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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. Are odorant-binding proteins involved in odorant discrimination?

    Science.gov (United States)

    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. PMID:8985600

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

    OpenAIRE

    Allen, Caroline; Havlíček, Jan; Roberts, S. Craig

    2015-01-01

    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...

  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. 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.

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

    Science.gov (United States)

    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. PMID:25912271

  12. Discriminating parts from the whole: determinants of odor mixture perception in squirrel monkeys, Saimiri sciureus.

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    Laska, M; Hudson, R

    1993-08-01

    In a task designed to simulate olfactory-guided foraging, the ability of squirrel monkeys to discriminate an artificial 12-component odorant from 3-, 6-, 9- or 11-component submixtures was investigated. A combination of factors was found to contribute to the animals' performance: 1. Discriminability generally decreased as the number of components in the submixture increased. 2. Submixtures did not contribute equally to mixture perception, and one component in particular (cineole) disproportionately influenced stimulus discriminability. 3. Interactive effects between submixtures resulted in marked deviations from the general pattern of discriminability. 4. Changes in the relative concentration of submixtures could also influence discriminability. 5. Finally, individual differences in responsiveness to particular stimuli were apparent. These findings demonstrate that the interaction between components in odor mixtures can be complex and that seemingly small changes in composition can strongly affect perception and thus potential signal function. It is therefore suggested that in future investigations of squirrel monkey semiochemistry, the method of systematically varying submixtures may be particularly useful in defining the contribution of components to a signal. PMID:8410741

  13. 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.

  14. Effects of Vomeronasal Organ Removal on Olfactory Sex Discrimination and Odor Preferences of Female Ferrets

    OpenAIRE

    Woodley, S.K.; Cloe, A.L.; Waters, P; Baum, M.J.

    2004-01-01

    Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-operated control (VNOi) females reliably discriminated between male- and female-derived anal scent gland as well as fresh urina...

  15. Implicit and Explicit Measurements of Affective Responses to Food Odors.

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    He, Wei; de Wijk, René A; de Graaf, Cees; Boesveldt, Sanne

    2016-10-01

    One of the main functions of olfaction is to activate approach/avoidance behavior, toward or away from people, foods, or other odor sources. These behaviors are partly automated and therefore poorly accessible via introspection. Explicit tests need therefore be complemented by implicit tests to provide additional insights into the underlying processes of these behaviors. Affective responses to seven food odors plus one control nonodor were assessed in 28 female participants (18-30 years) using explicit tests [pleasantness, intensity, and non-verbal emotional ratings (PrEmo)] as well as implicit tests that reflect dynamic expressive emotional reactions (facial expressions) as well as behavioral-preparation responses (autonomic nervous system responses: heart rate, skin conductance, and skin temperature). Explicit tests showed significant differences in pleasantness (P emotions (P emotional responses were summarized by valence (explaining 83% of the responses variance) and arousal (14%) as principal components. Early implicit facial and ANS responses (after 1s) seem to reflect the odors' arousal, whereas later ANS responses (after 3-4s) reflected the odors' valence. The results suggest that explicit measures primarily reflect the odors' valence, as result of from relatively long (conscious) processing, which may be less relevant for odor acceptance in the real world where fast and automated processes based on arousal may play a larger role. PMID:27340136

  16. Effects of vomeronasal organ removal on olfactory sex discrimination and odor preferences of female ferrets.

    Science.gov (United States)

    Woodley, S K; Cloe, A L; Waters, P; Baum, M J

    2004-10-01

    Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-operated control (VNOi) females reliably discriminated between male- and female-derived anal scent gland as well as fresh urinary odors in habituation/dishabituation tests. However, VNOi females spent significantly more time than VNOx subjects investigating male urinary odors in these tests. Also, VNOi females, but not VNOx subjects, preferred to investigate day-old male versus female urine spots as well as wooden blocks that had previously been soiled by male versus female ferrets. Both groups of female ferrets preferred to approach volatile odors from a breeding male instead of an estrous female in Y-maze tests and both groups showed similar levels of receptive sexual behavior in response to a male's neck grip. The VNO is apparently not required for olfactory sex discrimination or mate recognition in this carnivore, but instead may play a role in promoting continued contact with nonvolatile body odors previously deposited by opposite-sex conspecifics during territorial scent marking. PMID:15466811

  17. Applying medicinal chemistry strategies to understand odorant discrimination

    OpenAIRE

    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...

  18. Neuronal pattern separation in the olfactory bulb improves odor discrimination learning

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    Lagier, Samuel; Begnaud, Frédéric; Rodriguez, Ivan; Carleton, Alan

    2015-01-01

    Neuronal pattern separation is thought to enable the brain to disambiguate sensory stimuli with overlapping features thereby extracting valuable information. In the olfactory system, it remains unknown whether pattern separation acts as a driving force for sensory discrimination and the learning thereof. Here we show that overlapping odor-evoked input patterns to the mouse olfactory bulb (OB) are dynamically reformatted in the network at the timescale of a single breath, giving rise to separated patterns of activity in ensemble of output neurons (mitral/tufted cells; M/T). Strikingly, the extent of pattern separation in M/T assemblies predicts behavioral discrimination performance during the learning phase. Furthermore, exciting or inhibiting GABAergic OB interneurons, using optogenetics or pharmacogenetics, altered pattern separation and thereby odor discrimination learning in a bidirectional way. In conclusion, we propose that the OB network can act as a pattern separator facilitating olfactory stimuli distinction, a process that is sculpted by synaptic inhibition. PMID:26301325

  19. A Discriminant Distance Based Composite Vector Selection Method for Odor Classification

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    Sang-Il Choi

    2014-04-01

    Full Text Available We present a composite vector selection method for an effective electronic nose system that performs well even in noisy environments. Each composite vector generated from a electronic nose data sample is evaluated by computing the discriminant distance. By quantitatively measuring the amount of discriminative information in each composite vector, composite vectors containing informative variables can be distinguished and the final composite features for odor classification are extracted using the selected composite vectors. Using the only informative composite vectors can be also helpful to extract better composite features instead of using all the generated composite vectors. Experimental results with different volatile organic compound data show that the proposed system has good classification performance even in a noisy environment compared to other methods.

  20. 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.

  1. 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

  2. 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.

  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. Rats assess degree of relatedness from human odors.

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    Ables, Erin M; Kay, Leslie M; Mateo, Jill M

    2007-04-23

    Despite widespread interest in the evolutionary implications of human olfactory communication, the mechanisms underlying human odor production are still poorly understood. Previous studies have demonstrated that human odor cues are related to variations in the major histocompatibility complex, but it is unclear whether odors are associated with overall genotypic variation. In this study, we investigated whether more closely related humans produce more similar odor cues. To assess objective odor qualities we tested odor similarity using rats in a habituation-discrimination paradigm. Rats were first habituated to a referent human odor and were then presented with two test odors obtained from individuals related in different degrees to the referent. Investigation times for each odor were compared. Because rats investigate novel odors longer than familiar odors, we were able to determine which test odor the rats perceived as more similar to the referent human odor. For six of ten odor donor families, rats investigated the odor of the less closely related individual significantly longer than that of the more closely related individual, and investigation durations were in the expected direction for all families. These results indicate that similarity of human odor cues is associated with degree of genetic relatedness, with more closely related humans producing more similar odor cues. This study supports the hypothesis that odor cues provide information regarding degree of relatedness and may thus affect a wide variety of human behaviors, including kin preferences, nepotism, and mate choice. PMID:17261318

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

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    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.

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

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    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.

  7. Sexual odor discrimination and physiological profiles in adult male rats after a neonatal, short term, reversible nasal obstruction.

    Science.gov (United States)

    Thornton, S N; Padzys, G S; Trabalon, M

    2014-05-01

    The present study was designed to examine behavioral responses (interpreted as preferences) to olfactory cues (nest bedding odor and odors of estrous and anestrus females) in adult male rats after they had a short term reversible, bilateral, nasal obstruction (RbNO) as developing rat pups. These results were compared to behavior of control (untreated) and sham operated male littermates. Behavioral tests and physiological parameters were analyzed 90 days after recovery of nasal breathing. Experiments investigated the time spent in arms or the center of a maze of male rats in response to odors from the nest bedding or from adult females. There were no differences in responses between untreated, sham and RbNO adult male rats to fresh and nest bedding odors. RbNO males spent more time in the center of the maze when given a choice of estrus or anestrus female odors, or bedding odors from untreated or sham operated female rats. In contrast untreated and sham male rats preferred the odors of estrous females and of untreated or sham females. Plasma corticosterone levels in the males increased during the behavioral tests. Plasma testosterone levels were significantly lower in RbNO males compared to untreated males and did not increase during the behavioral tests compared to sham operated males. Males from all groups had similar preferences for the odor of bedding from adult RbNO females. Plasma levels of cholesterol and triglycerides were increased in RbNO adults. In conclusion, short term nasal obstruction in males while juvenile has long term consequences on hormones and behavioral preferences, thus potential partner selection when adult. PMID:24769524

  8. Amount of ingested custard dessert as affected by its color, odor, and texture

    NARCIS (Netherlands)

    Wijk, R.A. de; Polet, I.A.; Engelen, L.; Doorn, R.M. van; Prinz, J.F.

    2004-01-01

    The effects of nonoral sensations, such as visual texture and odor, on the size of the first bite were investigated in a series of studies using specially constructed food delivery cups with lower, from which custards were ingested ("ingested custard"), and upper, from which a custard was viewed and

  9. Alcohol Binding to the Odorant Binding Protein LUSH: Multiple Factors Affecting Binding Affinities

    OpenAIRE

    Ader, Lauren; Jones, David N. M.; Lin, Hai

    2010-01-01

    Density function theory (DFT) calculations have been carried out to investigate the binding of alcohols to the odorant binding protein LUSH from Drosophila melanogaster. LUSH is one of the few proteins known to bind to ethanol at physiologically relevant concentrations and where high-resolution structural information is available for the protein bound to alcohol at these concentrations. The structures of the LUSH–alcohol complexes identify a set of specific hydrogen-bonding interactions as cr...

  10. 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.

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

    Science.gov (United States)

    Thomas-Danguin, Thierry; Sinding, Charlotte; Romagny, Sébastien; El Mountassir, Fouzia; Atanasova, Boriana; Le Berre, Elodie; Le Bon, Anne-Marie; Coureaud, Gérard

    2014-01-01

    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. PMID:24917831

  12. 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.

  13. Breath odor

    Science.gov (United States)

    Bad breath; Halitosis ... Some disorders will produce distinct breath odors. Bad breath related to poor oral hygiene is most common and caused by release of sulphur compounds by bacteria in the mouth. A fruity odor ...

  14. 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.

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

    Science.gov (United States)

    Lee, Chien-Cheng; Huang, Shin-Sheng; Shih, Cheng-Yuan

    2010-12-01

    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.

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

    OpenAIRE

    Lee Chien-Cheng; Huang Shin-Sheng; Shih Cheng-Yuan

    2010-01-01

    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 RD...

  17. Discrimination and evocation of affectively intoned speech in patients with right parietal disease.

    Science.gov (United States)

    Tucker, D M; Watson, R T; Heilman, K M

    1977-10-01

    Patients with right parietal disease have disturbed comprehension of affective speech. Ability to discriminate affective speech (make same/different discriminations) and ability to repeat emotionally bland sentences with affective tones were tested in three groups of subjects--patients with right parietal dysfunction and neglect, conduction aphasics with left hemispheric lesions, and patients without intracranial disease. Patients with right parietal dysfunction performed significantly poorer than did aphasic controls on both a recognition and discrimination task. Patients with right parietal dysfunction also scored poorer on the evocative task than the nonaphasic controls. PMID:561908

  18. Hedonic appreciation and verbal description of pleasant and unpleasant odors in untrained, trainee cooks, flavorists and perfumers

    Directory of Open Access Journals (Sweden)

    Caroline eSezille

    2014-01-01

    Full Text Available Olfaction is characterized by a salient hedonic dimension. Previous studies have shown that these affective responses to odors are modulated by physicochemical, physiological and cognitive factors. The present study examined expertise influenced processing of pleasant and unpleasant odors on both perceptual and verbal levels. For this, performance on 2 olfactory tasks was compared between novices, trainee cooks and experts (perfumers and flavorists: members of all groups rated the intensity and pleasantness of pleasant and unpleasant odors (perceptual tasks. They were also asked to describe each of the 20 odorants as precisely as possible (verbal description task. On a perceptual level, results revealed that there were no group-related differences in hedonic ratings for unpleasant and pleasant odors. On a verbal level, descriptions of smells were richer (e.g. chemical, olfactory qualities and olfactory sources terms and did not refer to pleasantness in experts compared to untrained subjects who used terms referring to odor sources (e.g. candy accompanied by terms referring to odor hedonics. In conclusion, the present study suggests that as novices, experts are able to perceptually discriminate odors on the basis of their pleasantness. However, on a semantic level, they conceptualize odors differently, being inclined to avoid any reference to odor hedonics.

  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. The odor of a plant metabolite affects life history traits in dietary restricted adult olive flies.

    Science.gov (United States)

    Gerofotis, Christos D; Ioannou, Charalampos S; Nakas, Christos T; Papadopoulos, Nikos T

    2016-01-01

    Food quality shapes life history traits either directly or through response of individuals to additional environmental factors, such as chemical cues. Plant extracts used as food additives modulate key life history traits; however little is known regarding such effects for olfactory chemical cues. Exploiting an interesting experimental system that involves the olive fly (Bactrocera oleae) and the plant metabolite α-pinene we asked whether exposure of adults to this compound modulates adult longevity and female reproduction in similar manner in a stressful - dietary (protein) restricted (DR) and in a relaxed- full diet (FD) feeding environment. Accordingly, we exposed males and females to the aroma of α-pinene and measured lifespan and age-specific fecundity in the above two dietary contexts. Our results demonstrate that exposure to α-pinene increased longevity in males and fecundity in females only under dietary restricted conditions. In relaxed food conditions, females exposed to α-pinene shifted high egg-laying towards younger ages compared to non-exposed ones. This is the first report demonstrating that a plant compound affects key life history traits of adult olive flies through olfaction. These effects are sex-specific and more pronounced in dietary restricted adults. Possible underlying mechanisms and the ecological significance are discussed. PMID:27339862

  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. 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.

  4. Olfactory sensitivity for six predator odorants in CD-1 mice, human subjects, and spider monkeys.

    Directory of Open Access Journals (Sweden)

    Amir Sarrafchi

    Full Text Available 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.

  5. Breath odor

    Science.gov (United States)

    ... distinct breath odors. Bad breath related to poor oral hygiene is most common and caused by release of ... supplements? Do you smoke? What home care and oral hygiene measures have you tried? How effective are they? ...

  6. 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.

  7. 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.

  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. The relation between modeled odor exposure from livestock farming and odor annoyance among neighboring residents in the Netherlands.

    OpenAIRE

    Boers, D; Geelen, L; Erbrink, H.; Smit, L A M; Heederik, D; Hooiveld, M; Yzermans, C.J.; Huijbergts, M.; Wouters, I.M.

    2016-01-01

    Purpose: Odor annoyance is an important environmental stressor for neighboring residents of livestock farms and may affect their quality of life and health. However, little is known about the relation between odor exposure due to livestock farming and odor annoyance. Even more, the relation between odor exposure and odor annoyance is rather complicated due to variable responses among individuals to comparable exposure levels and a large number of factors (such as age, gender, education) that ...

  10. Use of fuzzy logic models for prediction of taste and odor compounds in algal bloom-affected inland water bodies.

    Science.gov (United States)

    Bruder, Slawa; Babbar-Sebens, Meghna; Tedesco, Lenore; Soyeux, Emmanuel

    2014-03-01

    Mechanistic modeling of how algal species produce metabolites (e.g., taste and odor compounds geosmin and 2-methyl isoborneol (2-MIB)) as a biological response is currently not well understood. However, water managers and water utilities using these reservoirs often need methods for predicting metabolite production, so that appropriate water treatment procedures can be implemented. In this research, a heuristic approach using Adaptive Network-based Fuzzy Inference System (ANFIS) was developed to determine the underlying nonlinear and uncertain quantitative relationship between observed cyanobacterial metabolites (2-MIB and geosmin), various algal species, and physical and chemical variables. The model is proposed to be used in conjunction with numerical water quality models that can predict spatial-temporal distribution of flows, velocities, water quality parameters, and algal functional groups. The coupling of the proposed metabolite model with the numerical water quality models would assist various utilities which use mechanistic water quality models to also be able to predict distribution of taste and odor metabolites, especially when monitoring of metabolites is limited. The proposed metabolite model was developed and tested for the Eagle Creek Reservoir in Indiana (USA) using observations over a 3-year period (2008-2010). Results show that the developed models performed well for geosmin (R (2) = 0.83 for all training data and R (2) = 0.78 for validation of all 10 data points in the validation dataset) and reasonably well for the 2-MIB (R (2) = 0.82 for all training data and R (2) = 0.70 for 7 out of 10 data points in the validation dataset). PMID:24242080

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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. PMID:27047324

  17. 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.

  18. 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.

  19. The Influence of Trigeminal Stimulation on Children's Judgements of Odor.

    Science.gov (United States)

    Engen, Trygg; Moskowitz, Linda

    Children's preference for odors, some of which presumably had marked trigeminal (noxious) effects, was assessed with the use of the method of pair comparison. Although the children, from 4 to 7 years old, were able to discriminate between the intensities of the odors, they were neither attracted nor repelled by them as much as the adults. In other…

  20. Canine detection odor signatures for explosives

    Science.gov (United States)

    Williams, Marc; Johnston, J. M.; Cicoria, Matt; Paletz, E.; Waggoner, L. Paul; Edge, Cindy C.; Hallowell, Susan F.

    1998-12-01

    Dogs are capable of detecting and discriminating a number of compounds constituting a complex odor. However, they use only a few of these to recognize a substance. The focus of this research is to determine the compounds dogs learn to use in recognizing explosives. This is accomplished by training dogs under behavioral laboratory conditions to respond differentially on separate levers to 1) blank air, 2) a target odor, such as an explosive, and 3) all other odors (non-target odors). Vapor samples are generated by a serial dilution vapor generator whose operation and output is characterized by GC/MS. Once dogs learn this three-lever discrimination, testing sessions are conducted containing a number of probe trials in which vapor from constituent compounds of the target is presented. Which lever the dogs respond to on these probe trials indicates whether they can smell the compound at all (blank lever) or whether it smells like toe target odor (e.g., the explosive) or like something else. This method was conducted using TNT, C-4, and commercial dynamite. The data show the dogs' reactions to each of the constituent compounds tested for each explosive. Analysis of these data reveal the canine detection odor signature for these explosives.

  1. 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

  2. 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…

  3. 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.

  4. 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.

  5. Classification of odorants across layers in locust olfactory pathway.

    Science.gov (United States)

    Sanda, Pavel; Kee, Tiffany; Gupta, Nitin; Stopfer, Mark; Bazhenov, Maxim

    2016-05-01

    Olfactory processing takes place across multiple layers of neurons from the transduction of odorants in the periphery, to odor quality processing, learning, and decision making in higher olfactory structures. In insects, projection neurons (PNs) in the antennal lobe send odor information to the Kenyon cells (KCs) of the mushroom bodies and lateral horn neurons (LHNs). To examine the odor information content in different structures of the insect brain, antennal lobe, mushroom bodies and lateral horn, we designed a model of the olfactory network based on electrophysiological recordings made in vivo in the locust. We found that populations of all types (PNs, LHNs, and KCs) had lower odor classification error rates than individual cells of any given type. This improvement was quantitatively different from that observed using uniform populations of identical neurons compared with spatially structured population of neurons tuned to different odor features. This result, therefore, reflects an emergent network property. Odor classification improved with increasing stimulus duration: for similar odorants, KC and LHN ensembles reached optimal discrimination within the first 300-500 ms of the odor response. Performance improvement with time was much greater for a population of cells than for individual neurons. We conclude that, for PNs, LHNs, and KCs, ensemble responses are always much more informative than single-cell responses, despite the accumulation of noise along with odor information. PMID:26864765

  6. 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.

  7. 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…

  8. 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.

  9. 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…

  10. 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. PMID:26648891

  11. 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.

  12. Host plant odors represent immiscible information entities - blend composition and concentration matter in hawkmoths.

    Directory of Open Access Journals (Sweden)

    Anna Späthe

    Full Text Available Host plant choice is of vital importance for egg laying herbivorous insects that do not exhibit brood care. Several aspects, including palatability, nutritional quality and predation risk, have been found to modulate host preference. Olfactory cues are thought to enable host location. However, experimental data on odor features that allow choosing among alternative hosts while still in flight are not available. It has previously been shown that M. sexta females prefer Datura wrightii compared to Nicotiana attenuata. The bouquet of the latter is more intense and contains compounds typically emitted by plants after feeding-damage to attract the herbivore's enemies. In this wind tunnel study, we offered female gravid hawkmoths (Manduca sexta odors from these two ecologically relevant, attractive, non-flowering host species. M. sexta females preferred surrogate leaves scented with vegetative odors form both host species to unscented control leaves. Given a choice between species, females preferred the odor bouquet emitted by D. wrightii to that of N. attenuata. Harmonizing, i.e. adjusting, volatile intensity to similar levels did not abolish but significantly weakened this preference. Superimposing, i.e. mixing, the highly attractive headspaces of both species, however, abolished discrimination between scented and non-scented surrogate leaves. Beyond ascertaining the role of blend composition in host plant choice, our results raise the following hypotheses. (i The odor of a host species is perceived as a discrete odor 'Gestalt', and its core properties are lost upon mixing two attractive scents (ii. Stimulus intensity is a secondary feature affecting olfactory-based host choice (iii. Constitutively smelling like a plant that is attracting herbivore enemies may be part of a plant's strategy to avoid herbivory where alternative hosts are available to the herbivore.

  13. 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.

  14. Silencing the odorant receptor co-receptor RproOrco affects the physiology and behavior of the Chagas disease vector Rhodnius prolixus.

    Science.gov (United States)

    Franco, Thiago A; Oliveira, Daniele S; Moreira, Monica F; Leal, Walter S; Melo, Ana C A

    2016-02-01

    Olfaction is one of the main sensory modalities that allow insects to interpret their environment. Several proteins, including odorant-binding proteins (OBPs) and odorant receptors (ORs), are involved in this process. Odorant receptors are ion channels formed by a binding unit OR and an odorant receptor co-receptor (Orco). The main goal of this study was to characterize the Orco gene of Rhodnius prolixus (RproOrco) and to infer its biological functions using gene silencing. The full-length RproOrco gene sequence was downloaded from VectorBase. This gene has 7 introns and is located in the genome SuperContig GL563069: 1,017,713-1,023,165. RproOrco encodes a protein of 473 amino acids, with predicted 7 transmembrane domains, and is highly expressed in the antennae during all R. prolixus developmental stages. The RNAi technique effectively silenced RproOrco, reducing the gene's expression by approximately 73%. Interestingly, the effect of gene silencing persisted for more than 100 days, indicating a prolonged effect of dsRNA that was maintained even after molting. The phenotypic effects of silencing involved the following: (1) loss of the ability to find a vertebrate host in a timely manner, (2) decreased ingested blood volume, (3) delayed and decreased molt rate, (4) increased mortality rate, and (5) decreased egg laying. Our data strongly suggest that dsOrco disrupts R. prolixus host-finding behavior, which is further reflected in the blood ingestion, molting, mortality, and egg laying data. This study clearly demonstrates that Orco is an excellent target for controlling triatomine populations. Thus, the data presented here open new possibilities for the control of vector-borne diseases. PMID:25747010

  15. Optimization of the Odor Microclimate

    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...

  16. Consumer Information and Price Discrimination: Does the Internet Affect the Pricing of New Cars to Women and Minorities?

    OpenAIRE

    Fiona Scott Morton; Florian Zettelmeyer; Jorge Silva-Risso

    2001-01-01

    Mediating transactions through the Internet removes important cues that salespeople can use to assess a consumer's willingness to pay. We analyze whether dealers' difficulty in identifying consumer characteristics on the Internet and consumers' ease in finding information affect race and gender discrimination in car retailing. Using a large dataset of transaction prices for new automobiles, the first part of the paper analyzes the relationship between car prices and demographics. We find that...

