O) and electron capture detectors (ECD). FPA results for mixed chlorobromoanisoles gave a theoretical OTCs range from 2 to 30 ng/L, the 2,6-diBr-3Cl-anisole being the most odorous compound. Rubber is the general descriptor described by panelists for these compounds, although earthy and musty are the following most cited descriptors.

  14. [Odor Emission Characteristics from Biochemical Treatment Facilities of Kichen Waste in China].

    Science.gov (United States)

    Zhang, Yan; Wang, Yuan-gang; Lu, Zhi-qiang; Han, Meng; Shang, Xi-bin; Cao, Yan; Zhang, Jun

    2015-10-01

    Xining, Ningbo and Beijing were closen as the representative cities about biochemical treatment of kichen waste. The treatment facilities of these cities were investigated and set as the sampling points. The main compositions and the material contents were analyzed by GC/MS, the odor concertration was obtained by the Triangle odor bag method. The results showed that oxygenated hydrocarbons including alcohol, aldehyde, ketone, ester were higher than others in the odor gases, however, the largest contribution to odor pollution were sulfocompounds and the 2nd materials were terpenes; According to the research of the three enterprises, ethyl alcohol, limonene, sulfuretted hydrogen, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, acetaldehyde and ethyl acetate were likely to be considered as the typical odorants from the biochemical treatment facilities of kichen waste.

  15. Odor-Specific Habituation Arises from Interaction of Afferent Synaptic Adaptation and Intrinsic Synaptic Potentiation in Olfactory Cortex

    Science.gov (United States)

    Linster, Christiane; Menon, Alka V.; Singh, Christopher Y.; Wilson, Donald A.

    2009-01-01

    Segmentation of target odorants from background odorants is a fundamental computational requirement for the olfactory system and is thought to be behaviorally mediated by olfactory habituation memory. Data from our laboratory have shown that odor-specific adaptation in piriform neurons, mediated at least partially by synaptic adaptation between…

  16. Attractiveness of MM-X traps baited with human or synthetic odor to mosquitoes (Diptera: Culicidae) in The Gambia

    NARCIS (Netherlands)

    Qiu, Y.T.; Smallegange, R.C.; Braak, ter C.J.F.; Spitzen, J.; Loon, van J.J.A.; Jawara, M.; Milligan, P.; Galimard, A.M.S.; Beek, van T.A.; Knols, B.G.J.; Takken, W.

    2007-01-01

    Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to

  17. A conserved aspartic acid is important for agonist (VUAA1 and odorant/tuning receptor-dependent activation of the insect odorant co-receptor (Orco.

    Directory of Open Access Journals (Sweden)

    Brijesh N Kumar

    Full Text Available Insect odorant receptors function as heteromeric odorant-gated cation channels comprising a conventional odorant-sensitive tuning receptor, and a conserved co-receptor (Orco. An Orco agonist, VUAA1, is able to activate both heteromeric and homomeric Orco-containing channels. Very little is known about specific residues in Orco that contribute to cation permeability and gating. We investigated the importance of two conserved Asp residues, one in each of transmembrane domains 5 and 7, for channel function by mutagenesis. Drosophila melanogaster Orco and its substitution mutants were expressed in HEK cells and VUAA1-stimulated channel activity was determined by Ca(2+ influx and whole-cell patch clamp electrophysiology. Substitution of D466 in transmembrane 7 with amino acids other than glutamic acid resulted in a substantial reduction in channel activity. The D466E Orco substitution mutant was ~2 times more sensitive to VUAA1. The permeability of the D466E Orco mutant to cations was unchanged relative to wild-type Orco. When D466E Orco is co-expressed with a conventional tuning odorant receptor, the heteromeric complex also shows increased sensitivity to an odorant. Thus, the effect of the D466E mutation is not specific to VUAA1 agonism or dependent on homomeric Orco assembly. We suggest the gain-of-activation characteristic of the D466E mutant identifies an amino acid that is likely to be important for activation of both heteromeric and homomeric insect odorant receptor channels.

  18. A Conserved Aspartic Acid Is Important for Agonist (VUAA1) and Odorant/Tuning Receptor-Dependent Activation of the Insect Odorant Co-Receptor (Orco)

    Science.gov (United States)

    Kumar, Brijesh N.; Taylor, Robert W.; Pask, Gregory M.; Zwiebel, Laurence J.; Newcomb, Richard D.; Christie, David L.

    2013-01-01

    Insect odorant receptors function as heteromeric odorant-gated cation channels comprising a conventional odorant-sensitive tuning receptor, and a conserved co-receptor (Orco). An Orco agonist, VUAA1, is able to activate both heteromeric and homomeric Orco-containing channels. Very little is known about specific residues in Orco that contribute to cation permeability and gating. We investigated the importance of two conserved Asp residues, one in each of transmembrane domains 5 and 7, for channel function by mutagenesis. Drosophila melanogaster Orco and its substitution mutants were expressed in HEK cells and VUAA1-stimulated channel activity was determined by Ca2+ influx and whole-cell patch clamp electrophysiology. Substitution of D466 in transmembrane 7 with amino acids other than glutamic acid resulted in a substantial reduction in channel activity. The D466E Orco substitution mutant was ∼2 times more sensitive to VUAA1. The permeability of the D466E Orco mutant to cations was unchanged relative to wild-type Orco. When D466E Orco is co-expressed with a conventional tuning odorant receptor, the heteromeric complex also shows increased sensitivity to an odorant. Thus, the effect of the D466E mutation is not specific to VUAA1 agonism or dependent on homomeric Orco assembly. We suggest the gain-of-activation characteristic of the D466E mutant identifies an amino acid that is likely to be important for activation of both heteromeric and homomeric insect odorant receptor channels. PMID:23894621

  19. Experiential effects of appetitive and nonappetitive odors on feeding behavior in the blowfly, Phormia regina: a putative role for tyramine in appetite regulation.

    Science.gov (United States)

    Nisimura, Tomoyosi; Seto, Atsushi; Nakamura, Kyoko; Miyama, Mayumi; Nagao, Takashi; Tamotsu, Satoshi; Yamaoka, Ryohei; Ozaki, Mamiko

    2005-08-17

    In humans, appetite is affected by food experiences and food flavors. In the blowfly Phormia regina, we found that feeding threshold to sugar increased in the presence of the odor of D-limonene and decreased in the presence of the odor of dithiothreitol (DTT). Using these odors as representative nonappetitive and appetitive flavors, we demonstrated the role played by tyramine (TA) in appetite regulation by experiences of food flavors. When fed with sucrose flavored with D-limonene for 5 d after emergence, flies showed subsequent decreased appetite to plain sucrose, whereas when they were fed with sucrose flavored by DTT they showed increased appetite. However, mushroom body (MB)-ablated flies did not show these patterns. This suggests that MB, one of the primary memory centers of the insect brain, is necessary for the flies to apply previous experiences of food flavors to appetitive learning behaviors. In addition, flies' previously acquired decreased or increased appetites showed parallel changes with both octopamine (OA) and tyramine levels in the brain. However, injection experiments with OA, TA, or their agonist and antagonist indicated that TA more directly mediates feeding threshold determination, which was affected by acquired memories of food flavors.

