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Sample records for enhance odor detection

  1. Odors Pulsed at Wing Beat Frequencies are Tracked by Primary Olfactory Networks and Enhance Odor Detection

    PubMed Central

    Tripathy, Shreejoy J.; Peters, Oakland J.; Staudacher, Erich M.; Kalwar, Faizan R.; Hatfield, Mandy N.; Daly, Kevin C.

    2009-01-01

    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 (200 μM) 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. PMID:20407584

  2. Unconscious odor detection could not be due to odor itself.

    PubMed

    Jacquot, Laurence; Monnin, Julie; Brand, Gérard

    2004-03-26

    Unconscious odor detection has been demonstrated but the mechanisms implied in this process have been poorly studied. In so far, most odorants activate both olfactory and trigeminal systems, it is relevant to explore how each system could be involved in the unconscious detection processes. This study used three methods to determine the detection thresholds for three odorants. The results showed that (1). psychophysical were lower than self-evaluated thresholds whatever the odorant; (2). an odorant with trigeminal component had the ability to produce an autonomic (skin conductance response-SCR) activation with lower concentrations than psychophysical and self-evaluated thresholds; on the contrary, an odorant, which stimulates only the olfactory system, induces an autonomic activation only with higher concentrations than psychophysical and self-evaluated thresholds. These findings suggest that unconscious odor detection could be due to the trigeminal component of odorants.

  3. Odors enhance visual attention to congruent objects.

    PubMed

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

    2010-06-01

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

  4. Effects of extraneous odors on canine detection

    NASA Astrophysics Data System (ADS)

    Waggoner, L. Paul; Jones, Meredith H.; Williams, Marc; Johnston, J. M.; Edge, Cindy C.; Petrousky, James A.

    1998-12-01

    Dogs are often required to detect target substances under challenging conditions. One of these challenges is to detect contraband in the presence of extraneous odors, whether they are part of the ambient environment or placed there for the purpose of evading detection. This paper presents the results of two studies evaluating the ability of dogs to detect target substances in the presence of varying concentrations of extraneous odors. The studies were conducted under behavioral laboratory conditions, providing good control over vapor sources and a clear basis for evaluation of detection responses. Dogs were trained to sample an air stream consisting of the extraneous odor only or the extraneous odor plus the target odor and then press the appropriate lever to earn food. The results are described in terns of the ability of dogs to detect target odors in the presence of a wide range of concentrations of the extraneous odors.

  5. Enhancement of Retronasal Odors by Taste

    PubMed Central

    Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

    2012-01-01

    Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste (“sweet,” “sour,” “salty,” and “bitter”) and odor (“other”) intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste–odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of “cherry” and “vanilla” flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods. PMID:21798851

  6. Pattern Recognition for Selective Odor Detection with Gas Sensor Arrays

    PubMed Central

    Kim, Eungyeong; Lee, Seok; Kim, Jae Hun; Kim, Chulki; Byun, Young Tae; Kim, Hyung Seok; Lee, Taikjin

    2012-01-01

    This paper presents a new pattern recognition approach for enhancing the selectivity of gas sensor arrays for clustering intelligent odor detection. The aim of this approach was to accurately classify an odor using pattern recognition in order to enhance the selectivity of gas sensor arrays. This was achieved using an odor monitoring system with a newly developed neural-genetic classification algorithm (NGCA). The system shows the enhancement in the sensitivity of the detected gas. Experiments showed that the proposed NGCA delivered better performance than the previous genetic algorithm (GA) and artificial neural networks (ANN) methods. We also used PCA for data visualization. Our proposed system can enhance the reproducibility, reliability, and selectivity of odor sensor output, so it is expected to be applicable to diverse environmental problems including air pollution, and monitor the air quality of clean-air required buildings such as a kindergartens and hospitals. PMID:23443378

  7. Detection of smoldering combustion of coal with an odor meter

    SciTech Connect

    Edwards, J.C.

    1995-05-01

    A commercially available odor meter was evaluated as a detector of smoldering coal combustion, and compared with incipient carbon monoxide (CO) and hydrogen sulfide (H{sub 2}S) detection and a commercially available ionization-type smoke detector. Ten smoldering coal combustion experiments were conducted. For eight of the experiments, Pittsburgh seam coal with an average particle diameter of approximately 5 cm was heated by embedded electrical strip heaters. For two of the experiments mine size Pittsburgh seam coal was heated. Heating rates of 0.5, 0.8, and 1.1. kw were selected to provide experimental conditions characteristic of very slow and moderately fast heating for coal sample mass between 3 and 10 kg. It was found that the odor meter and smoke detector alarm had a good correlation, with the odor meter alarm occurring prior to the smoke alarm in four of the ten experiments. The odor meter gave an increase in its output signal above ambient equivalent to detecting 1 ppm of H{sub 2}S (ten times the odor threshold of H{sub 2}S) as an alarm value. This observed odor meter response occurred prior to the electrochemical detection of H{sub 2}S for five of the six experiments for which it was evaluated. In all six experiments for which the smoke optical density was evaluated, it was less than 0.023 m{sup -1} prior to the odor meter reaching alarm. In each of the eight experiments with 5 cm diameter coal particles the CO exceeded 5 ppm at odor meter alarm, while for the two experiments with mine size coal the CO was less than 3 ppm at odor meter alarm. The odor meter, as tested, is not a significant improvement over smoke and CO detectors. Because the odor meter responds to a variety of chemical compounds, with suitable modification and increased sensitivity it may be useful for detection of mine fires and thereby enhance mine safety.

  8. Molecular basis of odor detection in insects.

    PubMed

    Benton, Richard

    2009-07-01

    Olfactory systems are evolutionarily ancient, underlying the common requirement for all animals to sense and respond to diverse volatile chemical signals in their environment. Odor detection is mediated by odorant receptors (ORs) that, in most olfactory systems, comprise large families of divergent G protein-coupled receptors. Here, I discuss our and others' recent investigations of ORs in the fruit fly, Drosophila melanogaster, which have revealed insights into the distinct evolutionary origin and molecular function of insect ORs. I also describe a bioinformatics strategy that we developed to identify molecules that function with these insect-specific receptors in odor detection.

  9. Odor and pheromone detection in Drosophila melanogaster.

    PubMed

    Smith, Dean P

    2007-08-01

    Drosophila melanogaster has proven to be a useful model system to probe the mechanisms underlying the detection, discrimination, and perception of volatile odorants. The relatively small receptor repertoire of 62 odorant receptors makes the goal of understanding odor responses from the total receptor repertoire approachable in this system, and recent work has been directed toward this goal. In addition, new work not only sheds light but also raises more questions about the initial steps in odor perception in this system. Odorant receptor genes in Drosophila are predicted to encode seven transmembrane receptors, but surprising data suggest that these receptors may be inverted in the plasma membrane compared to classical G-protein coupled receptors. Finally, although some Drosophila odorant receptors are activated directly by odorant molecules, detection of a volatile pheromone, 11-cis vaccenyl acetate requires an extracellular adapter protein called LUSH for activation of pheromone sensitive neurons. Because pheromones are used by insects to trigger mating and other behaviors, these insights may herald new approaches to control behavior in pathogenic and agricultural pest insects.

  10. Canine detection odor signatures for explosives

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  12. Odor compound detection in male euglossine bees.

    PubMed

    Schiestl, F P; Roubik, D W

    2003-01-01

    Male euglossine bees collect fragrances from various sources, which they store and use for as yet unknown purposes. They are attracted, often specifically, to single odor compounds and blends thereof. We used gas chromatography with electroantennographic detection (GC-EAD) and electroantennography (EAG) to investigate the response to 8 odor compounds by males of two euglossine species, Euglossa cybelia Moure and Eulaema polychroma (Mocsàry). In E. cybelia, we recorded EAD reactions in response to 1,8-cineole, methyl benzoate, benzyl actetate, methyl salicylate, eugenol, and methyl cinnamate. E. polychroma responded to the same compounds in EAG experiments, while (1s)(-)alpha-pinene and beta-pinene failed to trigger EAD or EAG responses in the bees. Blends of two compounds triggered larger responses than single compounds in EAG experiments with E. polychroma, however, when alpha-pinene was added, reactions decreased. In the light of existing data on the bees' behavior towards these odor compounds, our work indicates that both peripheral and central nervous processes influence the attraction of euglossine bees to odors.

  13. Odor Detection in Manduca sexta Is Optimized when Odor Stimuli Are Pulsed at a Frequency Matching the Wing Beat during Flight

    PubMed Central

    Daly, Kevin C.; Kalwar, Faizan; Hatfield, Mandy; Staudacher, Erich; Bradley, Samual P.

    2013-01-01

    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 temporal structure in

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

    PubMed

    Daly, Kevin C; Kalwar, Faizan; Hatfield, Mandy; Staudacher, Erich; Bradley, Samual P

    2013-01-01

    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 temporal structure in

  15. Performance of mice in an automated olfactometer: odor detection, discrimination and odor memory.

    PubMed

    Bodyak, N; Slotnick, B

    1999-12-01

    Mice were trained on a variety of odor detection and discrimination tasks in 100- or 200-trial sessions using a go, no-go discrete trials operant conditioning procedure. Odors, presented for 1 s on each trial, were generated by an air dilution olfactometer (for threshold tests) and an easily constructed eight-channel liquid dilution unit (for two- and multiple-odor discrimination tasks). Mice rapidly acquired the operant task and demonstrated excellent stimulus control by odor vapors. Their absolute detection threshold for ethyl acetate was similar to that obtained with rats using similar methods. They readily acquired four separate two-odor discrimination tasks and continued to perform well when all eight odors were presented in random order in the same session and when reinforcement probability for correct responding was decreased from 1 to 0.5. Memory for these eight odors, assessed under extinction after a 32 day rest period, was essentially perfect. Time spent sampling the odor on S+ and S- trials was highly correlated with response accuracy. When accuracy was at chance levels (e.g. initial trials on a novel task), stimulus sampling time on both S+ and S- trials was approximately 0.5-0.7 s. As response accuracy increased, sampling time on S+ trials tended to increase and remain higher than sampling time on S- trials.

  16. A broadly tuned mouse odorant receptor that detects nitrotoluenes

    PubMed Central

    Li, Jingyi; Haddad, Rafi; Chen, Sisi; Santos, Vanessa; Luetje, Charles W.

    2012-01-01

    Mammals employ large numbers of odorant receptors to sample and identify volatile chemicals in the environment. These receptors are thought to vary not only in specificity for particular odorants, but also in breadth of tuning. That is, some odorant receptors are narrowly focused on a few closely related structures, while other odorant receptors may be “broadly tuned”, responding to a wide variety of odorant structures. Here we have performed a detailed examination the mouse odorant receptor MOR256-17, demonstrating that this receptor is broadly tuned. This receptor responds to odorant structures that span a significant portion of a multi-dimensional odor space. However, we found that broad tuning was not a defining characteristic of other members the MOR256 subfamily. Two additional members of this odorant receptor subfamily (MOR256-8 and MOR256-22) were more narrowly focused on small sets of odorant structures. Interestingly, the receptive range of MOR256-17 encompassed a variety of nitrotoluenes, including various TNT synthesis intermediates, degradation products and TNT itself, suggesting the potential utility of odorant receptors in the development of sensing technologies for the detection of explosives and other forms of contraband. PMID:22443178

  17. Odor detection threshold, but not odor identification, is impaired in children with autism.

    PubMed

    Dudova, Iva; Vodicka, Jan; Havlovicova, Marketa; Sedlacek, Zdenek; Urbanek, Tomas; Hrdlicka, Michal

    2011-07-01

    The aim of our study was to examine odor detection thresholds and odor identification in autistic subjects. Thirty-five patients with Asperger's syndrome and high functioning autism (mean age 10.8 ± 3.6 years; 31 boys) were compared with 35 healthy control subjects (mean age 10.4 ± 2.4 years; 28 boys). There were no significant differences between groups with regard to mean age (p = 0.598) and gender proportion (p = 0.324). Olfactory testing used the Sniffin' Sticks test (threshold and identification parts only). Participants with Asperger's syndrome and high functioning autism, in comparison with healthy controls, were significantly impaired relative to odor detection thresholds (6.3 ± 3.1 vs. 7.9 ± 2.0; p = 0.025). Autistic participants were significantly better in correctly identifying the odor of an orange (94 vs. 63%; p < 0.05) and significantly worse at correctly identifying the odor of cloves (40 vs. 74%; p < 0.05). With regard to identification of fourteen other substances, there were no significant differences. There was no significant difference between autistic and control subjects on the total score of olfactory identification (p = 0.799). Odor identification ability (as expressed by this total score) correlated significantly with age in the control group (p = 0.049), but not in the autism group (p = 0.103). We found impaired odor detection and almost normal odor identification in children with autism. Implications for further research are discussed.

  18. Sampling Technique for Robust Odorant Detection Based on MIT RealNose Data

    NASA Technical Reports Server (NTRS)

    Duong, Tuan A.

    2012-01-01

    This technique enhances the detection capability of the autonomous Real-Nose system from MIT to detect odorants and their concentrations in noisy and transient environments. The lowcost, portable system with low power consumption will operate at high speed and is suited for unmanned and remotely operated long-life applications. A deterministic mathematical model was developed to detect odorants and calculate their concentration in noisy environments. Real data from MIT's NanoNose was examined, from which a signal conditioning technique was proposed to enable robust odorant detection for the RealNose system. Its sensitivity can reach to sub-part-per-billion (sub-ppb). A Space Invariant Independent Component Analysis (SPICA) algorithm was developed to deal with non-linear mixing that is an over-complete case, and it is used as a preprocessing step to recover the original odorant sources for detection. This approach, combined with the Cascade Error Projection (CEP) Neural Network algorithm, was used to perform odorant identification. Signal conditioning is used to identify potential processing windows to enable robust detection for autonomous systems. So far, the software has been developed and evaluated with current data sets provided by the MIT team. However, continuous data streams are made available where even the occurrence of a new odorant is unannounced and needs to be noticed by the system autonomously before its unambiguous detection. The challenge for the software is to be able to separate the potential valid signal from the odorant and from the noisy transition region when the odorant is just introduced.

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

    PubMed

    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.

  20. Variable selection based cotton bollworm odor spectroscopic detection

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  1. Good odorant practices ensure safer operations. [Natural gas odorant detection methods

    SciTech Connect

    Oudman, P. )

    1993-12-01

    Regulations in Canada and the US require that combustible gas used as a fuel be odorized at such a level that a concentration in air of one-fifth the lower explosive limit the gas can be readily detected and recognized by a person with a normal sense of smell. These regulations do not specify how the odorant level should be determined. However, since the requirement is related to smell, the level should be determined by an olfactory method. There are two odorant monitoring methods commonly used by gas companies, the olfactory (odorometer) and the instrumentation (gas chromatograph) methods. The instrument method provides only quantitative results, which somehow must be related to an olfactory response. This paper discusses these methods.

  2. Presynaptic GABA Receptors Mediate Temporal Contrast Enhancement in Drosophila Olfactory Sensory Neurons and Modulate Odor-Driven Behavioral Kinetics

    PubMed Central

    Demir, Mahmut; Gorur-Shandilya, Srinivas; Kunst, Michael; Nitabach, Michael N.

    2016-01-01

    Contrast enhancement mediated by lateral inhibition within the nervous system enhances the detection of salient features of visual and auditory stimuli, such as spatial and temporal edges. However, it remains unclear how mechanisms for temporal contrast enhancement in the olfactory system can enhance the detection of odor plume edges during navigation. To address this question, we delivered to Drosophila melanogaster flies pulses of high odor intensity that induce sustained peripheral responses in olfactory sensory neurons (OSNs). We use optical electrophysiology to directly measure electrical responses in presynaptic terminals and demonstrate that sustained peripheral responses are temporally sharpened by the combined activity of two types of inhibitory GABA receptors to generate contrast-enhanced voltage responses in central OSN axon terminals. Furthermore, we show how these GABA receptors modulate the time course of innate behavioral responses after odor pulse termination, demonstrating an important role for temporal contrast enhancement in odor-guided navigation. PMID:27588305

  3. Airborne Human Odorants: Detection, Dispersion and Characterization

    DTIC Science & Technology

    2012-03-01

    density of eccrine glands , the axillae contain large numbers of sebaceous and apocrine glands . The interactions between the cutaneous microflora and skin...odorants we have chosen for study are emitted from the body in axillary sweat which is a complex mixture of water, protein, lipids and other small

  4. Canine detection odor signatures for mine-related explosives

    NASA Astrophysics Data System (ADS)

    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.

  5. Odor detection thresholds in a population of older adults.

    PubMed

    Schubert, Carla R; Fischer, Mary E; Pinto, A Alex; Klein, Barbara E K; Klein, Ronald; Cruickshanks, Karen J

    2017-06-01

    To measure odor detection thresholds and associated nasal and behavioral factors in an older adult population. Cross-sectional cohort study. Odor detection thresholds were obtained using an automated olfactometer on 832 participants, aged 68 to 99 (mean age = 77) years in the 21-year (2013-2016) follow-up visit of the Epidemiology of Hearing Loss Study. The mean odor detection threshold (ODT) score was 8.2 (range = 1-13; standard deviation = 2.54), corresponding to an n-butanol concentration of slightly less than 0.03%. Older participants were significantly more likely to have lower (worse) ODT scores than younger participants (P < .001). There were no significant differences in mean ODT scores between men and women. Older age was significantly associated with worse performance in multivariable regression models, and exercising at least once per week was associated with reduced odds of having a low (≤5) ODT score. Cognitive impairment was also associated with poor performance, whereas a history of allergies or a deviated septum was associated with better performance. Odor detection threshold scores were worse in older age groups but similar between men and women in this large population of older adults. Regular exercise was associated with better odor detection thresholds, adding to the evidence that decline in olfactory function with age may be partly preventable. 3b. Laryngoscope, 127:1257-1262, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Enhancement of Odor Sensitivity Following Repeated Odor and Visual Fear Conditioning.