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

    Directory of Open Access Journals (Sweden)

    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

  18. 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…

  19. 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

  20. Effectiveness of predator odors as gray squirrel repellents

    OpenAIRE

    Rosell, Frank

    2001-01-01

    The ability of gray squirrels (Sciurus carolinensis) to discriminate between different predator odors and the use of predator odors to deter gray squirrels from foraging on plants have not been previously investigated. To test the hypothesis that predator scent decreases foraging, I investigated the effect of such scent on consumption of butternuts (Juglans cinerea) in the field. Results showed that (i) red fox (Vulpes vulpes) scent was significantly more effective than either a control or hu...

  1. Simple circular odor chart for characterization of trace amounts of odorants discharged from thirteen odor sources

    Energy Technology Data Exchange (ETDEWEB)

    Hoshika, Y.; Nihei, Y.; Muto, G.

    1981-04-01

    A simple circular odor chart is proposed for the explanation of the relationship between sensory responses (to odor quality and intensity) to odors and chemical analysis data of the odorants responsible for each odor discharged from thirteen odor sources. The odorants were classified into eight odorant groups and were analyzed by a systematic gas chromatographic (GC) technique. The characterization of the trace amounts of the odorants was carried out by using the values of a new proposed unit (pOU) based on the ratio of detected concentration to recognition threshold value. The calculated pOU values of the eight groups were plotted in circular charts. It was found that the shape and size of each circular odor chart represent the quality and the intensity of each odor.

  2. 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.

  3. 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.

  4. 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.

  5. 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. PMID:27148138

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Odors pulsed at wing beat frequencies are tracked by primary olfactory networks and enhance odor detection

    Directory of Open Access Journals (Sweden)

    Shreejoy Tripathy

    2010-03-01

    Full Text Available Each down stroke of an insect’s wings accelerates axial airflow over the antennae. Modeling studies suggest that this can greatly enhance penetration of air and air-born odorants through the antennal sensilla thereby periodically increasing odorant-receptor interactions. Do these periodic changes result in entrainment of neural responses in the antenna and antennal lobe (AL? Does this entrainment affect olfactory acuity? To address these questions, we monitored antennal and AL responses in the moth Manduca sexta while odorants were pulsed at frequencies from 10-72 Hz, encompassing the natural wingbeat frequency. Power spectral density (PSD analysis was used to identify entrainment of neural activity. Statistical analysis of PSDs indicates that the antennal nerve tracked pulsed odor up to 30 Hz. Furthermore, at least 50% of AL local field potentials (LFPs and between 7-25% of unitary spiking responses also tracked pulsed odor up to 30 Hz in a frequency-locked manner. Application of bicuculline (200µM abolished pulse tracking in both LFP and unitary responses suggesting that GABAA receptor activation is necessary for pulse tracking within the AL. Finally, psychophysical measures of odor detection establish that detection thresholds are lowered when odor is pulsed at 20 Hz. These results suggest that AL networks can respond to the oscillatory dynamics of stimuli such as those imposed by the wing beat in a manner analogous to mammalian sniffing.

  12. An Artificial Neural Networks-Based on-Line Monitoring Odor Sensing System

    Directory of Open Access Journals (Sweden)

    Yousif A. Bastaki

    2009-01-01

    Full Text Available Problem statement: There have been many works for odor recognition using different sensor arrays and pattern recognition techniques in last decades. Approach: Although an odor is usually recorded utilizing language expression, it is too difficult for laymen to associate actual odor with that expression. Results: 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. Conclusion/Recommendations: In this study, we have developed odor sensing system with the capability of the discrimination among closely similar 20 different odor patterns and proposed an on-line classification method using a handheld odor meter (OMX-GR sensor and neural network.

  13. 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.

  14. 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. PMID:24904081

  15. Humans can Discriminate more than one Trillion Olfactory Stimuli

    OpenAIRE

    Bushdid, C.; Magnasco, M. O.; Vosshall, L. B.; Keller, A.

    2014-01-01

    Humans can discriminate several million different colors and almost half a million different tones, but the number of discriminable olfactory stimuli remains unknown. The lay and scientific literature typically claims that humans can discriminate 10,000 odors, but this number has never been empirically validated. Here, we determined the resolution of the human sense of smell by testing the capacity of humans to discriminate odor mixtures with varying numbers of shared components. Based on the...

  16. 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.

  17. 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. PMID:21849606

  18. 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.

  19. 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 ...

  20. Canine detection odor signatures for mine-related explosives

    Science.gov (United States)

    Johnston, James M.; Williams, Marc; Waggoner, L. Paul; Edge, Cindy C.; Dugan, Regina E.; Hallowell, Susan F.

    1998-09-01

    Dogs are capable of detecting and discriminating a number of compounds constituting a complex odor. However, they use only a few of these to recognize a substance. The focus of this research is to determine the compounds dogs learn to use in recognizing explosives used in land mines. This is accomplished by training dogs under behavioral laboratory conditions to respond differentially on separate levers to (1) blank air, (2) a target odor such as an explosive, and (3) all other odors (non-target odors). Vapor samples are generated by a serial dilution vapor generator whose operation and output is characterized by GC/MS. Once dogs learn this three-lever discrimination, testing sessions are conducted containing a number of probe trials in which vapor from constituent compounds is presented. Which lever the dogs respond to on these probe trials indicates whether they can smell the compound at all (blank lever) or whether it smells like the target odor (e.g., the explosive) or like something else. This method was conducted using TNT and C-4. The data show the dogs' reactions to each of the constituent compounds tested for each explosive. Analysis of these data reveal the canine detection odor signature for these explosives.

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. Fancy Citrus, Feel Good: Positive Judgment of Citrus Odor, but Not the Odor Itself, Is Associated with Elevated Mood during Experienced Helplessness.

    Science.gov (United States)

    Hoenen, Matthias; Müller, Katharina; Pause, Bettina M; Lübke, Katrin T

    2016-01-01

    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 < 0.001), 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 = 0.019). 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. PMID:26869973

  7. 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

    2016-01-01

    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. PMID:27130519

  8. 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.

  9. Vomeronasal organ lesion disrupts social odor recognition, behaviors and fitness in golden hamsters.

    Science.gov (United States)

    Liu, Yingjuan; Zhang, Jinhua; Liu, Dingzhen; Zhang, Jianxu

    2014-06-01

    Most studies support the viewpoint that the vomeronasal organ has a profound effect on conspecific odor recognition, scent marking and mating behavior in the golden hamster (Mesocricetus auratus). However, the role of the vomeronasal organ in social odor recognition, social interaction and fitness is not well understood. Therefore, we conducted a series of behavioral and physiological tests to examine the referred points in golden hamster. We found that male hamsters with vomeronasal organ lesion showed no preference between a predator odor (the anal gland secretion of the Siberian weasels (Mustela sibirica) and putative female pheromone components (myristic acid and palmitic acid), but were still able to discriminate between these 2 kinds of odors. In behavioral tests of anxiety, we found that vomeronasal organ removal causes female hamsters to spend much less time in center grids and to cross fewer center grids and males to make fewer crossings between light and dark boxes than sham-operated controls. This indicates that a chronic vomeronasal organ lesion induced anxious responses in females. In aggressive behavioral tests, we found that a chronic vomeronasal organ lesion decreased agonistic behavior in female hamsters but not in males. The pup growth and litter size show no differences between the 2 groups. All together, our data suggested that vomeronasal organ ablation disrupted the olfactory recognition of social chemosignals in males, and induced anxiety-like and aggressive behavior changes in females. However, a vomeronasal organ lesion did not affect the reproductive capacity and fitness of hamsters. Our studies may have important implications concerning the role of the vomeronasal organ in golden hamsters and also in rodents. PMID:24952966

  10. 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.

  11. The workings of homonormativity: lesbian, gay, bisexual, and queer discourses on discrimination and public displays of affections in Portugal.

    Science.gov (United States)

    de Oliveira, João Manuel; Costa, Carlos Gonçalves; Nogueira, Conceição

    2013-01-01

    This article analyzes how heteronormative discourse may be (re)produced by the very same people it serves to oppress, binding heteronormativity to a specific form of homonormativity. Furthermore, this article also links Portuguese history and society by discussing the context and the recent legal changes that led to legislation providing for same-sex marriage. Using thematic analysis of 14 interviews, this article demonstrates how heteronorms are upheld in the discourses of the lesbian, gay, bisexual, and queer (LGBQ) participants. Themes linked to public displays of affection and discrimination emerged from the interviews. Participant discourses are analyzed in terms of their incorporation of heteronorms. Homonormativity is present in both the themes subject to analysis. Analysis of the interviews shows how transgressing the heteronorm implies costs and is ultimately perceived as a personal risk. This article concludes that the lack of discursive resistance denies the possibility of re-signification and subversion even in LGBQ discourses. This clearly indicates the pervasiveness of discourses reiterating heteronorms, even those issued by those most oppressed by such norms. PMID:24059969

  12. 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.

  13. 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…

  14. 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.

  15. Differential odor processing in two olfactory pathways in the honeybee.

    Science.gov (United States)

    Yamagata, Nobuhiro; Schmuker, Michael; Szyszka, Paul; Mizunami, Makoto; Menzel, Randolf

    2009-01-01

    An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN). Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons) of two types of PNs - lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentration, which may be optimized for fine, concentration-invariant odor discrimination. In mPN boutons, however, we found clear rising concentration dependence, broader tuning profiles at a high concentration, which may be optimized for concentration coding. In addition, we found more mixture suppression in lPNs than in mPNs, indicating lPNs better adaptation for synthetic mixture processing. These results suggest a functional division of odor processing in both PN types. PMID:20198105

  16. Differential odor processing in two olfactory pathways in the honeybee

    Directory of Open Access Journals (Sweden)

    Nobuhiro Yamagata

    2009-12-01

    Full Text Available An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN. Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons of two types of PNs - lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentration, which may be optimized for fine, concentration-invariant odor discrimination. In mPN boutons, however, we found clear rising concentration dependence, broader tuning profiles at a high concentration, which may be optimized for concentration coding. In addition, we found more mixture suppression in lPNs than in mPNs, indicating lPNs better adaptation for synthetic mixture processing. These results suggest a functional division of odor processing in both PN types.

  17. 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.

  18. Numerical simulations of odorant detection by biologically inspired sensor arrays.

    Science.gov (United States)

    Schuech, R; Stacey, M T; Barad, M F; Koehl, M A R

    2012-03-01

    The antennules of many marine crustaceans enable them to rapidly locate sources of odorant in turbulent environmental flows and may provide biological inspiration for engineered plume sampling systems. A substantial gap in knowledge concerns how the physical interaction between a sensing device and the chemical filaments forming a turbulent plume affects odorant detection and filters the information content of the plume. We modeled biological arrays of chemosensory hairs as infinite arrays of odorant flux-detecting cylinders and simulated the fluid flow around and odorant flux into the hair-like sensors as they intercepted a single odorant filament. As array geometry and sampling kinematics were varied, we quantified distortion of the flux time series relative to the spatial shape of the original odorant filament as well as flux metrics that may be important to both organisms and engineered systems attempting to measure plume structure and/or identify chemical composition. The most important predictor of signal distortion is the ratio of sensor diameter to odorant filament width. Achieving high peak properties (e.g. sharpness) of the flux time series and maximizing the total number of odorant molecules detected appear to be mutually exclusive design goals. Sensor arrays inspired specifically by the spiny lobster Panulirus argus and mantis shrimp Gonodactylaceus falcatus introduce little signal distortion but these species' neural systems may not be able to resolve plume structure at the level of individual filaments via temporal properties of the odorant flux. Current chemical sensors are similarly constrained. Our results suggest either that the spatial distribution of flux across the aesthetasc array is utilized by P. argus and G. falcatus, or that such high spatiotemporal resolution is unnecessary for effective plume tracking. PMID:22155966

  19. 77 FR 22381 - Odorant Fade in Railroad Tank Cars

    Science.gov (United States)

    2012-04-13

    ... Federal Railroad Administration Odorant Fade in Railroad Tank Cars AGENCY: Federal Railroad Administration... odorant during the transportation cycle (commonly known as ``odorant fade''). This safety advisory... odorization standards and procedures, and take appropriate actions to guard against odorant fade in...

  20. 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.

  1. 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.

  2. Odorant Normative Data for Use in Olfactory Memory Experiments: Dimension Selection and Analysis of Individual Differences.

    Science.gov (United States)

    Moss, Andrew G; Miles, Christopher; Elsley, Jane V; Johnson, Andrew J

    2016-01-01

    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. PMID:27605921

  3. 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

  4. DETERMINATION OF HENRY'S LAW CONSTANTS OF ODOROUS CONTAMINANTS AND THEIR APPLICATION TO HUMAN PERCEPTION

    OpenAIRE

    Omur, Pinar

    2004-01-01

    Although utilities attempt to avoid offensive smelling compounds in consumer's drinking water, their efforts are often hampered by a lack of data or knowledge of the physical, chemical, and sensory properties of odorants. Many factors affect the ability of a consumer to detect odors, including: concentration, presence of chlorine/other odorants, temperature, and the individual's sensitivity. This research developed a simplified static-headspace technique to determine Henry's Law constants...

  5. 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. PMID:23685976

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Behavioral responses to odors from other species: introducing a complementary model of allelochemics involving vertebrates

    Directory of Open Access Journals (Sweden)

    Birte L Nielsen

    2015-06-01

    Full Text Available It has long been known that the behavior of an animal can be affected by odors from another species. Such interspecific effects of odorous compounds (allelochemics are usually characterized according to who benefits (emitter, receiver, or both and the odors categorized accordingly (allomones, kairomones, and synomones, respectively, which has its origin in the definition of pheromones, i.e. intraspecific communication via volatile compounds. When considering vertebrates, however, interspecific odor-based effects exist which do not fit well in this paradigm. Three aspects in particular do not encompass all interspecific semiochemical effects: one relates to the innateness of the behavioral response, another to the origin of the odor, and the third to the intent of the message. In this review we focus on vertebrates, and present examples of behavioral responses of animals to odors from other species with specific reference to these three aspects. Searching for a more useful classification of allelochemical effects we examine the relationship between the valence of odors (attractive through to aversive, and the relative contributions of learned and unconditioned (innate behavioral responses to odors from other species. We propose that these two factors (odor valence and learning may offer an alternative way to describe the nature of interspecific olfactory effects involving vertebrates compared to the current focus on who benefits.

  11. 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. PMID:22226622

  12. 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.

  13. Olfactory preference conditioning changes the reward value of reinforced and non-reinforced odors

    Directory of Open Access Journals (Sweden)

    Nicolas eTorquet

    2014-07-01

    Full Text Available Olfaction is a determinant for the organization of rodent behavior. In a feeding context, rodents must quickly discriminate whether a nutrient can be ingested or whether it represents a potential danger to them. To understand the learning processes that support food choice, aversive olfactory learning and flavor appetitive learning have been extensively studied. In contrast, little is currently known about olfactory appetitive learning and its mechanisms. We designed a new paradigm to study conditioned olfactory preference in rats. After 8 days of exposure to a pair of odors (one paired with sucrose and the other with water, rats developed a strong and stable preference for the odor associated with the sucrose solution. A series of experiments were conducted to further analyze changes in reward value induced by this paradigm for both stimuli. As expected, the reward value of the reinforced odor changed positively. Interestingly, the reward value of the alternative odor decreased. This devaluation had an impact on further odor comparisons that the animal had to make. This result suggests that appetitive conditioning involving a comparison between two odors not only leads to a change in the reward value of the reinforced odor, but also induces a stable devaluation of the non-reinforced stimulus.

  14. Olfactory preference conditioning changes the reward value of reinforced and non-reinforced odors

    Science.gov (United States)

    Torquet, Nicolas; Aimé, Pascaline; Messaoudi, Belkacem; Garcia, Samuel; Ey, Elodie; Gervais, Rémi; Julliard, A. Karyn; Ravel, Nadine

    2014-01-01

    Olfaction is determinant for the organization of rodent behavior. In a feeding context, rodents must quickly discriminate whether a nutrient can be ingested or whether it represents a potential danger to them. To understand the learning processes that support food choice, aversive olfactory learning and flavor appetitive learning have been extensively studied. In contrast, little is currently known about olfactory appetitive learning and its mechanisms. We designed a new paradigm to study conditioned olfactory preference in rats. After 8 days of exposure to a pair of odors (one paired with sucrose and the other with water), rats developed a strong and stable preference for the odor associated with the sucrose solution. A series of experiments were conducted to further analyze changes in reward value induced by this paradigm for both stimuli. As expected, the reward value of the reinforced odor changed positively. Interestingly, the reward value of the alternative odor decreased. This devaluation had an impact on further odor comparisons that the animal had to make. This result suggests that appetitive conditioning involving a comparison between two odors not only leads to a change in the reward value of the reinforced odor, but also induces a stable devaluation of the non-reinforced stimulus. PMID:25071486

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

    NARCIS (Netherlands)

    Schreuder, Eliane; Hoeksma, Marco R.; Smeets, Monique A M; Semin, Gün 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

  16. Still Eating Despite Decreased Olfactory Pleasure-The Influence of Odor Liking and Wanting on Food Intake.

    Science.gov (United States)

    Sailer, Uta; Triscoli, Chantal; Croy, Ilona

    2016-07-01

    Typically, the subjective pleasantness of an odor decreases after it has been repeatedly smelled. This study investigates how the pleasantness ("liking") and the wish to be further exposed to the same odor ("wanting") are affected by variety on a longer time scale, and how they relate to actual food intake. Twenty-five participants rated a coconut odor presented 120 times for its liking and wanting before being offered coconut sweets. The amount eaten was assessed. Individual patterns of change were described by fitting 3 different models to the ratings. To study effects of variety on odor evaluation, the ratings were compared with a previous study where coconut was 1 of 3 odors presented in an alternating way. Initially, both liking and wanting the odors were high, but decreased over repetitions in 75% of the subjects. About 40% of all subjects showed an exponential change of ratings, 40% a step-like change, and 20% a linear change. Food intake was not related to the pattern of change in the ratings. Moreover, decreased olfactory pleasure did not seem to affect eating behavior. However, participants who rated the coconut odor higher at the beginning ate twice as many sweets as the others. Odor variety did not affect the experienced pleasure of smelling (liking), but did affect the motivation to experience the same smell again (wanting). This has not been reported for food or touch stimulation and may be specific for the perception of odors. PMID:26976121

  17. Could humans recognize odor by phonon assisted tunneling?

    CERN Document Server

    Brookes, J C; Horsfield, A P; Stoneham, A M; Brookes, Jennifer C.; Hartoutsiou, Filio

    2006-01-01

    Our sense of smell relies on sensitive, selective atomic-scale processes that are initiated when a scent molecule meets specific receptors in the nose. However, the physical mechanisms of detection are not clear. While odorant shape and size are important, experiment indicates these are insufficient. One novel proposal suggests inelastic electron tunneling from a donor to an acceptor mediated by the odorant actuates a receptor, and provides critical discrimination. We test the physical viability of this mechanism using a simple but general model. Using values of key parameters in line with those for other biomolecular systems, we find the proposed mechanism is consistent both with the underlying physics and with observed features of smell, provided the receptor has certain general properties. This mechanism suggests a distinct paradigm for selective molecular interactions at receptors (the swipe card model): recognition and actuation involve size and shape, but also exploit other processes.

  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. Masera's organ responds to odorants.

    Science.gov (United States)

    Marshall, D A; Maruniak, J A

    1986-02-26

    Electroolfactogram (EOG) recordings from the rat septal olfactory organ (SO) provide the first demonstration of its broad-range chemosensitivity, and clearly establish this structure as a functioning component of the mammalian intranasal chemosensory system. SO sensitivity to lower concentrations of at least one common test odorant (pentyl acetate) exceeds that at sites located on the septal portion of the main olfactory neuroepithelium. Signals from the SO, as first proposed, thus could have an alerting function and provide information relevant to odor stimulus assessment. PMID:3697687

  20. 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.

  1. 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.

  2. 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

    2014-01-01

    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. PMID:25106739

  3. 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. PMID:25106739

  4. Affectivity

    OpenAIRE

    Stenner, Paul; Greco, Monica

    2013-01-01

    The concept of affectivity has assumed central importance in much recent scholarship, and many in the social sciences and humanities now talk of an ‘affective turn’. The concept of affectivity at play in this ‘turn’ remains, however, somewhat vague and slippery. Starting with Silvan Tomkins’ influential theory of affect, this paper will explore the relevance of the general assumptions (or ‘utmost abstractions’) that inform thinking about affectivity. The technological and instrumentalist char...

  5. 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.

  6. Space Takes Time: Concentration Dependent Output Codes from Primary Olfactory Networks Rapidly Provide Additional Information at Defined Discrimination Thresholds.

    Directory of Open Access Journals (Sweden)

    Kevin C Daly

    2016-01-01

    Full Text Available As odor concentration increases, primary olfactory network representations expand in spatial distribution, temporal complexity and duration. However, the direct relationship between concentration dependent odor representations and the psychophysical thresholds of detection and discrimination is poorly understood. This relationship is absolutely critical as thresholds signify transition points whereby representations become meaningful to the organism. Here, we matched stimulus protocols for psychophysical assays and intracellular recordings of antennal lobe projection neurons in the moth Manduca sexta to directly compare psychophysical thresholds and the output representations they elicit. We first behaviorally identified odor detection and discrimination thresholds across an odor dilution series for a panel of structurally similar odors. We then characterized spatiotemporal spiking patterns across a population of individually filled and identified antennal lobe projection neurons in response to those odors at concentrations below, at, and above identified thresholds. Using spatial and spatiotemporal based analyses we observed that each stimulus produced unique representations, even at sub-threshold concentrations. Mean response latency did not decrease and the percent glomerular activation did not increase with concentration until undiluted odor. Furthermore, correlations between spatial patterns for odor decreased, but only significantly with undiluted odor. Using time-integrated Euclidean distance measures, we determined that added spatiotemporal information was present at the discrimination but not detection threshold. This added information was evidenced by an increase in integrated distance between the sub-detection and discrimination threshold concentrations (of the same odor that was not present in comparison of the sub-detection and detection threshold. After consideration of delays for information to reach the AL we find that it takes

  7. Space Takes Time: Concentration Dependent Output Codes from Primary Olfactory Networks Rapidly Provide Additional Information at Defined Discrimination Thresholds.

    Science.gov (United States)

    Daly, Kevin C; Bradley, Samual; Chapman, Phillip D; Staudacher, Erich M; Tiede, Regina; Schachtner, Joachim

    2015-01-01

    As odor concentration increases, primary olfactory network representations expand in spatial distribution, temporal complexity and duration. However, the direct relationship between concentration dependent odor representations and the psychophysical thresholds of detection and discrimination is poorly understood. This relationship is absolutely critical as thresholds signify transition points whereby representations become meaningful to the organism. Here, we matched stimulus protocols for psychophysical assays and intracellular recordings of antennal lobe (AL) projection neurons (PNs) in the moth Manduca sexta to directly compare psychophysical thresholds and the output representations they elicit. We first behaviorally identified odor detection and discrimination thresholds across an odor dilution series for a panel of structurally similar odors. We then characterized spatiotemporal spiking patterns across a population of individually filled and identified AL PNs in response to those odors at concentrations below, at, and above identified thresholds. Using spatial and spatiotemporal based analyses we observed that each stimulus produced unique representations, even at sub-threshold concentrations. Mean response latency did not decrease and the percent glomerular activation did not increase with concentration until undiluted odor. Furthermore, correlations between spatial patterns for odor decreased, but only significantly with undiluted odor. Using time-integrated Euclidean distance (ED) measures, we determined that added spatiotemporal information was present at the discrimination but not detection threshold. This added information was evidenced by an increase in integrated distance between the sub-detection and discrimination threshold concentrations (of the same odor) that was not present in comparison of the sub-detection and detection threshold. After consideration of delays for information to reach the AL we find that it takes ~120-140 ms for the AL to

  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. Elaborated Odor Test for Extended Exposure

    Science.gov (United States)

    Buchanan, Vanessa D.; Henry, Emily J.; Mast, Dion J.; Harper, Susana A.; Beeson, Harold D.; Tapia, Alma S.