  20. Workplace racial composition, perceived discrimination, and organizational attachment.

    Science.gov (United States)

    Stainback, Kevin; Irvin, Matthew

    2012-05-01

    Prior research has devoted considerable attention to the relationship between the racial and ethnic composition of jobs and various indicators of organizational attachment. Fewer studies, however, examine how workplace racial composition affects individuals' experiences of racial discrimination or how these experiences impact workers' organizational attachment. To address this lacuna, we first examine the effects of workplace racial composition on perceived racial and ethnic discrimination. Next, we examine whether perceived racial discrimination mediates the association between racial composition and organizational attachment observed in prior studies. Finally, we explore whether these relationships are similar (symmetric) or different (non-symmetric) for non-Whites and Whites. The analyses indicate: (1) working with predominately same-race coworkers tends to diminish perceptions of racial discrimination, (2) perceived racial discrimination mediates some of the effects of racial/ethnic composition on organizational attachment, and (3) some non-symmetric effects between non-Whites and Whites are found. We conclude with implications for future research.

  1. Value transfer contributes to ambiguous-cue discrimination learning.

    Science.gov (United States)

    Urcuioli, Peter J; Michalek, Sarah

    2007-08-01

    Pigeons learned two concurrent simultaneous discriminations in which the S- for one served as the S+ for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S- more often than the S+ on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S+ transfers to its companion S-, contributes to ambiguous-cue performances.

  2. A salty-congruent odor enhances saltiness: functional magnetic resonance imaging study.

    Science.gov (United States)

    Seo, Han-Seok; Iannilli, Emilia; Hummel, Cornelia; Okazaki, Yoshiro; Buschhüter, Dorothee; Gerber, Johannes; Krammer, Gerhard E; van Lengerich, Bernhard; Hummel, Thomas

    2013-01-01

    Excessive intake of dietary salt (sodium chloride) may increase the risk of chronic diseases. Accordingly, various strategies to reduce salt intake have been conducted. This study aimed to investigate whether a salty-congruent odor can enhance saltiness on the basis of psychophysical (Experiment 1) and neuroanatomical levels (Experiment 2). In Experiment 1, after receiving one of six stimulus conditions: three odor conditions (odorless air, congruent, or incongruent odor) by two concentrations (low or high) of either salty or sweet taste solution, participants were asked to rate taste intensity and pleasantness. In Experiment 2, participants received the same stimuli during the functional magnetic resonance imaging scan. In Experiment 1, compared with an incongruent odor and/or odorless air, a congruent odor enhanced not only taste intensity but also either pleasantness of sweetness or unpleasantness of saltiness. In Experiment 2, a salty-congruent combination of odor and taste produced significantly higher neuronal activations in brain regions associated with odor-taste integration (e.g., insula, frontal operculum, anterior cingulate cortex, and orbitofrontal cortex) than an incongruent combination and/or odorless air with taste solution. In addition, the congruent odor-induced saltiness enhancement was more pronounced in the low-concentrated tastant than in the high-concentrated one. In conclusion, this study demonstrates the congruent odor-induced saltiness enhancement on the basis of psychophysical and neuroanatomical results. These findings support an alternative strategy to reduce excessive salt intake by adding salty-congruent aroma to sodium reduced food. However, there are open questions regarding the salty-congruent odor-induced taste unpleasantness.

  3. Effects of odor familiarity on the development of systematic exploration in the spiny mouse, Acomys cahirinus.

    Science.gov (United States)

    Birke, L I; Sadler, D

    1987-11-01

    Developmental changes in patterns of exploration by infant spiny mice, Acomys cahirinus are described. These were investigated using an unbaited radial maze and under three odor conditions; that is, animals were tested in the presence of either familiar (own) odors, unfamiliar conspecific odors, or no odors (washed floor). Two hypotheses were tested. The first was based on the results of a pilot study, and was that adult animals would explore the radial maze in a systematic and predictable fashion tending to move from one arm to the next sequentially. It was hypothesized that infants would adopt this sequential strategy only gradually, as they matured. The second hypothesis was that such patterns of exploration would depend upon the olfactory environment; the presence of familiar odors might facilitate systematic patterns of exploration in very young Acomys. The results showed that both adults and juveniles were less likely to move sequentially when tested with no conspecific odor present; sequential patterns of movement were most likely in the presence of unfamiliar odor, however. The only significant change with age in infants was found for animals tested with unfamiliar odors; these animals showed a dramatic increase in sequential behavior between 3 and 7 days of age. Two additional experiments are reported, which investigated the preferences of infant Acomys for unfamiliar conspecific odors, and it was found that very young (about 3 days) animals exhibit a preference for odors derived from unfamiliar conspecific litters, even when tested in the physical presence of their own parents. The results are discussed with reference to the use of olfactory information as directional cues for animals exploring the radial maze.

  4. Illuminating odors: when optogenetics brings to light unexpected olfactory abilities

    Science.gov (United States)

    Grimaud, Julien

    2016-01-01

    For hundreds of years, the sense of smell has generated great interest in the world literature, oenologists, and perfume makers but less of scientists. Only recently this sensory modality has gained new attraction in neuroscience when original tools issued from physiology, anatomy, or molecular biology were available to decipher how the brain makes sense of olfactory cues. However, this move was promptly dampened by the difficulties of developing quantitative approaches to study the relationship between the physical characteristics of stimuli and the sensations they create. An upswing of olfactory investigations occurred when genetic tools could be used in combination with devices borrowed from the physics of light (a hybrid technique called optogenetics) to scrutinize the olfactory system and to provide greater physiological precision for studying olfactory-driven behaviors. This review aims to present the most recent studies that have used light to activate components of the olfactory pathway, such as olfactory receptor neurons, or neurons located further downstream, while leaving intact others brain circuits. With the use of optogenetics to unravel the mystery of olfaction, scientists have begun to disentangle how the brain makes sense of smells. In this review, we shall discuss how the brain recognizes odors, how it memorizes them, and how animals make decisions based on odorants they are capable of sensing. Although this review deals with olfaction, the role of light will be central throughout. PMID:27194792

  5. Biofiltration of odorous fume emitted from recycled nylon melting operations.

    Science.gov (United States)

    Chen, Kuan-Po; Chang, Hsiao-Yu; Chou, Ming-Shean

    2013-11-01

    This study aimed to develop a biofilter packed only with fern chips for the removal of odorous compounds from recycled nylon melting operations. The fern chip biofilters could avoid the shortcomings of traditional media, such as compaction, drying, and breakdown, which lead to the performance failure of the biofilters. A pilot-scale biofilter consisting of an acrylic column (14 cm2 x 120 cm height) packed with fern chips to a volume of around 19.6 L was used for the test. Experimental results indicate that oxygen- and nitrogen-containing hydrocarbons as well as paraffins were major volatile organic compounds (VOCs) emitted from thermal smelting of recycled nylon at 250 degrees C. With operation conditions of medium pH of 5.5-7.0, empty bed retention time (EBRT) of 6-12 sec, influent total hydrocarbon (THC) concentrations of 0.65-2.61 mg m(-3), and volumetric organic loading of 0.05-0.85 g m(-3) hr(-1), the fern-chip-packed biofilter with nutrients of milk, potassium dihydrogen phosphate, and glucose could achieve an overall THC removal efficiency of around 80%. Burnt odor emitted from the smelting of the recycled nylon could be eliminated by the biofilter.