    PubMed

    Parma, Valentina; Ferraro, Stefania; Miller, Stacie S; Åhs, Fredrik; Lundström, Johan N

    2015-09-01

    Odor detection sensitivity can be rapidly altered by fear conditioning; whether this effect is augmented over time is not known. The present study aimed to test whether repeated conditioning sessions induce changes in odor detection threshold as well as in conditioned responses and whether olfactory stimuli evoke stronger conditioned responses than visual stimuli. The repeated conditioning group participated in repeated sessions over 2 weeks whereas the single conditioning group participated in 1 conditioning session; both groups were presented with visual and olfactory stimuli, were paired with an electric shock (CS+) and 2 matched control stimuli not paired with shock (CS-) while olfactory detection threshold and skin conductance responses (SCRs) were measured before and after the last session. We found increased sensitivity for the CS+ odor in the repeated but not in the single conditioning group, consistent with changes in olfactory sensitivity following repeated aversive learning and of a similar magnitude to what has previously been demonstrated in the periphery. SCR to the visual and olfactory CS+ were similar between groups, indicating that sensory thresholds can change without corresponding change in conditioned responses. In conclusion, repeated conditioning increases detection sensitivity and reduces conditioned responses, suggesting that segregated processes influence perception and conditioned responses.

  7. Detection and avoidance of a carnivore odor by prey

    PubMed Central

    Ferrero, David M.; Lemon, Jamie K.; Fluegge, Daniela; Pashkovski, Stan L.; Korzan, Wayne J.; Datta, Sandeep Robert; Spehr, Marc; Fendt, Markus; Liberles, Stephen D.

    2011-01-01

    Predator–prey relationships provide a classic paradigm for the study of innate animal behavior. Odors from carnivores elicit stereotyped fear and avoidance responses in rodents, although sensory mechanisms involved are largely unknown. Here, we identified a chemical produced by predators that activates a mouse olfactory receptor and produces an innate behavioral response. We purified this predator cue from bobcat urine and identified it to be a biogenic amine, 2-phenylethylamine. Quantitative HPLC analysis across 38 mammalian species indicates enriched 2-phenylethylamine production by numerous carnivores, with some producing >3,000-fold more than herbivores examined. Calcium imaging of neuronal responses in mouse olfactory tissue slices identified dispersed carnivore odor-selective sensory neurons that also responded to 2-phenylethylamine. Two prey species, rat and mouse, avoid a 2-phenylethylamine odor source, and loss-of-function studies involving enzymatic depletion of 2-phenylethylamine from a carnivore odor indicate it to be required for full avoidance behavior. Thus, rodent olfactory sensory neurons and chemosensory receptors have the capacity for recognizing interspecies odors. One such cue, carnivore-derived 2-phenylethylamine, is a key component of a predator odor blend that triggers hard-wired aversion circuits in the rodent brain. These data show how a single, volatile chemical detected in the environment can drive an elaborate danger-associated behavioral response in mammals. PMID:21690383

  8. Odor identification as an early marker for Alzheimer's disease: impact of lexical functioning and detection sensitivity.

    PubMed

    Morgan, C D; Nordin, S; Murphy, C

    1995-10-01

    The impact of lexical functioning and detection sensitivity on the deficit of odor identification in Alzheimer's disease (AD) was studied in persons diagnosed with probable and questionable AD. Tests consisted of lexical-based odor identification, lexical-based picture identification, picture-based odor identification, and odor-detection threshold. Results suggest (1) that odor identification is poorer than picture identification in probable and questionable AD, (2) that odor identification continues to be poor even when lexical demands are eliminated, (3) that odor detection does contribute to the odor-identification deficit, but does not account for it completely, and (4) that odor identification tests have a correct classification rate of 83-100%. Odor identification tests can be very useful tools in diagnosing AD and should be considered an important addition to existing diagnostic test batteries.

  9. Context odor presentation during sleep enhances memory in honeybees.

    PubMed

    Zwaka, Hanna; Bartels, Ruth; Gora, Jacob; Franck, Vivien; Culo, Ana; Götsch, Moritz; Menzel, Randolf

    2015-11-02

    Sleep plays an important role in stabilizing new memory traces after learning [1-3]. Here we investigate whether sleep's role in memory processing is similar in evolutionarily distant species and demonstrate that a context trigger during deep-sleep phases improves memory in invertebrates, as it does in humans. We show that in honeybees (Apis mellifera), exposure to an odor during deep sleep that has been present during learning improves memory performance the following day. Presentation of the context odor during wake phases or novel odors during sleep does not enhance memory. In humans, memory consolidation can be triggered by presentation of a context odor during slow-wave sleep that had been present during learning [3-5]. Our results reveal that deep-sleep phases in honeybees have the potential to prompt memory consolidation, just as they do in humans. This study provides strong evidence for a conserved role of sleep-and how it affects memory processes-from insects to mammals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. OR2M3: A Highly Specific and Narrowly Tuned Human Odorant Receptor for the Sensitive Detection of Onion Key Food Odorant 3-Mercapto-2-methylpentan-1-ol.

    PubMed

    Noe, Franziska; Polster, Johannes; Geithe, Christiane; Kotthoff, Matthias; Schieberle, Peter; Krautwurst, Dietmar

    2016-12-04

    The detection of key food odorants appears to be an important capability of odorant receptors. Here, thiols occupy an outstanding position among the 230 known key food odorants because of their very low odor thresholds. Members of the homologous series of 3-mercapto-2-methylalkan-1-ols have been described as onion key food odorants or food constituents and are detected at logarithmically different thresholds. 3-Mercapto-2-methylpentan-1-ol being the only key food odorant within this series also has the lowest odor threshold. Most odorants typically activate combinations of odorant receptors, which may be narrowly or broadly tuned. Consequently, a specific receptor activation pattern will define an odor quality. In contrast, here we show that just 1 of the 391 human odorant receptors, OR2M3, responded exclusively to 3-mercapto-2-methylpentan-1-ol of the 190 key food odorants tested, with a half maximal effective concentration at submicromolar concentration. Moreover, neither the Denisovan OR2M3 nor the closest OR2M3 homologs from five species did respond to this compound. This outstanding specificity of extremely narrowly tuned human OR2M3 can explain both odor qualities and odor threshold trend within a homologous series of 3-mercapto-2-methylalkan-1-ols and suggests a modern human-specific, food-related function of OR2M3 in detecting a single onion key food odorant.

  11. Sparse, Decorrelated Odor Coding in the Mushroom Body Enhances Learned Odor Discrimination

    PubMed Central

    Lin, Andrew C.; Bygrave, Alexei; de Calignon, Alix; Lee, Tzumin; Miesenböck, Gero

    2014-01-01

    Summary Sparse coding may be a general strategy of neural systems to augment memory capacity. In Drosophila, sparse odor coding by the Kenyon cells of the mushroom body is thought to generate a large number of precisely addressable locations for the storage of odor-specific memories. However, it remains untested how sparse coding relates to behavioral performance. Here we demonstrate that sparseness is controlled by a negative feedback circuit between Kenyon cells and the GABAergic anterior paired lateral (APL) neuron. Systematic activation and blockade of each leg of this feedback circuit show that Kenyon cells activate APL and APL inhibits Kenyon cells. Disrupting the Kenyon cell-APL feedback loop decreases the sparseness of Kenyon cell odor responses, increases inter-odor correlations, and prevents flies from learning to discriminate similar, but not dissimilar, odors. These results suggest that feedback inhibition suppresses Kenyon cell activity to maintain sparse, decorrelated odor coding and thus the odor-specificity of memories. PMID:24561998

  12. Computational modeling and experimental validation of odor detection behaviours of classically conditioned parasitic wasp, Microplitis croceipes.

    USDA-ARS?s Scientific Manuscript database

    To further improve the sensitivity of odor¬ and odor concentration detection of the Wasp Hound, searching behaviors of a food-conditioned wasp in a confined area with the conditioning odor were recorded. The experiments were recorded using a video camera. First, the wasps are individually hand condi...

  13. Individual human odor fallout as detected by trained canines.

    PubMed

    Vyplelová, Petra; Vokálek, Václav; Pinc, Ludvík; Pacáková, Zuzana; Bartoš, Luděk; Santariová, Milena; Čapková, Zuzana

    2014-01-01

    We tested the hypothesis that if odor fallout (the release of a human's odor onto an untouched object) in human subjects exists, then holding a hand above an absorbent will produce a detectable scent which will be subsequently matched in a detection test by trained canines. Scents were collected from seven males to sterile cotton absorbent squares. The left hand was used to get the control scent and the right hand served as the target scent. Each experimental subject was sitting; his left hand was laid down on a cotton square for 3 min. The right hand was held 5 cm above another cotton square for 3 min. The scent identification was done by two specially trained police German shepherds. These canines had routinely performed scent identification line-ups as part of criminal investigation procedures. Both canines performed 14 line-ups and correctly matched the collected scents of all test subjects. The results suggest the existence of human odor fallout, whereby a human scent trace is left by humans even if they do not touch an object.

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

    PubMed Central

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

    2014-01-01

    Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analyses—using discriminant analysis of principal components and random forest approaches—revealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection. PMID:24982164

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

    PubMed

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

    2014-07-29

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

  16. Crucial role of copper in detection of metal-coordinating odorants

    PubMed Central

    Duan, Xufang; Block, Eric; Li, Zhen; Connelly, Timothy; Zhang, Jian; Huang, Zhimin; Su, Xubo; Pan, Yi; Wu, Lifang; Chi, Qiuyi; Thomas, Siji; Zhang, Shaozhong; Ma, Minghong; Matsunami, Hiroaki; Chen, Guo-Qiang; Zhuang, Hanyi

    2012-01-01

    Odorant receptors (ORs) in olfactory sensory neurons (OSNs) mediate detection of volatile odorants. Divalent sulfur compounds, such as thiols and thioethers, are extremely potent odorants. We identify a mouse OR, MOR244-3, robustly responding to (methylthio)methanethiol (MeSCH2SH; MTMT) in heterologous cells. Found specifically in male mouse urine, strong-smelling MTMT [human threshold 100 parts per billion (ppb)] is a semiochemical that attracts female mice. Nonadjacent thiol and thioether groups in MTMT suggest involvement of a chelated metal complex in MOR244-3 activation. Metal ion involvement in thiol–OR interactions was previously proposed, but whether these ions change thiol-mediated OR activation remained unknown. We show that copper ion among all metal ions tested is required for robust activation of MOR244-3 toward ppb levels of MTMT, structurally related sulfur compounds, and other metal-coordinating odorants (e.g., strong-smelling trans-cyclooctene) among >125 compounds tested. Copper chelator (tetraethylenepentamine, TEPA) addition abolishes the response of MOR244-3 to MTMT. Histidine 105, located in the third transmembrane domain near the extracellular side, is proposed to serve as a copper-coordinating residue mediating interaction with the MTMT–copper complex. Electrophysiological recordings of the OSNs in the septal organ, abundantly expressing MOR244-3, revealed neurons responding to MTMT. Addition of copper ion and chelator TEPA respectively enhanced and reduced the response of some MTMT-responding neurons, demonstrating the physiological relevance of copper ion in olfaction. In a behavioral context, an olfactory discrimination assay showed that mice injected with TEPA failed to discriminate MTMT. This report establishes the role of metal ions in mammalian odor detection by ORs. PMID:22328155

  17. Crucial role of copper in detection of metal-coordinating odorants.

    PubMed

    Duan, Xufang; Block, Eric; Li, Zhen; Connelly, Timothy; Zhang, Jian; Huang, Zhimin; Su, Xubo; Pan, Yi; Wu, Lifang; Chi, Qiuyi; Thomas, Siji; Zhang, Shaozhong; Ma, Minghong; Matsunami, Hiroaki; Chen, Guo-Qiang; Zhuang, Hanyi

    2012-02-28

    Odorant receptors (ORs) in olfactory sensory neurons (OSNs) mediate detection of volatile odorants. Divalent sulfur compounds, such as thiols and thioethers, are extremely potent odorants. We identify a mouse OR, MOR244-3, robustly responding to (methylthio)methanethiol (MeSCH(2)SH; MTMT) in heterologous cells. Found specifically in male mouse urine, strong-smelling MTMT [human threshold 100 parts per billion (ppb)] is a semiochemical that attracts female mice. Nonadjacent thiol and thioether groups in MTMT suggest involvement of a chelated metal complex in MOR244-3 activation. Metal ion involvement in thiol-OR interactions was previously proposed, but whether these ions change thiol-mediated OR activation remained unknown. We show that copper ion among all metal ions tested is required for robust activation of MOR244-3 toward ppb levels of MTMT, structurally related sulfur compounds, and other metal-coordinating odorants (e.g., strong-smelling trans-cyclooctene) among >125 compounds tested. Copper chelator (tetraethylenepentamine, TEPA) addition abolishes the response of MOR244-3 to MTMT. Histidine 105, located in the third transmembrane domain near the extracellular side, is proposed to serve as a copper-coordinating residue mediating interaction with the MTMT-copper complex. Electrophysiological recordings of the OSNs in the septal organ, abundantly expressing MOR244-3, revealed neurons responding to MTMT. Addition of copper ion and chelator TEPA respectively enhanced and reduced the response of some MTMT-responding neurons, demonstrating the physiological relevance of copper ion in olfaction. In a behavioral context, an olfactory discrimination assay showed that mice injected with TEPA failed to discriminate MTMT. This report establishes the role of metal ions in mammalian odor detection by ORs.

  18. Determination of odor detection threshold in the Gottingen minipig.

    PubMed

    Søndergaard, Lene Vammen; Holm, Ida E; Herskin, Mette S; Dagnæs-Hansen, Frederik; Johansen, Marianne G; Jørgensen, Arne Lund; Ladewig, Jan

    2010-10-01

    The aim of the study was to examine the ability of Göttingen minipigs to acquire an olfaction-based operant conditioning task and to determine the detection threshold for ethyl acetate and ethanol. We used an automated olfactometer developed for rodents to train and test 14 pigs. Odor sampling and reliable responding were obtained after three to fifteen 160-trial sessions. Successful transfer of the task from ethyl acetate to ethanol was achieved in 1-4 sessions. Detection threshold for ethyl acetate varied between 10(-2)% and 10(-6)% v/v and for ethanol between 0.1% and 5 × 10(-6)% v/v. The results provide evidence that minipigs can successfully acquire 2-odorant discrimination using a food-rewarded instrumental conditioning paradigm for testing olfactory function. This olfactory discrimination paradigm provides reliable measures of olfactory sensitivity and thereby enables detection of changes in olfaction in a porcine model of Alzheimer's disease currently being developed.

  19. The role of congruency and pleasantness in odor-induced taste enhancement.

    PubMed

    Schifferstein, H N; Verlegh, P W

    1996-10-01

    Although odorants and tastants are perceived by two different senses, the rated intensity of a tastant may increase if an odorant is added. The size of the odor-induced taste enhancement is said to depend on the perceptual similarity between the tastant and the odorant, and on the task instruction which affects subjects' working concepts of attribute categories. It is investigated whether congruency or pleasantness (halo-effects) can replace perceptual similarity in accounting for odor-induced taste enhancement. Sweetness intensity, pleasantness, and degree of congruency are determined for three sucrose/odorant combinations. Odor-induced enhancement is found only for congruent mixtures (sucrose/strawberry and sucrose/lemon). In addition, highly congruent mixtures are more pleasant than expected under additivity. The pleasantness judgments for incongruent combinations (sucrose/ham) follow a subtractive rule. The congruency ratings can account for a significant part of the pleasantness ratings, but not for the degree of sweetness enhancement. Also, the pleasantness ratings are not related to the degree of enhancement. Therefore, congruency or pleasantness ratings cannot replace similarity ratings in accounting for odor-induced taste enhancement.

  20. Colorimetric sensor for bad odor detection using automated color correction

    NASA Astrophysics Data System (ADS)

    Schmitt, K.; Tarantik, K.; Pannek, C.; Benito-Altamirano, I.; Casals, O.; Fàbrega, C.; Romano-Rodríguez, A.; Wöllenstein, J.; Prades, J. D.

    2017-06-01

    Colorimetric sensors based on color-changing dyes offer a convenient approach for the quantitative measurement of gases. An integrated, mobile colorimetric sensor can be particularly helpful for occasional gas measurements, such as informal air quality checks for bad odors. In these situations, the main requirement is high availability, easy usage, and high specificity towards one single chemical compound, combined with cost-efficient production. In this contribution, we show how a well stablished colorimetric method can be adapted for easy operation and readout, making it suitable for the untrained end user. As an example, we present the use of pH indicators for the selective and reversible detection of NH3 in air (one relevant gas contributing to bad odors) using gas-sensitive layers dip coated on glass substrates. Our results show that the method can be adapted to detect NH3 concentrations lower than 1 ppm, with measure-to-result times in the range of a few minutes. We demonstrate that the color measurements can be carried out with the optical signals of RGB sensors, without losing quantitative performance.

  1. Chemosensory danger detection in the human brain: Body odor communicating aggression modulates limbic system activation.

    PubMed

    Mutic, Smiljana; Brünner, Yvonne F; Rodriguez-Raecke, Rea; Wiesmann, Martin; Freiherr, Jessica

    2017-02-28

    Although the sense of smell is involved in numerous survival functions, the processing of body odor emitted by dangerous individuals is far from understood. The aim of the study was to explore how human fight chemosignals communicating aggression can alter brain activation related to an attentional bias and danger detection. While the anterior cingulate cortex (ACC) was seen involved in processing threat-related emotional information, danger detection and error evaluation, it still remains unknown whether human chemosignals communicating aggression can potentially modulate this activation. In the fMRI experiment, healthy male and female normosmic odor recipients (n=18) completed a higher-order processing task (emotional Stroop task with the word categories anger, anxiety, happiness and neutral) while exposed to aggression and exercise chemosignals (collected from a different group of healthy male donors; n=16). Our results provide first evidence that aggression chemosignals induce a time-sensitive attentional bias in chemosensory danger detection and modulate limbic system activation. During exposure to aggression chemosignals compared to exercise chemosignals, functional imaging data indicates an enhancement of thalamus, hypothalamus and insula activation (p<.05, FWE-corrected). Together with the thalamus, the ACC was seen activated in response to threat-related words (p<.001). Chemosensory priming and habituation to body odor signals are discussed.