    2016-01-01

    Concerns were raised when incidental exposure to a proprietary bonding material revealed the material had an irritating odor. The NASA-STD-6001B document describes a supplemental test method option for programs to evaluate materials with odor concerns (Test 6, Odor Assessment). In addition to the supplemental standard odor assessment with less than 10 seconds of exposure, the NASA White Sands Test Facility (WSTF) Materials Flight Acceptance Testing section was requested to perform an odor test with an extended duration to evaluate effects of an extended exposure and to more closely simulate realistic exposure scenarios. With approval from the NASA Johnson Space Center Industrial Hygienist, WSTF developed a 15-minute odor test method. WSTF performed this extended-duration odor test to evaluate the odor and physical effects of the bonding material configured between two aluminum plates, after the safety of the gas was verified via toxicity analysis per NASA-STD-6001B Test 7, Determination of Offgassed Products. During extended-duration testing, odor panel members were arranged near the test material in a small room with the air handlers and doors closed to minimize dilution. The odor panel members wafted gas toward themselves and recorded their individual assessments of odor and physical effects at various intervals during the 15-minute exposure and posttest. A posttest interview was conducted to obtain further information. Testing was effective in providing data for comparison and selection of an optimal offgassing and odor containment configuration. The developed test method for extended exposure is proposed as a useful tool for further evaluating materials with identified odors of concern if continued use of the material is anticipated.

  10. 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

  11. 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.

  12. 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.

  13. Verbal memory elicited by ambient odor.

    Science.gov (United States)

    Smith, D G; Standing, L; de Man, A

    1992-04-01

    This study examined whether an ambient odor can act as a contextual cue for retrieval of verbal stimuli. Subjects (N = 47) learned a list of 24 words while exposed to one of two odors (either jasmine incense or Lauren perfume) and subsequently relearned the list with either the same or the alternative odor present. Superior memory for the word list was found when the odor present during the relearning session was the same one that had been present at the time of initial learning, thereby demonstrating context-dependent memory. There were no differences in initial learning between the two odor conditions. No differences in pleasantness or intensity were found between the odors. PMID:1594391

  14. An odor flux model for cattle feedlots

    Energy Technology Data Exchange (ETDEWEB)

    Ormerod, R.J. [Dames & Moore, Brisbane (Australia)

    1994-12-31

    Odor nuisance associated with cattle feedlots has been an issue of major interest and concern to regulators, rural communities and the beef industry in Australia over the past decade. Methods of assessing the likely impacts of new feedlots on community odor exposure are still being developed, but in the past few years much has been learnt about the processes of odor generation, flux and dispersion as well as the acceptability of feedlot odor to exposed communities. This paper outlines a model which simulates the complex physical and chemical processes leading to odor emissions in a simple and practical framework. The model, named BULSMEL, has been developed as a response to regulatory requirements for quantitative assessments of odor impact. It will continue to be refined as more data are gathered.

  15. Normalized neural representations of natural odors

    OpenAIRE

    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 t...

  16. Odorant Category Profile Selectivity of Olfactory Cortex

    OpenAIRE

    Yoshida, Ikue; Mori, Kensaku

    2007-01-01

    The olfactory cortex receives converging axonal inputs from many mitral and tufted cells in the olfactory bulb. Recent studies indicate that single cortical neurons integrate signals from diverse odorants. However, there remains a basic question, namely, the signals from which kinds of odorants are integrated by the individual cortical neurons? The present study examined the possibility that some cortical neurons integrate signals from distinct component odorants of natural foods because indi...

  17. Cross-cultural color-odor associations.

    Directory of Open Access Journals (Sweden)

    Carmel A Levitan

    Full Text Available 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., an inherent mapping between color and odor, statistical reasons (i.e., covariance in experience, and/or semantically-mediated reasons (i.e., stemming from language. The present study probed this question by testing color-odor correspondences in 6 different cultural groups (Dutch, Netherlands-residing-Chinese, German, Malay, Malaysian-Chinese, and US residents, using the same set of 14 odors and asking participants to make congruent and incongruent color choices for each odor. We found consistent patterns in color choices for each odor within each culture, showing that participants were making non-random color-odor matches. We used representational dissimilarity analysis to probe for variations in the patterns of color-odor associations across cultures; we found that US and German participants had the most similar patterns of associations, followed by German and Malay participants. The largest group differences were between Malay and Netherlands-resident Chinese participants and between Dutch and Malaysian-Chinese participants. We conclude that culture plays a role in color-odor crossmodal associations, which likely arise, at least in part, through experience.

  18. Chemical communication: does odor plume shape matter?

    OpenAIRE

    Lof, M.E.; Hemerik, L.; Gee, de, A.W.J.

    2007-01-01

    Many insects use chemical information to gather information about their environment. Infochemicals are spread into the environment as the wind disperses the odor molecules from the source. The structure of an odor plume around a food source is complex and time-dependent. At a large scale, it meanders as it moves with the wind. At a smaller scale, patches with odors are interspersed with regions of clean air. In this study, we compare a plume model that takes the features of a real odor plume ...

  19. Use of a Modified Vector Model for Odor Intensity Prediction of Odorant Mixtures

    Directory of Open Access Journals (Sweden)

    Luchun Yan

    2015-03-01

    Full Text Available Odor intensity (OI indicates the perceived intensity of an odor by the human nose, and it is usually rated by specialized assessors. In order to avoid restrictions on assessor participation in OI evaluations, the Vector Model which calculates the OI of a mixture as the vector sum of its unmixed components’ odor intensities was modified. Based on a detected linear relation between the OI and the logarithm of odor activity value (OAV—a ratio between chemical concentration and odor threshold of individual odorants, OI of the unmixed component was replaced with its corresponding logarithm of OAV. The interaction coefficient (cosα which represented the degree of interaction between two constituents was also measured in a simplified way. Through a series of odor intensity matching tests for binary, ternary and quaternary odor mixtures, the modified Vector Model provided an effective way of relating the OI of an odor mixture with the lnOAV values of its constituents. Thus, OI of an odor mixture could be directly predicted by employing the modified Vector Model after usual quantitative analysis. Besides, it was considered that the modified Vector Model was applicable for odor mixtures which consisted of odorants with the same chemical functional groups and similar molecular structures.

  20. Kraft Board Odor Evaluation by Gas Chromatography and Odor Judging Panel.

    Science.gov (United States)

    Fontenot, J. L.

    This is an experimental study which was undertaken to determine if a gas chromatographic technique could be used to measure paperboard odor levels. Because there are many variations to odor testing using a panel of judges - which is the generally accepted method - the author states that, obviously, an objective method for ascertaining odor levels…

  1. Kinetics of odorant compounds in wine brandies aged in different systems.

    Science.gov (United States)

    Caldeira, Ilda; Santos, Rui; Ricardo-da-Silva, Jorge M; Anjos, Ofélia; Mira, Helena; Belchior, A Pedro; Canas, Sara

    2016-11-15

    The odorants compounds of aged wine brandies comprise compounds deriving from the wood, from the distillate and from the reactions that occur inside the barrel. The aim of this work was to study the kinetics of the odorant compounds of a wine brandy during two years of ageing in two ageing systems. The odorant compounds in the analysed brandies changed significantly over the time, but with different evolution patterns. The wood related compounds increased over time, with the highest increase in the first months of ageing. The kinetics of cis, trans-β-methyl-γ-octalactone, acetovanillone and of seven volatile phenols are established for the first time in brandies. Moreover, a significant effect of the ageing system was found on the kinetics of the wood related compounds. These results pointed out the interest of these compounds as a tool to discriminate different ageing technologies. PMID:27283715

  2. Behavioral Responses of CD-1 Mice to Six Predator Odor Components.

    Science.gov (United States)

    Sievert, Thorbjörn; Laska, Matthias

    2016-06-01

    Mammalian prey species are able to detect predator odors and to display appropriate defensive behavior. However, there is only limited knowledge about whether single compounds of predator odors are sufficient to elicit such behavior. Therefore, we assessed if predator-naïve CD-1 mice (n = 60) avoid sulfur-containing compounds that are characteristic components of natural predator odors and/or display other indicators of anxiety. A 2-compartment test arena was used to assess approach/avoidance behavior, general motor activity, and the number of fecal pellets excreted when the animals were presented with 1 of 6 predator odor components in one compartment and a blank control in the other compartment. We found that 2 of the 6 predator odor components (2-propylthietane and 3-methyl-1-butanethiol) were significantly avoided by the mice. The remaining 4 predator odor components (2,2-dimethylthietane, 3-mercapto-3-methylbutan-1-ol, 3-mercapto-3-methylbutyl-1-formate, and methyl-2-phenylethyl sulphide) as well as a nonpredator-associated fruity odor (n-pentyl acetate) were not avoided. Neither the general motor activity nor the number of excreted fecal pellets, both widely used measures of stress- or anxiety-related behavior, were systematically affected by any of the odorants tested. Further, we found that small changes in the molecular structure of a predator odor component can have a marked effect on its behavioral significance as 2-propylthietane was significantly avoided by the mice whereas the structurally related 2,2-dimethylthietane was not. We conclude that sulfur-containing volatiles identified as characteristic components of the urine, feces, and anal gland secretions of mammalian predators can be, but are not necessarily sufficient to elicit defensive behaviors in a mammalian prey species. PMID:26892309

  3. Olfactory discrimination ability of human subjects for enantiomers with an isopropenyl group at the chiral center.

    Science.gov (United States)

    Laska, Matthias

    2004-02-01

    The ability of 20 human subjects to distinguish between nine enantiomeric odor pairs sharing an isopropenyl group at the chiral center was tested in a forced-choice triangular test procedure. I found (i). that as a group, the subjects were only able to significantly discriminate the optical isomers of limonene, carvone, dihydrocarvone, dihydrocarveol and dihydrocarvyl acetate, whereas they failed to distinguish between the (+)- and (-)-forms of perillaalcohol, perillaaldehyde, isopulegol and limonene oxide; (ii). marked interindividual differences in discrimination performance, ranging from subjects who were able to significantly discriminate between eight of the nine odor pairs to subjects who failed to do so with six of the nine tasks; and (iii). that with none of the nine odor pairs the antipodes were reported to differ significantly in subjective intensity when presented at equal concentrations. Additional tests of the chemesthetic potency and threshold measurements of the optical isomers of dihydrocarvone, dihydrocarveol, and dihydrocarvyl acetate suggest that the discriminability of these three enantiomeric odor pairs is indeed due to differences in odor quality. Analysis of structure-activity relationships suggest that the combined presence of (i). an isopropenyl group at the chiral center; (ii). a methyl group at the para-position; and/or (iii). an oxygen-containing group at the meta-position allows for the discrimination of enantiomeric odor pairs. PMID:14977811

  4. 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.

  5. 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…

  6. 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.

  7. 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.

  8. 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.

  9. Military Discrimination.

    Science.gov (United States)

    Hunter, Richard W.

    1981-01-01

    Argues that while a certain level of fairness is necessary in considering the equity of compulsory military service, the most important issue is that of "winning the war." Also asserts that sex, age, and race discrimination are more important than social class discrimination in military service. (Author/GC)

  10. Predicting the response of olfactory sensory neurons to odor mixtures from single odor response

    Science.gov (United States)

    Marasco, Addolorata; de Paris, Alessandro; Migliore, Michele

    2016-04-01

    The response of olfactory receptor neurons to odor mixtures is not well understood. Here, using experimental constraints, we investigate the mathematical structure of the odor response space and its consequences. The analysis suggests that the odor response space is 3-dimensional, and predicts that the dose-response curve of an odor receptor can be obtained, in most cases, from three primary components with specific properties. This opens the way to an objective procedure to obtain specific olfactory receptor responses by manipulating mixtures in a mathematically predictable manner. This result is general and applies, independently of the number of odor components, to any olfactory sensory neuron type with a response curve that can be represented as a sigmoidal function of the odor concentration.

  11. A Neural Mechanism of Taste Perception Modulated by Odor Information.

    Science.gov (United States)

    Shimemura, Takahiro; Fujita, Kazuhisa; Kashimori, Yoshiki

    2016-09-01

    Taste perception is significantly affected by other sensory modalities such as vision, smell, and somatosensation. Such taste sensation elicited by integrating gustatory and other sensory information is referred to as flavor. Although experimental studies have demonstrated the characteristics of flavor perception influenced by other sensory modalities and the involved brain areas, it remains unknown how flavor emerges from the brain circuits. Of the involved brain areas, orbitofrontal cortex (OFC), as well as gustatory cortex (GC), plays a dominant role in flavor perception. We develop here a neural model of gustatory system which consists of GC and OFC networks and examine the neural mechanism of odor-induced taste perception. Using the model, we show that flavor perception is shaped by experience-dependent learning of foods with congruent taste-odor pairs, providing a unique representation of flavor through the interaction between OFC and GC neurons. Our model also shows that feedback signals from OFC to GC modulate the dynamic stability of taste attractors in GC, leading to the enhancement or suppression of taste responses by smells. Furthermore, modeling shows that spatial variability in GC activity evoked by tastants determines to what extent odor enhances congruent taste responses. The results suggest that flavor perception is deeply associated with dynamic stability of GC attractors through the interaction between GC and OFC. PMID:27178285

  12. h(odor): Interactive Discovery of Hypotheses on the Structure-Odor Relationship in Neuroscience

    OpenAIRE

    Bosc, Guillaume; Plantevit, Marc; Boulicaut, Jean-François; Bensafi, Moustafa; Kaytoue, Mehdi

    2016-01-01

    International audience From a molecule to the brain perception, olfaction is a complex phenomenon that remains to be fully understood in neuroscience. Latest studies reveal that the physico-chemical properties of volatile molecules can partly explain the odor perception. Neuroscientists are then looking for new hypotheses to guide their research: physico-chemical descriptors distinguishing a subset of perceived odors. To answer this problem, we present the platform h(odor) that implements ...

  13. Chemosensory communication of gender information: Masculinity bias in body odor perception and femininity bias introduced by chemosignals during social perception

    Directory of Open Access Journals (Sweden)

    Smiljana eMutic

    2016-01-01

    Full Text Available Human body odor is a source of important social information. In this study, we explore whether the sex of an individual can be established based on smelling axillary odor and whether exposure to male and female odors biases chemosensory and social perception. In a double-blind, pseudo-randomized application, 31 healthy normosmic heterosexual male and female raters were exposed to male and female chemosignals (odor samples of 27 heterosexual donors collected during a cardio workout and a no odor sample. Recipients rated chemosensory samples on a masculinity-femininity scale and provided intensity, familiarity and pleasantness ratings. Additionally, the modulation of social perception (gender-neutral faces and personality attributes and affective introspection (mood by male and female chemosignals was assessed. Male and female axillary odors were rated as rather masculine, regardless of the sex of the donor. As opposed to the masculinity bias in the odor perception, a femininity bias modulating social perception appeared. A facilitated femininity detection in gender-neutral faces and personality attributes in association with both male and female chemosignals appeared. No chemosensory effect on mood of the rater was observed. The results are discussed with regards to the use of male and female chemosignals in affective and social communication.

  14. 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.

  15. Brain responses to odor mixtures with sub-threshold components

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    Thomas eHummel

    2013-10-01

    Full Text Available Although most odorants we encounter in daily life are mixtures of several chemical substances, we still lack significant information on how we perceive and how the brain processes mixtures of odorants. We aimed to investigate the processing of odor mixtures using behavioral measures and functional magnetic resonance imaging (fMRI. The odor mixture contained a target odor (ambroxan in a concentration at which it could be perceived by half of the subjects (sensitive group; the other half could not perceive the odor (insensitive group. In line with previous findings on multi-component odor mixtures, both groups of subjects were not able to distinguish a complex odor mixture containing or not containing the target odor. However, sensitive subjects had stronger activations than insensitive subjects in chemosensory processing areas such as the insula when exposed to the mixture containing the target odor. Furthermore, the sensitive group exhibited larger brain activations when presented with the odor mixture containing the target odor compared to the odor mixture without the target odor; this difference was smaller, though present for the insensitive group. In conclusion, we show that a target odor presented within a mixture of odors can influence brain activations although on a psychophysical level subjects are not able to distinguish the mixture with and without the target. On the practical side these results suggest that the addition of a certain compound to a mixture of odors may not be detected on a cognitive level; however, this additional odor may significantly change the cerebral processing of this mixture. In this context, FMRI offers unique possibilities to look at the subliminal effects of odors.

  16. Odor valence linearly modulates attractiveness, but not age assessment, of invariant facial features in a memory-based rating task.

    Directory of Open Access Journals (Sweden)

    Janina Seubert

    Full Text Available Scented cosmetic products are used across cultures as a way to favorably influence one's appearance. While crossmodal effects of odor valence on perceived attractiveness of facial features have been demonstrated experimentally, it is unknown whether they represent a phenomenon specific to affective processing. In this experiment, we presented odors in the context of a face battery with systematic feature manipulations during a speeded response task. Modulatory effects of linear increases of odor valence were investigated by juxtaposing subsequent memory-based ratings tasks--one predominantly affective (attractiveness and a second, cognitive (age. The linear modulation pattern observed for attractiveness was consistent with additive effects of face and odor appraisal. Effects of odor valence on age perception were not linearly modulated and may be the result of cognitive interference. Affective and cognitive processing of faces thus appear to differ in their susceptibility to modulation by odors, likely as a result of privileged access of olfactory stimuli to affective brain networks. These results are critically discussed with respect to potential biases introduced by the preceding speeded response task.

  17. A fruity note: crossmodal associations between odors and musical notes.

    Science.gov (United States)

    Crisinel, Anne-Sylvie; Spence, Charles

    2012-02-01

    Odors are notoriously difficult to describe, but they seem prone to a variety of crossmodal associations. In the present study, we generalize the previously-shown association between odors (from perfumery) and pitch (Belkin et al. 1997) to odors related to food and drink (in this case those associated with wine). We also demonstrate that, to a lesser extent (25% of the odor tested), participants preferentially match specific odors to certain types of instruments. The ratings of the odors along a number of dimensions are used in principal components analysis (PCA) to explore the psychological dimensions underlying the odor-pitch associations. The results demonstrate that both pleasantness and complexity, but not intensity, appear to play a role when choosing a pitch to match an odor. Our results suggest that these features of odor stimuli constitute psychological dimensions that can be consistently matched to auditory features. PMID:21852708

  18. 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.

  19. Electronic Olfactory Sensor Based on A. mellifera Odorant-Binding Protein 14 on a Reduced Graphene Oxide Field-Effect Transistor.

    Science.gov (United States)

    Larisika, Melanie; Kotlowski, Caroline; Steininger, Christoph; Mastrogiacomo, Rosa; Pelosi, Paolo; Schütz, Stefan; Peteu, Serban F; Kleber, Christoph; Reiner-Rozman, Ciril; Nowak, Christoph; Knoll, Wolfgang

    2015-11-01

    An olfactory biosensor based on a reduced graphene oxide (rGO) field-effect transistor (FET), functionalized by the odorant-binding protein 14 (OBP14) from the honey bee (Apis mellifera) has been designed for the in situ and real-time monitoring of a broad spectrum of odorants in aqueous solutions known to be attractants for bees. The electrical measurements of the binding of all tested odorants are shown to follow the Langmuir model for ligand-receptor interactions. The results demonstrate that OBP14 is able to bind odorants even after immobilization on rGO and can discriminate between ligands binding within a range of dissociation constants from K(d)=4 μM to K(d)=3.3 mM. The strongest ligands, such as homovanillic acid, eugenol, and methyl vanillate all contain a hydroxy group which is apparently important for the strong interaction with the protein. PMID:26364873

  20. Interaction between cAMP and intracellular Ca(2+)-signaling pathways during odor-perception and adaptation in Drosophila.

    Science.gov (United States)

    Murmu, Meena Sriti; Martin, Jean-René

    2016-09-01

    Binding of an odorant to olfactory receptors triggers cascades of second messenger systems in olfactory receptor neurons (ORNs). Biochemical studies indicate that the transduction mechanism at ORNs is mediated by cyclic adenosine monophosphate (cAMP) and/or inositol,1,4,5-triphosphate (InsP3)-signaling pathways in an odorant-dependent manner. However, the interaction between these two second messenger systems during olfactory perception or adaptation processes is much less understood. Here, we used interfering-RNAi to disrupt the level of cAMP alone or in combination with the InsP3-signaling pathway cellular targets, InsP3 receptor (InsP3R) or ryanodine receptor (RyR) in ORNs, and quantify at ORN axon terminals in the antennal lobe, the odor-induced Ca(2+)-response. In-vivo functional bioluminescence Ca(2+)-imaging indicates that a single 5s application of an odor increased Ca(2+)-transients at ORN axon terminals. However, compared to wild-type controls, the magnitude and duration of ORN Ca(2+)-response was significantly diminished in cAMP-defective flies. In a behavioral assay, perception of odorants was defective in flies with a disrupted cAMP level suggesting that the ability of flies to correctly detect an odor depends on cAMP. Simultaneous disruption of cAMP level and InsP3R or RyR further diminished the magnitude and duration of ORN response to odorants and affected the flies' ability to detect an odor. In conclusion, this study provides functional evidence that cAMP and InsP3-signaling pathways act in synergy to mediate odor processing within the ORN axon terminals, which is encoded in the magnitude and duration of ORN response. PMID:27212269

  1. [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.

  2. How do mice follow odor trails?

    Science.gov (United States)

    Zwicker, David; Trastour, Sophie; Mishra, Shruti; Mathis, Alexander; Murthy, Venkatesh; Brenner, Michael P.

    2015-11-01

    Mice are excellent at following odor trails e.g. to locate food or to find mates. However, it is not yet understood what navigation strategies they use. In principle, they could either evaluate temporal differences between sniffs or they could use concurrent input from the two nostrils. It is unknown to what extend these two strategies contribute to mice's performance. When mice follow trails, odors evaporate from the ground, are transported by flow in the air, and are then inhaled with the two nostrils. In order to differentiate between the two navigation strategies, we determine what information the mouse receives: first, we calculate the airflow by numerically solving the incompressible Navier-Stokes equations. We then determine the spatiotemporal odor concentration from the resulting advection-diffusion equations. Lastly, we determine the odor amount in each nostril by calculating the inhalation volumes using potential flow theory. Taken together, we determine the odor amount in each nostril during each sniff, allowing a detailed study of navigation strategies.

  3. Sensitivity of physiological emotional measures to odors depends on the product and the pleasantness ranges used

    Directory of Open Access Journals (Sweden)

    Aline Marie Pichon

    2015-12-01

    Full Text Available Emotions are characterized by synchronized changes in several components of an organism. Among them, physiological variations provide energy support for the expression of approach/avoid action tendencies induced by relevant stimuli, while self-reported subjective pleasantness feelings integrate all other emotional components and are plastic.Consequently, emotional responses evoked by odors should be highly differentiated when they are linked to different functions of olfaction (e.g., avoiding environmental hazards. As this differentiation has been observed for contrasted odors (very pleasant or unpleasant, we questioned whether subjective and physiological emotional response indicators could still disentangle subtle affective variations when no clear functional distinction is made (mildly pleasant or unpleasant fragrances. Here, we compared the sensitivity of behavioral and physiological (respiration, skin conductance, facial electromyography (EMG, and heart rate indicators in differentiating odor-elicited emotions in two situations: when a wide range of odor families was presented (e.g., fruity, animal, covering different functional meanings; or in response to a restricted range of products in one particular family (fragrances. Results show clear differences in physiological indicators to odors that display a wide range of reported pleasantness, but these differences almost entirely vanish when fragrances are used even though their subjective pleasantness still differed. Taken together, these results provide valuable information concerning the ability of classic verbal and psychophysiological measures to investigate subtle differences in emotional reactions to a restricted range of similar olfactory stimuli.

  4. 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.

  5. Reading Out Olfactory Receptors: Feedforward Circuits Detect Odors in Mixtures without Demixing.

    Science.gov (United States)

    Mathis, Alexander; Rokni, Dan; Kapoor, Vikrant; Bethge, Matthias; Murthy, Venkatesh N

    2016-09-01

    The olfactory system, like other sensory systems, can detect specific stimuli of interest amidst complex, varying backgrounds. To gain insight into the neural mechanisms underlying this ability, we imaged responses of mouse olfactory bulb glomeruli to mixtures. We used this data to build a model of mixture responses that incorporated nonlinear interactions and trial-to-trial variability and explored potential decoding mechanisms that can mimic mouse performance when given glomerular responses as input. We find that a linear decoder with sparse weights could match mouse performance using just a small subset of the glomeruli (∼15). However, when such a decoder is trained only with single odors, it generalizes poorly to mixture stimuli due to nonlinear mixture responses. We show that mice similarly fail to generalize, suggesting that they learn this segregation task discriminatively by adjusting task-specific decision boundaries without taking advantage of a demixed representation of odors. PMID:27593177

  6. 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.