  6. Identification and origin of odorous sulfur compounds in cooked ham.

    Science.gov (United States)

    Thomas, Caroline; Mercier, Frédéric; Tournayre, Pascal; Martin, Jean-Luc; Berdagué, Jean-Louis

    2014-07-15

    The aim of this work was to identify and gain further knowledge on the origin of sulfur compounds present in the volatile fraction of cooked ham, and on their role in the aroma of this product. To this end, we performed analyses by one- and two-dimensional gas chromatography coupled with mass spectrometry, and olfactometry. Among the odorant sulfur compounds identified, three furans present in trace amounts proved to have very intense odours responsible for the "meaty, cooked ham" notes of this pork product. They were 2-methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan and bis(2-methyl-3-furyl) disulphide. Addition of thiamine or cysteine also enabled us to study the effect of these odour precursors on the formation of odorant furans during the cooking of ham. The results revealed a direct link between the thermal degradation of thiamine and the formation of these compounds. By contrast, addition of cysteine in the presence of fructose or xylose did not appreciably increase their production.

  7. Odorous house ants (Tapinoma sessile) as back-seat drivers of localized ant decline in urban habitats.

    Science.gov (United States)

    Salyer, Adam; Bennett, Gary W; Buczkowski, Grzegorz A

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban 'invasion'. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a "back

  8. Discriminative Shape Alignment

    DEFF Research Database (Denmark)

    Loog, M.; de Bruijne, M.

    2009-01-01

    The alignment of shape data to a common mean before its subsequent processing is an ubiquitous step within the area shape analysis. Current approaches to shape analysis or, as more specifically considered in this work, shape classification perform the alignment in a fully unsupervised way......, not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two......-dimensional shapes from a two-class recognition problem....

  9. Mexico City air pollution adversely affects olfactory function and intranasal trigeminal sensitivity.

    Science.gov (United States)

    Guarneros, Marco; Hummel, Thomas; Martínez-Gómez, Margaríta; Hudson, Robyn

    2009-11-01

    Surprisingly little is known about the effects of big-city air pollution on olfactory function and even less about its effects on the intranasal trigeminal system, which elicits sensations like burning, stinging, pungent, or fresh and contributes to the overall chemosensory experience. Using the Sniffin' Sticks olfactory test battery and an established test for intranasal trigeminal perception, we compared the olfactory performance and trigeminal sensitivity of residents of Mexico City, a region with high air pollution, with the performance of a control population from the Mexican state of Tlaxcala, a geographically comparable but less polluted region. We compared the ability of 30 young adults from each location to detect a rose-like odor (2-phenyl ethanol), to discriminate between different odorants, and to identify several other common odorants. The control subjects from Tlaxcala detected 2-phenyl ethanol at significantly lower concentrations than the Mexico City subjects, they could discriminate between odorants significantly better, and they performed significantly better in the test of trigeminal sensitivity. We conclude that Mexico City air pollution impairs olfactory function and intranasal trigeminal sensitivity, even in otherwise healthy young adults.

  10. Hunger state affects both olfactory abilities and gustatory sensitivity.

    Science.gov (United States)

    Hanci, Deniz; Altun, Huseyin

    2016-07-01

    Chemical senses such as odor, taste and appearance are directly related with appetite. Understanding the relation between appetite and flavor is getting more important due to increasing number of obese patients worldwide. The literature on the studies investigating the change in olfactory abilities and gustatory sensitivity mostly performed using food-related odors and tastes rather than standardized tests were developed to study olfaction and gustation. Therefore, results are inconsistent and the relationship between olfactory and gustatory sensitivity with respect to the actual state of human satiety is still not completely understood. Here, for the first time in literature, we investigated the change in both olfactory abilities and gustatory sensitivity in hunger and in satiety using 123 subjects (37 men, 86 women; mean age 31.4 years, age range 21-41 years). The standardized Sniffin' Sticks Extended Test and Taste Strips were used for olfactory testing and gustatory sensitivity, respectively. TDI score (range 1-48) was calculated as the collective scores of odor threshold (T), odor discrimination (D) and odor identification (I). The evaluation was performed in two successive days where the hunger state of test subjects was confirmed by blood glucose test strips (mean blood glucose level 90.0 ± 5.6 mg/dl in hunger and 131.4 ± 8.1 mg/dl in satiety). The results indicated statistically significant decrease in olfaction in satiety compared to hunger (mean TDI 39.3 ± 1.1 in hunger, 37.4 ± 1.1 in satiety, p hunger (p satiety (p hunger state.

  11. The consequence of fetal ethanol exposure and adolescent odor re-exposure on the response to ethanol odor in adolescent and adult rats

    Directory of Open Access Journals (Sweden)

    Molina Juan C

    2009-01-01

    Full Text Available Abstract Background An epidemiologic predictive relationship exists between fetal ethanol exposure and the likelihood for adolescent use. Further, an inverse relationship exists between the age of first experience and the probability of adult abuse. Whether and how the combined effects of prenatal and adolescent ethanol experiences contribute to this progressive pattern remains unknown. Fetal ethanol exposure directly changes the odor attributes of ethanol important for both ethanol odor preference behavior and ethanol flavor perception. These effects persist only to adolescence. Here we tested whether adolescent ethanol odor re-exposure: (Experiment 1 augments the fetal effect on the adolescent behavioral response to ethanol odor; and/or (Experiment 2 perpetuates previously observed adolescent behavioral and neurophysiological responses into adulthood. Methods Pregnant rats received either an ethanol or control liquid diet. Progeny (observers experienced ethanol odor in adolescence via social interaction with a peer (demonstrators that received an intragastric infusion of either 1.5 g/kg ethanol or water. Social interactions were scored for the frequency that observers followed their demonstrator. Whole-body plethysmography evaluated the unconditioned behavioral response of observers to ethanol odor in adolescence (P37 or adulthood (P90. The olfactory epithelium of adults was also examined for its neural response to five odorants, including ethanol. Results Experiment 1: Relative to fetal or adolescent exposure alone, adolescent re-exposure enhanced the behavioral response to ethanol odor in P37 animals. Compared to animals with no ethanol experience, rats receiving a single experience (fetal or adolescent show an enhanced, yet equivalent, ethanol odor response. Fetal ethanol experience also increased olfactory-guided following of an intoxicated peer. Experiment 2: Combined exposure yielded persistence of the behavioral effects only in adult

  12. Genomic architecture of MHC-linked odorant receptor gene repertoires among 16 vertebrate species.

    Science.gov (United States)

    Santos, Pablo Sandro Carvalho; Kellermann, Thomas; Uchanska-Ziegler, Barbara; Ziegler, Andreas