  2. Ability of mice to detect estrous odor in bovine urine: roles of hormones and behavior in odor discrimination.

    PubMed

    Rameshkumar, Kamatchi; Achiraman, Shanmugam; Karthikeyan, Kandasamy; Archunan, Govindaraju

    2008-04-01

    This study was designed to evaluate the ability of mice to discriminate cow urinary odor from different reproductive phases, with a view toward detecting the estrous phase. Experiments were also carried out to establish the relationship between androgen and mouse behaviors during estrous detection. Further, the study was also intended to establish the relationship between androgen and behaviors in estrous detection. Bovine urine was collected during estrus and non-estrous periods, i.e., prepubertal, preovulatory, ovulatory, postovulatory, pregnancy, and lactation. Behavioral analyses were carried out in a Y-maze apparatus, in which the mice were acclimatized in before odor-preference tests. The number and duration of visits, and grooming behavior by male responders towards the urine samples, were recorded. Intact male mice showed a higher response towards estrus urine samples than towards non-estrous urine. By contrast, orchidectomized mice failed to discriminate estrous urine, whereas castrated mice treated with testosterone regained the ability to discriminate estrus odor. A higher level of grooming behavior was found in males exposed to estrous urine than to urine of other phases. These results suggest that normal mice have the ability to detect estrus, and that this discriminating ability is androgen dependent. The grooming behavior shown by males in response to estrous urine may be taken as a key parameters in estrous detection. The results further suggest that bovine estrous urine produces specific odors that probably involve both intraspecific and interspecific communication.

  3. Maintenance energy requirements of odor detection, explosive detection and human detection working dogs.

    PubMed

    Mullis, Rebecca A; Witzel, Angela L; Price, Joshua

    2015-01-01

    Despite their important role in security, little is known about the energy requirements of working dogs such as odor, explosive and human detection dogs. Previous researchers have evaluated the energy requirements of individual canine breeds as well as dogs in exercise roles such as sprint racing. This study is the first to evaluate the energy requirements of working dogs trained in odor, explosive and human detection. This retrospective study evaluated twenty adult dogs who maintained consistent body weights over a six month period. During this time, the average energy consumption was [Formula: see text] or two times the calculated resting energy requirement ([Formula: see text]). No statistical differences were found between breeds, age or sex, but a statistically significant association (p = 0.0033, R-square = 0.0854) was seen between the number of searches a dog performs and their energy requirement. Based on this study's population, it appears that working dogs have maintenance energy requirements similar to the 1974 National Research Council's (NRC) maintenance energy requirement of [Formula: see text] (National Research Council (NRC), 1974) and the [Formula: see text] reported for young laboratory beagles (Rainbird & Kienzle, 1990). Additional research is needed to determine if these data can be applied to all odor, explosive and human detection dogs and to determine if other types of working dogs (tracking, search and rescue etc.) have similar energy requirements.

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

    PubMed

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

    2015-05-15

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

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

    NASA Technical Reports Server (NTRS)

    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.

  6. A salty-congruent odor enhances saltiness: functional magnetic resonance imaging study.

    PubMed

    Seo, Han-Seok; Iannilli, Emilia; Hummel, Cornelia; Okazaki, Yoshiro; Buschhüter, Dorothee; Gerber, Johannes; Krammer, Gerhard E; van Lengerich, Bernhard; Hummel, Thomas

    2013-01-01

    Excessive intake of dietary salt (sodium chloride) may increase the risk of chronic diseases. Accordingly, various strategies to reduce salt intake have been conducted. This study aimed to investigate whether a salty-congruent odor can enhance saltiness on the basis of psychophysical (Experiment 1) and neuroanatomical levels (Experiment 2). In Experiment 1, after receiving one of six stimulus conditions: three odor conditions (odorless air, congruent, or incongruent odor) by two concentrations (low or high) of either salty or sweet taste solution, participants were asked to rate taste intensity and pleasantness. In Experiment 2, participants received the same stimuli during the functional magnetic resonance imaging scan. In Experiment 1, compared with an incongruent odor and/or odorless air, a congruent odor enhanced not only taste intensity but also either pleasantness of sweetness or unpleasantness of saltiness. In Experiment 2, a salty-congruent combination of odor and taste produced significantly higher neuronal activations in brain regions associated with odor-taste integration (e.g., insula, frontal operculum, anterior cingulate cortex, and orbitofrontal cortex) than an incongruent combination and/or odorless air with taste solution. In addition, the congruent odor-induced saltiness enhancement was more pronounced in the low-concentrated tastant than in the high-concentrated one. In conclusion, this study demonstrates the congruent odor-induced saltiness enhancement on the basis of psychophysical and neuroanatomical results. These findings support an alternative strategy to reduce excessive salt intake by adding salty-congruent aroma to sodium reduced food. However, there are open questions regarding the salty-congruent odor-induced taste unpleasantness.

  7. Ontogeny of the enhanced fetal-ethanol-induced behavioral and neurophysiologic olfactory response to ethanol odor.

    PubMed

    Eade, Amber M; Sheehe, Paul R; Youngentob, Steven L

    2010-02-01

    Studies report a fundamental relationship between chemosensory function and the responsiveness to ethanol, its component orosensory qualities, and its odor as a consequence of fetal ethanol exposure. Regarding odor, fetal exposed rats display enhanced olfactory neural and behavioral responses to ethanol odor at postnatal (P) day 15. Although these consequences are absent in adults (P90), the behavioral effect has been shown to persist into adolescence (P37). Given the developmental timing of these observations, we explored the decay in the response to ethanol odor by examining ages between P37 and young adulthood. Moreover, we sought to determine whether the P15 neurophysiologic effect persists, at least, to P40. Behavioral and olfactory epithelial (OE) responses of fetal ethanol exposed and control rats were tested at P40, P50, P60, or P70. Whole-body plethysmography was used to quantify each animal's innate behavioral response to ethanol odor. We then mapped the odorant-induced activity across the OE in response to different odorants, including ethanol, using optical recording methods. Relative to controls, ethanol exposed animals showed an enhanced behavioral response to ethanol odor that, while significant at each age, decreased in magnitude. These results, in conjunction with previous findings, permitted the development of an ontologic odor response model of fetal exposure. The fitted model exemplifies that odor-mediated effects exist at birth, peak in adolescence and then decline, becoming absent by P90. There was no evidence of an effect on the odor response of the OE at any age tested. Fetal exposure yields an enhanced behavioral response to ethanol odor that peaks in adolescence and wanes through young adulthood. This occurs absent an enhanced response of the OE. This latter finding suggests that by P40 the OE returns to an ethanol "neutral" status and that central mechanisms, such as ethanol-induced alterations in olfactory bulb circuitry, underlie the

  8. Different thresholds for detection and discrimination of odors in the honey bee (Apis mellifera).

    PubMed

    Wright, Geraldine A; Smith, Brian H

    2004-02-01

    Naturally occurring odors used by animals for mate recognition, food identification and other purposes must be detected at concentrations that vary across several orders of magnitude. Olfactory systems must therefore have the capacity to represent odors over a large range of concentrations regardless of dramatic changes in the salience, or perceived intensity, of a stimulus. The stability of the representation of an odor relative to other odors across concentration has not been extensively evaluated. We tested the ability of honey bees to discriminate pure odorants across a range of concentrations at and above their detection threshold. Our study showed that pure odorant compounds became progressively easier for honey bees to discriminate with increasing concentration. Discrimination is, therefore, a function of odorant concentration. We hypothesize that the recruitment of sensory cell populations across a range of concentrations may be important for odor coding, perhaps by changing its perceptual qualities or by increasing its salience against background stimuli, and that this mechanism is a general property of olfactory systems.

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

    PubMed

    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. Copyright © 2016 the American Physiological Society.

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

    PubMed Central

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

    2016-01-01

    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

  11. Artificial odor map and discrimination of odorants using the odor separating system

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    In this research, achievement of the odor discrimination was examined. At first, odor separating system was developed which imitates the odor receptive mechanism of biological olfaction. A rough detection of odor becomes possible with this device. Therefore, this device makes it possible to measure the molecular size and the polarity of odorant and discriminate the mixed odor. Then, measuring representative odor molecules belonging to biological glomeruli clusters, odor information is extracted from time course patterns obtained by the system. The extracted features could be used for odor mapping close to the odor map created in the odor receptive mechanism which can classify odor quality by their odor cluster attributes.

  12. [Detection of TVOC and odor in industrial park using electronic nose].

    PubMed

    Tian, Xiu-Ying; Cai, Qiang; Ye, Zhao-Xia; Guo, Wei; Lu, Yan-Wen; Zhang, Yong-Ming

    2011-12-01

    The main volatile compounds belong to TVOC or odor which may generate from industrial park,special sensors were adopted to build electronic nose for detecting those compounds. TVOC pollution index (TPI) and odor pollution index (OPI) were designed as well as detecting method based on electronic nose in the field. On this basis, considering the pollution situation of chemical industrial of Zhapu port in Jiaxing, six detecting points were selected to be tested by electronic nose on site. Each sensor responses processed by principal components analysis (PCA), two principal components were extracted, that is, eight sensors can be divided into two groups including the types of TVOC (S1) and odor (S2-S8). Meanwhile, the on site collected samples were qualitatively analyzed with GC/ MS. At each testing point, integral area percentage of the compounds being a part of TVOC accumulated mostly over 90% and to odor, mostly was below 10%. Results show: (1) Choosing appropriate sensors combining PCA can preliminarily reflect the pollution condition of TVOC and odor in industrial park; (2) Combining pollution indexes measured with electronic nose and results of qualitative analysis with GC/MS can generally concluded the overall pollution situation of TVOC and odor in industrial park and distribution of each pollutant; (3) Application of electronic noses and GIS to detect TVOC and odor in industrial park can preliminary assess space pollution situation in industrial park.

  13. An algorithm for 353 odor detection thresholds in humans.

    PubMed

    Abraham, Michael H; Sánchez-Moreno, Ricardo; Cometto-Muñiz, J Enrique; Cain, William S

    2012-03-01

    One hundred and ninety three odor detection thresholds, ODTs, obtained by Nagata using the Japanese triangular bag method can be correlated as log (1/ODT) by a linear equation with R(2) = 0.748 and a standard deviation, SD, of 0.830 log units; the latter may be compared with our estimate of 0.66 log units for the self-consistency of Nagata's data. Aldehydes, acids, unsaturated esters, and mercaptans were included in the equation through indicator variables that took into account the higher potency of these compounds. The ODTs obtained by Cometto-Muñiz and Cain, by Cometto-Muñiz and Abraham, and by Hellman and Small could be put on the same scale as those of Nagata to yield a linear equation for 353 ODTs with R(2) = 0.759 and SD = 0.819 log units. The compound descriptors are available for several thousand compounds, and can be calculated from structure, so that further ODT values on the Nagata scale can be predicted for a host of volatile or semivolatile compounds.

  14. An Algorithm for 353 Odor Detection Thresholds in Humans

    PubMed Central

    Sánchez-Moreno, Ricardo; Cometto-Muñiz, J. Enrique; Cain, William S.

    2012-01-01

    One hundred and ninety three odor detection thresholds, ODTs, obtained by Nagata using the Japanese triangular bag method can be correlated as log (1/ODT) by a linear equation with R2 = 0.748 and a standard deviation, SD, of 0.830 log units; the latter may be compared with our estimate of 0.66 log units for the self-consistency of Nagata's data. Aldehydes, acids, unsaturated esters, and mercaptans were included in the equation through indicator variables that took into account the higher potency of these compounds. The ODTs obtained by Cometto-Muñiz and Cain, by Cometto-Muñiz and Abraham, and by Hellman and Small could be put on the same scale as those of Nagata to yield a linear equation for 353 ODTs with R2 = 0.759 and SD = 0.819 log units. The compound descriptors are available for several thousand compounds, and can be calculated from structure, so that further ODT values on the Nagata scale can be predicted for a host of volatile or semivolatile compounds. PMID:21976369

  15. Mechanisms of Odor-Tracking: Multiple Sensors for Enhanced Perception and Behavior

    PubMed Central

    Gomez-Marin, Alex; Duistermars, Brian J.; Frye, Mark A.; Louis, Matthieu

    2010-01-01

    Early in evolution, the ability to sense and respond to changing environments must have provided a critical survival advantage to living organisms. From bacteria and worms to flies and vertebrates, sophisticated mechanisms have evolved to enhance odor detection and localization. Here, we review several modes of chemotaxis. We further consider the relevance of a striking and recurrent motif in the organization of invertebrate and vertebrate sensory systems, namely the existence of two symmetrical olfactory sensors. By combining our current knowledge about the olfactory circuits of larval and adult Drosophila, we examine the molecular and neural mechanisms underlying robust olfactory perception and extend these analyses to recent behavioral studies addressing the relevance and function of bilateral olfactory input for gradient detection. Finally, using a comparative theoretical approach based on Braitenberg's vehicles, we speculate about the relationships between anatomy, circuit architecture and stereotypical orientation behaviors. PMID:20407585

  16. Determining human exposure and sensory detection of odorous compounds released during showering.

    PubMed

    Omür-Ozbek, Pinar; Gallagher, Daniel L; Dietrich, Andrea M

    2011-01-15

    Modeling of human exposure to aqueous algal odorants geosmin (earthy), 2-methylisoborneol (musty), and (trans,cis)-2,6-nonadienal (cucumber, fishy), and the solvent trichloroethylene (sweet chemical), was investigated to improve the understanding of water-air transfer by including humans as sensors to detect contaminants. A mass-transfer model was employed to determine indoor air concentrations when water was used for showering under varying conditions (shower stall volume, water and air flow rate, temperature, aqueous odorant concentration, shower duration). Statistical application of multiple linear regression and tree regression were employed to determine critical model parameters. The model predicted that concentrations detectable to the human senses were controlled by temperature, odor threshold, and aqueous concentration for the steady-state model, whereas shower volume, air flow, and water flow are also important for the dynamic model and initial detection of the odorant immediately after the showering is started. There was excellent agreement of model predictions with literature data for human perception of algal odorants in their homes and complaints to water utilities. TCE performed differently than the algal odorants due to its higher Henry's law constant, in spite of similar gas and liquid diffusivities. The use of nontoxic odorants offers an efficient tool to calibrate indoor air/water shower models.

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

    PubMed Central

    Pregitzer, Pablo; Schubert, Marco; Breer, Heinz; Hansson, Bill S.; Sachse, Silke; Krieger, Jürgen

    2012-01-01

    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 (AL), 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 (PBP) HvirPBP2 and the pheromone receptor (PR) 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. PMID:23060749

  18. Olfaction in the Psychosis Prodrome: Electrophysiological and Behavioral Measures of Odor Detection

    PubMed Central

    Kayser, Jürgen; Tenke, Craig E.; Kroppmann, Christopher J.; Alschuler, Daniel M.; Ben-David, Shelly; Fekri, Shiva; Bruder, Gerard E.; Corcoran, Cheryl M.

    2013-01-01

    Smell identification deficits (SIDs) are relatively specific to schizophrenia and its negative symptoms, and may predict transition to psychosis in clinical high-risk (CHR) individuals. Moreover, eventrelated potentials (ERPs) to odors are reduced in schizophrenia. This study examined whether CHR patients show SIDs and abnormal olfactory N1 and P2 potentials. ERPs (49 channels) were recorded from 21 CHR and 20 healthy participants (13 males/group; ages 13–27 years) during an odor detection task using three concentrations of hydrogen sulfide (H2S) or blank air presented unilaterally by a constant-flow olfactometer. Neuronal generator patterns underlying olfactory ERPs were identified and measured by principal components analysis (unrestricted Varimax) of reference-free current source densities (CSD). Replicating previous findings, CSD waveforms to H2S stimuli were characterized by an early N1 sink (345 ms, lateral-temporal) and a late P2 source (600 ms, mid-frontocentroparietal). N1 and P2 varied monotonically with odor intensity (strong > medium > weak) and did not differ across groups. Patients and controls also showed comparable odor detection and had normal odor identification and thresholds (Sniffin’ Sticks). However, olfactory ERPs strongly reflected differences in odor intensity and detection in controls, but these associations were substantially weaker in patients. Moreover, severity of negative symptoms in patients was associated with reduced olfactory ERPs and poorer odor detection, identification and thresholds. Three patients who developed psychosis had poorer odor detection and thresholds, and marked reductions of N1 and P2. Thus, despite the lack of overall group differences, olfactory measures may be of utility in predicting transition to psychosis among CHR patients. PMID:23856353

  19. Bulbar acetylcholine enhances neural and perceptual odor discrimination.

    PubMed

    Chaudhury, Dipesh; Escanilla, Olga; Linster, Christiane

    2009-01-07

    Experimental and modeling data suggest that the circuitry of the main olfactory bulb (OB) plays a critical role in olfactory discrimination. Processing of such information arises from the interaction between OB output neurons local interneurons, as well as interactions between the OB network and centrifugal inputs. Cholinergic input to the OB in particular has been hypothesized to regulate mitral cell odorants receptive fields (ORFs) and behavioral discrimination of similar odorants. We recorded from individual mitral cells in the OB in anesthetized rats to determine the degree of overlap in ORFs of individual mitral cells after exposure to odorant stimuli. Increasing the efficacy of the cholinergic neurotransmission in the OB by addition of the anticholinesterase drug neostigmine (20 mM) sharpened the ORF responses of mitral cells. Furthermore, coaddition of either the nicotinic antagonist methyllycaconitine citrate hydrate (MLA) (20 mM) or muscarinic antagonist scopolamine (40 mM) together with neostigmine (20 mM) attenuated the neostigmine-dependent sharpening of ORFs. These electrophysiological findings are predictive of accompanying behavioral experiments in which cholinergic modulation was manipulated by direct infusion of neostigmine, MLA, and scopolamine into the OB during olfactory behavioral tasks. Increasing the efficacy of cholinergic action in the OB increased perceptual discrimination of odorants in these experiments, whereas blockade of nicotinic or muscarinic receptors decreased perceptual discrimination. These experiments show that behavioral discrimination is modulated in a manner predicted by the changes in mitral cell ORFs by cholinergic drugs. These results together present a first direct comparison between neural and perceptual effects of a bulbar neuromodulator.