  7. Optimizing odor identification testing as quick and accurate diagnostic tool for Parkinson's disease

    Science.gov (United States)

    Mahlknecht, Philipp; Pechlaner, Raimund; Boesveldt, Sanne; Volc, Dieter; Pinter, Bernardette; Reiter, Eva; Müller, Christoph; Krismer, Florian; Berendse, Henk W.; van Hilten, Jacobus J.; Wuschitz, Albert; Schimetta, Wolfgang; Högl, Birgit; Djamshidian, Atbin; Nocker, Michael; Göbel, Georg; Gasperi, Arno; Kiechl, Stefan; Willeit, Johann; Poewe, Werner

    2016-01-01

    ABSTRACT Introduction The aim of this study was to evaluate odor identification testing as a quick, cheap, and reliable tool to identify PD. Methods Odor identification with the 16‐item Sniffin' Sticks test (SS‐16) was assessed in a total of 646 PD patients and 606 controls from three European centers (A, B, and C), as well as 75 patients with atypical parkinsonism or essential tremor and in a prospective cohort of 24 patients with idiopathic rapid eye movement sleep behavior disorder (center A). Reduced odor sets most discriminative for PD were determined in a discovery cohort derived from a random split of PD patients and controls from center A using L1‐regularized logistic regression. Diagnostic accuracy was assessed in the rest of the patients/controls as validation cohorts. Results Olfactory performance was lower in PD patients compared with controls and non‐PD patients in all cohorts (each P 3 years of disease duration were excluded from analysis. All 8 incident PD cases among patients with idiopathic rapid eye movement sleep behavior disorder were predicted with the SS‐16 and the SS‐8 (sensitivity, 100%; positive predictive value, 61.5%). Conclusions Odor identification testing provides excellent diagnostic accuracy in the distinction of PD patients from controls and diagnostic mimics. A reduced set of eight odors could be used as a quick tool in the workup of patients presenting with parkinsonism and for PD risk indication. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society PMID:27159493

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

    OpenAIRE

    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-sev...

  9. 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.

  10. 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

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

    Science.gov (United States)

    Nilsson, Sara; Sjöberg, Johanna; Amundin, Mats; Hartmann, Constanze; Buettner, Andrea; Laska, Matthias

    2014-01-01

    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 enrichment

  12. 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. 

  13. The dark side of subtle discrimination: how targets respond to different forms of discrimination

    OpenAIRE

    Cihangir, Sezgin

    2008-01-01

    This thesis investigates the role of several individual and social factors (i.e., personal self-esteem, social norms and social influence) that directly affect how people deal with uncertainty, in reaction to blatant versus subtle discrimination. While responses to blatant discrimination were not affected by any of these factors, these factors determined to a significant degree responses to subtle discrimination. The main idea throughout the thesis is that blatant discrimination involves a cl...

  14. Recovery of Agricultural Odors and Odorous Compounds from Polyvinyl Fluoride Film Bags

    Directory of Open Access Journals (Sweden)

    Jacek A. Koziel

    2010-09-01

    Full Text Available Accurate sampling methods are necessary when quantifying odor and volatile organic compound emissions at agricultural facilities. The commonly accepted methodology in the U.S. has been to collect odor samples in polyvinyl fluoride bags (PVF, brand name Tedlar® and, subsequently, analyze with human panelists using dynamic triangular forced-choice olfactometry. The purpose of this research was to simultaneously quantify and compare recoveries of odor and odorous compounds from both commercial and homemade PVF sampling bags. A standard gas mixture consisting of p-cresol (40 µg m−3 and seven volatile fatty acids: acetic (2,311 µg m−3, propionic (15,800 µg m−3, isobutyric (1,686 µg m−3, butyric (1,049 µg m−3, isovaleric (1,236 µg m−3, valeric (643 µg m−3, and hexanoic (2,158 µg m−3 was placed in the PVF bags at times of 1 h, 1 d, 2 d, 3 d, and 7 d prior to compound and odor concentration analyses. Compound concentrations were quantified using sorbent tubes and gas chromatography/mass spectrometry. Odor concentration, intensity, and hedonic tone were measured using a panel of trained human subjects. Compound recoveries ranged from 2 to 40% after 1 h and 0 to 14% after 7 d. Between 1 h and 7 d, odor concentrations increased by 45% in commercial bags, and decreased by 39% in homemade bags. Minimal changes were observed in intensity and hedonic tone over the same time period. These results suggest that PVF bags can bias individual compound concentrations and odor as measured by dynamic triangular forced-choice olfactometry.

  15. 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.

  16. Odor Impression Prediction from Mass Spectra

    Science.gov (United States)

    Nakamoto, Takamichi

    2016-01-01

    The sense of smell arises from the perception of odors from chemicals. However, the relationship between the impression of odor and the numerous physicochemical parameters has yet to be understood owing to its complexity. As such, there is no established general method for predicting the impression of odor of a chemical only from its physicochemical properties. In this study, we designed a novel predictive model based on an artificial neural network with a deep structure for predicting odor impression utilizing the mass spectra of chemicals, and we conducted a series of computational analyses to evaluate its performance. Feature vectors extracted from the original high-dimensional space using two autoencoders equipped with both input and output layers in the model are used to build a mapping function from the feature space of mass spectra to the feature space of sensory data. The results of predictions obtained by the proposed new method have notable accuracy (R≅0.76) in comparison with a conventional method (R≅0.61). PMID:27326765

  17. 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.

  18. The Effects of Odor Quality and Temporal Asynchrony on Modulation of Taste Intensity by Retronasal Odor.

    Science.gov (United States)

    Isogai, Tomoyuki; Wise, Paul M

    2016-09-01

    The experiments had 2 main goals: 1) to add to the sparse literature on how retronasal aromas interact with bitter tastes, and 2) to determine whether modulation of taste intensity by aroma depends on temporal contiguity, as one might expect if flavor interactions depend on cross-modal binding (similar to object perception in other modalities). An olfactometer-gustometer allowed independent oral presentation of odorized air and liquid samples. First, using simultaneous presentation of odors and tastes (Experiments 1a-d) we found that a "sweet-smelling" aroma enhanced the rated sweetness of sucrose and decreased the rated bitterness of sucrose octaacetate (SOA), and that a "bitter-smelling" aroma enhanced the bitterness of SOA and decreased the sweetness of sucrose. Thus, with respect to effects on taste intensity, sweet and bitter aromas mimicked mixture-interactions between sweet and bitter tastes under current conditions. Next (Experiment 2), both odors were again paired with both tastes, with a parametric manipulation of odor onset. Odor presentation ranged from before taste delivery to after taste delivery. Enhancement of taste intensity was greatest with simultaneous onset, and greatly attenuated with offsets of 1s. These results are consistent with the idea that enhancement of taste by retronasal aroma depends on a temporal binding window like many other cross-modal interactions. The effects of temporal offsets on suppression of taste were inconclusive. These findings are discussed within the context of past work on odor-taste interactions. PMID:27143280

  19. 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.

  20. 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.

  1. 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 physiology in response to odor cues may be dependent on social rank in this species. PMID:24375480

  2. 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.

  3. Diversity, Discrimination, and Performance

    OpenAIRE

    Jonathan S. Leonard; Levine, David I.

    2006-01-01

    Employee diversity may affect business performance both as a result of customer discrimination and as a result of how members of a group work with each other in teams. We test for both channels with data from more than 800 retail stores employing over 70,000 individuals matched to Census data on the demographics of the community. We find little payoff to matching employee demographics to those of potential customers except when the customers do not speak English. Although age diversity doe...

  4. The effect of meat consumption on body odor attractiveness.

    Science.gov (United States)

    Havlicek, Jan; Lenochova, Pavlina

    2006-10-01

    Axillary body odor is individually specific and potentially a rich source of information about its producer. Odor individuality partly results from genetic individuality, but the influence of ecological factors such as eating habits are another main source of odor variability. However, we know very little about how particular dietary components shape our body odor. Here we tested the effect of red meat consumption on body odor attractiveness. We used a balanced within-subject experimental design. Seventeen male odor donors were on "meat" or "nonmeat" diet for 2 weeks wearing axillary pads to collect body odor during the final 24 h of the diet. Fresh odor samples were assessed for their pleasantness, attractiveness, masculinity, and intensity by 30 women not using hormonal contraceptives. We repeated the same procedure a month later with the same odor donors, each on the opposite diet than before. Results of repeated measures analysis of variance showed that the odor of donors when on the nonmeat diet was judged as significantly more attractive, more pleasant, and less intense. This suggests that red meat consumption has a negative impact on perceived body odor hedonicity. PMID:16891352

  5. 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.

  6. 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 < 0.001). The comparison of gustatory sensitivity indicated significantly higher sensitivity to sweet, sour and salty in hunger (p < 0.001), but significantly higher sensitivity to bitter tastant in satiety (p < 0.001). With this prospective study, we were able to show that both olfactory abilities and gustatory sensitivity were affected by hunger state. PMID:25744049

  7. Honeybees (Apis mellifera) learn to discriminate the smell of organic compounds from their respective deuterated isotopomers.

    Science.gov (United States)

    Gronenberg, Wulfila; Raikhelkar, Ajay; Abshire, Eric; Stevens, Jennifer; Epstein, Eric; Loyola, Karin; Rauscher, Michael; Buchmann, Stephen

    2014-03-01

    The understanding of physiological and molecular processes underlying the sense of smell has made considerable progress during the past three decades, revealing the cascade of molecular steps that lead to the activation of olfactory receptor (OR) neurons. However, the mode of primary interaction of odorant molecules with the OR proteins within the sensory cells is still enigmatic. Two different concepts try to explain these interactions: the 'odotope hypothesis' suggests that OR proteins recognize structural aspects of the odorant molecule, whereas the 'vibration hypothesis' proposes that intra-molecular vibrations are the basis for the recognition of the odorant by the receptor protein. The vibration hypothesis predicts that OR proteins should be able to discriminate compounds containing deuterium from their common counterparts which contain hydrogen instead of deuterium. This study tests this prediction in honeybees (Apis mellifera) using the proboscis extension reflex learning in a differential conditioning paradigm. Rewarding one odour (e.g. a deuterated compound) with sucrose and not rewarding the respective analogue (e.g. hydrogen-based odorant) shows that honeybees readily learn to discriminate hydrogen-based odorants from their deuterated counterparts and supports the idea that intra-molecular vibrations may contribute to odour discrimination. PMID:24452031

  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. Feature-level signal processing for near-real-time odor identification

    Science.gov (United States)

    Roppel, Thaddeus A.; Padgett, Mary Lou; Waldemark, Joakim T. A.; Wilson, Denise M.

    1998-09-01

    Rapid detection and classification of odor is of particular interest in applications such as manufacturing of consumer items, food processing, drug and explosives detection, and battlefield situation assessment. Various detection and classification techniques are under investigation so that end users can have access to useful information from odor sensor arrays in near-real-time. Feature-level data clustering and classification techniques are proposed that are (1) parallelizable to permit efficient hardware implementation, (2) adaptable to readily incorporate new data classes, (3) capable of gracefully handling outlier data points and failed sensor conditions, and (4) can provide confidence intervals and/or a traceable decision record along with each classification to permit validation and verification. Results from using specific techniques will be presented and compared. The techniques studied include principal components analysis, automated outlier determination, radial basis functions (RBF), multi-layer perceptrons (MLP), and pulse-coupled neural networks (PCNN). The results reported here are based on data from a testbed in which a gas sensor array is exposed to odor samples on a continuous basis. We have reported previously that more detailed and faster discrimination can be obtained by using sensor transient response in addition to steady state response. As the size of the data set grows we are able to more accurately model performance of a sensor array under realistic conditions.

  10. 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.

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

    Science.gov (United States)

    Liu, Feng; Liu, Nannan

    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 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. PMID:26522967

  12. Walking patterns induced by learned odors in the honeybee, Apis mellifera L.

    Science.gov (United States)

    Yamashita, Toshiya; Haupt, S Shuichi; Ikeno, Hidetoshi; Ai, Hiroyuki

    2016-01-01

    The odor localization strategy induced by odors learned via differential conditioning of the proboscis extension response was investigated in honeybees. In response to reward-associated but not non-reward-associated odors, learners walked longer paths than non-learners and control bees. When orange odor reward association was learned, the path length and the body turn angles were small during odor stimulation and greatly increased after stimulation ceased. In response to orange odor, bees walked locally with alternate left and right turns during odor stimulation to search for the reward-associated odor source. After odor stimulation, bees walked long paths with large turn angles to explore the odor plume. For clove odor, learning-related modulations of locomotion were less pronounced, presumably due to a spontaneous preference for orange in the tested population of bees. This study is the first to describe how an odor-reward association modulates odor-induced walking in bees. PMID:26567342

  13. Infants' discrimination of happy and sad music.

    Science.gov (United States)

    Flom, Ross; Gentile, Douglas A; Pick, Anne D

    2008-12-01

    Infants can detect information specifying affect in infant- and adult-directed speech, familiar and unfamiliar facial expressions, and in point-light displays of facial expressions. We examined 3-, 5-, 7-, and 9-month-olds' discrimination of musical excerpts judged by adults and preschoolers as happy and sad. In Experiment 1, using an infant-controlled habituation procedure, 3-, 5-, 7-, and 9-month-olds heard three musical excerpts that were rated as either happy or sad. Following habituation, infants were presented with two new musical excerpts from the other affect group. Nine-month-olds discriminated the musical excerpts rated as affectively different. Five- and seven-month-olds discriminated the happy and sad excerpts when they were habituated to sad excerpts but not when they were habituated to happy excerpts. Three-month-olds showed no evidence of discriminating the sad and happy excerpts. In Experiment 2, 5-, 7-, and 9-month-olds were presented with two new musical excerpts from the same affective group as the habituation excerpts. At no age did infants discriminate these novel, yet affectively similar, musical excerpts. In Experiment 3, we examined 5-, 7-, and 9-month-olds' discrimination of individual excerpts rated as affectively similar. Only the 9-month-olds discriminated the affectively similar individual excerpts. Results are discussed in terms of infants' ability to discriminate affect across a variety of events and its relevance for later social-communicative development. PMID:18502515

  14. Mass discrimination

    International Nuclear Information System (INIS)

    The pertinent and well-known problem of the discriminative effect produced by small orifices used in mass-spectrometric ion sampling from gas discharges is one which is unfortunately not well understood. The problem has been investigated experimentally by Kingsman and Rees and by Milloy and Elford for particular experimental conditions. Parkes has investigated the problem theoretically for high-pressure discharges, where convective flow through the hole dominates. The present communication seeks to provide a simple method for calculating ion transmission coefficients through such orifices for the special case where the gas mean free path is greater than the orifice diameter and the ions have ab imposed additional axial velocity component due either to an electric-field drift velocity or to a flow velocity (flowing afterglows). (orig.)

  15. 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.

  16. 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. PMID:15961521

  17. Odor control in composting plants: results from full-scale experiences.

    Science.gov (United States)

    Canovai, Alessandro; Valentini, Federico; Manetti, Edoardo; Zagaroli, Mauro

    2004-01-01

    The development and spread of mechanical biological treatment (MBT) and composting plants is often hindered by the problems and concerns arising from emission bad odors. Several technologies are now available to process exhausted air originated from these or similar plants. Exhausted air emissions contain a large amount of organic compounds, most of them in very low concentrations. This determines the advantage in using biological abatement systems (biofilters) instead of physical-chemical treatments. This article describes the operative results obtained in two Italian waste treatment plants, one in Albano, near Rome, and the other in the "ex-Maserati area" of Milan, including (i) the analysis of operational parameters as temperature, pH. humidity, loss of pressure of the biofilter affecting the biofiltration efficiency, for both chemical parameters and odorous compound concentration, measured by means of odor panel evaluation technique and (ii) the efficiency of the biofiltration system for several compounds present in air emissions, analyzing organic substances by means of gas chromatography/mass spectrometry. The two plants used similar biofiltration systems except for the material used as biofilter bed. A bioscrubber pretreatment of the air flow coming from the aerobic reactor was tested in the Albano plant for the purpose of reducing the odor concentration of the most impacting flow going to the biofilter. PMID:15137709

  18. Odor and pheromone sensing via chemoreceptors.

    Science.gov (United States)

    Ma, Minghong

    2012-01-01

    Evolutionally, chemosensation is an ancient but yet enigmatic sense. All organisms ranging from the simplest unicellular form to the most advanced multicellular creature possess the capability to detect chemicals in the surroundings. Conversely, all living things emit some forms of smells, either as communicating signals or as by-products of metabolism. Many species (from worms, insects to mammals) rely on the olfactory systems which express a large number of chemoreceptors to locate food and mates and to avoid danger. Most chemoreceptors expressed in olfactory organs are G-protein coupled receptors (GPCRs) and can be classified into two major categories: odorant receptors (ORs) and pheromone receptors, which principally detect general odors and pheromones, respectively. In vertebrates, these two types of receptors are often expressed in two distinct apparatuses: The main olfactory epithelium (MOE) and the vomeronasal organ (VNO), respectively. Each olfactory sensory neuron (OSN) in the MOE typically expresses one type of OR from a large repertoire. General odors activate ORs and their host OSNs (ranging from narrowly- to broadly-tuned) in a combinatorial manner and the information is sent to the brain via the main olfactory system leading to perception of smells. In contrast, pheromones stimulate relatively narrowly-tuned receptors and their host VNO neurons and the information is sent to the brain via the accessory olfactory system leading to behavioral and endocrinological changes. Recent studies indicate that the functional separation between these two systems is blurred in some cases and there are more subsystems serving chemosensory roles. This chapter focuses on the molecular and cellular mechanisms underlying odor and pheromone sensing in rodents, the best characterized vertebrate models.

  19. Odor and pheromone sensing via chemoreceptors.

    Science.gov (United States)

    Ma, Minghong

    2012-01-01

    Evolutionally, chemosensation is an ancient but yet enigmatic sense. All organisms ranging from the simplest unicellular form to the most advanced multicellular creature possess the capability to detect chemicals in the surroundings. Conversely, all living things emit some forms of smells, either as communicating signals or as by-products of metabolism. Many species (from worms, insects to mammals) rely on the olfactory systems which express a large number of chemoreceptors to locate food and mates and to avoid danger. Most chemoreceptors expressed in olfactory organs are G-protein coupled receptors (GPCRs) and can be classified into two major categories: odorant receptors (ORs) and pheromone receptors, which principally detect general odors and pheromones, respectively. In vertebrates, these two types of receptors are often expressed in two distinct apparatuses: The main olfactory epithelium (MOE) and the vomeronasal organ (VNO), respectively. Each olfactory sensory neuron (OSN) in the MOE typically expresses one type of OR from a large repertoire. General odors activate ORs and their host OSNs (ranging from narrowly- to broadly-tuned) in a combinatorial manner and the information is sent to the brain via the main olfactory system leading to perception of smells. In contrast, pheromones stimulate relatively narrowly-tuned receptors and their host VNO neurons and the information is sent to the brain via the accessory olfactory system leading to behavioral and endocrinological changes. Recent studies indicate that the functional separation between these two systems is blurred in some cases and there are more subsystems serving chemosensory roles. This chapter focuses on the molecular and cellular mechanisms underlying odor and pheromone sensing in rodents, the best characterized vertebrate models. PMID:22399397

  20. 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.

  1. 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.

  2. Recent developments in the chemistry of sandalwood odorants.

    Science.gov (United States)

    Brocke, Constanze; Eh, Marcus; Finke, Anja

    2008-06-01

    Natural sandalwood oil, a unique and valuable ingredient in fine perfumery, has been the focus of scientific interest for many years. Due to its scarcity and its high price, the search for novel synthetic raw materials imitating the characteristic odor profile of sandalwood oil is as challenging as ever. In this context, the preparation of the novel sandalwood odorants 26, 33, and 39 will be discussed, including their sensory properties and structure-odor relationship. PMID:18618410

  3. Olfactory discrimination ability of South African fur seals (Arctocephalus pusillus) for enantiomers.

    Science.gov (United States)

    Kim, Sunghee; Amundin, Mats; Laska, Matthias

    2013-06-01

    Using a food-rewarded two-choice instrumental conditioning paradigm we assessed the ability of South African fur seals, Arctocephalus pusillus, to discriminate between 12 enantiomeric odor pairs. The results demonstrate that the fur seals as a group were able to discriminate between the optical isomers of carvone, dihydrocarvone, dihydrocarveol, menthol, limonene oxide, α-pinene, fenchone (all p isopulegol, rose oxide, and camphor (all p > 0.05). 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 enantiomeric odor pairs. A comparison between the discrimination performance of the fur seals and that of other species tested previously on the same set of enantiomers (or subsets thereof) suggests that the olfactory discrimination capabilities of this marine mammal are surprisingly well developed and not generally inferior to that of terrestrial mammals such as human subjects and non-human primates. 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. Taken together, the results of the present study support the notion that the sense of smell may play an important and hitherto underestimated role in regulating the behavior of fur seals. PMID:23011284

  4. An in vitro study of manure composition on the biochemical origins, composition, and accumulation of odorous compounds in cattle feedlots.

    Science.gov (United States)

    Miller, D N; Varel, V H

    2002-09-01

    Very little is known about the biochemical origin of cattle feedlot odors and the environmental factors controlling their production. The tie between diet and manure composition is well established, but the effect of different manure compositions on odorous chemical production is unknown. This study describes the effect of starch, casein, and cellulose substrate additions to slurries of fresh (manure (> 1 d) on the anaerobic production of fermentation products and the consumption of substrates relative to no addition treatments. Aged cattle manure accumulated more VFA (245 to 290 mM) than the fresh manure (91 to 181 mM) irrespective of substrate additions (P manures, VFA concentrations were increased (P manure increased VFA content relative to no addition treatments (P manure (no addition and protein treatments), indicating that some protein fermentation occurred in those treatments. Based upon substrate loss, starch fermentation was the dominant process in both manures and all treatments with losses exceeding 18.6 g/L. Protein fermentation occurred only in the aged manure, specifically the no addition and protein treatments, when starch was no longer available. The production of odorous compounds from manure was controlled by substrate availability and pH, with pH related to lactate accumulation. We believe that calcareous soil and lactate-consuming microorganisms in the aged manure slurries minimized slurry acidification and resulted in greater accumulations of odorous products. Substrate additions had little effect on the overall accumulation of odor compounds in manure but had profound effects on odor compound composition. We propose that modifying cattle diets to limit starch and protein excretion would profoundly affect the production and accumulation of odor compounds in feedlots. PMID:12349997

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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].

  10. 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.

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

    OpenAIRE

    Anne-Claude eLuisier; Genevieve ePetitpierre; Camille eFerdenzi; Annick eClerc-Berod; Agnes eGiboreau; Catherine eRouby; Moustafa eBENSAFI

    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 importa...

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

    OpenAIRE

    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 importa...

  13. An antennal carboxylesterase from Drosophila melanogaster, Esterase 6, is a candidate Odorant-Degrading Enzyme towards food odorants

    OpenAIRE

    Thomas eChertemps; Faisal eYounus; Claudia eSteiner; Nicolas eDurand; Chris eCoppin; Gunjan ePandey; John eOakeshott; Martine eMaïbèche

    2015-01-01

    Reception of odorant molecules within insect olfactory organs involves several sequential steps, including their transport through the sensillar lymph, interaction with the respective sensory receptors, and subsequent inactivation. Odorant-Degrading Enzymes (ODEs) putatively play a role in signal dynamics by rapid degradation of odorants in the vicinity of the receptors, but this hypothesis is mainly supported by in vitro results. We have recently shown that an extracellular carboxylesterase,...

  14. An antennal carboxylesterase from Drosophila melanogaster, esterase 6, is a candidate odorant-degrading enzyme toward food odorants

    OpenAIRE

    Chertemps, Thomas; Younus, Faisal; Steiner, Claudia; Durand, Nicolas; Coppin, Chris W.; Pandey, Gunjan; Oakeshott, John G.; Maïbèche, Martine

    2015-01-01

    International audience; Reception of odorant molecules within insect olfactory organs involves several sequential steps, including their transport through the sensillar lymph, interaction with the respective sensory receptors, and subsequent inactivation. Odorant-degrading enzymes (ODEs) putatively play a role in signal dynamics by rapid degradation of odorants in the vicinity of the receptors, but this hypothesis is mainly supported by in vitro results. We have recently shown that an extrace...

  15. 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.