    2010-09-01

    The recent sequencing and assembly of the genomes of different organisms have shown that almost all vertebrates studied in detail so far have one or more clusters of genes encoding odorant receptors (OR) in close physical linkage to the major histocompatibility complex (MHC). It has been postulated that MHC-linked OR genes could be involved in MHC-influenced mate choice, comprising both pre- as well as post-copulatory mechanisms. We have therefore carried out a systematic comparison of protein sequences of these receptors from the genomes of man, chimpanzee, gorilla, orangutan, rhesus macaque, mouse, rat, dog, cat, cow, pig, horse, elephant, opossum, frog and zebra fish (amounting to a total of 559 protein sequences) in order to identify OR families exhibiting evolutionarily conserved MHC linkage. In addition, we compared the genomic structure of this region within these 16 species, accounting for presence or absence of OR gene families, gene order, transcriptional orientation and linkage to the MHC or framework genes. The results are presented in the form of gene maps and phylogenetic analyses that reveal largely concordant repertoires of gene families, at least among tetrapods, although each of the eight taxa studied (primates, rodents, ungulates, carnivores, proboscids, marsupials, amphibians and teleosts) exhibits a typical architecture of MHC (or MHC framework loci)-linked OR genes. Furthermore, the comparison of the genomic organization of this region has implications for phylogenetic relationships between closely related taxa, especially in disputed cases such as the evolutionary history of even- and odd-toed ungulates and carnivores. Finally, the largely conserved linkage between distinct OR genes and the MHC supports the concept that particular alleles within a given haplotype function in a concerted fashion during self-/non-self-discrimination processes in reproduction.

  13. Transgenerational Consequences of Racial Discrimination for African American Health

    OpenAIRE

    Goosby, Bridget J.; Heidbrink, Chelsea

    2013-01-01

    Disparities in African American health remain pervasive and persist transgenerationally. There is a growing consensus that both structural and interpersonal racial discrimination are key mechanisms affecting African American health. The Biopsychosocial Model of Racism as a Stressor posits that the persistent stress of experiencing discrimination take a physical toll on the health of African Americans and is ultimately manifested in the onset of illness. However, the degree to which the health...

  14. Microbial diversity associated with odor modification for production of fertilizers from chicken litter.

    Science.gov (United States)

    Enticknap, Julie J; Nonogaki, Hirofumi; Place, Allen R; Hill, Russell T

    2006-06-01

    Litter from the chicken industry can present several environmental challenges, including offensive odors and runoff into waterways leading to eutrophication. An economically viable solution to the disposal of waste from chicken houses is treatment to produce a natural, granulated fertilizer that can be commercially marketed for garden and commercial use. Odor of the final product is important in consumer acceptance, and an earthy odor is desirable. By understanding and manipulating the microbial processes occurring during this process, it may be possible to modify the odors produced. Geosmin and related volatiles produced by soil actinomycetes are responsible for earthy odors, and actinomycetes are likely to be present in the composting manure. Bacterial communities at each stage of the process were analyzed by culturing studies and denaturing gradient gel electrophoresis (DGGE). The processing steps changed the culturable bacterial community, but the total community was shown by DGGE to be stable throughout the process. A local agricultural soil was analyzed in parallel as a potential source of geosmin-producing actinomycetes. This agricultural soil had higher microbial diversity than the compost at both the culturable and the molecular levels. Actinomycete bacteria were isolated and analyzed by AromaTrax, a gas chromatography-olfactometry system. This system enables the odor production of individual isolates to be monitored, allowing for rational selection of strains for augmentation experiments to improve the odor of the final fertilizer product.

  15. The Hydrodynamics and Odorant Transport Phenomena of Olfaction in the Hammerhead Shark

    Science.gov (United States)

    Rygg, Alex; Craven, Brent

    2013-11-01

    The hammerhead shark possesses a unique head morphology that is thought to facilitate enhanced olfactory performance. The olfactory organs, located at the distal ends of the cephalofoil, contain numerous lamellae that increase the surface area for olfaction. Functionally, for the shark to detect chemical stimuli, water-borne odors must reach the olfactory sensory epithelium that lines these lamellae. Thus, odorant transport from the aquatic environment to the sensory epithelium is the first critical step in olfaction. Here we investigate the hydrodynamics and odorant transport phenomena of olfaction in the hammerhead shark based on an anatomically-accurate reconstruction of the head and olfactory chamber from high-resolution micro-CT and MRI scans of a cadaver specimen. Computational fluid dynamics (CFD) simulations of water flow in the reconstructed model reveal the external and internal hydrodynamics of olfaction during swimming. Odorant transport in the olfactory organ is investigated using a multi-scale approach, whereby molecular dynamics (MD) simulations are used to calculate odorant partition coefficients that are subsequently utilized in macro-scale CFD simulations of odorant deposition. The hydrodynamic and odorant transport results are used to elucidate several important features of olfactory function in the hammerhead shark.

  16. Study of odor inside cars; Kuruma no nioi ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S.; Ito, H.; Sakakibara, K.; Kaitani, K.; Hamada, C. [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsuo, M. [Toyota Motor Corp., Aichi (Japan)

    1998-05-01

    This paper describes odor in automotive cabin. Odor of new cars is rapidly disappeared during the use. This is greatly due to the adaptation of olfaction. The generation of odor is also decreased. It was found that aliphatic and aromatic hydrocarbons were rapidly disappeared. Decrements of oxygen containing and sulfur compounds were low. For amines, high boiling amines increased after three months. The odor component from crews was derived from the exhalation. Trimethylamine, methyl sulfide as well as iso-prene were detected. They could be derived from tobacco smoke, perfume and hair conditioner. Exhaust gas of diesel vehicle going ahead is one of unpleasant odors from the running atmosphere. A correlation coefficient 0.77 was obtained between the stimulation and aldehyde/ketone. A correlation equation was deduced using stimulation, discomfort degree and odor characteristics as object variables and using logarithms of trace analysis values as explanation variables. There are still a lot of unknown issues concerning combined odors. 9 refs., 9 figs., 1 tab.

  17. Quantum Calculation for Musk Molecules Infrared Spectra towards the Understanding of Odor

    Directory of Open Access Journals (Sweden)

    Elaine Rose Maia

    2014-01-01

    Full Text Available It is not clear so far how humans can recognize odor. One of the theories regarding structure-odor relationship is vibrational theory, which claims that odors can be recognized by their modes of vibration. In this sense, this paper brings a novel comparison made between musky and nonmusky molecules, as to check the existence of correlation between their modes on the infrared spectra and odor. For this purpose, sixteen musky odorants were chosen, as well as seven other molecules that are structurally similar to them, but with no musk odor. All of them were submitted to solid theoretical methodology (using molecular mechanics/molecular dynamics and Neglect of Diatomic Differential Overlap Austin Model 1 methods to optimize geometries as to achieve density functional theory spectra information, with both Gradient Corrected Functional Perdew-Wang generalized-gradient approximation (GGA/PW91 and hybrid Becke, three-parameter, Lee-Yang-Parr (B3LYP functional. For a proper analysis over spectral data, a mathematical method was designed, generating weighted averages for theoretical frequencies and computing deviations from these averages. It was then devised that musky odorants satisfied demands of the vibrational theory, while nonmusk compounds belonging either to nitro group or to acyclic group failed to fulfill the same criteria.