  20. Fasting increases and satiation decreases olfactory detection for a neutral odor in rats.

    PubMed

    Aimé, P; Duchamp-Viret, P; Chaput, M A; Savigner, A; Mahfouz, M; Julliard, A K

    2007-05-16

    Olfaction plays a fundamental role in feeding behavior, but changes in olfactory acuity according to feeding states have never been precisely demonstrated in animals. The present study assesses the olfactory detection performance of fasted or satiated rats placed under a strictly controlled food-intake regimen. We did this using a conditioned odor aversion (COA) protocol which induced in rats an almost total aversion to an ISO-odorized drink at 10(-5) (1 microl in 100 ml of water). The rats (either fasted or satiated) were then presented with different concentrations of ISO-odorized water to compare their ability to detect and so avoid the ISO drink. In both states, the rats consumed significantly larger volumes of ISO at 10(-10), 10(-9) and 10(-8) than at 10(-5), suggesting lower detection at these three concentrations, although the fasted rats consumed significantly less ISO drink than did the satiated ones, showing better ISO detection at these concentrations. These experiments provide original data demonstrating the expected fact that olfactory sensitivity increases in fasted animals. Since these results were obtained using a neutral odor, we suggest that olfactory acuity increases during fasting, enabling animals to more easily detect both food and environmental odors such as those of predators. This would have an obvious eco-ethological role by increasing the relevance of olfactory inputs when seeking food.

  1. Enhancement of Odor-Induced Activity in the Canine Brain by Zinc Nanoparticles: A Functional MRI Study in Fully Unrestrained Conscious Dogs.

    PubMed

    Jia, Hao; Pustovyy, Oleg M; Wang, Yun; Waggoner, Paul; Beyers, Ronald J; Schumacher, John; Wildey, Chester; Morrison, Edward; Salibi, Nouha; Denney, Thomas S; Vodyanoy, Vitaly J; Deshpande, Gopikrishna

    2016-01-01

    Using noninvasive in vivo functional magnetic resonance imaging (fMRI), we demonstrate that the enhancement of odorant response of olfactory receptor neurons by zinc nanoparticles leads to increase in activity in olfaction-related and higher order areas of the dog brain. To study conscious dogs, we employed behavioral training and optical motion tracking for reducing head motion artifacts. We obtained brain activation maps from dogs in both anesthetized state and fully conscious and unrestrained state. The enhancement effect of zinc nanoparticles was higher in conscious dogs with more activation in higher order areas as compared with anesthetized dogs. In conscious dogs, voxels in the olfactory bulb and hippocampus showed higher activity to odorants mixed with zinc nanoparticles as compared with pure odorants, odorants mixed with gold nanoparticles as well as zinc nanoparticles alone. These regions have been implicated in odor intensity processing in other species including humans. If the enhancement effect of zinc nanoparticles observed in vivo are confirmed by future behavioral studies, zinc nanoparticles may provide a way for enhancing the olfactory sensitivity of canines for detection of target substances such as explosives and contraband substances at very low concentrations, which would otherwise go undetected. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    PubMed Central

    Wongchoosuk, Chatchawal; Lutz, Mario; Kerdcharoen, Teerakiat

    2009-01-01

    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. PMID:22399995

  3. An odor detection system based on automatically trained mice by relative go no-go olfactory operant conditioning

    PubMed Central

    He, Jing; Wei, JingKuan; Rizak, Joshua D.; Chen, YanMei; Wang, JianHong; Hu, XinTian; Ma, YuanYe

    2015-01-01

    Odor detection applications are needed by human societies in various circumstances. Rodent offers unique advantages in developing biologic odor detection systems. This report outlines a novel apparatus designed to train maximum 5 mice automatically to detect odors using a new olfactory, relative go no-go, operant conditioning paradigm. The new paradigm offers the chance to measure real-time reliability of individual animal’s detection behavior with changing responses. All of 15 water-deprivation mice were able to learn to respond to unpredictable delivering of the target odor with higher touch frequencies via a touch sensor. The mice were continually trained with decreasing concentrations of the target odor (n-butanol), the average correct percent significantly dropped when training at 0.01% solution concentration; the alarm algorithm showed excellent recognition of odor detection behavior of qualified mice group through training. Then, the alarm algorithm was repeatedly tested against simulated scenario for 4 blocks. The mice acted comparable to the training period during the tests, and provided total of 58 warnings for the target odor out of 59 random deliveries and 0 false alarm. The results suggest this odor detection method is promising for further development in respect to various types of odor detection applications. PMID:25944031

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  5. Neuropeptide Y enhances olfactory mucosa responses to odorant in hungry rats.

    PubMed

    Negroni, Julia; Meunier, Nicolas; Monnerie, Régine; Salesse, Roland; Baly, Christine; Caillol, Monique; Congar, Patrice

    2012-01-01

    Neuropeptide Y (NPY) plays an important role in regulating appetite and hunger in vertebrates. In the hypothalamus, NPY stimulates food intake under the control of the nutritional status. Previous studies have shown the presence of NPY and receptors in rodent olfactory system, and suggested a neuroproliferative role. Interestingly, NPY was also shown to directly modulate olfactory responses evoked by a food-related odorant in hungry axolotls. We have recently demonstrated that another nutritional cue, insulin, modulates the odorant responses of the rat olfactory mucosa (OM). Therefore, the aim of the present study was to investigate the potential effect of NPY on rat OM responses to odorants, in relation to the animal's nutritional state. We measured the potential NPY modulation of OM responses to odorant, using electro-olfactogram (EOG) recordings, in fed and fasted adult rats. NPY application significantly and transiently increased EOG amplitudes in fasted but not in fed rats. The effects of specific NPY-receptor agonists were similarly quantified, showing that NPY operated mainly through Y1 receptors. These receptors appeared as heterogeneously expressed by olfactory neurons in the OM, and western blot analysis showed that they were overexpressed in fasted rats. These data provide the first evidence that NPY modulates the initial events of odorant detection in the rat OM. Because this modulation depends on the nutritional status of the animal, and is ascribed to NPY, the most potent orexigenic peptide in the central nervous system, it evidences a strong supplementary physiological link between olfaction and nutritional processes.

  6. Neuropeptide Y Enhances Olfactory Mucosa Responses to Odorant in Hungry Rats

    PubMed Central

    Negroni, Julia; Meunier, Nicolas; Monnerie, Régine; Salesse, Roland; Baly, Christine; Caillol, Monique; Congar, Patrice

    2012-01-01

    Neuropeptide Y (NPY) plays an important role in regulating appetite and hunger in vertebrates. In the hypothalamus, NPY stimulates food intake under the control of the nutritional status. Previous studies have shown the presence of NPY and receptors in rodent olfactory system, and suggested a neuroproliferative role. Interestingly, NPY was also shown to directly modulate olfactory responses evoked by a food-related odorant in hungry axolotls. We have recently demonstrated that another nutritional cue, insulin, modulates the odorant responses of the rat olfactory mucosa (OM). Therefore, the aim of the present study was to investigate the potential effect of NPY on rat OM responses to odorants, in relation to the animal's nutritional state. We measured the potential NPY modulation of OM responses to odorant, using electro-olfactogram (EOG) recordings, in fed and fasted adult rats. NPY application significantly and transiently increased EOG amplitudes in fasted but not in fed rats. The effects of specific NPY-receptor agonists were similarly quantified, showing that NPY operated mainly through Y1 receptors. These receptors appeared as heterogeneously expressed by olfactory neurons in the OM, and western blot analysis showed that they were overexpressed in fasted rats. These data provide the first evidence that NPY modulates the initial events of odorant detection in the rat OM. Because this modulation depends on the nutritional status of the animal, and is ascribed to NPY, the most potent orexigenic peptide in the central nervous system, it evidences a strong supplementary physiological link between olfaction and nutritional processes. PMID:23024812

  7. Enhancement of spatial learning by predator odor in mice: involvement of amygdala and hippocampus.

    PubMed

    Galliot, Emmanuel; Levaillant, Maryline; Beard, Elidie; Millot, Jean-Louis; Pourié, Gregory

    2010-02-01

    Olfaction has particular links with learning and memory compared with other sensory cues, due to the interrelations between their neural circuitry. The present study deals with the effects of a putative stressor (i.e. a predator odor) on visuo-spatial learning in mice. Firstly, the results show that a predator odor spread during the Morris water maze task led to learning enhancement. In addition, a stereotaxic approach was used to investigate the involvement of the amygdala in this hippocampus-dependent type of learning. Thus, the performance of mice in visuo-spatial learning under predator odor conditions was dramatically reduced by an ibotenate bilateral amygdala lesion. The involvement of the amygdala was confirmed by a reduced expression of c-fos in the CA1 hippocampus of amygdala-lesioned mice at the end of the learning procedure. Mild exposure to a predator odor during hippocampus-dependent learning therefore leads to an enhancement of performance through the co-activation of the amygdala, probably by a stress mediated mechanism.

  8. Odor detection thresholds of naphthenic acids from commercial sources and oil sands process-affected water.

    PubMed

    Edge, Kristyn; Barona, Brenda; Young, Rozlyn F; Fedorak, Phillip M; Wismer, Wendy V

    2010-11-01

    Naphthenic acids (NAs) occur naturally in various petroleums and in oil sands tailings waters and have been implicated as potential fish tainting compounds. In this study, trained sensory panels and the general population from a university were used to determine the odor detection thresholds of two commercial NAs preparations (Acros and Merichem) and of NAs extracted from an oil sands experimental reclamation pond (Pond 9). Using the three-alternative forced choice method, a concentration series of NAs were presented to the sensory panels in phosphate buffer (pH 8) and in steamed fish (Sander vitreus). In buffer, the odor detection thresholds of Acros, Merichem and Pond 9 NAs, as evaluated by the trained panelists, were 1.5, 0.04, and 1.0 mg L(-1), respectively. Only the detection threshold for the Merichem NAs was significantly different (p<0.01) than the other two sources. Based on the general population assessments, all three odor detection thresholds were significantly different from one another; 4.8, 0.2, and 2.5 mg L(-1) for Acros, Merichem, and Pond 9 NAs, respectively (p<0.01). The odor detection thresholds of Merichem and Pond 9 NAs in steamed fish were 0.6 and 12 mg kg(-1), respectively and were significantly different from each other (p<0.01). The detection threshold of Acros NAs was estimated to be >21 mg kg(-1). For the steamed fish evaluations, the odor descriptors of all three of the NAs preparations was given as chemical in nature (Acros: oil, plastic; Merichem: gasoline; Pond 9: gasoline, tar). Exposure of live rainbow trout to a non-lethal concentration of Merichem NAs (3 mg L(-1) for 10 d) imparted an odor to the fish flesh. Analyses of the three NAs preparations by gas chromatography-mass spectrometry showed that each had a unique distribution of acids. We conclude that the source of the NAs is important when interpreting odor threshold data and that the two commercial preparations of NAs that were tested do not represent oil sands waters

  9. Capacitance-modulated transistor detects odorant binding protein chiral interactions

    PubMed Central

    Mulla, Mohammad Yusuf; Tuccori, Elena; Magliulo, Maria; Lattanzi, Gianluca; Palazzo, Gerardo; Persaud, Krishna; Torsi, Luisa

    2015-01-01

    Peripheral events in olfaction involve odorant binding proteins (OBPs) whose role in the recognition of different volatile chemicals is yet unclear. Here we report on the sensitive and quantitative measurement of the weak interactions associated with neutral enantiomers differentially binding to OBPs immobilized through a self-assembled monolayer to the gate of an organic bio-electronic transistor. The transduction is remarkably sensitive as the transistor output current is governed by the small capacitance of the protein layer undergoing minute changes as the ligand–protein complex is formed. Accurate determination of the free-energy balances and of the capacitance changes associated with the binding process allows derivation of the free-energy components as well as of the occurrence of conformational events associated with OBP ligand binding. Capacitance-modulated transistors open a new pathway for the study of ultra-weak molecular interactions in surface-bound protein–ligand complexes through an approach that combines bio-chemical and electronic thermodynamic parameters. PMID:25591754

  10. Capacitance-modulated transistor detects odorant binding protein chiral interactions

    NASA Astrophysics Data System (ADS)

    Mulla, Mohammad Yusuf; Tuccori, Elena; Magliulo, Maria; Lattanzi, Gianluca; Palazzo, Gerardo; Persaud, Krishna; Torsi, Luisa

    2015-01-01

    Peripheral events in olfaction involve odorant binding proteins (OBPs) whose role in the recognition of different volatile chemicals is yet unclear. Here we report on the sensitive and quantitative measurement of the weak interactions associated with neutral enantiomers differentially binding to OBPs immobilized through a self-assembled monolayer to the gate of an organic bio-electronic transistor. The transduction is remarkably sensitive as the transistor output current is governed by the small capacitance of the protein layer undergoing minute changes as the ligand-protein complex is formed. Accurate determination of the free-energy balances and of the capacitance changes associated with the binding process allows derivation of the free-energy components as well as of the occurrence of conformational events associated with OBP ligand binding. Capacitance-modulated transistors open a new pathway for the study of ultra-weak molecular interactions in surface-bound protein-ligand complexes through an approach that combines bio-chemical and electronic thermodynamic parameters.

  11. Computational modeling and experimental validation of odor detection behaviors of classically conditioned parasitic wasp, Microplitis croceipes.

    PubMed

    Zhou, Zhongkun; Kulasiri, Don; Samarasinghe, Sandhya; Rains, Glen; Olson, Dawn M

    2015-01-01

    A prototype chemical sensor named Wasp hound® that utilizes five classically conditioned parasitoid wasps, Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), to detect volatile odors was successfully implemented in a previous study. To improve the odor-detecting ability of Wasp Hound®, searching behaviors of an individual wasp in a confined area are studied and modeled through stochastic differential equations in this paper. The wasps are conditioned to 20 mg of coffee when associated with food and subsequently, tested to 5, 10, 20, and 40 mg of coffee. A stochastic model is developed and validated based on three positive behavioral responses (walking, rotation around odor source, and self-rotation) from conditioned wasps at four different test dosages. The model is capable to reproducing the behaviors of conditioned wasps, and can be used to improve the ability of Wasp Hound® to assess changes in odor concentration. The model simulation results show the behaviors of conditioned wasps are significantly different when tested at different coffee dosages. We conjecture that the searching behaviors of conditioned wasps are based on the temporal and spatial neuron activity of olfactory receptor neurons and glomeruli, which are strongly correlated to the training dosages. The overall results demonstrate the utility of mathematical models for interpreting experimental observations, gaining novel insights into the dynamic behavior of classically conditioned wasps, as well as broadening the practical uses of Wasp Hound. © 2014 American Institute of Chemical Engineers.

  12. Analytical determination and detection of individual odor signatures

    NASA Astrophysics Data System (ADS)

    Kramer, Ryan M.; Grigsby, Claude C.

    2012-06-01

    Despite the fact that therapeutic approaches and diagnostic capabilities have made tremendous advances in the past few decades, the associated costs with these treatments continue to rise. This fact, coupled with a rapidly aging population, threatens to cripple our nation's capability to deliver quality healthcare at reasonable and affordable price points. The research community must therefore look to implementing transformational approaches that revolutionize both the way we diagnose and treat patients. Emerging multi-disciplinary research in the fields of molecular biology, systems biology, and solid-state sensing is poised to make such a contribution. Here we highlight key critical insights in the field of human derived volatile organic compound (VOC) signatures and the potential for non-invasive diagnostics. With the aim of developing future VOC-based diagnostics, we identify some critical gaps in our knowledge of how these often complex signatures are influenced by genetics, physiological state, and population variance. Also, we highlight a few canine and solid-state sensing strategies to demonstrate that VOC-based breath diagnostics are feasible and we suggest a bio-inspired approach for optimizing sensor architectures. VOC based diagnostics should drastically enhance early detection of multiple diseases, increase the time for therapeutic intervention, provide the capability to monitor in real-time the efficacy of therapeutic treatments, provide the context of emerging pathological outbreaks across participating populations, and potentially decrease mortality associated with many diseases by orders of magnitude.

  13. Gas Chromatography Analysis with Olfactometric Detection (GC-O) as a Useful Methodology for Chemical Characterization of Odorous Compounds

    PubMed Central

    Brattoli, Magda; Cisternino, Ezia; Dambruoso, Paolo Rosario; de Gennaro, Gianluigi; Giungato, Pasquale; Mazzone, Antonio; Palmisani, Jolanda; Tutino, Maria

    2013-01-01

    The gas chromatography-olfactometry (GC-O) technique couples traditional gas chromatographic analysis with sensory detection in order to study complex mixtures of odorous substances and to identify odor active compounds. The GC-O technique is already widely used for the evaluation of food aromas and its application in environmental fields is increasing, thus moving the odor emission assessment from the solely olfactometric evaluations to the characterization of the volatile components responsible for odor nuisance. The aim of this paper is to describe the state of the art of gas chromatography-olfactometry methodology, considering the different approaches regarding the operational conditions and the different methods for evaluating the olfactometric detection of odor compounds. The potentials of GC-O are described highlighting the improvements in this methodology relative to other conventional approaches used for odor detection, such as sensoristic, sensorial and the traditional gas chromatographic methods. The paper also provides an examination of the different fields of application of the GC-O, principally related to fragrances and food aromas, odor nuisance produced by anthropic activities and odorous compounds emitted by materials and medical applications. PMID:24316571

  14. Gas chromatography analysis with olfactometric detection (GC-O) as a useful methodology for chemical characterization of odorous compounds.

    PubMed

    Brattoli, Magda; Cisternino, Ezia; Dambruoso, Paolo Rosario; de Gennaro, Gianluigi; Giungato, Pasquale; Mazzone, Antonio; Palmisani, Jolanda; Tutino, Maria

    2013-12-05

    The gas chromatography-olfactometry (GC-O) technique couples traditional gas chromatographic analysis with sensory detection in order to study complex mixtures of odorous substances and to identify odor active compounds. The GC-O technique is already widely used for the evaluation of food aromas and its application in environmental fields is increasing, thus moving the odor emission assessment from the solely olfactometric evaluations to the characterization of the volatile components responsible for odor nuisance. The aim of this paper is to describe the state of the art of gas chromatography-olfactometry methodology, considering the different approaches regarding the operational conditions and the different methods for evaluating the olfactometric detection of odor compounds. The potentials of GC-O are described highlighting the improvements in this methodology relative to other conventional approaches used for odor detection, such as sensoristic, sensorial and the traditional gas chromatographic methods. The paper also provides an examination of the different fields of application of the GC-O, principally related to fragrances and food aromas, odor nuisance produced by anthropic activities and odorous compounds emitted by materials and medical applications.