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

    Science.gov (United States)

    Al Aïn, Syrina; Belin, Laurine; Patris, Bruno; Schaal, Benoist

    2012-01-01

    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. PMID:23133511

  17. Taste-Potentiated Odor Aversion Learning in Rats with Lesions of the Insular Cortex

    OpenAIRE

    Lin, Jian-You; Roman, Christopher; Reilly, Steve

    2009-01-01

    The current study assessed the influence of excitotoxic lesions of the insular cortex (IC) on taste-potentiated odor aversion (TPOA) learning. Water-deprived rats initially received a single odor-toxicosis or odor/taste-toxicosis pairing and were subsequently tested, in separate trials, with the odor and the taste stimulus. Indicating TPOA, neurologically intact rats conditioned with the odor/taste compound stimulus acquired significantly stronger odor aversions than normal rats conditioned w...

  18. 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.

  19. 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.

  20. THE POTENTIAL EFFECT OF AMBIENT ARSENIC IN DRINKING WATER ON ODOR IDENTIFICATION IN AN AGRICULTURAL SAMPLE IN INNER MONGOLIA

    Science.gov (United States)

    There is some evidence that chronic exposure to arsenic (As) can have neuropathic and neurosensory effects in humans. It is unknown if As exposure affects the sense of smell. To determine if the ability to identify odors is impaired by chronic As exposure via drinking water, 15...

  1. 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.

  2. Evaluation of the Effectiveness of Five Odor Reducing Agents for Sewer System Odors Using an On-Line Total Reduced Sulfur Analyzer

    OpenAIRE

    Hyunook Kim; Joungdu Shin; Hyunjoo Lee; Il Choi

    2012-01-01

    Sewer odors have been a concern to citizens of the Metropolitan Seoul region, which has installed combined sewer systems (CSSs) in 86% of its area. Although a variety of odorants are released from sewers, volatile sulfur compounds (VSCs) have been recognized as major ones. A number of technologies have been proposed to monitor or control odors from sewers. One of the most popular strategies adopted for the control of sewage odor is by applying a commercial odor-reducing agent into the sewer. ...

  3. Labor market discrimination and capital investment: the effects of fan discrimination on stadium investment

    OpenAIRE

    Bodvarsson, Örn B.; Humphreys, Brad R.

    2009-01-01

    We investigate the possibility that labor market discrimination affects economic outcomes in the complementary capital market. Previous research contains ample theoretical justification, and empirical evidence, that discrimination affects wages and employment in labor markets. However, the effects of discrimination against minority labor on transactions in markets for other inputs used in production are not known. We develop a model of the optimal capital stock put in place in the presence of...

  4. Change of odor characteristics of fuel gas

    International Nuclear Information System (INIS)

    For safety reasons, very small amounts of tetrahydrothiophene (THT) are added to the natural gas distributed through pipelines in Switzerland. The aim is to give the naturally odorless gas a strong smell of mineral coal gas so that inhabitants will be warned of gas leaks. However, experts suspected that this typical smell would be lost when natural gas flows through soils that are polluted with mineral oils and that the nauseous odor would be replaced by a pleasant one. This suspicion was confirmed by flow tests carried out with different types of soil (organic substances' share: 6.6 - 11.4%; various pollutants). (author)

  5. 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...... 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...

  6. Price discrimination and business-cycle risk

    OpenAIRE

    Cornia, Marco; Gerardi, Kristopher S.; Shapiro, Adam Hale

    2011-01-01

    A parsimonious theoretical model of second degree price discrimination suggests that the business cycle will affect the degree to which firms are able to price-discriminate between different consumer types. We analyze price dispersion in the airline industry to assess how price discrimination can expose airlines to aggregate-demand fluctuations. Performing a panel analysis on seventeen years of data covering two business cycles, we find that price dispersion is highly procyclical. Estimates s...

  7. 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.

  8. 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.

  9. 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

  10. Odor control in swine buildings: recycle flush vs. automated scraper

    Science.gov (United States)

    A research project was conducted to compare odor concentrations in exhaust of traditional flush barns and barns equipped with automated scrapers. The study was conducted at commercial tunnel-ventilated swine barns in northwest Missouri. Odor samples were collected from the barn exhaust in polyvinyl ...

  11. 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.

  12. 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.

  13. Odors Best at Evoking Emotionally Charged Memories

    Institute of Scientific and Technical Information of China (English)

    E.J.Mundell; 汪阿宝

    2001-01-01

    西方富国的科研人员进行了一些在我们看来多少有些“荒诞”的实验。本文就是一例。但是,细读之下,你不仅为其认真的实验态度所感动,而且,也会觉得“荒诞”之中也有不少“正经”因素。说不准,一项“荒诞”的实验引发了震惊世界的科研成果!本文的标题理解起来不易,弄懂了标题,文章的中心思想也就在其中了。Odors Best at Evoking Emotionally Charged Memories可以完整地表达为:Odors are best at evoking memories which are emotionally charged.可译:气味最能激活与情感相连的记忆。本文的首句和标题呼应,值得玩味。

  14. Nuisance Odors: Is there a Concern - 12340

    International Nuclear Information System (INIS)

    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

  15. 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

  16. 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. PMID:25111824

  17. 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.

  18. 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....... In this paper I address these issues. First, I offer a taxonomy of discrimination. I then argue that discrimination is bad, when it is, because it harms people. Finally, I criticize a rival, disrespect-based account according to which discrimination is bad regardless of whether it causes harm....

  19. Concentrations of aroma compounds and odor activity values of odorant series in different olive cultivars and their oils.

    Science.gov (United States)

    Reboredo-Rodríguez, Patricia; González-Barreiro, Carmen; Cancho-Grande, Beatriz; Simal-Gándara, Jesús

    2013-06-01

    Olives from Picual, Arbequina, Manzanilla de Sevilla, and Local cultivars together with their corresponding oils were analyzed in terms of odor activity values (OAVs) to establish the relationship between the aromatic profile of both olives and oils. The OAVs for the different compounds were classified in nine odorant series: grass, leaf, wood, bitter, sweet, pungent, olive fruit, apple, and banana. The total intensities for every aromatic series were calculated as the sum of the OAVs of each compound associated with this series. As a result, olives had characteristic profiles. Picual cultivar had not a clear sensory characterization from the volatile compounds. Arbequina cultivar was mainly characterized by apple and bitter odorant series; Manzanilla de Sevilla by apple, bitter, and grass odorant series; and Local variety by banana and olive fruit. However, in the oils obtained from those olives, these differences disappeared, and all oils showed the same profile with pungent, bitter, and wood odorant series most strongly contributing. PMID:23659432

  20. 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.

  1. 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...

  2. Empirical model of odor emission from deep-pit swine finishing barns to derive a standardized odor emission factor

    Science.gov (United States)

    Schauberger, Günther; Lim, Teng-Teeh; Ni, Ji-Qin; Bundy, Dwaine S.; Haymore, Barry L.; Diehl, Claude A.; Duggirala, Ravi K.; Heber, Albert J.

    2013-02-01

    Odor emission from swine housing is influenced by the herd characteristics and building environment. The following three specific factors were identified as inputs to a swine house odor emission model: indoor temperature, barn ventilation rate, and pig activity. Model input parameters were determined based on tests of four, identical, 1000-head, mechanically-ventilated swine finishing houses. Each building had two sidewall curtains, a curtain on the west end wall, five exhaust fans on the east end wall, four pit ventilation fans, and long-term manure storage beneath a fully slatted floor. Odor concentrations of 112 odor samples were determined using dynamic forced-choice olfactometry with four to six trained panelists. The emission model showed that the standard live mass specific odor emission factor was 48 OU s-1 per 500 kg live mass or animal unit (AU), and it corresponded to an indoor temperature of T0 = 20 °C, a ventilation rate of V0 = 200 m3 h-1 (55.6 × 10-3 m3 s-1) per pig (maximum capacity for summer time), and the daily mean animal activity. The rate of odor emission from a swine finishing house can be calculated based on these parameters coupled with the number of animals, the mean live mass, and the standard live mass specific odor emission factor. Using this process-based odor emission model, the odor emission estimation and therefore the input for odor dispersion models can be improved to obtain more reliable estimates of separation distance for siting future pig farms.

  3. 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.

  4. 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.

  5. 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.

  6. Odor recognition memory: two encoding trials are better than one.

    Science.gov (United States)

    Nguyen, Lauren A; Ober, Beth A; Shenaut, Gregory K

    2012-10-01

    The primary purpose of this study was to determine the effect of one versus two encoding trials in the classical yes/no recognition memory paradigm using olfactory stimuli. A group of 24 young adults rated 18 standard microencapsulated odorant targets for familiarity (first encoding block) or pleasantness (second encoding block). Once-encoded targets were in only one block and twice-encoded targets were in both, with items counterbalanced across participants. Participants performed a 20-min nonverbal distractor task followed by a yes/no recognition test incorporating 18 additional odors as foils. Memory performance for twice-encoded targets was superior to that for once-encoded targets. For once-encoded targets, performance did not differ between those rated for familiarity versus those rated for pleasantness. Less pleasant odors produced overall better recognition, with a tendency for less familiar odors to produce overall better recognition. There was a tendency for the second encoding trial to have a larger effect for less pleasant or familiar odors than for more pleasant or familiar odors. The main conclusion is that recognition memory for odors is better for items encoded two times than for items encoded only once. Implications of these findings and suggestions for future research are discussed. PMID:22843762

  7. 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.

  8. 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.

  9. 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. PMID:23118203

  10. 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. PMID:26991044

  11. 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.

  12. Involvement of TRPV1 in the Olfactory Bulb in Rimonabant-Induced Olfactory Discrimination Deficit.

    Science.gov (United States)

    Hu, Sherry Shu-Jung

    2016-02-29

    Rimonabant is well recognized as a cannabinoid CB₁ receptor antagonist/inverse agonist. Rimonabant not only antagonizes the effects induced by exogenous cannabinoids and endocannabinoids at CB₁ receptors, it also exerts several pharmacological and behavioral effects independent of CB₁ receptor inactivation. For example, rimonabant can function as a low-potency mixed agonist/antagonist of the transient receptor potential vanilloid receptor 1 (TRPV1). Hence, it is important to explain the underlying mechanisms of the diverse physiological effects induced by rimonabant with caution. Interestingly, CB₁ receptor has recently been suggested to play a role in olfactory functions. Olfaction not only is involved in food intake, visual perception and social interaction, but also is proposed as a putative marker for schizophrenia and autism. Therefore, the present study aimed to investigate whether CB₁ receptor and TRPV1 played a role in olfactory functions. We first used the genetic disruption approach to examine the role of CB₁ receptor in olfactory functions and found that CB₁ knockout mice exhibited olfactory discrimination deficit. However, it is important to point out that these CB₁ knockout mice, despite their normal locomotivity, displayed deficiencies in the olfactory foraging and novel object exploration tasks. These results imply that general exploratory behaviors toward odorant and odorless objects are compromised in CB₁ knockout mice. We next turned to the pharmacological approach to examine the role of CB₁ receptor and TRPV1 in olfactory functions. We found that the short-term administration of rimonabant, injected systemically or directly into the olfactory bulb (OB), impaired olfactory discrimination that was rescued by the TRPV1 antagonist capsazepine (CPZ), via the same route of rimonabant, in wild-type mice. These results suggest that TRPV1 in the OB is involved in rimonabant-induced olfactory discrimination deficit. However, the

  13. Sparse discriminant analysis

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Hastie, Trevor; Witten, Daniela;

    2011-01-01

    commonplace in biological and medical applications. In this setting, a traditional approach involves performing feature selection before classification. We propose sparse discriminant analysis, a method for performing linear discriminant analysis with a sparseness criterion imposed such that classification...... and feature selection are performed simultaneously. Sparse discriminant analysis is based on the optimal scoring interpretation of linear discriminant analysis, and can be extended to perform sparse discrimination via mixtures of Gaussians if boundaries between classes are nonlinear or if subgroups...... are present within each class. Our proposal also provides low-dimensional views of the discriminative directions. © 2011 American Statistical Association and the American Society for Qualitys....

  14. 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.

  15. Presence of conspecifics and their odor-impregnated objects reverse stress-decreased neurogenesis in mouse dentate gyrus.

    Science.gov (United States)

    Cherng, Chianfang G; Lin, Pei-Syuan; Chuang, Jia-Ying; Chang, Wan-Ting; Lee, Yung-Shuan; Kao, Gour-Shenq; Lai, Yu-Ting; Yu, Lung

    2010-03-01

    Stress and corticosterone level are thought to negatively associate with neurogenesis in mammalian brains. Social support can diminish many adverse effects of stress. The present study examined the modulating effect of social support on stress-decreased cell proliferation and neuronal differentiation in a mouse model. A randomly-scheduled foot shock followed by restraint in water was used as a profound stress-provoking regimen. Bromodeoxyuridine (BrdU) staining was used to indicate newly mitotic cells and doublecortin (DCx) staining was used to reveal immature neurons. This stress-provoking regimen rapidly decreased BrdU- and BrdU/DCx-labeled cells in the dentate gyrus. However, such a stress-provoking regimen did not affect the number of these labeled cells in the subventricular zone. Familiar and unfamiliar mice' company throughout the stress regimen completely reversed the stress-decreased cell proliferation and neuronal genesis in the dentate gyrus. Likewise, both odor-familiar (from their home cages) and -unfamiliar (from cages other than their home cages) wooden blocks completely reversed the stress-decreased BrdU/DCx-labeled cells in the dentate gyrus. In contrast, wooden blocks free of any odor and camphor odor alone failed to affect the stress-decreased BrdU- or BrdU/DCx-labeled cells. Finally, we showed that conspecifics or their odors during the stress regimen reversed the stress-decreased cell proliferation and neuronal differentiation in the dentate gyrus via a corticosterone-independent mechanism. We conclude that stress and familiarity distinctively affect neurogenesis in the dentate gyrus and subventricular zone. Conspecific companions or presence of their odors reverse stress-decreased neurogenesis in the dentate gyrus, suggesting that social support during stress exposure may improve neurogenesis-related psychological functions. PMID:19943847

  16. 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.

  17. 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)

  18. Host status and fruit odor response of Drosophila suzukii (Diptera: Drosophilidae) to figs and mulberries.

    Science.gov (United States)

    Yu, Doris; Zalom, F G; Hamby, K A

    2013-08-01

    Drosophila suzukii Matsumura (Diptera: Drosophilidae) is an agricultural pest with a wide host range. It is known to infest fruit that are still ripening on the plant, as well as rotting and damaged fruit. Our study sought to determine whether D. suzukii use mulberries (Morus spp.) and figs (Ficus carica (L.)) as hosts, as their host status was ambiguous. Accordingly, we collected 25 field-infested fruit and counted the numbers of D. suzukii emerging from them. We also sought to determine whether female D. suzukii would respond to olfactory cues from ripe figs and mulberries. As the host population has been known to impact host odor response, flies from mulberry, fig, and cherry origins were tested in "one-choice" olfactometry studies. Our results show that mulberries and figs can serve as hosts for D. suzukii and that female flies will respond to their odors. The host population did affect response to fruit odors, although further studies are necessary to determine habitat fidelity. This has implications for management of this pest, especially in backyard and mixed fruit orchard situations, which commonly occur in the current range of D. suzukii, and fig and mulberry may serve as a pest reservoir for other hosts and cultivated crops.

  19. 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

  20. 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.

  1. 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.

  2. Olfactory discrimination ability for aliphatic esters in squirrel monkeys and humans.

    Science.gov (United States)

    Laska, M; Freyer, D

    1997-08-01

    Using a behavioral paradigm designed to simulate olfactory-guided foraging, the ability of five squirrel monkeys to distinguish iso-amyl acetate from n- and iso-forms of other acetic esters (ethyl acetate to decyl acetate) and from other esters carrying the iso-amyl group (iso-amyl propionate to iso-amyl capronate) was investigated. We found (i) that all five animals were clearly able to discriminate between all odor pairs tested; (ii) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length of both the aliphatic alcohol group and the aliphatic acid group of the esters; and (iii) that iso- and n-amyl acetate were perceived as qualitatively similar despite different steric conformation. Using a triple-forced choice procedure, 20 human subjects were tested on the same tasks in parallel and showed a very similar pattern of discrimination performance compared with the squirrel monkeys. Thus, the results of this study provide evidence of well-developed olfactory discrimination ability in squirrel monkeys for aliphatic esters and support the assumption that human and non-human primates may share common principles of odor quality perception. PMID:9279468

  3. 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.

  4. 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.

  5. 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.

  6. 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.

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

    International Nuclear Information System (INIS)

    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.

  8. 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.

  9. Visualizing mushroom body response to a conditioned odor in honeybees

    Science.gov (United States)

    Faber, Till; Menzel, Randolf

    2001-11-01

    Combining differential conditioning with optophysiological recordings of bee brain activity allows the investigation of learning-related changes in complex neural systems. In this study we focused on the mushroom bodies of the bee brain. Presenting different odors to the animal leads to significant activation of the mushroom body lips. After differential conditioning, the rewarded odor leads to stronger activation than it did before training. Activation by the unrewarded odor remains unchanged. These results resemble findings in the bee's antennal lobes, which are the first olfactory relay station in the insect brain. As an integrative neural network, enhanced activation of the mushroom body lip may carry additional information, i.e., for processing odor concentrations.

  10. Odor Modification in Salmon Hydrolysates Using the Maillard Reaction

    OpenAIRE

    Kouakou, Christelle; Berge, Jean-pascal; Baron, Regis; Lethuaut, Laurent; PROST, Carole; Cardinal, Mireille

    2014-01-01

    The aim of this work was to study the effect of adding sugar during proteolysis to promote the Maillard reaction and mask the initial fish odor and off-flavors generated. An experimental design, based on the Doehlert plan, was used to study the influence of hydrolysis conditions (time, temperature, sugar, and antioxidant addition) on the odor characteristics of hydrolysates, soluble protein levels, and amino acid content. Results showed that the lowest level of sugar (10g of D-xylose added to...

  11. 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.

  12. A rare case of fish odor syndrome presenting as depression

    OpenAIRE

    Khan, Shahbaz Ali; Shagufta, K.

    2014-01-01

    A young lady presents to the psychiatry out-patient department with depressive symptoms. Evaluation revealed long standing stressor in the form of a foul odor emanating from her body and over a period of time resulting in social withdrawal and depression with significant impairment of day-to-day functioning. A diagnosis of trimethylaminurea (fish odor syndrome) and adjustment disorder was arrived at. Careful empathetic handling with psychoeducation, behavioral and cognitive counseling and a s...

  13. Common Promoter Elements in Odorant and Vomeronasal Receptor Genes

    OpenAIRE

    Jussara S Michaloski; Galante, Pedro A. F.; Nagai, Maíra H.; Lucia Armelin-Correa; Ming-Shan Chien; Hiroaki Matsunami; Bettina Malnic

    2011-01-01

    In mammals, odorants and pheromones are detected by hundreds of odorant receptors (ORs) and vomeronasal receptors (V1Rs and V2Rs) expressed by sensory neurons that are respectively located in the main olfactory epithelium and in the vomeronasal organ. Even though these two olfactory systems are functionally and anatomically separate, their sensory neurons show a common mechanism of receptor gene regulation: each neuron expresses a single receptor gene from a single allele. The mechanisms unde...

  14. 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.

  15. Reducing the indoor odorous charge in waste treatment facilities

    OpenAIRE

    Gallego Piñol, Eva; Roca Mussons, Francisco Javier; Perales Lorente, José Francisco

    2014-01-01

    Characterising and determining the odorous charge of indoor air through Odour Units (OU) is an advantageous approach to evaluate indoor air quality and discomfort inside municipal solid waste facilities. The assessment of the OU can be done through the determination of Volatile Organic Compounds (VOC) concentrations and their odour thresholds. The aim of the study was to evaluate the differences in the odorous charge in the organic matter pit of a mechanical-biological waste treat...

  16. 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.

  17. 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...... has positive spillovers, inducing employment increases in the other sector. Discrimination may induce immigrants to train more or less than natives, depending on the sector where it is present. Welfare tends to be most negatively affected by discrimination among highproductivity workers....

  18. 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.

  19. 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.

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

    OpenAIRE

    Syrina Al Aïn; Laurine Belin; Bruno Patris; Benoist Schaal

    2012-01-01

    International audience 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 lact...

  1. 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...

  2. Territorial analysis of discriminated groups

    OpenAIRE

    Mihaela Hrisanta MOSORA

    2013-01-01

    Labour market discrimination may lead to segregation resulting in the separation between the majority and the minority group at the local level, occupational level, educational level in public spaces etc. In this study we analysed the distribution of the Rroma population at local level, because they are regarded as the most vulnerable group in Romania. We also analysed the extent to which spatial localization affects the poverty rate in this community. Data were provided by “A social map of P...

  3. 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

    OBJECTIVE/HYPOTHESIS:: Self-ratings of olfactory function correlates often poorly with results of objective smell tests. We explored them relative to self-rating of odor annoyance, to odor identification ability, and to mean perceived intensity of odors, and estimated relative genetic and environ......OBJECTIVE/HYPOTHESIS:: Self-ratings of olfactory function correlates often poorly with results of objective smell tests. We explored them relative to self-rating of odor annoyance, to odor identification ability, and to mean perceived intensity of odors, and estimated relative genetic...... 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...

  4. Identification, quantification and treatment of fecal odors released into the air at two wastewater treatment plants.

    Science.gov (United States)

    Zhou, Yubin; Hallis, Samantha A; Vitko, Tadeo; Suffet, Irwin H Mel

    2016-09-15

    Odorous emissions from wastewater treatment plants (WWTPs) are an annoyance for neighboring communities. This article, for the first time, quantitatively reports on an evaluation of the presence of fecal odorants identified in air samples from two exemplary WWTPs by the odor profile method (OPM) and chemical analysis. The fecal odorants indole and skatole were identified by Gas Chromatography-Mass Spectrometry. The odor threshold concentration of skatole was determined to be 0.327 ng/L (60 pptV) in Teflon Bags by an expert panel. Skatole was found to be the primary chemical leading to fecal odor, due to its odor concentration to odor threshold concentration ratio that ranged from 2.8 to 22.5. The Weber-Fechner law was followed by pure skatole, but was not applicable when there was a mixture of fecal odorants and other odorant types present in WWTP air emission samples. This is probably caused by antagonism with other odorant types. Several existing odor control treatment methods for fecal odorants were evaluated at different wastewater treatment operations at two WWTPs by the OPM and chemical analysis for indole and skatole. Chemical scrubbing and biofiltration performed best in removing fecal odors among current control technologies. PMID:27235805

  5. Odor characterization from barns and slurry treatment facilities at a commercial swine facility in South Korea

    Science.gov (United States)

    Jo, Sang-Hee; Kim, Ki-Hyun; Jeon, Byong-Hun; Lee, Min-Hee; Kim, Yong-Hyun; Kim, Bo-Won; Cho, Sung-Back; Hwang, Ok-Hwa; Bhattacharya, Satya Sundar

    2015-10-01

    In this study, emission characteristics of major odorants in pig confinement facilities were investigated through comparative analysis between odorant composition and odor intensity. Odorant samples in ambient air were collected from five different paired sampling sites: (1) in- and outside of windowless pig barn, (2) in- and outside of open pig barn, (3) before/after slurry treatment (via liquid fertilization), (4) before/after composting, and (5) two reference background sites on a pig confinement facility. A total of 47 compounds consisting of key offensive odorants (such as reduced sulfur and volatile organic compounds) were measured from each selected site. When the results are compared in terms of odor intensity, a list of odorants (sulfur compounds, volatile fatty acids, phenols, and indoles) were generally seen at enhanced levels on most sites. In two types of pig barn facilities (windowless ('W') and open ('O')), butyric and valeric acid were the predominant species. The removal efficiency of odorants was quite different between the two slurry treatment approaches of composting and liquid fertilization. Although the efficiencies of odor removal in the former were not sufficient, that of the latter was fairly significant in terms of odor intensity. However, some odorants like hydrogen sulfide, methanethiol, p-cresol, and butyric acid were still retained above the odor threshold level. Accordingly, odorant emissions from animal housing facilities can be characterized most effectively by key odorants such as volatile fatty acids and reduced sulfur species.

  6. Understanding the underlying dimensions in perfumers' odor perception space as a basis for developing meaningful odor maps.