  18. DoOR 2.0 - Comprehensive Mapping of Drosophila melanogaster Odorant Responses

    Science.gov (United States)

    Münch, Daniel; Galizia, C. Giovanni

    2016-02-01

    Odors elicit complex patterns of activated olfactory sensory neurons. Knowing the complete olfactome, i.e. the responses in all sensory neurons for all relevant odorants, is desirable to understand olfactory coding. The DoOR project combines all available Drosophila odorant response data into a single consensus response matrix. Since its first release many studies were published: receptors were deorphanized and several response profiles were expanded. In this study, we add unpublished data to the odor-response profiles for four odorant receptors (Or10a, Or42b, Or47b, Or56a). We deorphanize Or69a, showing a broad response spectrum with the best ligands including 3-hydroxyhexanoate, alpha-terpineol, 3-octanol and linalool. We include all of these datasets into DoOR, provide a comprehensive update of both code and data, and new tools for data analyses and visualizations. The DoOR project has a web interface for quick queries (http://neuro.uni.kn/DoOR), and a downloadable, open source toolbox written in R, including all processed and original datasets. DoOR now gives reliable odorant-responses for nearly all Drosophila olfactory responding units, listing 693 odorants, for a total of 7381 data points.

  19. Critical components of odors in evaluating the performance of food waste composting plants

    Energy Technology Data Exchange (ETDEWEB)

    Mao, I-F. [Institute of Environmental Health Sciences, National Yang-Ming University, No. 155, Sec.2, Li-Nong St., Beitou, Taipei, Taiwan (China)]. E-mail: ifmao@ym.edu.tw; Tsai, C.-J. [Institute of Environmental Health Sciences, National Yang-Ming University, No. 155, Sec.2, Li-Nong St., Beitou, Taipei, Taiwan (China); Shen, S.-H. [Department of Environment Management, Jin Wen Institute of Technology, No. 99, An-Chung Rd., Hsin-Tien City, Taipei, Taiwan (China); Lin, T.-F. [Institute of Environmental Engineering, National Cheng Kung University, No. 1, Ta-Hsueh Rd., Tainan, Taiwan (China); Chen, W.-K. [Department of Environment Management, Jin Wen Institute of Technology, No. 99, An-Chung Rd., Hsin-Tien City, Taipei, Taiwan (China); Chen, M.-L. [Institute of Environmental Health Sciences, National Yang-Ming University, No. 155, Sec.2, Li-Nong St., Beitou, Taipei, Taiwan (China)]. E-mail: mlchen@ym.edu.tw

    2006-11-01

    The current Taiwan government policy toward food waste management encourages composting for resource recovery. This study used olfactometry, gas chromatography-mass spectrometry (GC-MS) and gas detector tubes to evaluate the ambient air at three of the largest food waste composting plants in Taiwan. Ambient air inside the plants, at exhaust outlets and plant boundaries was examined to determine the comprehensive odor performance, critical components, and odor elimination efficiencies of various odor control engineering. Analytical results identified 29 compounds, including ammonia, amines, acetic acid, and multiple volatile organic compounds (VOCs) (hydrocarbons, ketones, esters, terpenes and S-compounds) in the odor from food waste composting plants. Concentrations of six components - ammonia, amines, dimethyl sulfide, acetic acid, ethyl benzene and p-Cymene - exceeded human olfactory thresholds. Ammonia, amines, dimethyl sulfide and acetic acid accounted for most odors compared to numerous VOCs. The results also show that the biotrickling filter was better at eliminating the concentrations of odor, NH{sub 3}, amines, S-compounds and VOCs than the chemical scrubber and biofilters. All levels measured by olfactometry at the boundaries of food waste composting plants (range, 74-115 Odor Concentration (OC)) exceeded Taiwan's EPA standard of 50 OC. This study indicated that the malodor problem continued to be a significant problem for food waste recovery.

  20. DoOR 2.0--Comprehensive Mapping of Drosophila melanogaster Odorant Responses.

    Science.gov (United States)

    Münch, Daniel; Galizia, C Giovanni

    2016-02-25

    Odors elicit complex patterns of activated olfactory sensory neurons. Knowing the complete olfactome, i.e. the responses in all sensory neurons for all relevant odorants, is desirable to understand olfactory coding. The DoOR project combines all available Drosophila odorant response data into a single consensus response matrix. Since its first release many studies were published: receptors were deorphanized and several response profiles were expanded. In this study, we add unpublished data to the odor-response profiles for four odorant receptors (Or10a, Or42b, Or47b, Or56a). We deorphanize Or69a, showing a broad response spectrum with the best ligands including 3-hydroxyhexanoate, alpha-terpineol, 3-octanol and linalool. We include all of these datasets into DoOR, provide a comprehensive update of both code and data, and new tools for data analyses and visualizations. The DoOR project has a web interface for quick queries (http://neuro.uni.kn/DoOR), and a downloadable, open source toolbox written in R, including all processed and original datasets. DoOR now gives reliable odorant-responses for nearly all Drosophila olfactory responding units, listing 693 odorants, for a total of 7381 data points.

  1. Crossmodal effect of music and odor pleasantness on olfactory quality perception

    Directory of Open Access Journals (Sweden)

    Carlos eVelasco

    2014-11-01

    Full Text Available Previous research has demonstrated that ratings of the perceived pleasantness and quality of odors can be modulated by auditory stimuli presented at around the same time. Here, we extend these results by assessing whether the hedonic congruence between odor and sound stimuli can modulate the perception of odor intensity, pleasantness, and quality in untrained participants. Unexpectedly, our results reveal that broadband white noise, which was rated as unpleasant in a follow-up experiment, actually had a more pronounced effect on participants’ odor ratings than either the consonant or dissonant musical selections. In particular, participants rated the six smells used as being less pleasant and less sweet when they happened to be listening to white noise, as compared to any one of the other music conditions. What is more, these results also add evidence to the existence a close relationship between an odor’s hedonic character and the perception of odor quality. So, for example, independent of the sound condition, pleasant odors were rated as sweeter, less dry, and brighter than the unpleasant odors. These results are discussed in terms of their implications for the understanding of crossmodal correspondences between olfactory and auditory stimuli.

  2. Dynamics of autonomic nervous system responses and facial expressions to odors

    Directory of Open Access Journals (Sweden)

    Wei eHe

    2014-02-01

    Full Text Available Why we like or dislike certain products may be better captured by physiological and behavioral measures of the autonomic nervous system than by conscious or classical sensory tests. Responses to pleasant and unpleasant food odors presented in varying concentrations were assessed continuously using facial expressions and responses of the autonomic nervous system (ANS. Results of 26 young and healthy female participants showed that the unpleasant fish odor triggered higher heart rates and skin conductance responses, lower skin temperature, fewer neutral facial expressions and more disgusted and angry expressions (p < .05. Neutral facial expressions differentiated between odors within 100 ms, after the start of the odor presentation followed by expressions of disgust (180 ms, anger (500 ms, surprised (580 ms, sadness (820 ms, scared (1020 ms, and happy (1780 ms (all p values < .05. Heart rate differentiated between odors after 400 ms, whereas skin conductance responses differentiated between odors after 3920 ms. At shorter intervals (between 520 and 1000 ms and between 2690 and 3880 ms skin temperature for fish was higher than that for orange, but became considerable lower after 5440 ms. This temporal unfolding of emotions in reactions to odors, as seen in facial expressions and physiological measurements supports sequential appraisal theories.

  3. Cyanotoxin mixtures and taste-and-odor compounds in cyanobacterial blooms from the midwestern united states

    Science.gov (United States)

    Graham, J.L.; Loftin, K.A.; Meyer, M.T.; Ziegler, A.C.