  15. No influence of scopolamine hydrobromide on odor detection performance of rats.

    PubMed

    Doty, Richard L; Bagla, Ritu; Misra, Robert; Mueller, Eric; Kerr, Kara-Lynne

    2003-11-01

    Despite speculation that the muscarinic cholinergic antagonist, scopolamine, may influence the olfactory sensitivity of rats, there have been no definitive studies on this point to date. In this study, we examined the influence of a range of doses of scopolamine hydrobromine (namely, 0.10, 0.125, 0.15 and 0.20 mg/kg i.p.) on the odor detection performance of 15 adult male Long-Evans rats to ethyl acetate. Air-dilution olfactometry and a go/no-go operant signal detection task were employed. The drug conditions and a saline control were administered to each animal in an order counterbalanced by Latin squares, with 2 day intervals interspersed between tests. Scopolamine had no significant influence on odor detection performance per se, as measured by percent correct S+ and S- responses and a non-parametric signal detection measure of sensitivity. This is in contrast to the relatively large effects previously observed in the same test paradigm for such drugs as the D-1 agonist SKF 38393 and the D-2 agonist quinpirole. These data suggest that scopolamine has no meaningful influence on a well-practiced odor detection task.

  16. Fluprazine hydrochloride: no influence on the odor detection performance of male rats.

    PubMed

    Doty, R L; Li, C; Risser, J M

    1990-03-01

    Fluprazine hydrochloride (DU 27716) decreases copulatory and offensive attack behaviors of male rats and increases their latency to locate buried food in an open field. Since such behaviors are mediated to some degree by the olfactory system, several investigators have hypothesized that this drug may produce an overall impairment in olfactory sensitivity. To test this hypothesis, the influences of five doses of fluprazine hydrochloride (1.0, 2.5, 5.0, 7.5 and 10.0 mg/kg IP) on the odor detection performance of 12 adult male Long Evans rats was assessed, relative to saline, using high precision olfactometry and a go/no-go operant odor detection task. Treatments were administered every 3rd day in counterbalanced order, with the drug or saline injections occurring 30 minutes before the 260-trial test sessions. No significant influence of fluprazine was observed on odor detection performance, as measured by the nonparametric signal detection sensitivity index SI and the percentage of correct trials. These results indicate that fluprazine does not induce generalized olfactory impairment.

  17. Odor control in lagoons.

    PubMed

    Zhang, X L; Yan, S; Tyagi, R D; Surampalli, R Y

    2013-07-30

    Lagoons are widely used in rural area for wastewater treatment; however, the odor problem has hampered its application. The root of odor emission from lagoons varies from one to another. The key of controlling the odor is to find out the cause and accordingly provide strategies. Various physical, chemical, and biological methods have been reported and applied for odor control. Physical technologies such as masking, capturing and sorption are often employed to mitigate the pressure from compliant while not to cut off the problem. Chemical technologies which act rapidly and efficiently in odor control, utilize chemicals to damage the odorant production root or convert odorant to odorless substances. Biological methods such as aeration, biocover and biofiltration control the odor by enhancing aerobic condition or developing methanogens in lagoon, and biologically decomposing the odorants. Comparing to physical and chemical methods, biological methods are more feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. A non-invasive tool for detecting cervical cancer odor by trained scent dogs.

    PubMed

    Guerrero-Flores, Héctor; Apresa-García, Teresa; Garay-Villar, Ónix; Sánchez-Pérez, Alejandro; Flores-Villegas, David; Bandera-Calderón, Artfy; García-Palacios, Raúl; Rojas-Sánchez, Teresita; Romero-Morelos, Pablo; Sánchez-Albor, Verónica; Mata, Osvaldo; Arana-Conejo, Víctor; Badillo-Romero, Jesús; Taniguchi, Keiko; Marrero-Rodríguez, Daniel; Mendoza-Rodríguez, Mónica; Rodríguez-Esquivel, Miriam; Huerta-Padilla, Víctor; Martínez-Castillo, Andrea; Hernández-Gallardo, Irma; López-Romero, Ricardo; Bandala, Cindy; Rosales-Guevara, Juan; Salcedo, Mauricio

    2017-01-26

    Cervical Cancer (CC) has become a public health concern of alarming proportions in many developing countries such as Mexico, particularly in low income sectors and marginalized regions. As such, an early detection is a key medical factor in improving not only their population's quality of life but also its life expectancy. Interestingly, there has been an increase in the number of reports describing successful attempts at detecting cancer cells in human tissues or fluids using trained (sniffer) dogs. The great odor detection threshold exhibited by dogs is not unheard of. However, this represented a potential opportunity to develop an affordable, accessible, and non-invasive method for detection of CC. Using clicker training, a male beagle was trained to recognize CC odor. During training, fresh CC biopsies were used as a reference point. Other samples used included cervical smears on glass slides and medical surgical bandages used as intimate sanitary pads by CC patients. A double-blind procedure was exercised when testing the beagle's ability to discriminate CC from control samples. The beagle was proven able to detect CC-specific volatile organic compounds (VOC) contained in both fresh cervical smear samples and adsorbent material samples. Beagle's success rate at detecting and discriminating CC and non-CC odors, as indicated by specificity and sensitivity values recorded during the experiment, stood at an overall high (>90%). CC-related VOC in adsorbent materials were detectable after only eight hours of use by CC patients. Present data suggests different applications for VOC from the uterine cervix to be used in the detection and diagnosis of CC. Furthermore, data supports the use of trained dogs as a viable, affordable, non-invasive and, therefore, highly relevant alternative method for detection of CC lesions. Additional benefits of this method include its quick turnaround time and ease of use while remaining highly accurate and robust.

  19. Novel Thioester Prodrug of N-acetylcysteine for Odor Masking and Bioavailability Enhancement.

    PubMed

    Bhilare, Neha V; Dhaneshwar, Suneela S; Sinha, Akanksha J; Kandhare, Amit D; Bodhankar, Subhash L

    2016-01-01

    The mucolytic N-acetylcysteine (NAC) is used to control the excessive mucus secretion if mucus is the underlying cause of broncho-constriction. Its major drawbacks are poor bioavailability due to extensive first pass effect, poor lipophilicity, high protein binding and offensive odor. For minimizing above shortcomings of NAC, in present study thioester (A1) prodrug of NAC was synthesized by conventional as well as microwave-assisted methods. Release studies of A-1 were carried out using HPLC and pharmacological evaluation was performed in ovalbumin-induced model of pulmonary inflammation in Sprague dawley rats. A-1 was found to be stable in HCl buffer, phosphate buffer, stomach homogenates but furnished 30% NAC in 6h and 1.7% of NAC in 4h when incubated with small intestinal and liver homogenates respectively. Upon oral administration of A-1 to rats, 4.85% NAC was detected in blood at 8h. Urine samples pooled over a period of 24h exhibited 0.75% NAC while negligible concentration was found in 24 h pooled samples of feces. The findings of this preliminary investigation demonstrated significant effects of thioester prodrug A-1 as compared to NAC through reduction of lung inflammation, airway eosinophilia and reversal of lung function parameters in ovalbumin- challenged rats at half the equimolar dose of NAC. Interestingly masking thiol group through thioester formation resulted in odorless prodrug. We propose that thioester prodrug using palmitic acid as a carrier is a promising strategy to enhance bioavailability of NAC by increasing its lipophilicity/ absorption and minimizing its first pass metabolism.

  20. Reading out olfactory receptors: Feedforward circuits detect odors in mixtures without demixing

    PubMed Central

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

    2016-01-01

    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

  1. Ligand Specificity and Evolution of Mammalian Musk Odor Receptors: Effect of Single Receptor Deletion on Odor Detection.

    PubMed

    Sato-Akuhara, Narumi; Horio, Nao; Kato-Namba, Aya; Yoshikawa, Keiichi; Niimura, Yoshihito; Ihara, Sayoko; Shirasu, Mika; Touhara, Kazushige

    2016-04-20

    Musk odors have been used widely for fragrance and medicine for >2000 years because of their fascinating scent and physiological effects. Therefore, fragrance manufacturers have been eager to develop high-quality musk compounds that are safe and easily synthesized. We recently identified muscone-responsive olfactory receptors (ORs) MOR215-1 and OR5AN1 in mice and humans, respectively (Shirasu et al., 2014). In this study, we identified musk ORs that are evolutionarily closely related to MOR215-1 or OR5AN1 in various primates and investigated structure-activity relationships for various musk odorants and related compounds. We found that each species has one or two functional musk ORs that exhibit specific ligand spectra to musk compounds. Some of them, including the human OR5AN1, responded to nitro musks with chemical properties distinct from muscone. The ligand specificity of OR5AN1 reflects the perception of musk odors in humans. Genetic deletion of MOR215-1 in mice resulted in drastic reduction of sensitivity to muscone, suggesting that MOR215-1 plays a critical role in muscone perception. Therefore, the current study reveals a clear link between the identified OR and muscone perception. Moreover, the strategy established for screening ligands for the muscone OR may facilitate the development of novel and commercially useful musk odors. The long-sought musk odor receptor family in mammals was discovered and found to be well conserved and narrowly tuned to musk odors. In mice, deletion of the most sensitive musk receptor resulted in drastic reduction in sensitivity to muscone, demonstrating a strong link between receptor and odor perception. In humans, we found one musk receptor that recognized both macrocyclic and nitro musks that had distinct chemical structures. The structure-activity relationships were in a good agreement with human sensory perception and therefore may be used to develop novel musk aroma in fragrance fields. Finally, identification of a

  2. Genetic variation in the odorant receptor OR2J3 is associated with the ability to detect the "grassy" smelling odor, cis-3-hexen-1-ol.

    PubMed

    McRae, Jeremy F; Mainland, Joel D; Jaeger, Sara R; Adipietro, Kaylin A; Matsunami, Hiroaki; Newcomb, Richard D

    2012-09-01

    The ability to detect many odors varies among individuals; however, the contribution of genotype to this variation has been assessed for relatively few compounds. We have identified a genetic basis for the ability to detect the flavor compound cis-3-hexen-1-ol. This compound is typically described as "green grassy" or the smell of "cut grass," with variation in the ability to detect it linked to single nucleotide polymorphisms (SNPs) in a region on human chromosome 6 containing 25 odorant receptor genes. We have sequenced the coding regions of all 25 receptors across an ethnically mixed population of 52 individuals and identified 147 sequence variants. We tested these for association with cis-3-hexen-1-ol detection thresholds and found 3 strongly associated SNPs, including one found in a functional odorant receptor (rs28757581 in OR2J3). In vitro assays of 13 odorant receptors from the region identified 3 receptors that could respond to cis-3-hexen-1-ol, including OR2J3. This gene contained 5 predicted haplotypes across the 52 individuals. We tested all 5 haplotypes in vitro and several amino acid substitutions on their own, such as rs28757581 (T113A). Two amino acid substitutions, T113A and R226Q, impaired the ability of OR2J3 to respond to cis-3-hexen-1-ol, and together these two substitutions effectively abolished the response to the compound. The haplotype of OR2J3 containing both T113A and R226Q explains 26.4% of the variation in cis-3-hexen-1-ol detection in our study cohort. Further research is required to examine whether OR2J3 haplotypes explain variation in perceived flavor experience and the consumption of foods containing cis-3-hexen-1-ol.

  3. Detection and discrimination of mixed odor strands in overlapping plumes using an insect-antenna-based chemosensor system.

    PubMed

    Myrick, Andrew J; Park, Kye Chung; Hetling, John R; Baker, Thomas C

    2009-01-01

    Olfactory signals, a major means of communication in insects, travel in the form of turbulent odor plumes. In terrestrial environments, an odor blend emitted from a single point source exists in every strand of the plume, whereas, in confluent plumes from two different odor sources, the strands have some chance of being coincident and comprising a new third odor in those strands. Insects have the ability to detect and interpret necessary olfactory information from individual filamentous odor strands in complex multifilament odor plumes. However, behaviorists have had no way to measure the stimulus situations they are presenting to their temporally acute insect subjects when performing Y-tube olfactometer or confluent pheromone plume wind tunnel assays. We have successfully measured the degree of plume-strand mixing in confluent plumes in a wind tunnel by using a multichannel insect-antenna-based chemosensor. A PC-based computer algorithm to analyze antennal signals from the probe portion of the system performed real-time signal processing and, following a short training session, classified individual odorant/mixture strands at sub-second temporal resolution and a few tens of millimeters of spatial resolution. In our studies, the chemosensor classified a higher frequency of strands of two different odorants emitted from two closely spaced filter papers as being "mixed" when the sources were located only 1 or 2 cm apart than when the sources were 5 or 10 cm apart. These experiments demonstrate the chemosensor's potential to be used for measuring odor stimulus situations in more complex multiple-plume environments.

  4. Availability of target odor compounds from seized ecstasy tablets for canine detection.

    PubMed

    Macias, Michael S; Furton, Kenneth G

    2011-11-01

    The aim of this study was to compare seized samples of 3,4-methylenedioxy-N-methylamphetamine (MDMA) pills, used to train law enforcement detection canine teams, to determine what differences exist in the chemical makeup and headspace odor and their effect on detectability. MDMA solutions were analyzed by liquid chromatography-mass spectrometry. Analysis of these samples showed a wide variance of MDMA (8-25%). Headspace SPME-GC/MS analysis showed that several compounds such as 3,4-methylenedioxyphenylacetone and 1-(3,4-methylenedioxyphenyl)-2-propanol are common among these MDMA samples regardless of starting compound and synthesis procedure. However, differences, such as the level of the various methylenedioxy starting compounds, were shown to affect the overall outcome of canine detection, indicating the need for more than one MDMA training aid. Combinations of compounds such as the primary odor piperonal in conjunction with a secondary compound such as MDP-2-OH or isosafrole are recommended to maximize detection of different illicit MDMA samples. © 2011 American Academy of Forensic Sciences.

  5. Exposure to odors of rivals enhances sexual motivation in male giant pandas.

    PubMed

    Bian, Xiaoxing; Liu, Dingzhen; Zeng, Hua; Zhang, Guiquan; Wei, Rongping; Hou, Rong

    2013-01-01

    Males will alter their mating behavior to cope with the presence of their competitors. Even exposure to odors from potential competitors can greatly increase male ejaculate expenditure in a variety of animals including insects, fishes, birds and rodents. Major efforts have been made to examine males' plastic responses to sperm competition and its fitness benefits. However, the effects of competitor absence on male's sexual motivation and behaviors remain unclear, which has been proposed to be one of the causes for the poor sexual performance of some captive mammals. This study revealed that sexual motivation can be greatly enhanced in captive male giant pandas (Ailuropoda melanoleuca) by exposure to chemosensory cues from either one or three conspecifics males. It had been shown that potential rivals' odors increased males' chemosensory investigation behavior, as well as their observing, following and sniffing behaviors towards estrous females. Behaviors changed regardless of the number of rivals (one or three). Our results demonstrate the effects of potential competition on male giant pandas' sexual motivation and behavioral coping strategy. We anticipate that our research will provide a fresh insight into the mechanisms underlying poor sexual performance in male captive mammals, and valuable information for the practical management and ex situ conservation of endangered species.

  6. Exposure to Odors of Rivals Enhances Sexual Motivation in Male Giant Pandas

    PubMed Central

    Bian, Xiaoxing; Liu, Dingzhen; Zeng, Hua; Zhang, Guiquan; Wei, Rongping; Hou, Rong

    2013-01-01

    Males will alter their mating behavior to cope with the presence of their competitors. Even exposure to odors from potential competitors can greatly increase male ejaculate expenditure in a variety of animals including insects, fishes, birds and rodents. Major efforts have been made to examine males' plastic responses to sperm competition and its fitness benefits. However, the effects of competitor absence on male's sexual motivation and behaviors remain unclear, which has been proposed to be one of the causes for the poor sexual performance of some captive mammals. This study revealed that sexual motivation can be greatly enhanced in captive male giant pandas (Ailuropoda melanoleuca) by exposure to chemosensory cues from either one or three conspecifics males. It had been shown that potential rivals' odors increased males' chemosensory investigation behavior, as well as their observing, following and sniffing behaviors towards estrous females. Behaviors changed regardless of the number of rivals (one or three). Our results demonstrate the effects of potential competition on male giant pandas' sexual motivation and behavioral coping strategy. We anticipate that our research will provide a fresh insight into the mechanisms underlying poor sexual performance in male captive mammals, and valuable information for the practical management and ex situ conservation of endangered species. PMID:23940532

  7. Mammalian olfactory receptors: molecular mechanisms of odorant detection, 3D-modeling, and structure-activity relationships.

    PubMed

    Persuy, Marie-Annick; Sanz, Guenhaël; Tromelin, Anne; Thomas-Danguin, Thierry; Gibrat, Jean-François; Pajot-Augy, Edith

    2015-01-01

    This chapter describes the main characteristics of olfactory receptor (OR) genes of vertebrates, including generation of this large multigenic family and pseudogenization. OR genes are compared in relation to evolution and among species. OR gene structure and selection of a given gene for expression in an olfactory sensory neuron (OSN) are tackled. The specificities of OR proteins, their expression, and their function are presented. The expression of OR proteins in locations other than the nasal cavity is regulated by different mechanisms, and ORs display various additional functions. A conventional olfactory signal transduction cascade is observed in OSNs, but individual ORs can also mediate different signaling pathways, through the involvement of other molecular partners and depending on the odorant ligand encountered. ORs are engaged in constitutive dimers. Ligand binding induces conformational changes in the ORs that regulate their level of activity depending on odorant dose. When present, odorant binding proteins induce an allosteric modulation of OR activity. Since no 3D structure of an OR has been yet resolved, modeling has to be performed using the closest G-protein-coupled receptor 3D structures available, to facilitate virtual ligand screening using the models. The study of odorant binding modes and affinities may infer best-bet OR ligands, to be subsequently checked experimentally. The relationship between spatial and steric features of odorants and their activity in terms of perceived odor quality are also fields of research that development of computing tools may enhance.

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

    PubMed Central

    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

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

    PubMed

    Gao, Xiang; Acar, Levent

    2016-07-04

    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.

  10. A physiological increase of insulin in the olfactory bulb decreases detection of a learned aversive odor and abolishes food odor-induced sniffing behavior in rats.