    Science.gov (United States)

    Zarzo, Manuel; Stanton, David T

    2009-02-01

    Various low-dimensional perceptual maps of fragrances have been proposed in the literature, as well as sensory maps for the odor descriptors most frequently applied in perfumery. To reach a consensus, however, seems difficult, if at all possible. In the present study, we applied principal components analysis to two databases. The first contains numeric odor profiles of 309 compounds based on 30 descriptors. The loading plot corresponding to the relevant components was strikingly similar to the odor effects diagram proposed by P. Jellinek (1951), primarily on the basis of his long experience as a perfumer. We obtained similar results in our analysis of the second database, which comprises 66 descriptors and contains the semantic descriptions of 119 perfume materials. On the basis of the results of both analyses, a commercial map of fragrances is discussed. Our findings suggest that it is possible to develop standard sensory maps of perfumery odor descriptors, if a consensus is first reached regarding which odorants best represent particular odor qualities. PMID:19304614

  7. Odor and Odorous Compound Emissions from Manure of Swine Fed Standard and Dried Distillers Grains with Soluble Supplemented Diets.

    Science.gov (United States)

    Trabue, Steven; Kerr, Brian; Scoggin, Kenwood

    2016-05-01

    This study was conducted to determine the impact of diets containing dried distillers grains with solubles (DDGS) on emissions of odor and odorous compounds from swine manure storage. Twenty-four pigs were fed either a corn-soybean meal (CSBM) diet or a diet containing 35% DDGS over a 42-d feeding trial. Their waste was collected and transferred to individual manure storage containers. Manure from pigs fed diets containing DDGS had significantly lower odorant emissions expressed in animal units for hydrogen sulfide (HS) and ammonia (NH) ( < 0.05) compared with pigs fed the CSBM diet, but emissions of volatile fatty acids and phenolic compounds were significantly higher ( < 0.05) for manures from animals fed the DDGS diet. There was no significant difference for indole compound emissions due to the dietary treatment applied. Emissions of volatile organic compounds (VOCs) from manure accounted for less than 0.1% of carbon consumed for either diet. There were no significant differences in odor emissions for either diet as quantified with human panels or measured as the sum total of the odor activity value. Manure odors from pigs fed the CSBM diet were dominated by HS, whereas animals fed the diet containing DDGS were dominated by VOCs. PMID:27136158

  8. Feasibility of an interval, inspiration-triggered nocturnal odorant application by a novel device: a patient-blinded, randomised crossover, pilot trial on mood and sleep quality of depressed female inpatients.

    Science.gov (United States)

    Vitinius, Frank; Hellmich, Martin; Matthies, Annalena; Bornkessel, Fabian; Burghart, Heiner; Albus, Christian; Huettenbrink, Karl-Bernd; Vent, Julia

    2014-09-01

    It has been suggested that certain odorants positively affect mood, but this has not yet been scientifically tested in humans. The aim of the current study was to demonstrate the feasibility of a new odorant applicator and to assess the effects of nocturnal intermittent rose odorant application on mood, and quality of sleep and dreams in depressed female inpatients. We hypothesised that mood as primary outcome will improve. Twenty-seven normosmic, 18- to 49-year-old female, depressed inpatients were investigated in a randomised, placebo-controlled, crossover study. Exclusion criteria were rhinitis, hyp- or anosmia. During sleep, an interval-controlled, inspiration-triggered applicator added rose concentrate to the inspirated air. There were three consecutive nights of each odorant and placebo application and a wash-out phase. Patients completed standardised questionnaires on mood, dreams, and sleep quality. Four patients dropped out (n = 1: non-compliance in filling in the questionnaires, n = 3: intolerance of nasal tube). Otherwise, this novel odorant applicator was well tolerated. Application of the odorant showed no significant mood differences between rose and placebo, however, some subdomains of sleep quality and mood showed a positive trend towards improvement by rose application. The feasibility of this new device and of nasal tubes could be shown. Odorant application is well tolerated. It may have a positive influence on quality of mood and sleep in depressed patients. A longer application phase is planned to obtain convincing evidence for our hypothesis. PMID:24390040

  9. 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

  10. 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.

  11. Odors Bias Time Perception in Visual and Auditory Modalities.

    Science.gov (United States)

    Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

    2016-01-01

    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 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 framework of

  12. 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

  13. Amphioxus (Branchiostoma floridae has orthologs of vertebrate odorant receptors

    Directory of Open Access Journals (Sweden)

    Taylor John S

    2009-10-01

    Full Text Available Abstract Background A common feature of chemosensory systems is the involvement of G protein-coupled receptors (GPCRs in the detection of environmental stimuli. Several lineages of GPCRs are involved in vertebrate olfaction, including trace amine-associated receptors, type 1 and 2 vomeronasal receptors and odorant receptors (ORs. Gene duplication and gene loss in different vertebrate lineages have lead to an enormous amount of variation in OR gene repertoire among species; some fish have fewer than 100 OR genes, while some mammals possess more than 1000. Fascinating features of the vertebrate olfactory system include allelic exclusion, where each olfactory neuron expresses only a single OR gene, and axonal guidance where neurons expressing the same receptor project axons to common glomerulae. By identifying homologous ORs in vertebrate and in non-vertebrate chordates, we hope to expose ancestral features of the chordate olfactory system that will help us to better understand the evolution of the receptors themselves and of the cellular components of the olfactory system. Results We have identified 50 full-length and 11 partial ORs in Branchiostoma floridae. No ORs were identified in Ciona intestinalis. Phylogenetic analysis places the B. floridae OR genes in a monophyletic clade with the vertebrate ORs. The majority of OR genes in amphioxus are intronless and many are also tandemly arrayed in the genome. By exposing conserved amino acid motifs and testing the ability of those motifs to discriminate between ORs and non-OR GPCRs, we identified three OR-specific amino acid motifs common in cephalochordate, fish and mammalian and ORs. Conclusion Here, we show that amphioxus has orthologs of vertebrate ORs. This conclusion demonstrates that the receptors, and perhaps other components of vertebrate olfaction, evolved at least 550 million years ago. We have also identified highly conserved amino acid motifs that may be important for maintaining

  14. Varietal differences of wheat for 13C-discrimination and 15N-uptake as affected by drought and its recovery. Final report for the period 1 January 1993 - 31 December 1994

    International Nuclear Information System (INIS)

    A Pot experiment was conducted to investigate the varietal differences of wheat for shoot dry weight, 13C-discrimination, total N-yield and 15N-uptake as affected by drought and its recovery. Four wheat varieties were exposed to different watering regimes (i.e., W0 as normal irrigation of W1 as water stress) during the following growth periods: (i) from 3-leaf stage to third nod stage; (ii) from 3 nod stage to heading; and (iii) from heading to milk-dough stage. For drought recovery study, the experiment included another three water regime treatments induced by varying the irrigation of plants during the selected growth periods (i.e., W10, W100 and W010). The results indicated that water stress during the selected growth periods greatly decreased shoot dry weight, nabla value, total N-yield and amount of nitrogen derived from fertilizer. The (i) and (ii) are considered critical growth periods as far as the above-mentioned parameters are considered. Expression of any tested parameter under water stress as percentage of that of the corresponding control indicated that Dalcahue, Sakha-69 and Bonadur were less sensitive to water stress than the other varieties at (i), (ii) and (iii) growth periods, respectively. On the other hand, Bonadur at (i) and (ii) growth periods and Sakha-69 at (iii) growth period were more sensitive than the other varieties. Exposing of wheat varieties to water stress during (i) and (ii) growth periods resulted in severe injury with regard to shoot dry weight, total N-yield and amount of nitrogen derived from fertilizer. Re-irrigation of the stressed wheat varieties, resulted in drought recovery with different magnitude depending on the variety and the growth period in which the plants were exposed to water stress. Generally, the results demonstrated that Bonadur has better capacity to recover from drought than the other varieties. Therefore, Bonadur may be considered a possible candidate for programs aimed at breeding wheat for drought

  15. Disability discrimination in healthcare services and employment.

    Science.gov (United States)

    Barber, Christopher

    2015-09-30

    This article discusses the meaning and philosophical basis of disability discrimination in health care. It focuses on aspects of language that influence discourse about disability and affect the experiences of people with disabilities. Reference is made to the experiences of those who have an autism spectrum condition, with a specific focus on three NHS employees with Asperger syndrome, in relation to disability discrimination. The implications for nurses and nursing are discussed. Recommendations are made for awareness raising and training. PMID:26419169

  16. 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

  17. Psychology of Fragrance Use: Perception of Individual Odor and Perfume Blends Reveals a Mechanism for Idiosyncratic Effects on Fragrance Choice

    OpenAIRE

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

    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...

  18. 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.

  19. Socially-Tolerable Discrimination

    OpenAIRE

    Amegashie, J. Atsu

    2008-01-01

    History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple rent-seeking model of conflict w...

  20. Socially-Tolerable Discrimination

    OpenAIRE

    Amegashie, J. Atsu

    2008-01-01

    History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple model of conflict which is drive...

  1. Socially-tolerable discrimination

    OpenAIRE

    Amegashie, J. Atsu

    2008-01-01

    History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple rent-seeking model of conflict w...

  2. Age Discrimination in Italy

    OpenAIRE

    Olga Rymkevitch; Claudia Villosio

    2007-01-01

    The Framework Directive on Equal Treatment in Employment and Occupation (2000/78/EC) included age as one of its prohibited grounds of discrimination. Member States were required to transpose this Directive by December 2003. In Italy age discrimination was explicitly regulated by means of Legislative Decree no. 216, 9 July 2003. The Decree introduced the new specific prohibition of discrimination, defining its application, exceptions and remedies. The purpose of this paper is to explore, in a ...

  3. 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.

  4. Mapping of Learned Odor-Induced Motivated Behaviors in the Mouse Olfactory Tubercle.

    Science.gov (United States)

    Murata, Koshi; Kanno, Michiko; Ieki, Nao; Mori, Kensaku; Yamaguchi, Masahiro

    2015-07-22

    An odor induces food-seeking behaviors when humans and animals learned to associate the odor with food, whereas the same odor elicits aversive behaviors following odor-danger association learning. It is poorly understood how central olfactory circuits transform the learned odor cue information into appropriate motivated behaviors. The olfactory tubercle (OT) is an intriguing area of the olfactory cortex in that it contains medium spiny neurons as principal neurons and constitutes a part of the ventral striatum. The OT is therefore a candidate area for participation in odor-induced motivated behaviors. Here we mapped c-Fos activation of medium spiny neurons in different domains of the mouse OT following exposure to learned odor cues. Mice were trained to associate odor cues to a sugar reward or foot shock punishment to induce odor-guided approach behaviors or aversive behaviors. Regardless of odorant types, the anteromedial domain of the OT was activated by learned odor cues that induced approach behaviors, whereas the lateral domain was activated by learned odor cues that induced aversive behaviors. In each domain, a larger number of dopamine receptor D1 type neurons were activated than D2 type neurons. These results indicate that specific domains of the OT represent odor-induced distinct motivated behaviors rather than odor stimuli, and raise the possibility that neuronal type-specific activation in individual domains of the OT plays crucial roles in mediating the appropriate learned odor-induced motivated behaviors. Significance statement: Although animals learn to associate odor cues with various motivated behaviors, the underlying circuit mechanisms are poorly understood. The olfactory tubercle (OT), a subarea of the olfactory cortex, also constitutes the ventral striatum. Here, we trained mice to associate odors with either reward or punishment and mapped odor-induced c-Fos activation in the OT. Regardless of odorant types, the anteromedial domain was

  5. 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

    2015-07-01

    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.

  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. PMID:27494786

  7. 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)...

  8. 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....

  9. Influence of Ambient Odors on Time Perception in a Retrospective Paradigm.

    Science.gov (United States)

    Brand, Gérard; Thiabaud, F; Dray, N

    2016-06-01

    Environmental stimuli can influence time perception, including sensory stimulations. Among them, odors are known to modulate emotion, attention, behavior, or performance, but few studies have investigated the possible effects of ambient odors on time perception. Thus, the present study aimed to compare in a retrospective paradigm the time estimation in three conditions, i.e., with phenyl ethyl alcohol as a pleasant odor, pyridine as unpleasant odor, and a control condition without ambient odor. A total of 90 participants (M age = 23 years, 10 months) took part in three different tasks, i.e., an aesthetic classification task, a sensorimotor checking task, and a mathematical operations task. Results showed a better accuracy of the time estimation in odor condition (1) independently of the characteristics of odorants (2) limited to tasks with a low cognitive involvement. These findings are discussed in relation to the possible role of attention and arousal in the modulation of time perception by ambient odors. PMID:27194618

  10. 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.

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

    Science.gov (United States)

    Gao, Xiang; Acar, Levent

    2016-01-01

    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. PMID:27384568

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

    Science.gov (United States)

    Gao, Xiang; Acar, Levent

    2016-01-01

    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. PMID:27384568

  13. 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.

  14. Characterization of odor-active compounds in guava wine.

    Science.gov (United States)

    Pino, Jorge A; Queris, Oscar

    2011-05-11

    The volatile compounds of guava wine were isolated by continuous solvent extraction and analyzed by GC-FID and GC-MS. A total of 124 volatile constituents were detected, and 102 of them were positively identified. The composition of guava wine included 52 esters, 24 alcohols, 11 ketones, 7 acids, 6 aldehydes, 6 terpenes, 4 phenols and derivatives, 4 lactones, 4 sulfur-compounds, and 5 miscellaneous compounds. The aroma-active areas in the gas chromatogram were screened by application of the aroma extract dilution analysis and by odor activity values. Twelve odorants were considered as odor-active volatiles: (E)-β-damascenone, ethyl octanoate, ethyl 3-phenylpropanoate, ethyl hexanoate, 3-methylbutyl acetate, 2-methyltetrahydrothiophen-3-one, 2,5-dimethyl-4-methoxy-3(2H)-furanone, ethyl (E)-cinnamate, ethyl butanoate, (E)-cinnamyl acetate, 3-phenylpropyl acetate, and ethyl 2-methylpropanoate. PMID:21417409

  15. 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......-generated scent marks to find a food source. Here we model odor supported place cells by using a simple feed-forward network and analyze the impact of olfactory cues on place cell formation and spatial navigation. The obtained place cells are used to solve a goal navigation task by a novel mechanism based on self......-marking by odor patches combined with a Q-learning algorithm. We also analyze the impact of place cell remapping on goal directed behavior when switching between two environments. We emphasize the importance of olfactory cues in place cell formation and show that the utility of environmental and self...

  16. 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.

  17. Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors

    OpenAIRE

    Kohl, James V.

    2012-01-01

    Background: Olfactory cues directly link the environment to gene expression. Two types of olfactory cues, food odors and social odors, alter genetically predisposed hormone-mediated activity in the mammalian brain. Methods: The honeybee is a model organism for understanding the epigenetic link from food odors and social odors to neural networks of the mammalian brain, which ultimately determine human behavior. Results: Pertinent aspects that extend the honeybee model to human behavior include...

  18. An Artificial Neural Networks-Based on-Line Monitoring Odor Sensing System

    OpenAIRE

    Yousif A. Bastaki

    2009-01-01

    Problem statement: There have been many works for odor recognition using different sensor arrays and pattern recognition techniques in last decades. Approach: Although an odor is usually recorded utilizing language expression, it is too difficult for laymen to associate actual odor with that expression. Results: 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 ...

  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. Evaluation of the Effectiveness of Five Odor Reducing Agents for Sewer System Odors Using an On-Line Total Reduced Sulfur Analyzer

    Directory of Open Access Journals (Sweden)

    Hyunook Kim

    2012-12-01

    Full Text Available Sewer odors have been a concern to citizens of the Metropolitan Seoul region, which has installed combined sewer systems (CSSs in 86% of its area. Although a variety of odorants are released from sewers, volatile sulfur compounds (VSCs have been recognized as major ones. A number of technologies have been proposed to monitor or control odors from sewers. One of the most popular strategies adopted for the control of sewage odor is by applying a commercial odor-reducing agent into the sewer. In this study, the effectiveness of five different commercial odor-reducing agents (i.e., an odor masking agent, an alkaline solution, two microbial agents, and a chemical oxidant was evaluated by continuously monitoring VSCs released from the sewer with an on-line total reduced sulfur (TRS analyzer before and after each agent was sprayed into CSSs at five different locations of the city. In short, when the effectiveness of odor treatment was tested in the sewer system using five commercial odor reducing treatments, only the chemical oxidant was good enough to reduce the odor in terms of TRS levels measured before and after the application (p < 0.01.

  1. Discriminants of multilinear systems

    OpenAIRE

    Emiris, Ioannis Z.; Vidunas, Raimundas

    2016-01-01

    We study well-constrained bilinear algebraic systems in order to formulate their discriminant. We derive a new determinantal formula for the discriminant of a multilinear system that appears in the study of Nash equilibria of multiplayer games with mixed strategies.

  2. 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....

  3. Structure-Odor Activity Studies on Monoterpenoid Mercaptans Synthesized by Changing the Structural Motifs of the Key Food Odorant 1-p-Menthene-8-thiol.

    Science.gov (United States)

    Schoenauer, Sebastian; Schieberle, Peter

    2016-05-18

    1-p-Menthene-8-thiol (1) has been discovered as the key odorant in grapefruit juice several decades ago and contributes to the overall odor of the fruit with an extremely low odor threshold of 0.000034 ng/L in air. This value is among the lowest odor thresholds ever reported for a food odorant. To check whether modifications in the structure of 1 would lead to changes in odor threshold and odor quality, 34 mercapto-containing p-menthane and 1-p-menthene derivatives as well as several aromatic and open-chain mercapto monoterpenoids were synthesized. Eighteen of them are reported for the first time in the literature, and their odor thresholds and odor qualities as well as analytical data are supplied. A comparison of the sensory data with those of 1 showed that hydrogenation of the double bond led to a clear increase in the odor threshold. Furthermore, moving the mercapto group into the ring always resulted in higher odor thresholds compared to thiols with a mercapto group in the side chains. Although all tertiary thiols always exhibited low odor thresholds, none of the 31 compounds reached the extremely low threshold of 1. Also, none of the synthesized mercapto monoterpenoids showed a similar odor quality resembling grapefruit. Although the saturated and aromatic analogues exhibited similar scents as 1, the aromas of the majority of the other compounds were described as sulfury, rubber-like, burned, soapy, or even mushroom-like. NMR and MS data as well as retention indices of the 23 newly reported sulfur-containing compounds might aid in future research to identify terpene-derived mercaptans possibly present in trace levels in foods. PMID:27121638

  4. REDUCING ODOR NUISANCE PRESSURE SEWERAGE SYSTEM USING FENTON'S REAGENT

    Directory of Open Access Journals (Sweden)

    Anna Nowicka

    2016-06-01

    Full Text Available The aim of this study was to propose a method to eliminate or reduce the occurrence of odor nuisance municipal sewage system located at one of the streets in Mława. In order to eliminate odor nuisance uses advanced oxidation processes. Studies aimed at determining the dose required reagents: PIX and hydrogen peroxide showed that the use of the lowest dose tested of 0,1 g of Fe2+/dm3 and 0,5 g H2O2/dm3 resulted in inhibition susceptibility wastewater rotting.

  5. 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.

  6. Narrow SAR in odorant sensing Orco receptor agonists.

    Science.gov (United States)

    Romaine, Ian M; Taylor, Robert W; Saidu, Samsudeen P; Kim, Kwangho; Sulikowski, Gary A; Zwiebel, Laurence J; Waterson, Alex G

    2014-06-15

    The systematic exploration of a series of triazole-based agonists of the cation channel insect odorant receptor is reported. The structure-activity relationships of independent sections of the molecules are examined. Very small changes to the compound structure were found to exert a large impact on compound activity. Optimal substitutions were combined using a 'mix-and-match' strategy to produce best-in-class compounds that are capable of potently agonizing odorant receptor activity and may form the basis for the identification of a new mode of insect behavior modification. PMID:24813736

  7. Odorant-regulated Ca2+ gradients in rat olfactory neurons

    OpenAIRE

    1993-01-01

    Olfactory neurons respond to odors with a change in conductance that mediates an influx of cations including Ca2+. The concomitant increase in [Cai] has been postulated to play a role in the adaptation to maintained odorant stimulation (Kurahashi, T., and T. Shibuya. 1990. Brain Research. 515:261-268. Kramer, R. H., and S. A. Siegelbaum. 1992. Neuron. 9:897-906. Zufall, F., G. M. Shepherd, and S. Firestein. 1991. Proceedings of the Royal Society of London, B. 246:225-230.) We have imaged the ...

  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. PMID:20212009

  10. Sensory Preconditioning in Newborn Rabbits: From Common to Distinct Odor Memories

    Science.gov (United States)

    Coureaud, Gerard; Tourat, Audrey; Ferreira, Guillaume

    2013-01-01

    This study evaluated whether olfactory preconditioning is functional in newborn rabbits and based on joined or independent memory of odorants. First, after exposure to odorants A+B, the conditioning of A led to high responsiveness to odorant B. Second, responsiveness to B persisted after amnesia of A. Third, preconditioning was also functional…

  11. 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…

  12. 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.

  13. 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.

  14. 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.

  15. 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

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

    International Nuclear Information System (INIS)

    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. - Highlights: ► Garlic and red wine were added to ground beef and irradiated at 5 kGy in the presence of charcoal pack. ► When the samples were irradiated with charcoal pack, the amount of volatile compounds decreased significantly and it affected sensory score. ► Thus, addition of charcoal pack to ground beef could reduce off-odor problems induced by irradiation. ► This effect was consistent when additives, such as garlic and red wine, were added into ground beef.

  17. Frequency discriminator/phase detector

    Science.gov (United States)

    Crow, R. B.

    1974-01-01

    Circuit provides dual function of frequency discriminator/phase detector which reduces frequency acquisition time without adding to circuit complexity. Both frequency discriminators, in evaluated frequency discriminator/phase detector circuits, are effective two decades above and below center frequency.

  18. 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.

  19. 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...

  20. 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.

  1. Odorous VOC emission following land application of swine manure slurry

    Science.gov (United States)

    Parker, David B.; Gilley, John; Woodbury, Bryan; Kim, Ki-Hyun; Galvin, Geordie; Bartelt-Hunt, Shannon L.; Li, Xu; Snow, Daniel D.

    2013-02-01

    Swine manure is often applied to crop land as a fertilizer source. Odor emissions from land-applied swine manure may pose a nuisance to downwind populations if manure is not applied with sufficient forethought. A research project was conducted to assess the time decay of odorous volatile organic compound (VOC) emissions following land application of swine manure. Three land application methods were compared: surface application, incorporation 24 h after surface application, and injection. Emission rates were measured in field plots using a small wind tunnel and sorbent tubes. VOCs including eight volatile fatty acids, five aromatics, and two sulfur-containing compounds were quantified by gas chromatography-mass spectrometry. In most cases, a first order exponential decay model adequately described the flux versus time relationship for the 24 h period following land application, but the model sometimes overestimated flux in the 6-24 h range. The same model but with the time term squared adequately predicted flux over the entire 24 h period. Three compounds (4-methylphenol, skatole, and 4-ethylphenol) accounted for 93 percent of the summed odor activity value. First order decay constants (k) for these three compounds ranged from 0.157 to 0.996 h-1. When compared to surface application, injection of swine manure resulted in 80-95 percent lower flux for the most odorous aromatic compounds. These results show that VOC flux decreases rapidly following land application of swine manure, declining below levels of detection and near background levels after 4 to 8 h.

  2. Metabolic and Sensory Influences on Odor Sensitivity in Humans

    NARCIS (Netherlands)

    Ramaekers, M.G.; Verhoef, Alard; Gort, G.; Luning, P.A.; Boesveldt, S.

    2015-01-01

    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 mea

  3. 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.

  4. Stressors impair odor recognition memory via an olfactory bulb-dependent noradrenergic mechanism

    Directory of Open Access Journals (Sweden)

    Laura C Manella

    2013-12-01

    Full Text Available Non-associative habituation and odor recognition tasks have been widely used to probe questions social recognition, odor memory duration, and odor memory specificity. Among others, these paradigms have provided valuable insight into how neuromodulation, and specifically norepinephrine/noradrenaline (NE influences odor memory. In general, NE levels are modulated by arousal, stress, and behavioral state, and there is sparse evidence of a direct relationship between NE and odor memory in adult rodents. The present study uses simple mild psychological stressors (bright light and sound, to modulate NE levels physiologically in order to probe its effect on olfactory memory. In rats with bilateral bulbar cannulations, we show that these stressors modulate olfactory memory and that this effect is at least partially mediated by olfactory bulb. Specifically, we show that the presence of stressors during the acquisition of odor memory suppresses memory for an odor when tested 30 minutes after the acquisition. This suppression is blocked by infusing NE antagonists into the olfactory bulb prior to odor acquisition. Additionally, we find that infusion of bulbar NE is sufficient to suppress odor memory in a manner mimicking that of our stressors. These effects are unlikely to be solely mediated by locomotor/exploratory changes produced by stressors, although these stressors influence certain behaviors not directly related to odor investigation. This study provides important information about how behaviorally relevant changes in NE can influence top-down sensory processing and odor memory.