    2010-01-01

    The mixtures of toxins and taste-and-odor compounds present during cyanobacterial blooms are not well characterized and of particular concern when evaluating potential human health risks. Cyanobacterial blooms were sampled in twenty-three Midwestern United States lakes and analyzed for community composition, thirteen cyanotoxins by liquid chromatography/mass spectrometry and immunoassay, and two taste-and-odor compounds by gas chromatography/mass spectrometry. Aphanizomenon, Cylindrospermopsis and/or Microcystis were dominant in most (96%) blooms, but community composition was not strongly correlated with toxin and taste-and-odor occurrence. Microcystins occurred in all blooms. Total microcystin concentrations measured by liquid chromatography/mass spectrometry and immunoassay were linearly related (rs = 0.76, p Geosmin (87%), 2-methylisoborneol (39%), anatoxin-a (30%), saxitoxins (17%), cylindrospermopsins (9%), and nodularin-R (9%) also were present in these blooms. Multiple classes of cyanotoxins occurred in 48% of blooms and 95% had multiple microcystin variants. Toxins and taste-and-odor compounds frequently co-occurred (91% of blooms), indicating odor may serve as a warning that cyanotoxins likely are present. However, toxins occurred more frequently than taste-and-odor compounds, so odor alone does not provide sufficient warning to ensure human-health protection. ?? This article not subject to U.S. Copyright. Published 2010 by the American Chemical Society.

  4. Chemical evaluation of odor reduction by soil injection of animal manure.

    Science.gov (United States)

    Feilberg Tavs Nyord, Anders; Hansen, Martin Nørregaard; Lindholst, Sabine

    2011-01-01

    Field application of animal manure is a major cause of odor nuisance in the local environment. Therefore, there is a need for methods for measuring the effect of technologies for reducing odor after manure application. In this work, chemical methods were used to identify key odorants from field application of pig manure based on experiments with surface application by trailing hoses and soil injection. Results from three consecutive years of field trials with full-scale equipment are reported. Methods applied were: membrane inlet mass spectrometry (MIMS), proton-transfer-reaction mass spectrometry (PTR-MS), gold-film hydrogen sulfide (H₂S) detection, all performed on site, and thermal desorption gas chromatography with mass spectrometry (TD-GC/MS) based on laboratory analyses of field samples. Samples were collected from a static flux chamber often used for obtaining samples for dynamic olfactometry. While all methods were capable of detecting relevant odorants, PTR-MS gave the most comprehensive results. Based on odor threshold values, 4-methylphenol, H₂S, and methanethiol are suggested as key odorants. Significant odorant reductions by soil injection were consistently observed in all trials. The flux chamber technique was demonstrated to be associated with critical errors due to compound instabilities in the chamber. This was most apparent for H₂S, on a time scale of a few minutes, and on a longer time scale for methanethiol.

  5. Odor-active constituents in fresh pineapple (Ananas comosus [L.] Merr.) by quantitative and sensory evaluation.

    Science.gov (United States)

    Tokitomo, Yukiko; Steinhaus, Martin; Büttner, Andrea; Schieberle, Peter

    2005-07-01

    By application of aroma extract dilution analysis (AEDA) to an aroma distillate prepared from fresh pineapple using solvent-assisted flavor evaporation (SAFE), 29 odor-active compounds were detected in the flavor dilution (FD) factor range of 2 to 4,096. Quantitative measurements performed by stable isotope dilution assays (SIDA) and a calculation of odor activity values (OAVs) of 12 selected odorants revealed the following compounds as key odorants in fresh pineapple flavor: 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDF; sweet, pineapple-like, caramel-like), ethyl 2-methylpropanoate (fruity), ethyl 2-methylbutanoate (fruity) followed by methyl 2-methylbutanoate (fruity, apple-like) and 1-(E,Z)-3,5-undecatriene (fresh, pineapple-like). A mixture of these 12 odorants in concentrations equal to those in the fresh pineapple resulted in an odor profile similar to that of the fresh juice. Furthermore, the results of omission tests using the model mixture showed that HDF and ethyl 2-methylbutanoate are character impact odorants in fresh pineapple.

  6. Maternal status regulates cortical responses to the body odor of newborns

    Directory of Open Access Journals (Sweden)

    Johan N Lundström

    2013-09-01

    Full Text Available Studies in non-human mammals have identified olfactory signals as prime mediators of mother-infant bonding and they have been linked with maternal attitudes and behavior in our own species as well. However, although the neuronal network processing infant cues has been studied for visual and auditory signals; to date, no such information exists for chemosensory signals. We contrasted the cerebral activity underlying the processing of infant odor properties in 15 women newly given birth for the first time and 15 women not given birth while smelling the body odor of unfamiliar 2 day-old newborn infants. Maternal status-dependent activity was demonstrated in the thalamus when exposed to the body odor of a newly born infant. Subsequent regions of interest analyses indicated that dopaminergic neostriatal areas are active in maternal-dependent responses. Taken together, these data suggests that body odors from 2 day-old newborns elicit activation in reward-related cerebral areas in women, regardless of their maternal status. These tentative data suggests that certain body odors might act as a catalyst for bonding mechanisms and highlights the need for future research on odor-dependent mother-infant bonding using parametric designs controlling for biological saliency and general odor perception effects.

  7. Women Status and their Discrimination

    OpenAIRE

    PEŠKOVÁ, Pavlína

    2008-01-01

    My work deal with women status and their discrimination. Chapter one contains women status in different historical periods and development of their status to bigger equal with men. There is also written about present feminist trends. Chapter two is about women discrimination. There is about women´ job discrimination, job segregation according to gender and inequality in payment. There is also written about women status at home and unequal duties at home among family mates. Chapter three is ab...

  8. Discriminant Analysis on Land Grading

    Institute of Scientific and Technical Information of China (English)

    LIU Yaolin; HOU Yajuan

    2004-01-01

    This paper proposes the discriminant analysis on land grading after analyzing the common methods and discussing the Fisher's discriminant in detail. Actually this method deduces the dimension from multi to single, thus it makes the feature vectors in n-dimension change to a scalar, and use this scalar to classify samples. This paper illustrates the result by giving an example of the residential land grading by the discriminant analysis.

  9. In vivo identification of eugenol-responsive and muscone-responsive mouse odorant receptors.

    Science.gov (United States)

    McClintock, Timothy S; Adipietro, Kaylin; Titlow, William B; Breheny, Patrick; Walz, Andreas; Mombaerts, Peter; Matsunami, Hiroaki

    2014-11-19

    Our understanding of mammalian olfactory coding has been impeded by the paucity of information about the odorant receptors (ORs) that respond to a given odorant ligand in awake, freely behaving animals. Identifying the ORs that respond in vivo to a given odorant ligand from among the ∼1100 ORs in mice is intrinsically challenging but critical for our understanding of olfactory coding at the periphery. Here, we report an in vivo assay that is based on a novel gene-targeted mouse strain, S100a5-tauGFP, in which a fluorescent reporter selectively marks olfactory sensory neurons that have been activated recently in vivo. Because each olfactory sensory neuron expresses a single OR gene, multiple ORs responding to a given odorant ligand can be identified simultaneously by capturing the population of activated olfactory sensory neurons and using expression profiling methods to screen the repertoire of mouse OR genes. We used this in vivo assay to re-identify known eugenol- and muscone-responsive mouse ORs. We identified additional ORs responsive to eugenol or muscone. Heterologous expression assays confirmed nine eugenol-responsive ORs (Olfr73, Olfr178, Olfr432, Olfr610, Olfr958, Olfr960, Olfr961, Olfr913, and Olfr1234) and four muscone-responsive ORs (Olfr74, Olfr235, Olfr816, and Olfr1440). We found that the human ortholog of Olfr235 and Olfr1440 responds to macrocyclic ketone and lactone musk odorants but not to polycyclic musk odorants or a macrocyclic diester musk odorant. This novel assay, called the Kentucky in vivo odorant ligand-receptor assay, should facilitate the in vivo identification of mouse ORs for a given odorant ligand of interest.