    PubMed

    Aimé, Pascaline; Hegoburu, Chloé; Jaillard, Tristan; Degletagne, Cyril; Garcia, Samuel; Messaoudi, Belkacem; Thevenet, Marc; Lorsignol, Anne; Duchamp, Claude; Mouly, Anne-Marie; Julliard, Andrée Karyn

    2012-01-01

    Insulin is involved in multiple regulatory mechanisms, including body weight and food intake, and plays a critical role in metabolic disorders such as obesity and diabetes. An increasing body of evidence indicates that insulin is also involved in the modulation of olfactory function. The olfactory bulb (OB) contains the highest level of insulin and insulin receptors (IRs) in the brain. However, a role for insulin in odor detection and sniffing behavior remains to be elucidated. Using a behavioral paradigm based on conditioned olfactory aversion (COA) to isoamyl-acetate odor, we demonstrated that an intracerebroventricular (ICV) injection of 14 mU insulin acutely decreased olfactory detection of fasted rats to the level observed in satiated animals. In addition, whereas fasted animals demonstrated an increase in respiratory frequency upon food odor detection, this effect was absent in fasted animals receiving a 14 mU insulin ICV injection as well as in satiated animals. In parallel, we showed that the OB and plasma insulin levels were increased in satiated rats compared to fasted rats, and that a 14 mU insulin ICV injection elevated the OB insulin level of fasted rats to that of satiated rats. We further quantified insulin receptors (IRs) distribution and showed that IRs are preferentially expressed in the caudal and lateral parts of the main OB, with the highest labeling found in the mitral cells, the main OB projection neurons. Together, these data suggest that insulin acts on the OB network to modulate olfactory processing and demonstrate that olfactory function is under the control of signals involved in energy homeostasis regulation and feeding behaviors.

  11. A Physiological Increase of Insulin in the Olfactory Bulb Decreases Detection of a Learned Aversive Odor and Abolishes Food Odor-Induced Sniffing Behavior in Rats

    PubMed Central

    Aimé, Pascaline; Hegoburu, Chloé; Jaillard, Tristan; Degletagne, Cyril; Garcia, Samuel; Messaoudi, Belkacem; Thevenet, Marc; Lorsignol, Anne; Duchamp, Claude; Mouly, Anne-Marie; Julliard, Andrée Karyn

    2012-01-01

    Insulin is involved in multiple regulatory mechanisms, including body weight and food intake, and plays a critical role in metabolic disorders such as obesity and diabetes. An increasing body of evidence indicates that insulin is also involved in the modulation of olfactory function. The olfactory bulb (OB) contains the highest level of insulin and insulin receptors (IRs) in the brain. However, a role for insulin in odor detection and sniffing behavior remains to be elucidated. Using a behavioral paradigm based on conditioned olfactory aversion (COA) to isoamyl-acetate odor, we demonstrated that an intracerebroventricular (ICV) injection of 14 mU insulin acutely decreased olfactory detection of fasted rats to the level observed in satiated animals. In addition, whereas fasted animals demonstrated an increase in respiratory frequency upon food odor detection, this effect was absent in fasted animals receiving a 14 mU insulin ICV injection as well as in satiated animals. In parallel, we showed that the OB and plasma insulin levels were increased in satiated rats compared to fasted rats, and that a 14 mU insulin ICV injection elevated the OB insulin level of fasted rats to that of satiated rats. We further quantified insulin receptors (IRs) distribution and showed that IRs are preferentially expressed in the caudal and lateral parts of the main OB, with the highest labeling found in the mitral cells, the main OB projection neurons. Together, these data suggest that insulin acts on the OB network to modulate olfactory processing and demonstrate that olfactory function is under the control of signals involved in energy homeostasis regulation and feeding behaviors. PMID:23251461

  12. Fuel cells and odorants for hydrogen.

    SciTech Connect

    Kopasz, J. P.; Chemical Engineering

    2007-09-01

    Odorants have been proposed as a reliable, inexpensive means to enable leak detection for hydrogen systems and increase public safety. However, traditional odorants cause problems for fuel cell systems. This paper examines the use of odorants for fuel cell systems, including the hydrogen storage. Current odorants and potential odorants have negative impacts on fuel cell performance. Odorants also appear to be problematic for most of the advanced hydrogen storage options. If odorants are used, the odorants will probably need to be removed from the hydrogen prior to the storage medium. Current hydrogen detectors are more reliable than the odorant-human detection system and should provide increased safety.

  13. A surface acoustic wave bio-electronic nose for detection of volatile odorant molecules.

    PubMed

    Di Pietrantonio, F; Benetti, M; Cannatà, D; Verona, E; Palla-Papavlu, A; Fernández-Pradas, J M; Serra, P; Staiano, M; Varriale, A; D'Auria, S

    2015-05-15

    In this work, a "bio-electronic nose" for vapour phase detection of odorant molecules based on surface acoustic wave (SAW) resonators is presented. The biosensor system is composed of an array of five SAW resonators coated with three types of odorant-binding proteins (OBPs): the wild-type OBP from bovine (wtbOBP), a double-mutant of the OBP from bovine (dmbOBP), and the wild-type OBP from pig (wtpOBP). High resolution deposition of OBPs onto the active area of SAW resonators was implemented through laser-induced forward transfer (LIFT). The resonant frequency shifts of the SAW resonators after the deposition of the biomolecules confirmed the immobilisation of the proteins onto the Al/Au inter-digital transducers (IDTs). In addition, a low increase of insertion losses with a limited degradation of Q-factors is reported. The "bio-electronic nose" fabricated by LIFT is tested in nitrogen upon exposure to separated concentrations of R-(-)-1-octen-3-ol (octenol) and R-(-)-carvone (carvone) vapours. The "bio-electronic nose" showed low detection limits for the tested compounds (i.e. 0.48 ppm for the detection of octenol, and 0.74 ppm for the detection of carvone). In addition, the bio-sensing system was able to discriminate the octenol molecules from the carvone molecules, making it pertinent for the assessment of food contamination by moulds, or for the evaluation of indoor air quality in buildings. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Effect of dietary fat source and exercise on odorant-detecting ability of canine athletes.

    PubMed

    Altom, Eric K; Davenport, Gary M; Myers, Lawrence J; Cummins, Keith A

    2003-10-01

    Eighteen male English Pointers (2-4 years of age, 23.94+/-0.54 kg body weight) were allotted to three diet and two physical conditioning groups to evaluate the effect of level and source of dietary fat on the olfactory acuity of canine athletes subjected to treadmill exercise. Diet groups (6 dogs/diet) consisted of commercially prepared diets (minimum of 26% crude protein) containing 12% fat as beef tallow (A), 16% fat provided by equivalent amounts of beef tallow and corn oil (B), or 16% fat provided by equivalent amounts of beef tallow and coconut oil (C). This dietary formulation resulted in approximately 60% of the total fatty acid being saturated for diets A and C, while approximately 72% of the total fatty acids were unsaturated in diet B. One-half of the dogs within each dietary group were subjected to treadmill exercise 3 times per week for 30 min (8.05 km/h, 0% grade) for 12 weeks. All dogs were subjected to a submaximal exercise stress test (8.05 km/h, 10% slope for 60 min) every four weeks beginning at week 0. Olfactory acuity was measured utilizing behavioral olfactometry before and after each physical stress test. Non-conditioned (NON) dogs displayed a greater decrease (P<0.05) in olfactory acuity following exercise, while physically conditioned (EXE) dogs did not show a change from pre-test values. A diet by treatment interaction (P<0.10) was detected over the course of the study. NON dogs fed coconut oil had decreased odorant-detecting capabilities when week 4 values were compared with week 12 values. Feeding a diet that is predominately high in saturated fat may affect the odorant-detecting capabilities of working dogs. Additionally, these data indicate that utilization of a moderate physical conditioning program can assist canine athletes in maintaining olfactory acuity during periods of intense exercise.

  15. Prenatal Alcohol Exposure Selectively Enhances Young Adult Perceived Pleasantness of Alcohol Odors

    PubMed Central

    Hannigan, John H.; Chiodo, Lisa M.; Sokol, Robert J.; Janisse, James; Delaney-Black, Virginia

    2015-01-01

    Prenatal Alcohol Exposure (PAE) can lead to life-long neurobehavioral and social problems that can include a greater likelihood of early use and/or abuse of alcohol compared to older teens and young adults without PAE. Basic research in animals demonstrates that PAE influences later postnatal responses to chemosensory cues (i.e., odor & taste) associated with alcohol. We hypothesized that PAE would be related to poorer abilities to identify odors of alcohol-containing beverages, and would alter perceived alcohol odor intensity and pleasantness. To address this hypothesis we examined responses to alcohol and other odors in a small sample of young adults with detailed prenatal histories of exposure to alcohol and other drugs. The key finding from our controlled analyses is that higher levels of PAE were related to higher relative ratings of pleasantness for alcohol odors. As far as we are aware, this is the first published study to report the influence of PAE on responses to alcohol beverage odors in young adults. These findings are consistent with the hypothesis that positive associations (i.e., “pleasantness”) to the chemosensory properties of alcohol (i.e., odor) are acquired prenatally and are retained for many years despite myriad interceding postnatal experiences. Alternate hypotheses may also be supported by the results. There are potential implications of altered alcohol odor responses for understanding individual differences in initiation of drinking, and alcohol seeking and high-risk alcohol-related behaviors in young adults. PMID:25600468

  16. Learning modifies odor mixture processing to improve detection of relevant components.

    PubMed

    Chen, Jen-Yung; Marachlian, Emiliano; Assisi, Collins; Huerta, Ramon; Smith, Brian H; Locatelli, Fernando; Bazhenov, Maxim

    2015-01-07

    Honey bees have a rich repertoire of olfactory learning behaviors, and they therefore are an excellent model to study plasticity in olfactory circuits. Recent behavioral, physiological, and molecular evidence suggested that the antennal lobe, the first relay of the olfactory system in insects and analog to the olfactory bulb in vertebrates, is involved in associative and nonassociative olfactory learning. Here we use calcium imaging to reveal how responses across antennal lobe projection neurons change after association of an input odor with appetitive reinforcement. After appetitive conditioning to 1-hexanol, the representation of an odor mixture containing 1-hexanol becomes more similar to this odor and less similar to the background odor acetophenone. We then apply computational modeling to investigate how changes in synaptic connectivity can account for the observed plasticity. Our study suggests that experience-dependent modulation of inhibitory interactions in the antennal lobe aids perception of salient odor components mixed with behaviorally irrelevant background odors.

  17. Learning Modifies Odor Mixture Processing to Improve Detection of Relevant Components

    PubMed Central

    Chen, Jen-Yung; Marachlian, Emiliano; Assisi, Collins; Huerta, Ramon; Smith, Brian H.

    2015-01-01

    Honey bees have a rich repertoire of olfactory learning behaviors, and they therefore are an excellent model to study plasticity in olfactory circuits. Recent behavioral, physiological, and molecular evidence suggested that the antennal lobe, the first relay of the olfactory system in insects and analog to the olfactory bulb in vertebrates, is involved in associative and nonassociative olfactory learning. Here we use calcium imaging to reveal how responses across antennal lobe projection neurons change after association of an input odor with appetitive reinforcement. After appetitive conditioning to 1-hexanol, the representation of an odor mixture containing 1-hexanol becomes more similar to this odor and less similar to the background odor acetophenone. We then apply computational modeling to investigate how changes in synaptic connectivity can account for the observed plasticity. Our study suggests that experience-dependent modulation of inhibitory interactions in the antennal lobe aids perception of salient odor components mixed with behaviorally irrelevant background odors. PMID:25568113

  18. Adding odor: Less distress and enhanced attention for 6-month-olds.

    PubMed

    Coffield, Caroline N; Mayhew, Estelle M Y; Haviland-Jones, Jeannette M; Walker-Andrews, Arlene S

    2014-05-01

    The effect of odor on cognitive and emotional processes has been studied in adults and children, but less so in infants. In this study twenty-seven six-month-olds were presented with a video while in either an odor (pine or baby-powder) or a no odor control condition. The video was a 92-s audiovisual presentation of a woman expressing happiness and sadness, with the order of emotion counterbalanced. Infant attention (looking time) and emotional expression (smiling, crying, mouthing) were coded. Infants looked longer in the presence of odor and expressed less crying and mouthing but more smiling behavior. Presence of odor markedly reduced infant emotional distress and increased attention, suggesting that the olfactory sensory system provides cues to infants that support mood regulation and maintain attention. These results have implications for optimizing infant environments for emotional health and cognitive development.

  19. Learning about natural variation of odor mixtures enhances categorization in early olfactory processing.

    PubMed

    Locatelli, Fernando F; Fernandez, Patricia C; Smith, Brian H

    2016-09-01

    Natural odors are typically mixtures of several chemical components. Mixtures vary in composition among odor objects that have the same meaning. Therefore a central 'categorization' problem for an animal as it makes decisions about odors in natural contexts is to correctly identify odor variants that have the same meaning and avoid variants that have a different meaning. We propose that identified mechanisms of associative and non-associative plasticity in early sensory processing in the insect antennal lobe and mammalian olfactory bulb are central to solving this problem. Accordingly, this plasticity should work to improve categorization of odors that have the opposite meanings in relation to important events. Using synthetic mixtures designed to mimic natural odor variation among flowers, we studied how honey bees learn about and generalize among floral odors associated with food. We behaviorally conditioned honey bees on a difficult odor discrimination problem using synthetic mixtures that mimic natural variation among snapdragon flowers. We then used calcium imaging to measure responses of projection neurons of the antennal lobe, which is the first synaptic relay of olfactory sensory information in the brain, to study how ensembles of projection neurons change as a result of behavioral conditioning. We show how these ensembles become 'tuned' through plasticity to improve categorization of odors that have the different meanings. We argue that this tuning allows more efficient use of the immense coding space of the antennal lobe and olfactory bulb to solve the categorization problem. Our data point to the need for a better understanding of the 'statistics' of the odor space. © 2016. Published by The Company of Biologists Ltd.

  20. Prenatal low-dose bisphenol A enhances behavioral responses induced by a predator odor.

    PubMed

    Fujimoto, Tetsuya; Kubo, Kazuhiko; Nishikawa, Yasuo; Aou, Shuji

    2015-01-01

    Bisphenol A (BPA) is an environmental endocrine disrupter (EED). Previous studies by our group showed that pre- and postnatal administration of low-level BPA induced depression-like behavior in rats. In this study, we evaluated the effects of prenatal BPA on behavioral responses to a predator odor by using a novel cross-form apparatus consisting of 4 plastic chambers. On the first day, nothing was placed into the chambers (Session 1). On the second day, a predator odor (fox odor) was located in separate chambers at 2 opposite corners of the apparatus (Session 2). Pregnant Wistar rats were exposed to low-dose BPA (less than the reference dose) during the 7 days just before birth, and the offspring of the treated rats were evaluated as adults. The locomotor activity and avoidance response of each rat on both test days were compared. The control and BPA groups showed reduced locomotor activity in the presence of the predator odor, but the odor-avoidance response was significant only in the BPA rats. The BPA-exposed rats were obviously sensitive to the predator odor. These results suggest that prenatal BPA exposure has an amplifying effect on avoidance responses to predator odor stress.

  1. Discrimination of Body Odor Using Odor Sieving Sensor System

    NASA Astrophysics Data System (ADS)

    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. Odor Measurement

    NASA Astrophysics Data System (ADS)

    Iwasaki, Yoshiharu

    It has been said that the measurement of odor is very difficult. Because almost odor samples have a large number of chemicals, and these olfactory thresholds are very low levels. For these reasons, the instrumental measurement method is not good, and the olfactory sensory methods are adopted in the world. Odor concentration scale had been widely used in the world. But, the measurement methods of odor concentration scale differ depend on the country. For example, in Japan, Triangle Odor Bag Method has been used from 30 years ago. Dynamic olfactometer is used in European countries. Triangle Odor Bag Method is introduced at the end of this paper.

  3. The AMPA receptor modulator S18986 in the prelimbic cortex enhances acquisition and retention of an odor-reward association.

    PubMed

    Yefimenko, Natalya; Portero-Tresserra, Marta; Martí-Nicolovius, Margarita; Guillazo-Blanch, Gemma; Vale-Martínez, Anna

    2013-08-26

    Systemic administration of S18986, a positive allosteric modulator of AMPA receptors, improves cognition. The present study further characterizes the drug's memory-enhancing properties and is the first to investigate its intracerebral effects on learning and memory. The results showed that rats receiving a single dose of S18986 (3 μg/site) into the prelimbic cortex, prior to olfactory discrimination acquisition, exhibited significantly shorter latencies and fewer errors to make the correct response, both in the acquisition and two drug-free retention tests. Such findings corroborate the involvement of glutamate receptors in odor-reward learning and confirm the role of the AMPAkine S18986 as a cognitive enhancer.

  4. Breath odor

    MedlinePlus

    ... drain their stomach. The breath may have an ammonia-like odor (also described as urine-like or " ... Is there a specific odor (such as fish, ammonia, fruit, feces, or alcohol)? Have you recently eaten ...

  5. Vaginal Odor

    MedlinePlus

    ... usually don't cause vaginal odors. Neither do yeast infections. Generally, if you have vaginal odor without ... Avoid douching. All healthy vaginas contain bacteria and yeast. The normal acidity of your vagina keeps bacteria ...

  6. Urine Odor

    MedlinePlus

    ... urine odor. Urine that contains a lot of water and few waste products has little to no odor. If urine becomes highly concentrated — a high level of waste products with little water — your urine may have a strong ammonia odor. ...

  7. Assessing human exposure and odor detection during showering with crude 4-(methylcyclohexyl)methanol (MCHM) contaminated drinking water.