  5. Multiplicities of dihedral discriminants

    Science.gov (United States)

    Mayer, Daniel C.

    1992-04-01

    Given the discriminant {d_k} of a quadratic field k, the number of cyclic relative extensions N\\vert k of fixed odd prime degree p with dihedral absolute Galois group of order 2p, which share a common conductor f, is called the multiplicity of the dihedral discriminant {d_N} = {f^{2(p - 1)}}d_k^p . In this paper, general formulas for multiplicities of dihedral discriminants are derived by analyzing the p-rank of the ring class group mod f of k. For the special case p = 3,{d_k} = - 3 , an elementary proof is given additionally. The theory is illustrated by a discussion of all known discriminants of multiplicity ≥ 5 of totally real and complex cubic fields.

  6. Angular velocity discrimination

    Science.gov (United States)

    Kaiser, Mary K.

    1990-01-01

    Three experiments designed to investigate the ability of naive observers to discriminate rotational velocities of two simultaneously viewed objects are described. Rotations are constrained to occur about the x and y axes, resulting in linear two-dimensional image trajectories. The results indicate that observers can discriminate angular velocities with a competence near that for linear velocities. However, perceived angular rate is influenced by structural aspects of the stimuli.

  7. Analytic boosted boson discrimination

    OpenAIRE

    Andrew J. Larkoski; Moult, Ian; Neill, Duff

    2015-01-01

    Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, $D_2$, valid for both signal and background jets. Our factorization t...

  8. 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.

  9. 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. PMID:27121043

  10. The role of metabotropic glutamate receptors and cortical adaptation in habituation of odor-guided behavior

    Science.gov (United States)

    Yadon, Carly A.; Wilson, Donald A.

    2005-01-01

    Decreases in behavioral investigation of novel stimuli over time may be mediated by a variety of factors including changes in attention, internal state, and motivation. Sensory cortical adaptation, a decrease in sensory cortical responsiveness over prolonged stimulation, may also play a role. In olfaction, metabotropic glutamate receptors on cortical afferent pre-synaptic terminals have been shown to underlie both cortical sensory adaptation and habituation of odor-evoked reflexes. The present experiment examined whether blockade of sensory cortical adaptation through bilateral infusion of the group III metabotropic glutamate receptor antagonist cyclopropyl-4-phosphonophenylglycine (CPPG) into the anterior piriform cortex could reduce habituation of a more complex odor-driven behavior such as investigation of a scented object or a conspecific. The results demonstrate that time spent investigating a scented jar, or a conspecific, decreases over the course of a continuous 10 minute trial. Acute infusion of CPPG bilaterally into the anterior piriform cortex significantly enhanced the time spent investigating the scented jar compared to investigation time in control rats, without affecting overall behavioral activity levels. Infusions into the brain outside of the piriform cortex were without effect. CPPG infusion into the piriform cortex also produced an enhancement of time spent investigating a conspecific, although this effect was not significant. PMID:16322361

  11. 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.

  12. Ethnic discrimination and the migration of skiled labor.

    OpenAIRE

    Docquier, Frédéric

    2003-01-01

    We develop a model of interdependency between emigration, education investment, and discrimination, in the context of an ethnically divided developing economy. Assuming a rent-extraction basis for discrimination, we first endogenize ethnic discrimination in the benchmark case of an economy closed to migration, and then explore how migration prospects affect ethnic inequality. Under the free migration assumption, we find the intuitive result that migration prospects have a protective effect on...

  13. Effects of harmonic roving on pitch discrimination

    DEFF Research Database (Denmark)

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

    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...

  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. 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.

  17. 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.

  18. An antennal carboxylesterase from Drosophila melanogaster, esterase 6, is a candidate odorant-degrading enzyme toward food odorants.

    Science.gov (United States)

    Chertemps, Thomas; Younus, Faisal; Steiner, Claudia; Durand, Nicolas; Coppin, Chris W; Pandey, Gunjan; Oakeshott, John G; Maïbèche, Martine

    2015-01-01

    Reception of odorant molecules within insect olfactory organs involves several sequential steps, including their transport through the sensillar lymph, interaction with the respective sensory receptors, and subsequent inactivation. Odorant-degrading enzymes (ODEs) putatively play a role in signal dynamics by rapid degradation of odorants in the vicinity of the receptors, but this hypothesis is mainly supported by in vitro results. We have recently shown that an extracellular carboxylesterase, esterase-6 (EST-6), is involved in the physiological and behavioral dynamics of the response of Drosophila melanogaster to its volatile pheromone ester, cis-vaccenyl acetate. However, as the expression pattern of the Est-6 gene in the antennae is not restricted to the pheromone responding sensilla, we tested here if EST-6 could play a broader function in the antennae. We found that recombinant EST-6 is able to efficiently hydrolyse several volatile esters that would be emitted by its natural food in vitro. Electrophysiological comparisons of mutant Est-6 null flies and a control strain (on the same genetic background) showed that the dynamics of the antennal response to these compounds is influenced by EST-6, with the antennae of the null mutants showing prolonged activity in response to them. Antennal responses to the strongest odorant, pentyl acetate, were then studied in more detail, showing that the repolarization dynamics were modified even at low doses but without modification of the detection threshold. Behavioral choice experiments with pentyl acetate also showed differences between genotypes; attraction to this compound was observed at a lower dose among the null than control flies. As EST-6 is able to degrade various bioactive odorants emitted by food and plays a role in the response to these compounds, we hypothesize a role as an ODE for this enzyme toward food volatiles. PMID:26594178

  19. An antennal carboxylesterase from Drosophila melanogaster, Esterase 6, is a candidate Odorant-Degrading Enzyme towards food odorants

    Directory of Open Access Journals (Sweden)

    Thomas eChertemps

    2015-11-01

    Full Text Available Reception of odorant molecules within insect olfactory organs involves several sequential steps, including their transport through the sensillar lymph, interaction with the respective sensory receptors, and subsequent inactivation. Odorant-Degrading Enzymes (ODEs putatively play a role in signal dynamics by rapid degradation of odorants in the vicinity of the receptors, but this hypothesis is mainly supported by in vitro results. We have recently shown that an extracellular carboxylesterase, esterase-6 (EST-6, is involved in the physiological and behavioural dynamics of the response of Drosophila melanogaster to its volatile pheromone ester, cis-vaccenyl acetate. However, as the expression pattern of the Est-6 gene in the antennae is not restricted to the pheromone responding sensilla, we tested here if EST-6 could play a broader function in the antennae. We found that recombinant EST-6 is able to efficiently hydrolyse several volatile esters that would be emitted by its natural food in vitro. Electrophysiological comparisons of mutant Est-6 null flies and a control strain (on the same genetic background showed that the dynamics of the antennal response to these compounds is influenced by EST-6, with the antennae of the null mutants showing prolonged activity in response to them. Antennal responses to the strongest odorant, pentyl acetate, were then studied in more detail, showing that the repolarization dynamics were modified even at low doses but without modification of the detection threshold. Behavioural choice experiments with pentyl acetate also showed differences between genotypes; attraction to this compound was observed at a lower dose among the null than control flies. As EST-6 is able to degrade various bioactive odorants emitted by food and plays a role in the response to these compounds, we hypothesize a role as an ODE for this enzyme toward food volatiles.

  20. Analgesia Is Enhanced by Providing Information regarding Good Outcomes Associated with an Odor: Placebo Effects in Aromatherapy?

    OpenAIRE

    Yuri Masaoka; Miho Takayama; Hiroyoshi Yajima; Akiko Kawase; Nobuari Takakura; Ikuo Homma

    2013-01-01

    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 t...

  1. 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. PMID:25300508

  2. 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.

  3. The Mouthparts Enriched Odorant Binding Protein 11 of the Alfalfa Plant Bug Adelphocoris lineolatus Displays a Preferential Binding Behavior to Host Plant Secondary Metabolites.

    Science.gov (United States)

    Sun, Liang; Wei, Yu; Zhang, Dan-Dan; Ma, Xiao-Yu; Xiao, Yong; Zhang, Ya-Nan; Yang, Xian-Ming; Xiao, Qiang; Guo, Yu-Yuan; Zhang, Yong-Jun

    2016-01-01

    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. PMID:27313540

  4. 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.

  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. Odorants for surveillance and control of the Asian Citrus Psyllid (Diaphorina citri.

    Directory of Open Access Journals (Sweden)

    Iliano V Coutinho-Abreu

    Full Text Available BACKGROUND: The Asian Citrus Psyllid (ACP, Diaphorina citri, can transmit the bacterium Candidatus Liberibacter while feeding on citrus flush shoots. This bacterium causes Huanglongbing (HLB, a major disease of citrus cultivation worldwide necessitating the development of new tools for ACP surveillance and control. The olfactory system of ACP is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents. RESULTS: In this study, we performed single-unit electrophysiology to identify odorants that are strong activators, inhibitors, and prolonged activators of ACP odorant receptor neurons (ORNs. We identified a suite of odorants that activated the ORNs with high specificity and sensitivity, which may be useful in eliciting behavior such as attraction. In separate experiments, we also identified odorants that evoked prolonged ORN responses and antagonistic odorants able to suppress neuronal responses to activators, both of which can be useful in lowering attraction to hosts. In field trials, we tested the electrophysiologically identified activating odorants and identified a 3-odor blend that enhances trap catches by ∼230%. CONCLUSION: These findings provide a set of odorants that can be used to develop affordable and safe odor-based surveillance and masking strategies for this dangerous pest insect.

  8. Odor assessment tools and odor emissions in industrial processes - doi: 10.4025/actascitechnol.v32i3.4778

    Directory of Open Access Journals (Sweden)

    Gersina Nobre da Rocha Carmo Junior

    2010-11-01

    Full Text Available Environmental odors are an inherent part of any given process and can frequently be a cause of public environmental discomfort. Brazilian regulations are now characterizing odors as a form of air pollution and state that odor discomfort on surrounding populations must be avoided by industries. No olfactometry-related technology is standardized or even recognized. This makes it vital to create a federal reference, at least methodological, on the subject. Thus, the present work had the objective to apply, adjust, and evaluate the results of different olfactometric techniques in three types of industries which are known as odorous. The points of most significant odor emission to wastewater treatment plants were located at the system inputs. The techniques that were used are based on international standards and regulations. In all case studies, the applied odor assessment methods (odor intensity, quality, hedonic character and concentration were found to be satisfactory for representing the odor situation. The method presented in this paper for evaluating the hedonic tone proved to be very convenient. These methodologies allowed for the results to be presented in a numerical form, providing with objective results from subjective analyses.

  9. DIFFERENTIAL PULSE HEIGHT DISCRIMINATOR

    Science.gov (United States)

    Test, L.D.

    1958-11-11

    Pulse-height discriminators are described, specifically a differential pulse-height discriminator which is adapted to respond to pulses of a band of amplitudes, but to reject pulses of amplitudes greater or less than tbe preselected band. In general, the discriminator includes a vacuum tube having a plurality of grids adapted to cut off plate current in the tube upon the application of sufficient negative voltage. One grid is held below cutoff, while a positive pulse proportional to the amplltude of each pulse is applled to this grid. Another grid has a negative pulse proportional to the amplitude of each pulse simultaneously applied to it. With this arrangement the tube will only pass pulses which are of sufficlent amplitude to counter the cutoff bias but not of sufficlent amplitude to cutoff the tube.

  10. Analytic Boosted Boson Discrimination

    CERN Document Server

    Larkoski, Andrew J; Neill, Duff

    2015-01-01

    Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, $D_2$, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted $Z...

  11. 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.

  12. Drugs, discrimination and disability.

    Science.gov (United States)

    Gibson, Frances

    2009-12-01

    Whether addiction to prohibited drugs should be classified as a disability for the purposes of disability discrimination is a controversial question in Australia. The leading Australian case of Marsden v Human Rights Equal Opportunity Commission & Coffs Harbour & District Ex-Servicemen & Women's Memorial Club Ltd (HREOC, No H98/51, 30 August 1999); [2000] FCA 1619 concerned a disability discrimination complaint brought by Mr Marsden as a result of his treatment by the club. The case was brought as a public interest test case by the New South Wales Legal Aid Commission. Mr Marsden was on a methadone program at the time. The reasoning of the decision at the Federal Court opened the way for a finding that dependence on illegal drugs constituted a disability under disability discrimination legislation. The media reaction to the court's decision led to State and federal governments proposing legislation limiting legal protection from discrimination for people addicted to illegal drugs on the basis of their drug use. While the proposed federal legislation lapsed after objections from a coalition of medical, legal and other advocacy groups, the New South Wales legislation still provides that, in employment matters, it is not unlawful to discriminate against a person on the ground of disability if the disability relates to the person's addiction to a prohibited drug and the person is actually addicted to a prohibited drug at the time of the discrimination. The article details the sequence of events in the Marsden case, reflects on the role of public interest litigation in achieving social justice outcomes and suggests that Australia's recent ratification of the Convention on the Rights of Persons with Disabilities on 17 July 2008 should encourage legislators to review legislation which may have a discriminatory effect on people suffering from addictions. PMID:20169800

  13. Topographical representation of odor hedonics in the olfactory bulb.

    Science.gov (United States)

    Kermen, Florence; Midroit, Maëllie; Kuczewski, Nicola; Forest, Jérémy; Thévenet, Marc; Sacquet, Joëlle; Benetollo, Claire; Richard, Marion; Didier, Anne; Mandairon, Nathalie

    2016-07-01

    Hedonic value is a dominant aspect of olfactory perception. Using optogenetic manipulation in freely behaving mice paired with immediate early gene mapping, we demonstrate that hedonic information is represented along the antero-posterior axis of the ventral olfactory bulb. Using this representation, we show that the degree of attractiveness of odors can be bidirectionally modulated by local manipulation of the olfactory bulb's neural networks in freely behaving mice. PMID:27273767

  14. Mosquito odorant receptor for DEET and methyl jasmonate

    OpenAIRE

    Xu, Pingxi; Choo, Young-Moo; De La Rosa, Alyssa; Walter S Leal

    2014-01-01

    DEET (N,N-diethyl-3-methylbenzamide) has intrigued medical entomologists, neurobiologists, insect physiologists, and chemical ecologists for decades, and hitherto it was not known how and why it works. We have discovered an odorant receptor in the southern house mosquito, which is essential for repellency, thus unravelling how DEET works. Additionally, we have identified a link between this synthetic repellent and methyl jasmonate, thus suggesting that DEET might work by mimicking defensive c...

  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. Differential odor processing in two olfactory pathways in the honeybee

    OpenAIRE

    Nobuhiro Yamagata; Michael Schmuker; Paul Szyszka; Makoto Mizunami; Randolf Menzel

    2009-01-01

    An important component in understanding central olfactory processing and coding in the insect brain relates to the characterization of the functional divisions between morphologically distinct types of projection neurons (PN). Using calcium imaging, we investigated how the identity, concentration and mixtures of odors are represented in axon terminals (boutons) of two types of PNs – lPN and mPN. In lPN boutons we found less concentration dependence, narrow tuning profiles at a high concentrat...

  17. Reactive Searching and Infotaxis in Odor Source Localization

    OpenAIRE

    Nicole Voges; Antoine Chaffiol; Philippe Lucas; Dominique Martinez

    2014-01-01

    Male moths aiming to locate pheromone-releasing females rely on stimulus-adapted search maneuvers complicated by a discontinuous distribution of pheromone patches. They alternate sequences of upwind surge when perceiving the pheromone and cross- or downwind casting when the odor is lost. We compare four search strategies: three reactive versus one cognitive. The former consist of pre-programmed movement sequences triggered by pheromone detections while the latter uses Bayesian inference to bu...

  18. Metabolic and Sensory Influences on Odor Sensitivity in Humans

    OpenAIRE

    Ramaekers, M.G.; Verhoef, Alard; Gort, G.; Luning, P.A.; Boesveldt, S.

    2015-01-01

    Our olfactory sense plays an important role in eating behavior by modulating our food preferencesand intake. However, hunger or satiety may also influence how we perceive odors. Albeitspeculative, contradictory results found in the past may have resulted from confounding by typeof meal that participants ate to induce satiety. We aimed to investigate the influence of hunger stateon olfactory sensitivity, comparing hunger to satiety using 2 different types of lunch to controlfor sensory-specifi...

  19. Perceived Odor-Taste Congruence Influences Intensity and Pleasantness Differently.

    Science.gov (United States)

    Amsellem, Sherlley; Ohla, Kathrin

    2016-10-01

    The role of congruence in cross-modal interactions has received little attention. In most experiments involving cross-modal pairs, congruence is conceived of as a binary process according to which cross-modal pairs are categorized as perceptually and/or semantically matching or mismatching. The present study investigated whether odor-taste congruence can be perceived gradually and whether congruence impacts other facets of subjective experience, that is, intensity, pleasantness, and familiarity. To address these questions, we presented food odorants (chicken, orange, and 3 mixtures of the 2) and tastants (savory-salty and sour-sweet) in pairs varying in congruence. Participants were to report the perceived congruence of the pairs along with intensity, pleasantness, and familiarity. We found that participants could perceive distinct congruence levels, thereby favoring a multilevel account of congruence perception. In addition, familiarity and pleasantness followed the same pattern as the congruence while intensity was highest for the most congruent and the most incongruent pairs whereas intensities of the intermediary-congruent pairs were reduced. Principal component analysis revealed that pleasantness and familiarity form one dimension of the phenomenological experience of odor-taste pairs that was orthogonal to intensity. The results bear implications for the understanding the behavioral underpinnings of perseverance of habitual food choices. PMID:27384192

  20. Dubowitz syndrome: common findings and peculiar urine odor

    Directory of Open Access Journals (Sweden)

    Chehade C

    2013-10-01

    Full Text Available Cynthia Chehade,1 Johnny Awwad,2 Nadine Yazbeck,1 Marianne Majdalani,1 Rima Wakim,1 Hala Tfayli,1 Chantal Farra1,31Department of Pediatrics and Adolescent Medicine, American University of Beirut Medical Center, Beirut, Lebanon; 2Department of Obstetrics and Gynecology, American University of Beirut Medical Center, Beirut, Lebanon; 3Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut, LebanonBackground: Dubowitz syndrome is a rare, autosomal recessive disorder characterized by intrauterine and postnatal growth retardation, severe microcephaly, psychomotor retardation, hyperactivity, eczema, and characteristic dysmorphic facial features. Although many cases have been reported, the cause of this disease is still unknown.Case: We present here the case of a Lebanese girl with Dubowitz syndrome in whom an unpleasant urine odor was persistently reported since birth.Conclusion: Although Dubowitz syndrome has been largely described in the medical literature, this is the first time that a peculiar urine odor was reported. This case report adds a new and unusual feature to the numerous findings related to this rare polymorphous syndrome.Keywords: Dubowitz syndrome, autosomal recessive, developmental delay, odorous urine

  1. Mosquito odorant receptor for DEET and methyl jasmonate.

    Science.gov (United States)

    Xu, Pingxi; Choo, Young-Moo; De La Rosa, Alyssa; Leal, Walter S

    2014-11-18

    Insect repellents are important prophylactic tools for travelers and populations living in endemic areas of malaria, dengue, encephalitis, and other vector-borne diseases. DEET (N,N-diethyl-3-methylbenzamide) is a 6-decade-old synthetic repellent, which is still considered the gold standard of mosquito repellents. Mosquitoes use their sense of smell to detect DEET, but there are currently two hypotheses regarding its mode of action: activation of ionotropic receptor IR40a vs. odorant receptor(s). Here, we demonstrate that DEET, picaridin, insect repellent 3535, and p-menthan-3,8-diol activate the odorant receptor CquiOR136 of the southern house mosquito, Culex quinquefasciatus. Electrophysiological and behavioral assays showed that CquiIR40a knockdown had no significant effect on DEET detection and repellency. By contrast, reduction of CquiOR136 transcript levels led to a significant decrease in electroantennographic responses to DEET and a complete lack of repellency. Thus, direct activation of an odorant receptor, not an ionotropic receptor, is necessary for DEET reception and repellency in Culex mosquitoes. Interestingly, methyl jasmonate, a repellent derived from the nonvolatile jasmonic acid in the signaling pathway of plant defenses, elicited robust responses in CquiOR136•CquiOrco-expressing Xenopus oocytes, thus suggesting a possible link between natural products with long insect-plant evolutionary history and synthetic repellents. PMID:25349401

  2. 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.

  3. Acute metal toxicology of olfaction in coho salmon: behavior, receptors, and odor-metal complexation

    Energy Technology Data Exchange (ETDEWEB)

    Rehnberg, B.C.; Schreck, C.B.

    1986-04-01

    The objective of this research was to determine the acute toxicities of mercury (Hg), copper (Cu), and zinc (Zn) to coho salmon olfaction. The authors used a behavioral assay of olfaction based on an avoidance reaction to L-serine in a two-choice Y-trough. A second objective was to gain some understanding of the mechanism of metal-induced olfactory inhibition by observing how metals affect the binding of L-serine to its olfactory cell membrane receptor. They have also taken the novel approach of addressing olfactory toxicology from the perspective of the odor molecule by considering metal speciation and metal-serpine complexation chemistry on the basis of chemical equilibrium computations.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Children's hedonic judgments of cigarette smoke odor: effects of parental smoking and maternal mood.

    Science.gov (United States)

    Forestell, Catherine A; Mennella, Julie A

    2005-12-01

    Age-appropriate tasks were used to assess 3- to 8-year-old children's liking, identification, and preference for a variety of odors, including that of exhaled cigarette smoke. Children whose parents smoke took longer to decide whether they liked the cigarette odor and were significantly more likely to prefer the odor of cigarette to the neutral and unfamiliar odor of green tea compared with children of nonsmokers. Among children of smokers, relative preferences for the cigarette odor were related to maternal mood disturbance and depression scores. These findings suggest that some early learning about cigarette smoke odor is based on sensory experiences at home and anchors it to the emotional context in which their mothers smoke. PMID:16366814

  9. Children’s Hedonic Judgments of Cigarette Smoke Odor: Effects of Parental Smoking and Maternal Mood

    Science.gov (United States)

    Forestell, Catherine A.; Monell, Julie A. Mennella

    2006-01-01

    Age-appropriate tasks were used to assess 3-to 8-year-old children’s liking, identification, and preference for a variety of odors, including that of exhaled cigarette smoke. Children whose parents smoke took longer to decide whether they liked the cigarette odor and were significantly more likely to prefer the odor of cigarette to the neutral and unfamiliar odor of green tea compared with children of nonsmokers. Among children of smokers, relative preferences for the cigarette odor were related to maternal mood disturbance and depression scores. These findings suggest that some early learning about cigarette smoke odor is based on sensory experiences at home and anchors it to the emotional context in which their mothers smoke. PMID:16366814

  10. Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization.

    Directory of Open Access Journals (Sweden)

    Jason B Castro

    Full Text Available In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain unclear. 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 dimensions 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.

  11. Categorical Dimensions of Human Odor Descriptor Space Revealed by Non-Negative Matrix Factorization

    Science.gov (United States)

    Castro, Jason B.; Ramanathan, Arvind; Chennubhotla, Chakra S.

    2013-01-01

    In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain unclear. 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 dimensions 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. PMID:24058466

  12. 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.

  13. 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.

  14. 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....

  15. 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

  16. Behavioral factors affecting exposure potential for household cleaning products.

    Science.gov (United States)

    Kovacs, D C; Small, M J; Davidson, C I; Fischhoff, B

    1997-01-01

    Behavioral experiments were performed on 342 subjects to determine whether behavior, which could affect the level of personal exposure, is exhibited in response to odors and labels which are commonly used for household chemicals. Potential for exposure was assessed by having subjects perform cleaning tasks presented as a product preference test, and noting the amount of cleaning product used, the time taken to complete the cleaning task, the product preference, and the exhibition of avoidance behavior. Product odor was found to affect product preference in the study with the pleasant odored product being preferred to the neutral and unpleasant products. Product odor was also found to influence the amount of product used; less of the odored products was used compared to the neutral product. The experiment also found that very few of the subjects in the study read the product labels, precluding analysis of the effect of such labels on product use. A postexperiment questionnaire on household cleaning product purchasing and use was administered to participants. The results indicate that significant gender differences exist. Women in the sample reported more frequent purchase and use of cleaning products resulting in an estimated potential exposure 40% greater than for the men in the sample. This finding is somewhat countered by the fact that women more frequently reported exposure avoidance behavior, such as using gloves. Additional significant gender differences were found in the stated importance of product qualities, such as odor and environmental quality. This study suggests the need for further research, in a more realistic use setting, on the impact of public education, labels, and product odor on preference, use, and exposure for different types of consumer products. PMID:9306234

  17. 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.