  10. Aroma of Turmeric: Dependence on the Combination of Groups of Several Odor Constituents.

    Science.gov (United States)

    Hasegawa, Toshio; Nakatani, Kenta; Fujihara, Takashi; Yamada, Hideo

    2015-06-01

    Turmeric is a popular material that plays an important role in the flavor and fragrance industries. Although many compounds have been reported as components of turmeric, its aroma profile has not been clarified. Recently we have developed a new approach for evaluating the complex odors of materials based on recent research on the mechanism of odor recognition. Here we report the characteristic aroma properties of turmeric obtained through the investigation of its aroma profile. The hexane extract of turmeric had a turmeric-like odor, whereas the steam distillate of turmeric had a pungent, non-turmeric-like odor. We carried out bulb-to-bulb distillations of the extract and the steam distillate. For the hexane extract, two fractions with completely different odors were obtained. One was a high boiling point fraction (group A) with a turmeric-like odor, which consisted of ar-turmerone and β-turmerone as the main components, and the other was a low boiling point fraction (group B), which consisted of α-curcumene and β-sesquiphellandrene. In contrast, the bulb-to-bulb distillation of the steam distillate gave a fraction (group C) with a very different odor from groups A and B. Group C was composed of several kinds of alcohols that were not present in groups A and B. These results indicate that the group C fraction causes the different, pungent odor of the turmeric oil obtained by steam distillation. The variation in the aroma of turmeric depended on the combination of these three groups of odor constituents.

  11. Simultaneous Sampling of Flow and Odorants by Crustaceans can Aid Searches within a Turbulent Plume

    Directory of Open Access Journals (Sweden)

    Swapnil Pravin

    2013-12-01

    Full Text Available Crustaceans such as crabs, lobsters and crayfish use dispersing odorant molecules to determine the location of predators, prey, potential mates and habitat. Odorant molecules diffuse in turbulent flows and are sensed by the olfactory organs of these animals, often using a flicking motion of their antennules. These antennules contain both chemosensory and mechanosensory sensilla, which enable them to detect both flow and odorants during a flick. To determine how simultaneous flow and odorant sampling can aid in search behavior, a 3-dimensional numerical model for the near-bed flow environment was created. A stream of odorant concentration was released into the flow creating a turbulent plume, and both temporally and spatially fluctuating velocity and odorant concentration were quantified. The plume characteristics show close resemblance to experimental measurements within a large laboratory flume. Results show that mean odorant concentration and it’s intermittency, computed as dc/dt, increase towards the plume source, but the temporal and spatial rate of this increase is slow and suggests that long measurement times would be necessary to be useful for chemosensory guidance. Odorant fluxes measured transverse to the mean flow direction, quantified as the product of the instantaneous fluctuation in concentration and velocity, v’c’, do show statistically distinct magnitude and directional information on either side of a plume centerline over integration times of <0.5 s. Aquatic animals typically have neural responses to odorant and velocity fields at rates between 50 and 500 ms, suggesting this simultaneous sampling of both flow and concentration in a turbulent plume can aid in source tracking on timescales relevant to aquatic animals.

  12. 电子鼻在酱油气味识别中的应用%Application of Electronic Nose in Odor Recognition of Soy Sauce

    Institute of Scientific and Technical Information of China (English)

    俞慧红; 崔晓红; 刘平

    2016-01-01

    为了探索电子鼻对酱油识别的可行性,利用电子鼻并结合感官鉴评对5种不同品牌的酱油进行了分析。通过 PCA 分析,发现5种酱油之间气味存在一定的差别;通过 LDA 分析,发现电子鼻可以完全区分5种酱油的气味;通过 Loading 分析,发现2号传感器对第一主成分的贡献率最大。利用 PLS 分析法建立酱油感官评分的模型,发现模型可以很好地预测酱油的感官评分。综上所述,电子鼻可用于酱油气味的识别和分析。%In order to explore the feasibility of soy sauce,electronic nose and sensory evaluation are applied for the analysis of five different brands of soy sauce.By principal component analysis,it is found that there are some differences in the odor among the five kinds of soy sauce.By linear discrimination analysis,it is found that electronic nose can distinguish the odor of five kinds of soy sauce entirely.By loading analysis,it is found that the second sensor of electronic nose plays a main role in the first principal component.A model of sensory evaluation is established by the method of PLS,it is found that the model can predict the sensory evaluation of soy sauce well.In summary,the electronic nose can be used to identify and analyze the odor of soy sauce.

  13. How Far Does a Receptor Influence Vibrational Properties of an Odorant?

    DEFF Research Database (Denmark)

    Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob

    2016-01-01

    -assisted electron transfer reaction. We consider this controversy by studying the influence of a receptor on the vibrational properties of an odorant in atomistic details as the coupling between electronic degrees of freedom of the receptor and the vibrations of the odorant is the key parameter of the vibrationally......-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify...

  14. The (+)-cis- and (+)-trans-Olibanic Acids: Key Odorants of Frankincense.

    Science.gov (United States)

    Cerutti-Delasalle, Céline; Mehiri, Mohamed; Cagliero, Cecilia; Rubiolo, Patrizia; Bicchi, Carlo; Meierhenrich, Uwe J; Baldovini, Nicolas

    2016-10-24

    Frankincense (olibanum) is one of the oldest aromatic materials used by humans, but the key molecular constituents contributing to its characteristic odor remained unknown. Reported herein is the discovery that (1S,2S)-(+)-trans- and (1S,2R)-(+)-cis-2-octylcyclopropyl-1-carboxylic acids are highly potent and substantive odorants occurring in ppm amounts in all of the frankincense samples analyzed, even those showing radically different volatile compositions. These cyclopropyl-derived acids provide the very characteristic old churchlike endnote of the frankincense odor.

  15. Odor Control Test Report of the Urine Containment Bag (UCB) for Orion Utilization

    Science.gov (United States)

    Casper, Stephanie; Williams, Nichole M. M.

    2010-01-01

    The purpose of this report is to summarize the conclusions for the odor control test of the Urine Containment Bag (UCB), P/N SDD46107234-306 in an environment simulating a space craft capsule. JSC 65891, Odor Control Test Plan of the Urine Containment Bag (UCB) for Orion Utilization, documents the test plan. The details of the test set-up and data reduction are detailed in the WSTF test report for this test WSTF #10-44500, Odor Control Test Plan of the Urine Containment Bag (UCB) for Orion Utilization,. This document outlines the project conclusions and forward plans with regard to trash containment for Constellation.