    PubMed

    Sain, Amanda E; Dietrich, Andrea M; Smiley, Elizabeth; Gallagher, Daniel L

    2015-12-15

    In 2014, crude (4-methylcyclohexyl)methanol (MCHM) spilled, contaminating the drinking water of 300,000 West Virginians and requiring "do not use" orders to protect human health. When the spill occurred, known crude MCHM physicochemical properties were insufficient to predict human inhalation and ingestion exposures. Objectives are (1) determine Henry's Law Constants (HLCs) for 4-MCHM isomers at 7, 25, 40, and 80°C using gas chromatography; (2) predict air concentrations of 4-MCHM and methyl-4-methylcyclohexanecarboxylate (MMCHC) during showering using an established shower model; (3) estimate human ingestion and inhalation exposure to 4-MCHM and MMCHC; and (4) determine if predicted air 4-MCHM exceeded odor threshold concentrations. Dimensionless HLCs of crude cis- and trans-4-MCHM were measured to be 1.42×10(-4)±6% and 3.08×10(-4)±3% at 25°C, respectively, and increase exponentially with temperature as predicted by the van't Hoff equation. Shower air concentrations for cis- and trans-4-MCHM are predicted to be 0.089 and 0.390ppm-v respectively after 10min, exceeding the US EPA's 0.01ppm-v air screening level during initial spill conditions. Human exposure doses were predicted using measured drinking water and predicted shower air concentrations and found to greatly exceed available guidance levels in the days directly following the spill. Odors would be rapidly detected by 50% of individuals at aqueous concentrations below analytical gas chromatographic detection limits. MMCHC, a minor odorous component (0.935%) of crude MCHM, is also highly volatile and therefore is predicted to contribute to inhalation exposures and odors experienced by consumers.

  8. Odor perception and odor awareness in congenital blindness.

    PubMed

    Beaulieu-Lefebvre, Mathilde; Schneider, Fabien C; Kupers, Ron; Ptito, Maurice

    2011-02-28

    It is generally acknowledged that people blind from birth develop supra-normal sensory abilities in order to compensate for their visual deficit. While extensive research has been done on the somatosensory and auditory modalities of the blind, information about their sense of smell remains scant. The goal of this study was therefore to compare odor perception and odor awareness in a group of 11 congenitally blind and 14 sighted control subjects. We measured odor detection threshold, odor discrimination and odor identification using the Sniffin'Sticks test. Participants also filled in the Odor Awareness Scale (OAS) to assess consciousness of olfactory sensations. Our data showed that blind subjects had a lower odor detection threshold compared to the sighted. However, no group differences were found for odor discrimination and odor identification. Interestingly, the OAS revealed that blind participants scored higher for odor awareness. The largest group differences were found for items of the OAS that measure responses to body odors and fragrances. We conclude that blind subjects rely more on their sense of smell than the sighted in order to assess their environment and to recognize places and other people. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Odor Mortis

    SciTech Connect

    Vass, Arpad Alexander

    2012-01-01

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

  10. QCM Odor Sensor Noticed by Boilling Point of Odor Substances

    NASA Astrophysics Data System (ADS)

    So, Yasuaki; Arai, Takayuki; Akiya, Masashiro

    In this paper, a improved method for detecting odor samples using mono-channel QCM LB film sensor is described. The sensing film deposited on the QCM was DOABr combined by PVSK as an under layer. The odor sensor was able to detect the usual frequency shift, the resistance shift and more the response time related to the boiling point and volatile rate of odor substances. The gradient of the curve for frequency vs. resistance shift decreased as coefficient of viscosity rate. Single odor samples, such as benzene, hexane and chloroform can be detected by these parameters. Mixed odor samples such as three kind of odor substances could be also detected by adding the response time measurement.

  11. Coding odor identity and odor value in awake rodents

    PubMed Central

    Nuñez-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 vs. 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 not only information on odor identity but also on 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. PMID:24767484

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

    PubMed

    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.

  13. Field-Effect Transistor Biosensor Platform Fused with Drosophila Odorant-Binding Proteins for Instant Ethanol Detection.

    PubMed

    Lim, Cheol-Min; Kwon, Jae Young; Cho, Won-Ju

    2017-04-26

    Odorant-binding proteins (OBPs) have attracted considerable attention as sensing substrates for the development of olfactory biosensors. The Drosophila LUSH protein is an OBP and is known to bind to various alcohols. Technology that uses the LUSH protein has great potential to provide crucial information through odorant detection. In this work, the LUSH protein was used as a sensing substrate to detect the ethanol concentration. Furthermore, we fused the LUSH protein with a silicon-on-insulator (SOI)-based ion-sensitive field-effect transistor (ISFET) to measure the electrical signals that arise from molecular interactions between the LUSH and ethanol. A dual-gate sensing system for self-amplification of the signal resulting from the molecular interaction between the LUSH and ethanol was then used to achieve a much higher sensitivity than a conventional ISFET. In the end, we successfully detected ethanol at concentrations ranging between 0.001 and 1% using the LUSH OBP-fused ISFET olfactory sensor. The OBP-fused SOI-based olfactory ISFET sensor can lead to the development of handheld sensors for various purposes such as detecting toxic chemicals, narcotics control, testing for food freshness, and noninvasive diagnoses.

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

    PubMed

    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.

  15. A novel quantitation approach for maximizing detectable targets for offensive/volatile odorants with diverse functional groups by thermal desorption-gas chromatography-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2016-07-01

    A multitude of analytical systems are needed to analyze diverse odorants with various functionalities. In this study, an experimental method was developed to assess the maximum covering range of odorants using a single experimental setup consisting of a thermal desorber-gas chromatography-mass spectrometry system. To this end, a total of 20 offensive odorants (aldehyde, ketone, ester, alcohol, aromatic, sulfide, amine, and carboxyl) were selected and tested by a single system. The analytical results of standards and environmental samples were evaluated in a number of respects. In the analysis of the standards, all targets were quantified via Carbopack (C + B + X) tube sampling while operating the thermal desorber at ‑25 °C. The method detection limits of 18 targets (exception of 2 out of the 20 targets: acetaldehyde and methanethiol) were excellent (mean 0.04 ± 0.03 ppb) in terms of their odor threshold values (74.7 ± 140 ~ 624 ± 1,729 ppb). The analysis of organic fertilizer plant samples at a pig farm (slurry treatment facility, compost facility, and ambient air) confirmed the presence of 18 odorants from 0.03 ppb (dimethyldisulfide, ambient sample) to 522 ppb (methyl ethyl ketone, slurry treatment facility). As such, our method allowed simultaneous quantitation of most key odorants with sufficient reliability and sensitivity.

  16. A novel quantitation approach for maximizing detectable targets for offensive/volatile odorants with diverse functional groups by thermal desorption-gas chromatography-mass spectrometry

    PubMed Central

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2016-01-01

    A multitude of analytical systems are needed to analyze diverse odorants with various functionalities. In this study, an experimental method was developed to assess the maximum covering range of odorants using a single experimental setup consisting of a thermal desorber-gas chromatography-mass spectrometry system. To this end, a total of 20 offensive odorants (aldehyde, ketone, ester, alcohol, aromatic, sulfide, amine, and carboxyl) were selected and tested by a single system. The analytical results of standards and environmental samples were evaluated in a number of respects. In the analysis of the standards, all targets were quantified via Carbopack (C + B + X) tube sampling while operating the thermal desorber at −25 °C. The method detection limits of 18 targets (exception of 2 out of the 20 targets: acetaldehyde and methanethiol) were excellent (mean 0.04 ± 0.03 ppb) in terms of their odor threshold values (74.7 ± 140 ~ 624 ± 1,729 ppb). The analysis of organic fertilizer plant samples at a pig farm (slurry treatment facility, compost facility, and ambient air) confirmed the presence of 18 odorants from 0.03 ppb (dimethyldisulfide, ambient sample) to 522 ppb (methyl ethyl ketone, slurry treatment facility). As such, our method allowed simultaneous quantitation of most key odorants with sufficient reliability and sensitivity. PMID:27404037

  17. A novel quantitation approach for maximizing detectable targets for offensive/volatile odorants with diverse functional groups by thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2016-07-11

    A multitude of analytical systems are needed to analyze diverse odorants with various functionalities. In this study, an experimental method was developed to assess the maximum covering range of odorants using a single experimental setup consisting of a thermal desorber-gas chromatography-mass spectrometry system. To this end, a total of 20 offensive odorants (aldehyde, ketone, ester, alcohol, aromatic, sulfide, amine, and carboxyl) were selected and tested by a single system. The analytical results of standards and environmental samples were evaluated in a number of respects. In the analysis of the standards, all targets were quantified via Carbopack (C + B + X) tube sampling while operating the thermal desorber at -25 °C. The method detection limits of 18 targets (exception of 2 out of the 20 targets: acetaldehyde and methanethiol) were excellent (mean 0.04 ± 0.03 ppb) in terms of their odor threshold values (74.7 ± 140 ~ 624 ± 1,729 ppb). The analysis of organic fertilizer plant samples at a pig farm (slurry treatment facility, compost facility, and ambient air) confirmed the presence of 18 odorants from 0.03 ppb (dimethyldisulfide, ambient sample) to 522 ppb (methyl ethyl ketone, slurry treatment facility). As such, our method allowed simultaneous quantitation of most key odorants with sufficient reliability and sensitivity.

  18. Effect of odor preexposure on acquisition of an odor discrimination in dogs.

    PubMed

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

    2014-06-01

    In two experiments, we investigated the impact of odor preexposure treatments on the acquisition of an olfactory discrimination in dogs. In the first experiment, four groups of dogs were each given five days' odor-exposure treatment prior to discrimination training. Dogs in the exposure group were exposed to anise extract (S+) for 30 min daily. Dogs in the Pavlovian-relevant pairing group received six daily delayed-conditioning trials to the same S+. The Pavlovian-irrelevant pairing group received conditioning trials to almond extract (S'). Dogs in the control group received no pretreatment. All of the dogs were then trained to detect S+ from a background pine odor (an AX-vs.-X discrimination). The Pavlovian-relevant pairing group acquired the odor discrimination significantly faster than all of the other exposure and control groups, and the remaining groups acquired the discrimination at the same rate as the no-exposure control group. In a second experiment, we extended these results to a within-subjects design using an AX-versus-BX discrimination. Six dogs were simultaneously trained on two different odor discriminations, one discrimination in which the S+ was previously Pavlovian conditioned, and one discrimination in which the S+ was novel. All of the dogs learned the odor discrimination with the previously conditioned S+ faster than they learned the novel odor discrimination, replicating the results of Experiment 1, and demonstrating that familiarity in the form of Pavlovian conditioning enhances odor-discrimination training. The potential mechanisms of the facilitated transfer of a Pavlovian conditioned stimulus to discrimination training are discussed.

  19. Combinatorial effects of odorants on mouse behavior

    PubMed Central

    Saraiva, Luis R.; Kondoh, Kunio; Ye, Xiaolan; Yoon, Kyoung-hye; Hernandez, Marcus; Buck, Linda B.

    2016-01-01

    The mechanisms by which odors induce instinctive behaviors are largely unknown. Odor detection in the mouse nose is mediated by >1, 000 different odorant receptors (ORs) and trace amine-associated receptors (TAARs). Odor perceptions are encoded combinatorially by ORs and can be altered by slight changes in the combination of activated receptors. However, the stereotyped nature of instinctive odor responses suggests the involvement of specific receptors and genetically programmed neural circuits relatively immune to extraneous odor stimuli and receptor inputs. Here, we report that, contrary to expectation, innate odor-induced behaviors can be context-dependent. First, different ligands for a given TAAR can vary in behavioral effect. Second, when combined, some attractive and aversive odorants neutralize one another’s behavioral effects. Both a TAAR ligand and a common odorant block aversion to a predator odor, indicating that this ability is not unique to TAARs and can extend to an aversive response of potential importance to survival. In vitro testing of single receptors with binary odorant mixtures indicates that behavioral blocking can occur without receptor antagonism in the nose. Moreover, genetic ablation of a single receptor prevents its cognate ligand from blocking predator odor aversion, indicating that the blocking requires sensory input from the receptor. Together, these findings indicate that innate odor-induced behaviors can depend on context, that signals from a single receptor can block innate odor aversion, and that instinctive behavioral responses to odors can be modulated by interactions in the brain among signals derived from different receptors. PMID:27208093

  20. A Light-Addressable Potentiometric Sensor for Odorant Detection Using Single Bioengineered Olfactory Sensory Neurons as Sensing Element.

    PubMed

    Wu, Chunsheng; Du, Liping; Tian, Yulan; Zhang, Xi; Wang, Ping

    2017-01-01

    A light-addressable potentiometric sensor (LAPS), a silicon-based surface potential detector, is combined with bioengineered olfactory sensory neurons (OSN) for odorant detection. A LAPS chip is used as a transducer to monitor cell membrane potential changes. In addition, a focused movable laser with a diameter comparable to cell sizes is employed to select the desirable single cell for measurement under a microscope. Bioengineered OSNs are coupled to the LAPS surface and employed as sensing elements, which are prepared by the expression of an olfactory receptor of C. elegans, ODR-10, on the plasma membrane of rat primary OSNs via transient transfection. The responses of bioengineered OSNs to diacetyl, isoamyl acetate, and acetic acid are monitored by extracellular recording using the LAPS chip. Features of the recorded extracellular potential firings are analyzed in frequency and time domains. We have shown that bioengineered OSNs can generate specific response signals upon the stimulation of diacetyl, which is the natural ligand of ODR-10. Moreover, different concentrations of diacetyl can elicit different temporal firing patterns in bioengineered OSNs, which permits the concentration detection of specific odorant molecules in solution.

  1. Pleasantness, familiarity, and identification of spice odors are interrelated and enhanced by consumption of herbs and food neophilia.

    PubMed

    Knaapila, Antti; Laaksonen, Oskar; Virtanen, Markus; Yang, Baoru; Lagström, Hanna; Sandell, Mari

    2017-02-01

    The primary dimension of odor is pleasantness, which is associated with a multitude of factors. We investigated how the pleasantness, familiarity, and identification of spice odors were associated with each other and with the use of the respective spice, overall use of herbs, and level of food neophobia. A total of 126 adults (93 women, 33 men; age 25-61 years, mean 39 years) rated the odors from 12 spices (oregano, anise, rosemary, mint, caraway, sage, thyme, cinnamon, fennel, marjoram, garlic, and clove) for pleasantness and familiarity, and completed a multiple-choice odor identification. Data on the use of specific spices, overall use of herbs, and Food Neophobia Scale score were collected using an online questionnaire. Familiar odors were mostly rated as pleasant (except garlic), whereas unfamiliar odors were rated as neutral (r = 0.63). We observed consistent and often significant trends that suggested the odor pleasantness and familiarity were positively associated with the correct odor identification, consumption of the respective spice, overall use of herbs, and food neophilia. Our results suggest that knowledge acquisition through repetitive exposure to spice odor with active attention may gradually increase the odor pleasantness within the framework set by the chemical characteristics of the aroma compound. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Detection of piperonal emitted from polymer controlled odor mimic permeation systems utilizing Canis familiaris and solid phase microextraction-ion mobility spectrometry.

    PubMed

    Macias, Michael S; Guerra-Diaz, Patricia; Almirall, José R; Furton, Kenneth G

    2010-02-25

    Currently, in the field of odor detection, there is generally a wider variation in limit of detections (LODs) for canines than instruments. The study presented in this paper introduces an improved protocol for the creation of controlled odor mimic permeation system (COMPS) devices for use as standards in canine training and discusses the canine detection thresholds of piperonal, a starting material for the illicit drug 3,4-methylenedioxymethamphetamine (MDMA), when exposed to these devices. Additionally, this paper describes the first-ever reported direct comparison of solid phase microextraction-ion mobility spectrometry (SPME-IMS) to canine detection for the MDMA odorant, piperonal. The research presented shows the reliability of COMPS devices as low cost field calibrants providing a wide range of odorant concentrations for biological and instrumental detectors. The canine LOD of piperonal emanating from the 100 ng s(-1) COMPS was found to be 1 ng as compared to the SPME-IMS LOD of piperonal in a static, closed system at 2 ng, with a linear dynamic range from 2 ng to 11 ng. The utilization of the COMPS devices would allow for training that will reduce the detection variability between canines and maintain improved consistency for training purposes. Since both SPME and IMS are field portable technologies, it is expected that this coupled method will be useful as a complement to canine detection for the field detection of MDMA. 2009 Elsevier Ireland Ltd. All rights reserved.

  3. Knockdown of microplitis mediator odorant receptor involved in the sensitive detection of two chemicals.

    PubMed

    Li, Ke-Ming; Ren, Li-Yan; Zhang, Yong-Jun; Wu, Kong-Ming; Guo, Yu-Yuan

    2012-03-01

    Odorant receptors are thought to play critical roles in the perception of chemosensory stimuli by insects. The primary method to address the functions of odorant receptors in insects is to use in vitro binding assays between the receptors and potential chemical stimuli. We injected MmedOrco dsRNA into the abdominal cavity of a braconid wasp, Microplitis mediator, and assayed for expression of this gene 72 h after treatment (RNAi). Quantitative real-time PCR demonstrated that the level of mRNA expression in MmedOrco dsRNA-treated M. mediator was significantly reduced (>90%) when compared with water-treated controls. Furthermore, electroantennogram (EAG) responses of M. mediator to two chemical attractants, nonanal and farnesene, were also reduced significantly (~70%) in RNAi-treated M. mediator when compared to controls. RNAi-treated M. mediator also responded by walking/flying at a lower rate to both chemicals when compared with controls in a Y-tube olfactometer bioassay, which provides direct evidence that MmedOrco plays an important role in perception of nonanal and farnesene in M. mediator.

  4. Quantitative measurement of odor detection thresholds using an air dilution olfactometer, and association with genetic variants in a sample of diverse ancestry

    PubMed Central

    Cook, Gillian R.; Krithika, S; Edwards, Melissa; Kavanagh, Paula

    2014-01-01

    Genetic association studies require a quantitative and reliable method for odor threshold assessment in order to examine the contribution of genetic variants to complex olfactory phenotypes. Our main goal was to assess the feasibility of a portable Scentroid air dilution olfactometer for use in such studies. Using the Scentroid SM110C and the SK5 n-butanol Sensitivity Kit (IDES Canada Inc.), n-butanol odor thresholds were determined for 182 individuals of diverse ancestry (mean age: 20.4 ± 2.5 years; n = 128 female; n = 54 male). Threshold scores from repeat participants were used to calculate a test–retest reliability coefficient, which was statistically significant (r = 0.754, p < 0.001, n = 29), indicating that the Scentroid provides reliable estimates of odor thresholds. In addition, we performed a preliminary genetic analysis evaluating the potential association of n-butanol odor thresholds to six single-nucleotide polymorphisms (SNPs) putatively involved in general olfactory sensitivity (GOS). The results of multiple linear regression analysis revealed no significant association between the SNPs tested and threshold scores. However, our sample size was relatively small, and our study was only powered to identify genetic markers with strong effects on olfactory sensitivity. Overall, we find that the Scentroid provides reliable quantitative measures of odor detection threshold and is well suited for genetic studies of olfactory sensitivity. PMID:25392755

  5. Quantitative measurement of odor detection thresholds using an air dilution olfactometer, and association with genetic variants in a sample of diverse ancestry.