  18. 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…

  19. 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…

  20. 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)

  1. Airborne Fraunhofer Line Discriminator

    Science.gov (United States)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  2. Digital frequency discriminator

    Science.gov (United States)

    Reid, W. J.

    1970-01-01

    Frequency discriminator has five integrated circuit chips interconnected to provide a divide function, exclusive OR function, phase shifting, and holding so that a single binary output signal results. The state of the binary signal indicates which one of the two input signals has a lower frequency than the other.

  3. RISE TIME DELAY DISCRIMINATOR

    Science.gov (United States)

    Johnstone, C.W.

    1959-09-29

    A pulse-height discriminator for generating an output pulse when the accepted input pulse is approximately at its maximum value is described. A gating tube and a negative bias generator responsive to the derivative of the input pulse and means for impressing the output of the bias generator to at least one control electrode of the gating tube are included.

  4. Airborne particulate discriminator

    Science.gov (United States)

    Creek, Kathryn Louise; Castro, Alonso; Gray, Perry Clayton

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  5. 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)

  6. Analytic boosted boson discrimination

    Science.gov (United States)

    Larkoski, Andrew J.; Moult, Ian; Neill, Duff

    2016-05-01

    Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D 2, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. Our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.

  7. 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)

  8. 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.

  9. Pattern Recognition Algorithm for High-Sensitivity Odorant Detection in Unknown Environments

    Science.gov (United States)

    Duong, Tuan A.

    2012-01-01

    In a realistic odorant detection application environment, the collected sensory data is a mix of unknown chemicals with unknown concentrations and noise. The identification of the odorants among these mixtures is a challenge in data recognition. In addition, deriving their individual concentrations in the mix is also a challenge. A deterministic analytical model was developed to accurately identify odorants and calculate their concentrations in a mixture with noisy data.

  10. Sensitivity and transduction mechanisms of responses to general odorants in turtle vomeronasal system

    OpenAIRE

    1991-01-01

    (a) The responses of the vomeronasal organ to general odorants in the turtle, Geoclemys reevesii, were measured by recording the accessory olfactory bulbar responses. The threshold concentrations of the vomeronasal responses to various odorants were similar to those in main olfactory bulbar responses, indicating that vomeronasal cells lacking cilia and olfactory cells having many cilia have similar sensitivities to general odorants. (b) The vomeronasal epithelium was perfused with 100 mM NaCl...

  11. Categorical Dimensions of Human Odor Descriptor Space Revealed by Non-Negative Matrix Factorization

    OpenAIRE

    Castro, Jason B; Ramanathan, Arvind; Chennubhotla, Chakra S.

    2013-01-01

    In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain unclear. 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 t...

  12. Impaired Odor Identification in Children with Histories of Heavy Prenatal Alcohol Exposure

    OpenAIRE

    Bower, Emily; Szajer, Jacquelyn; Mattson, Sarah N.; Riley, Edward P.; Murphy, Claire

    2013-01-01

    Prenatal alcohol exposure can lead to behavioral and cognitive impairments across multiple domains. Many of the brain regions impacted by prenatal alcohol exposure are also linked with olfactory processing, and odor identification deficits have been documented in certain neurological disorders associated with these brain regions. As odor identification following prenatal alcohol exposure is not well studied, we compared odor identification in children with prenatal exposure to alcohol (AE) to...

  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. PMID:24863138

  14. Measurement of the odor impact of a waste deposit using the SF6-tracer method

    International Nuclear Information System (INIS)

    Landfill gas emitted from a waste deposit often causes odor nuisance in the vicinity. For a new sanitary landfill to be established in an area where also other sources of odor existed, very low limits for additional odor nuisance were given by local authorities. To verify that the odor concentrations were below these limit values, the odor contributions of different sources had to be distinguished. Olfactometric methods, using human observers to estimate the intensity of odors, were not applicable to this problem. For direct measurements by analytical methods concentrations of odorous substances were too small. Therefore a tracer method was applied to measure the odor impact of the sanitary landfill to its environment. The emitted landfill gas was labelled with the tracer gas SF6. The tracer gas was parted to even amounts and released through ten special nozzles equally distributed over the surface of the landfill. In the area around the landfill the concentration of the tracer gas was measured by collecting air samples and analysing them with a gas chromatograph with an electron capture detector. Fifteen air sampling units were used to collect eight consecutive air samples at each selected point. These measurements gave the relation between the emission of landfill gas and the resulting concentrations in ambient air. With these transmission coefficients the concentrations of odorous gases at the sampling points were evaluated, using the emission concentrations measured by analytical techniques at the landfiIl site. The resulting odor concentrations were compared with values of odor thresholds to establish the odor impact of the waste deposit on the environment. (author)

  15. 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. PMID:26547014

  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. Target discrimination strategies in optics detection

    Science.gov (United States)

    Sjöqvist, Lars; Allard, Lars; Henriksson, Markus; Jonsson, Per; Pettersson, Magnus

    2013-10-01

    Detection and localisation of optical assemblies used for weapon guidance or sniper rifle scopes has attracted interest for security and military applications. Typically a laser system is used to interrogate a scene of interest and the retro-reflected radiation is detected. Different system approaches for area coverage can be realised ranging from flood illumination to step-and-stare or continuous scanning schemes. Independently of the chosen approach target discrimination is a crucial issue, particularly if a complex scene such as in an urban environment and autonomous operation is considered. In this work target discrimination strategies in optics detection are discussed. Typical parameters affecting the reflected laser radiation from the target are the wavelength, polarisation properties, temporal effects and the range resolution. Knowledge about the target characteristics is important to predict the target discrimination capability. Two different systems were used to investigate polarisation properties and range resolution information from targets including e.g. road signs, optical reflexes, rifle sights and optical references. The experimental results and implications on target discrimination will be discussed. If autonomous operation is required target discrimination becomes critical in order to reduce the number of false alarms.

  18. 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)

  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. Effects of odor generated from the glycine/glucose Maillard reaction on human mood and brainwaves.

    Science.gov (United States)

    Zhou, Lanxi; Ohata, Motoko; Arihara, Keizo

    2016-06-15

    Effects of the odor generated from the glycine/glucose Maillard reaction on human mood and brainwaves were investigated in the present study. Equimolar solutions of glucose and glycine were adjusted to pH 7 and pH 9 and heated at 90 °C for 30 min. The odor generated from the glycine/glucose Maillard reaction significantly decreased negative moods. Its effects on brainwaves differed according to pH; alpha brainwave distribution was increased after inhalation of the odor generated at pH 7, whereas it was decreased by the odor generated at pH 9. The effects on mood and brainwaves were also measured after inhalation of model solutions, which comprised of potent odorants determined by aroma extract dilution analysis (AEDA), and the results were similar to those obtained with the Maillard reaction samples. Therefore, odors constructed by potent odorants could influence human mood and brainwaves. Among all potent odorants, 2,3-dimethylpyrazine and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) were identified as the strongest, and high pH values resulted in higher yields of these odorants. Furthermore, DMHF was identified as the putative agent responsible for the decrease in alpha brainwave distribution after smelling the pH-9 Maillard reaction sample since higher concentrations of DMHF resulted in a similar effect. PMID:27087046

  1. 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.

  2. 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.

  3. 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 ...

  4. 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.

  5. 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. PMID:25554482

  6. 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.

  7. 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.

  8. Gender wage discrimination in Galicia

    OpenAIRE

    Pena-Boquete, Yolanda

    2005-01-01

    The wage discrimination by gender in the Galician region is one of the highest in Spain, although it presents one of the smallest wage gaps between men and women. The aim of this paper is to extend wage discrimination analysis in Galicia through two complementary theories. First, we approximate global discrimination with the Oaxaca decomposition. This method calculates the discrimination using women and men median characteristics, providing a measure based on the wage distribution average. Af...

  9. 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 cases a simple two element non-discriminating dosemeter will suffice. In cases where the use of discriminating dosemeters is justified, thermoluminescence dosemeters can be designed to provided information on radiation type and energy, but if further information is required the photographic film...

  10. 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…

  11. 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…

  12. Immunological self, nonself discrimination

    DEFF Research Database (Denmark)

    Guillet, J G; Lai, M Z; Briner, T J;

    1987-01-01

    -Ed-restricted. Comparison of the sequence of the repressor peptide with that of other peptides able to bind to (and be restricted by) I-Ed and a polymorphic region of the I-Ed molecule itself revealed a significant degree of homology. Thus, peptides restricted by a given class II molecule appear to be homologous...... that provides a basis for explaining self, nonself discrimination as well as alloreactivity....

  13. Gaussian Discriminating Strength

    OpenAIRE

    Rigovacca, Luca; Farace, Alessandro; De Pasquale, Antonella; Giovannetti, Vittorio

    2015-01-01

    We present a quantifier of non-classical correlations for bipartite, multi-mode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in A. Farace et al., New. J. Phys. 16, 073010 (2014). As the latter the new measure exploits the Quantum Chernoff Bound to gauge the susceptibility of the composite system with respect to local perturbations induced by unitary gates extracted from a suitable set of allowed transformations (the latter ...

  14. Introduction to multivariate discrimination

    OpenAIRE

    Kégl Balázs

    2013-01-01

    ISBN:978-2-7598-1032-1 International audience Multivariate discrimination or classification is one of the best-studied problem in machine learning, with a plethora of well-tested and well-performing algorithms. There are also several good general textbooks [1-9] on the subject written to an average engineering, computer science, or statistics graduate student; most of them are also accessible for an average physics student with some background on computer science and statistics. Hence, ...

  15. Measuring Discrimination in Education

    OpenAIRE

    Rema Hanna; Leigh Linden

    2009-01-01

    In this paper, we illustrate a methodology to measure discrimination in educational contexts. In India, we ran an exam competition through which children compete for a large financial prize. We recruited teachers to grade the exams. We then randomly assigned child "characteristics" (age, gender, and caste) to the cover sheets of the exams to ensure that there is no systematic relationship between the characteristics observed by the teachers and the quality of the exams. We find that teachers ...

  16. 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 ...

  17. 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.

  18. 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.

  19. Workplace Discrimination: An Additional Stressor for Internationally Educated Nurses.

    Science.gov (United States)

    Baptiste, Maria M

    2015-09-01

    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. PMID:26882517

  20. [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.

  1. 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.

  2. 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. PMID:19754174

  3. New Jersey– Sexual Orientation and Gender Identity Law and Documentation of Discrimination

    OpenAIRE

    Sears, Brad

    2009-01-01

    New Jersey’s Law Against Discrimination (“LAD”) protects against discrimination based on marital status, domestic partnership status, affectional or sexual orientation, gender identity or expression, and mental or physical disability, including AIDS and HIV related illnesses.1 In addition to the LAD, New Jersey’s Administrative Code includes an anti-discrimination policy for state government employees.2 This policy also prohibits discrimination on the basis of sexual orientation and gender id...

  4. Discrimination as a development barrier : possible effects of discrimination and fear of discrimination on sexual minorities: a capabilities approach to development perspective

    OpenAIRE

    Staupe-Delgado, Reidar

    2014-01-01

    The main objective of this study was to explore local people’s perceptions on Lesbian, Gay, Bi and Transvestite (LGBT) people in San Juan de Pasto (Pasto) in Colombia and how discrimination or fear of discrimination may have affected LGBT people’s capabilities and agency using the capabilities approach to development. To do this, two central concepts in the capability approach to development were employed. These concepts are capabilities and agency. Capabilities can be seen as institutional o...

  5. 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.

  6. 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.

  7. 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...

  8. A pleasant familiar odor influences perceived stress and peripheral nervous system activity during normal aging

    Directory of Open Access Journals (Sweden)

    Pauline eJoussain

    2014-02-01

    Full Text Available Effects of smells on stress have been demonstrated in animals and humans, suggesting that inhaling certain odorants may counteract the negative effects of stress. Because stress plays a key role in cerebral aging, the present study set out to examine whether positive odor effects on perceived stress can be achieved in elderly individuals. To this end, two groups of aged individuals (n=36 women, aged from 55 to 65 years, were tested. The first group was exposed for 5 days to a pleasant and, by end of exposure, familiar odor (exposure odor, whereas the other was exposed to a non-scented control stimulus. Stress and mood states were assessed before and after the 5-day odor exposure period. Psychophysiological markers were also assessed at the end of exposure, in response to the exposure odor and to a new odor. Results revealed that stress on this second exposure was decreased and zygomatic EMG activity was increased specifically in the group previously exposed to the odor (p< 0.05. Taken as a whole, these findings offer a new look at the relationship between perceived stress, olfaction and normal aging, opening up new research perspectives on the effect of olfaction on quality of life and well-being in aged individuals.

  9. 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.

  10. 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…

  11. 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

  12. 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.

  13. Odor and irritation thresholds for ammonia: A comparison between static and dynamic olfactometry

    NARCIS (Netherlands)

    Smeets, M.A.M.; Bulsing, P.J.; Rooden, van S.; Steinmann, R.; Ru, de J.A.; Ogink, N.W.M.; Thriel, van C.; Dalton, P.H.

    2007-01-01

    Odor and lateralization (irritation) thresholds (LTs) for ammonia vapor were measured using static and dynamic olfactometry. The purpose of the study was to explore the test-retest reliability and comparability of dynamic olfactometry methodology, generally used to determine odor thresholds followin

  14. 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.

  15. 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.

  16. 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.

  17. 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…

  18. 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.

  19. [Actinobacteria and their odor-producing capacities in a surface water in Shanghai].

    Science.gov (United States)

    Chen, Jiao; Bai, Xiao-hui; Lu, Ning; Wang, Xian-yun; Zhang, Yong-hui; Wu, Pan-cheng; Guo, Xin-chi

    2014-10-01

    The odor in raw water is one of the main sources of odor in drinking water. The occurrence of actinobacteria and their odor producing capacities in a reservoir in.Shanghai were investigated. Gauze's medium and membrane filtration were used for actinobacteria isolation. Through combined methods of 16S rRNA sequencing, colony and hyphae morphology, carbon source utilization, physiological and biochemical characteristics, 40 strains of actinobacteria were identified from the reservoir. Results showed that there were 38 Streptomyces, an Aeromicrobium and a Pseudonocardia. Liquid culture medium and the real reservoir water were used to test the odor producing capacity of these 40 strains of actinobacteria, and headspace solid phase microextraction (HS-SPME) and high resolution gas chromatography mass spectroscopy (GC/MS) were used to analyze the odor compounds 2-methylisoborneol (2-MIB) and geosmin (GSM) in the fermentation liquor. The test results showed that, the odor-producing capacities of these actinobacteria in different fermentation media showed different variation trends, even within the genera Streptomyces. The odor-producing capacity of actinobacteria in the liquid culture medium could not represent their states in the reservoir water or their actual odor contribution to the aquatic environment.

  20. Detection of pup odors by non-canonical adult vomeronasal neurons expressing an odorant receptor gene is influenced by sex and parenting status

    OpenAIRE

    Nakahara, Thiago S.; Cardozo, Leonardo M.; Ibarra-Soria, Ximena; Bard, Andrew D.; Carvalho, Vinicius M. A.; Trintinalia, Guilherme Z.; Logan, Darren W.; Papes, Fabio

    2016-01-01

    Background Olfaction is a fundamental sense through which most animals perceive the external world. The olfactory system detects odors via specialized sensory organs such as the main olfactory epithelium and the vomeronasal organ. Sensory neurons in these organs use G-protein coupled receptors to detect chemosensory stimuli. The odorant receptor (OR) family is expressed in sensory neurons of the main olfactory epithelium, while the adult vomeronasal organ is thought to express other types of ...

  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. PMID:17972729

  2. 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.

  3. 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

    Human genes encoding odorant receptors have been identified, but the contribution of genetic effects to total variation in specific odor perceptions is largely unknown. We estimated the relative contributions of genetic and environmental effects to variation in the perceived intensity...... 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....... Results from fitting univariate models including components for additive genetic (A), shared environmental (C), and non-shared environmental (E) effects to the data implied that non-shared environmental effects account for the most variation in ratings of individual odors while genetic effects play only...

  4. Emissão e controlo de odores em aterros sanitários

    OpenAIRE

    Mendes, Luís Ricardo Trindade

    2012-01-01

    Existem várias fontes naturais de odor, no entanto, com a crescente densidade populacional nos centros urbanos, as fontes de odor antropogénicas expõem a população a níveis de odor suscetíveis de causar incómodo significativo e diminuição da qualidade de vida. As estações de tratamento de resíduos constituem uma fonte de odor comum, motivo pelo qual a população rejeita constantemente a proximidade destas instalações. O crescente número de queixas perante a exposição ao odor revelou a neces...

  5. The Analysis of the Influence of Odorant's Complexity on Fractal Dynamics of Human Respiration.

    Science.gov (United States)

    Namazi, Hamidreza; Akrami, Amin; Kulish, Vladimir V

    2016-01-01

    One of the major challenges in olfaction research is to relate the structural features of the odorants to different features of olfactory system. However, no relationship has been yet discovered between the structure of the olfactory stimulus, and the structure of respiratory signal. This study reveals the plasticity of human respiratory signal in relation to 'complex' olfactory stimulus (odorant). We demonstrated that fractal temporal structure of respiration dynamics shifts towards the properties of the odorants used. The results show for the first time that more structurally complex a monomolecular odorant will result in less fractal respiratory signal. On the other hand, odorant with higher entropy will result the respiratory signal with lower entropy. The capability observed in this research can be further investigated and applied for treatment of patients with different respiratory diseases. PMID:27244590

  6. How Far Does a Receptor Influence Vibrational Properties of an Odorant?

    Directory of Open Access Journals (Sweden)

    Anna Reese

    Full Text Available The biophysical mechanism of the sense of smell, or olfaction, is still highly debated. The mainstream explanation argues for a shape-based recognition of odorant molecules by olfactory receptors, while recent investigations suggest the primary olfactory event to be triggered by a vibrationally-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 protein-odorant interactions. Finally, we judge whether the effects of the protein provide any indications towards the existing theories of olfaction.

  7. [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.

  8. 78 FR 42818 - SafetyAlert: Safety Alert: Risks Associated With Liquid Petroleum (LP) Gas Odor Fade

    Science.gov (United States)

    2013-07-17

    ... Liquid Petroleum (LP) Gas Odor Fade AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA... the risks associated with the under-odorization of Liquefied Petroleum Gases (LPG). LPG is an odorless and colorless gas that under certain conditions is required to be odorized for leak detection....

  9. 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…

  10. 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.

  11. 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...

  12. Discrimination in Grading

    OpenAIRE

    Hanna, Rema N.; Linden, Leigh L.

    2012-01-01

    We report the results of an experiment that was designed to test for discrimination in grading in India. We recruited teachers to grade exams. We randomly assigned child "characteristics" (age, gender, and caste) to the cover sheets of the exams to ensure that there is no relationship between these observed characteristics and the exam quality. We find that teachers give exams that are assigned to be lower caste scores that are about 0.03 to 0.08 standard deviations lower than those that are ...

  13. Estradiol rapidly modulates odor responses in mouse vomeronasal sensory neurons.

    Science.gov (United States)

    Cherian, S; Wai Lam, Y; McDaniels, I; Struziak, M; Delay, R J

    2014-06-01

    In rodents, many social behaviors are driven by the sense of smell. The vomeronasal organ (VNO), part of the accessory olfactory system mediates many of these chemically driven behaviors. The VNO is heavily vascularized, and is readily accessible to circulating peptide or steroid hormones. Potentially, this allows circulating hormones to alter behavior through modulating the output of the primary sensory neurons in the VNO, the vomeronasal sensory neurons (VSNs). Based on this, we hypothesized that steroid hormones, in particular 17β-estradiol, would modulate activity of VSNs. In this paper, we show that the estrogen receptors, GPR30 and ERα, were present in VSNs and that estradiol may be synthesized locally in the VNO. Our results also showed that 17β-estradiol decreased responses of isolated VSNs to dilute urine, a potent natural stimulus, with respect to current amplitudes and depolarization. Further, 17β-estradiol increased the latency of the first action potential (AP) and the AP amplitude. Additionally, calcium responses to sulfated steroids (present in the low molecular weight fraction of urine) that act as ligands for apical vomeronasal receptors were decreased by 17β-estradiol. In conclusion, we show that estradiol modulates odorant responses mediated by VSNs and hence paves the way for future studies to better understand the mechanisms by which odorant mediated behavior is altered by endocrine status of the animal. PMID:24680884

  14. Illuminating odors: when optogenetics brings to light unexpected olfactory abilities.

    Science.gov (United States)

    Grimaud, Julien; Lledo, Pierre-Marie

    2016-06-01

    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

  15. 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

  16. Odors enhance slow-wave activity in non-rapid eye movement sleep.

    Science.gov (United States)

    Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam; Hairston, Ilana S

    2016-05-01

    Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9-15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5-4 Hz) and slow spindle (9-12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations. PMID:26888107

  17. Odors enhance slow-wave activity in non-rapid eye movement sleep.

    Science.gov (United States)

    Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam; Hairston, Ilana S

    2016-05-01

    Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9-15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5-4 Hz) and slow spindle (9-12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations.

  18. The Odor Context Facilitates the Perception of Low-Intensity Facial Expressions of Emotion.

    Directory of Open Access Journals (Sweden)

    Arnaud Leleu

    Full Text Available It has been established that the recognition of facial expressions integrates contextual information. In this study, we aimed to clarify the influence of contextual odors. The participants were asked to match a target face varying in expression intensity with non-ambiguous expressive faces. Intensity variations in the target faces were designed by morphing expressive faces with neutral faces. In addition, the influence of verbal information was assessed by providing half the participants with the emotion names. Odor cues were manipulated by placing participants in a pleasant (strawberry, aversive (butyric acid, or no-odor control context. The results showed two main effects of the odor context. First, the minimum amount of visual information required to perceive an expression was lowered when the odor context was emotionally congruent: happiness was correctly perceived at lower intensities in the faces displayed in the pleasant odor context, and the same phenomenon occurred for disgust and anger in the aversive odor context. Second, the odor context influenced the false perception of expressions that were not used in target faces, with distinct patterns according to the presence of emotion names. When emotion names were provided, the aversive odor context decreased intrusions for disgust ambiguous faces but increased them for anger. When the emotion names were not provided, this effect did not occur and the pleasant odor context elicited an overall increase in intrusions for negative expressions. We conclude that olfaction plays a role in the way facial expressions are perceived in interaction with other contextual influences such as verbal information.

  19. The Odor Context Facilitates the Perception of Low-Intensity Facial Expressions of Emotion.

    Science.gov (United States)

    Leleu, Arnaud; Demily, Caroline; Franck, Nicolas; Durand, Karine; Schaal, Benoist; Baudouin, Jean-Yves

    2015-01-01

    It has been established that the recognition of facial expressions integrates contextual information. In this study, we aimed to clarify the influence of contextual odors. The participants were asked to match a target face varying in expression intensity with non-ambiguous expressive faces. Intensity variations in the target faces were designed by morphing expressive faces with neutral faces. In addition, the influence of verbal information was assessed by providing half the participants with the emotion names. Odor cues were manipulated by placing participants in a pleasant (strawberry), aversive (butyric acid), or no-odor control context. The results showed two main effects of the odor context. First, the minimum amount of visual information required to perceive an expression was lowered when the odor context was emotionally congruent: happiness was correctly perceived at lower intensities in the faces displayed in the pleasant odor context, and the same phenomenon occurred for disgust and anger in the aversive odor context. Second, the odor context influenced the false perception of expressions that were not used in target faces, with distinct patterns according to the presence of emotion names. When emotion names were provided, the aversive odor context decreased intrusions for disgust ambiguous faces but increased them for anger. When the emotion names were not provided, this effect did not occur and the pleasant odor context elicited an overall increase in intrusions for negative expressions. We conclude that olfaction plays a role in the way facial expressions are perceived in interaction with other contextual influences such as verbal information. PMID:26390036

  20. 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