  16. The Effects of Rotary Motion on Taste and Odor Ratings: Implications for Space Travel

    Science.gov (United States)

    1987-12-01

    Tereskova, in Vostok VI (1963), reported a reduced appetite for sweets and a desire for pungent food tastes. In Soyuz 26, Cosmonaut Gretchko found that...odorants used in the odor test Code Odo~r Source 1 BANANA Pentyl Butyrate 2362, lot 691-1d, Eastman, Rochester, N.Y. 2 BACON Imitation Bacon Flavor f-62 30...Givaudan Corp., 321 44th St., New York, N.Y., ESROLKO Div. 3 BEEF Imitation Beef Flavor 4452, McCormick & Co., Cockeysville,-Hd-., Industrial Div. 4

  17. Weight discrimination and bullying.

    Science.gov (United States)

    Puhl, Rebecca M; King, Kelly M

    2013-04-01

    Despite significant attention to the medical impacts of obesity, often ignored are the negative outcomes that obese children and adults experience as a result of stigma, bias, and discrimination. Obese individuals are frequently stigmatized because of their weight in many domains of daily life. Research spanning several decades has documented consistent weight bias and stigmatization in employment, health care, schools, the media, and interpersonal relationships. For overweight and obese youth, weight stigmatization translates into pervasive victimization, teasing, and bullying. Multiple adverse outcomes are associated with exposure to weight stigmatization, including depression, anxiety, low self-esteem, body dissatisfaction, suicidal ideation, poor academic performance, lower physical activity, maladaptive eating behaviors, and avoidance of health care. This review summarizes the nature and extent of weight stigmatization against overweight and obese individuals, as well as the resulting consequences that these experiences create for social, psychological, and physical health for children and adults who are targeted.

  18. Sulfuric odorous compounds emitted from pig-feeding operations

    Science.gov (United States)

    Kim, Ki Youn; Ko, Han Jong; Kim, Hyeon Tae; Kim, Yoon Shin; Roh, Young Man; Lee, Cheol Min; Kim, Hyun Soo; Kim, Chi Nyon

    The objective of the study was to quantify the concentration and emission levels of sulfuric odorous compounds emitted from pig-feeding operations. Five types of pig-housing rooms were studied: gestation, farrowing, nursery, growing and fattening rooms. The concentration range of sulfuric odorous compounds in these pig-housing rooms were 30-200 ppb for hydrogen sulfide (H 2S), 2.5-20 ppb for methyl mercaptan (CH 3SH), 1.5-12 ppb for dimethyl sulfide (DMS; CH 3SCH 3) and 0.5-7 ppb for dimethyl disulfide (DMDS; CH 3S 2CH 3), respectively. The emission rates of H 2S, CH 3SH, DMS and DMDS were estimated by multiplying the average concentration (mg m -3) measured near the air outlet by the mean ventilation rate (m 3 h -1) and expressed either per area (mg m -2 h -1) or animal unit (AU; liveweight of the pig, 500 kg) (mg pig -1 h -1). As a result, the emission rates of H 2S, CH 3SH, DMS and DMDS in the pig-housing rooms were 14-64, 0.8-7.3, 0.4-3.4 and 0.2-1.9 mg m -2 h -1, respectively, based on pig's activity space and 310-723, 18-80, 9-39 and 5-22 mg AU -1 h -1, respectively, based on pig's liveweight, which indicates that their emission rates were similar, whether based upon the pig's activity space or liveweight. In conclusion, the concentrations and emission rates of H 2S were highest in the fattening room followed by the growing, nursery, farrowing and gestation rooms whereas those of CH 3SH, DMS and DMDS concentrations were largest in the growing room followed by the nursery, gestation and farrowing rooms.

  19. Treatment of odorous volatile fatty acids using a biotrickling filter.

    Science.gov (United States)

    Tsang, Y F; Chua, H; Sin, S N; Chan, S Y

    2008-02-01

    In this study, a novel fibrous bioreactor was developed for treating odorous compounds present in contaminated air. The first stage of this work was a preliminary study which aimed at investigating the feasibility of using the fibrous bioreactor for the removal of malodorous volatile fatty acids (VFA) that is a common odorous contaminant generated from anaerobic degradation of organic compounds. The kinetics of microbial growth and VFA degradation in the selected culture, and the performance of the submerged bioreactor at different VFA mass loadings were studied. Above 95% of VFA removal efficiencies were achieved at mass loadings up to 22.4 g/m(3)/h. In the second stage, the odour treatment process was scaled up with system design and operational considerations. A trickling biofilter with synthetic fibrous packing medium was employed. The effects of inlet VFA concentration and empty bed retention time (EBRT) on the process performance were investigated. The bioreactor was effective in removing VFA at mass loadings up to 32 g/m(3)/h, beyond which VFA started to accumulate in the recirculation liquid, indicating the biofilm was unable to degrade all of the VFA introduced. Although VFA accumulated in the liquid phase, the removal efficiency remained above 99%. This suggested that the biochemical reaction rather than gas-liquid mass transfer was the limiting step of the treatment process. In addition, the biotrickling filter was stable for long-term operation with relatively low and steady pressure drop, no clogging and degeneration of the packing material occurred during the four-month study.

  20. Attracting, trapping and killing disease-transmitting mosquitoes using odor-baited stations - The Ifakara Odor-Baited Stations

    Science.gov (United States)

    2010-01-01

    Background To accelerate efforts towards control and possibly elimination of mosquito-borne diseases such as malaria and lymphatic filariasis, optimally located outdoor interventions could be used to complement existing intradomicilliary vector control methods such as house spraying with insecticides and insecticidal bednets. Methods We describe a new odor-baited station for trapping, contaminating and killing disease-transmitting mosquitoes. This device, named the 'Ifakara Odor-baited Station' (Ifakara OBS), is a 4 m3 hut-shaped canvas box with seven openings, two of which may be fitted with interception traps to catch exiting mosquitoes. It is baited with synthetic human odors and may be augmented with contaminants including toxic insecticides or biological agents. Results In field trials where panels of fabric were soaked in 1% pirimiphos-methyl solution and suspended inside the Ifakara OBS, at least 73.6% of Anopheles arabiensis, 78.7% of Culex and 60% of Mansonia mosquitoes sampled while exiting the OBS, died within 24 hours. When used simply as a trap and evaluated against two existing outdoor traps, Ifakara Tent trap and Mosquito Magnet-X®, the OBS proved more efficacious than the Ifakara Tent trap in catching all mosquito species found (P < 0.001). Compared to the Mosquito Magnet-X®, it was equally efficacious in catching An. arabiensis (P = 0.969), but was less efficacious against Culex (P < 0.001) or Mansonia species (P < 0.001). Conclusion The Ifakara OBS is efficacious against disease-carrying mosquitoes including the malaria vector, An. arabiensis and Culicine vectors of filarial worms and arboviruses. It can be used simultaneously as a trap and as a contamination or killing station, meaning most mosquitoes which escape trapping would leave when already contaminated and die shortly afterwards. This technique has potential to complement current vector control methods, by targeting mosquitoes in places other than human dwellings, but its effectiveness