    PubMed

    Cook, Gillian R; Krithika, S; Edwards, Melissa; Kavanagh, Paula; Parra, Esteban J

    2014-01-01

    Genetic association studies require a quantitative and reliable method for odor threshold assessment in order to examine the contribution of genetic variants to complex olfactory phenotypes. Our main goal was to assess the feasibility of a portable Scentroid air dilution olfactometer for use in such studies. Using the Scentroid SM110C and the SK5 n-butanol Sensitivity Kit (IDES Canada Inc.), n-butanol odor thresholds were determined for 182 individuals of diverse ancestry (mean age: 20.4 ± 2.5 years; n = 128 female; n = 54 male). Threshold scores from repeat participants were used to calculate a test-retest reliability coefficient, which was statistically significant (r = 0.754, p < 0.001, n = 29), indicating that the Scentroid provides reliable estimates of odor thresholds. In addition, we performed a preliminary genetic analysis evaluating the potential association of n-butanol odor thresholds to six single-nucleotide polymorphisms (SNPs) putatively involved in general olfactory sensitivity (GOS). The results of multiple linear regression analysis revealed no significant association between the SNPs tested and threshold scores. However, our sample size was relatively small, and our study was only powered to identify genetic markers with strong effects on olfactory sensitivity. Overall, we find that the Scentroid provides reliable quantitative measures of odor detection threshold and is well suited for genetic studies of olfactory sensitivity.

  6. Odor from a chemical perspective

    SciTech Connect

    Wray, T.K.

    1995-06-01

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

  7. Molecular profiling of activated olfactory neurons identifies odorant receptors for odors in vivo

    PubMed Central

    Jiang, Yue; Gong, Naihua Natalie; Hu, Xiaoyang Serene; Ni, Mengjue Jessica; Pasi, Radhika

    2015-01-01

    The mammalian olfactory system uses a large family of odorant receptors to detect and discriminate amongst a myriad of volatile odor molecules. Understanding odor coding requires comprehensive mapping between odorant receptors and corresponding odors. Here we present high–throughput in vivo identification of odorant receptor repertoires responding to odorants, using phosphorylated ribosome immunoprecipitation of mRNA from olfactory epithelium of odor–stimulated mice followed by RNA–Seq. This approach screens the endogenously expressed odorant receptors against an odor in one set of experiments, using awake and freely behaving mice. In combination with validations in a heterologous system, we identify sets of odorant receptors for two odorants, acetophenone and 2,5–dihydro–2,4,5–trimethylthiazoline (TMT), encompassing 69 odorant receptor–odorant pairs. We also identified shared amino acid residues specific to the acetophenone or TMT receptors, and developed models to predict receptor activation by acetophenone. This study provides a means to understand the combinatorial coding of odors in vivo. PMID:26322927

  8. Temporal predictability enhances auditory detection

    PubMed Central

    Lawrance, Emma L. A.; Harper, Nicol S.; Cooke, James E.; Schnupp, Jan W. H.

    2015-01-01

    Periodic stimuli are common in natural environments and are ecologically relevant, for example, footsteps and vocalizations. This study reports a detectability enhancement for temporally cued, periodic sequences. Target noise bursts (embedded in background noise) arriving at the time points which followed on from an introductory, periodic “cue” sequence were more easily detected (by ~1.5 dB SNR) than identical noise bursts which randomly deviated from the cued temporal pattern. Temporal predictability and corresponding neuronal “entrainment” have been widely theorized to underlie important processes in auditory scene analysis and to confer perceptual advantage. This is the first study in the auditory domain to clearly demonstrate a perceptual enhancement of temporally predictable, near-threshold stimuli. PMID:24907846

  9. Temporal predictability enhances auditory detection.

    PubMed

    Lawrance, Emma L A; Harper, Nicol S; Cooke, James E; Schnupp, Jan W H

    2014-06-01

    Periodic stimuli are common in natural environments and are ecologically relevant, for example, footsteps and vocalizations. This study reports a detectability enhancement for temporally cued, periodic sequences. Target noise bursts (embedded in background noise) arriving at the time points which followed on from an introductory, periodic "cue" sequence were more easily detected (by ∼1.5 dB SNR) than identical noise bursts which randomly deviated from the cued temporal pattern. Temporal predictability and corresponding neuronal "entrainment" have been widely theorized to underlie important processes in auditory scene analysis and to confer perceptual advantage. This is the first study in the auditory domain to clearly demonstrate a perceptual enhancement of temporally predictable, near-threshold stimuli.

  10. Odor-induced changes in taste perception.

    PubMed

    Djordjevic, J; Zatorre, R J; Jones-Gotman, M

    2004-12-01

    We investigated odor-induced changes in taste perception (OICTP), by examining the influence of strawberry and soy sauce odors on perceived sweetness (Experiment 1) and saltiness (Experiment 2). We explored whether taste-smell interactions occur at the central level, by delivering odorants (strawberry, soy sauce, odorless water) and tastants (sucrose, sodium chloride) separately, and whether effects of imagined odors are comparable to those of physically presented odors. We found specific taste-smell interactions: sweetness enhancement induced by strawberry odor and saltiness enhancement induced by soy sauce odor. These interactions were elicited with separate delivery of olfactory and gustatory stimuli. Secondly, we found a similar but rather limited effect with the imagined odors: imagined strawberry enhanced perceived sweetness of water solutions, and imagined soy sauce enhanced perceived saltiness of weak sodium chloride solutions. We concluded that OICTP is a centrally mediated phenomenon, and that imagined odors can to some extent induce changes in perceived taste intensity comparable to those elicited by perceived odors.

  11. Mapping odor valence in the brain of flies and mice.

    PubMed

    Knaden, Markus; Hansson, Bill S

    2014-02-01

    Why are some odors perceived as pleasant while others are not? We review current research on how pleasant and unpleasant odors, that is, odors with positive or negative valence, are processed in the brain of flies and mice. We conclude that in mice pleasant and unpleasant odors are detected via three olfactory subsystems with only one being fully dedicated to unpleasant odors, while the others detect both good and bad odors. Correspondingly, so far no clear segmentation into regions processing exclusively pleasant or unpleasant odors has been identified in the mouse brain. The situation is different in flies, where most odors are sensed via the antenna. Already at the antennal lobe level, that is, the first processing center for olfactory input, odorants seem to be categorized as pleasant or unpleasant. We furthermore discuss why animals at all should make a decision based on olfaction, and why a straightforward and fast processing of odorant valence might be important for survival and reproduction.

  12. Olfaction and Environment: Tsimane’ of Bolivian Rainforest Have Lower Threshold of Odor Detection Than Industrialized German People

    PubMed Central

    Sorokowska, Agnieszka; Sorokowski, Piotr; Hummel, Thomas; Huanca, Tomas

    2013-01-01

    Olfactory sensitivity varies between individuals. However, data regarding cross-cultural and inter-group differences are scarce. We compared the thresholds of odor detection of the traditional society of Tsimane’ (native Amazonians of the Bolivian rainforest; n = 151) and people living in Dresden (Germany; n = 286) using “Sniffin’ Sticks” threshold subtest. Tsimane’ detected n-butanol at significantly lower concentrations than the German subjects. The distribution of thresholds of the Tsimane’ was very specific, with 25% of Tsimane’ obtaining better results in the olfactory test than any member of the German group. These data suggest that differences in olfactory sensitivity seem to be especially salient between industrialized and non-industrialized populations inhabiting different environmental conditions. We hypothesize that the possible sources of such differences are: (i) the impact of pollution which impairs the olfactory abilities of people from industrialized countries; (ii) better training of olfaction because of the higher importance of smell in traditional populations; (iii) environmental pressures shaping olfactory abilities in these populations. PMID:23922693

  13. Hedonics of odors and odor descriptors

    SciTech Connect

    Dravnieks, A.; Masurat, T.; Lamm, R.A.

    1984-07-01

    The hedonic tone (pleasantness-unpleasantness) of an air pollution odor depends on its character and influences how annoying the odor may be. In the context of air pollution, both unpleasant and pleasant odors may become objectionable, while this is less likely for hedonically neutral odors. A profile of an odor consists of a list of odor descriptors and ratings of the applicabilities of each of the descriptors to the odor being characterized. The working hypothesis was that each of the descriptors can be assigned its own hedonic connotation (tone) from very pleasant, through neutral, to the very unpleasant. The hedonic tones of the descriptors could then be combined with the descriptor applicability percentages over the entire profile, producing a profile-derived hedonic index. The data that were used were profiles of odors and the hedonic ratings of the same odors made directly upon smelling these odors, obtained independently of the study.

  14. An assessment of detection canine alerts using flowers that release methyl benzoate, the cocaine odorant, and an evaluation of their behavior in terms of the VOCs produced.

    PubMed

    Cerreta, Michelle M; Furton, Kenneth G

    2015-06-01

    In recent years, the high frequency of illicit substance abuse reported in the United States has made the development of efficient and rapid detection methods important. Biological detectors, such as canines (Canis familiaris), are valuable tools for rapid, on-site identification of illicit substances. However, research indicates that in many cases canines do not alert to the contraband, but rather to the volatile organic compounds (VOCs) that are released from the contraband, referred to as the "active odor." In 2013, canine accuracy and reliability were challenged in the Supreme Court case, State of Florida v. Jardines. In this case, it was stated that if a canine alerts to the active odor, and not the contraband, the canine's accuracy and selectivity could be questioned, since many of these compounds have been found in common household products. Specifically, methyl benzoate, the active odor of cocaine, has been found to be the most abundant compound produced by snapdragon flowers. Therefore, the purpose of this study is to evaluate the odor profiles of various species of snapdragon flowers to assess how significantly methyl benzoate contributes to the total VOC profile or fragrance that is produced. Particularly, this study examines the VOCs released from newly grown snapdragon flowers and determines its potential at eliciting a false alert from specially trained detection canines. The ability of detection canines to differentiate between cocaine and snapdragon flowers was determined in order to validate the field accuracy and discrimination power of these detectors. An optimized method using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to test the different types and abundances of compounds generated from snapdragon flowers at various stages throughout the plants' life cycle. The results indicate that although methyl benzoate is present in the odor profile of snapdragon flowers, other

  15. Odor-active compounds in cardboard.

    PubMed

    Czerny, Michael; Buettner, Andrea

    2009-11-11

    The odor-active compounds of cardboard were identified by aroma extract dilution analysis and HRGC-MS analysis. In total, 36 compounds were detected with medium to high intensities during HRGC-olfactometry. The highest odor intensities were evaluated for vanillin, (E)-non-2-enal, (R/S)-gamma-nonalactone, 2-methoxyphenol, (R/S)-delta-decalactone, p-anisaldehyde, 3-propylphenol, and a woody-smelling unknown compound. Most of the identified compounds were described as odor-active cardboard constituents for the first time. Sensory experiments demonstrated that extensive release of odor-active compounds occurred upon moistening of the cardboard. Accordingly, data indicated that the odorants are present in cardboard in relatively high amounts. In a further sensory study, a transfer of the released odor to food was demonstrated in a model experiment showing that cardboards with high odor potential can cause unwanted flavor changes in foods.

  16. Odor detection ability and thallium-201 transport in the olfactory nerve of traumatic olfactory-impaired mice.

    PubMed

    Shiga, Hideaki; Kinoshita, Yayoi; Washiyama, Kohshin; Ogawa, Daisuke; Amano, Ryohei; Hirota, Kyoko; Tsukatani, Toshiaki; Furukawa, Mitsuru; Miwa, Takaki

    2008-09-01

    Although olfactory nerve damage is a contributing factor in the diagnosis of posttraumatic olfactory loss, at present, there are no methods to directly assess injury to these nerves. We have shown that following olfactory nerve injury in mice, thallium-201 (201 Tl) transport from the nasal cavity to the olfactory bulb decreases. To determine if olfactory function after nerve injury could be assessed with nasal administration of 201 Tl, we measured the correlation between odor detection ability (ODA) and the rate of transport of 201 Tl in olfactory nerves. Both ODA and 201 Tl transport were measured after bilateral olfactory nerve transection for a 4-week period. Cycloheximide solution was used for ODA against tap water. 201 Tl transport was measured as the ratio of radioactivity in the nasal cavity and olfactory bulb with gamma spectrometry. There was a significant correlation between ODA and the rate of 201 Tl transport in the olfactory nerve. These findings suggest that olfactory function after nerve injury can be objectively evaluated with the nasal administration of 201 Tl.

  17. Determination of ortho- and retronasal detection thresholds and odor impact of 2,5-dimethyl-3-methoxypyrazine in wine.

    PubMed

    Botezatu, Andreea; Pickering, Gary J

    2012-11-01

    2,5-Dimethyl-3-methoxypyrazine (DMMP) has been recently identified in both Coccinellidae-tainted (by either Coccinella septempunctata or Harmonia axyridis beetles) and untainted wines; however, little is known regarding its impact on wine aroma and flavor. The aims of this study were to obtain an accurate estimate of both the ortho- and retronasal detection thresholds of DMMP in red wine and to understand how DMMP contributes to the aroma profile of red wine. In the first study, thresholds were determined for 21 individuals using the ASTM E679 ascending forced choice method of limits. The orthonasal group best estimate threshold (BET) was 31 ng/L and the retronasal group BET was 70 ng/L. A moderate variation in individual thresholds was observed for the orthonasal modality (standard deviation (SD) = 19.8) and a larger variation was noted for retronasal thresholds (SD = 111.8). In the second study, a panel of 8 assessors performed descriptive sensory analysis on 3 red wines containing various concentrations of added DMMP (0, 50, and 120 ng/L). Results show significant changes in aroma characteristics in the 120 ng/L wine and smaller effects at the 50 ng/L level. Overall, wines spiked with DMMP generated lower intensity ratings for cherry and red berry descriptors and higher ratings for earthy/musty and green/vegetal descriptors. When considered with other recent results on DMMP concentrations found in wine, DMMP can be considered a hitherto undescribed impact odorant in some wine styles.

  18. Stress responses of adolescent male and female rats exposed repeatedly to cat odor stimuli, and long-term enhancement of adult defensive behaviors.

    PubMed

    Wright, Lisa D; Muir, Katherine E; Perrot, Tara S

    2013-07-01

    In order to characterize the short- and long-term effects of repeated stressor exposure during adolescence, and to compare the effects of using two sources of cat odor as stressor stimuli, male and female adolescent rats (postnatal day (PND) ∼ 38-46) were exposed on five occasions to either a control stimulus, a cloth stimulus containing cat hair/dander, or a section of cat collar previously worn by a cat. Relative to control stimulus exposure, activity was suppressed and defensive behavior enhanced during exposure to either cat odor stimulus (most pervasively in rats exposed to the collar). Only cloth-exposed rats showed elevated levels of corticosterone (CORT), and only after repeated stressor exposure, but interestingly, rats exposed to the collar stimulus during adolescence continued to show increased behavioral indices of anxiety in adulthood. In this group, the time an individual spent in physical contact with a cagemate during the final adolescent exposure was negatively related to stress-induced CORT output in adulthood, which suggests that greater use of social support during adolescent stress may facilitate adult behavioral coping, without necessitating increased CORT release. These findings demonstrate that adolescent male and female rats respond defensively to cat odor stimuli across repeated exposures and that exposure to such stressors during adolescence can augment adult anxiety-like behavior in similar stressful conditions. These findings also suggest a potential role for social behavior during adolescent stressor exposure in mediating long-term outcomes. Copyright © 2012 Wiley Periodicals, Inc.

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

    PubMed Central

    Yan, Luchun; Liu, Jiemin; Fang, Di

    2015-01-01

    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. PMID:25760055

  20. Characterization of odor emission on the working face of landfill and establishing of odorous compounds index.

    PubMed

    Wenjing, Lu; Zhenhan, Duan; Dong, Li; Jimenez, Luis Miguel Caicedo; Yanjun, Liu; Hanwen, Guo; Hongtao, Wang

    2015-08-01

    Temporal variation (seasonal and daily) of odor emission on the working face of a large sanitary landfill in China was characterized through a 2 yearlong case study. Odor pollution was most serious in spring and autumn, while lower odor concentrations were detected in summer and winter. The daily fluctuation of odor concentration on the working face showed that 2:00am, 6:00am, 2:00pm and 10:00pm were the "most probable times" for odor pollution occurrence, which deserves focused attention in odor control projects. Correlations analysis found that 41% of the variance in odor concentrations can be explained by the chemical concentrations of odorous compounds. Moreover, the selection criteria for the index of odorous compounds were also established by evaluating the odor concentration, contribution to odor strength and the frequency of each compound present in all the samples. Ethyl alcohol, α-piene, hydrogen sulfide, dimethyl sulfide, limonene, methyl mercaptan, dimethyl disulfide, and diethyl sulfide comprise the index of odorous compounds on the working face of typical municipal solid waste landfill in China.

  1. Factors Influencing Odor Sensitivity in the Dog

    DTIC Science & Technology

    1975-03-01

    AD-A008 942 FACTORS INFLUENCING ODOR SENSITIVITY IN THE DOG D. G. Moulton Pennsylvania University Prepared for: Air Force Office of Scientific...developed Tor the quartitative analysis of the relation between odor detection and sniff parameters. Thirsty dogs are rewarded with water for identifying...winch of two ports is associated with an odor . Sniff flow rate, frequency and amplitude are recorded from the output of a pn.^u.Tiotachometer

  2. Enhanced multifunctional paint for detection of radiation

    DOEpatents

    Farmer, Joseph C.; Moses, Edward Ira; Rubenchik, Alexander M.

    2017-03-07

    An enhanced multifunctional paint apparatus, systems, and methods for detecting radiation on a surface include providing scintillation particles; providing an enhance neutron absorptive material; providing a binder; combining the scintillation particles, the enhance neutron absorptive material, and the binder creating a multifunctional paint; applying the multifunctional paint to the surface; and monitoring the surface for detecting radiation.

  3. Odor Experience Facilitates Sparse Representations of New Odors in a Large-Scale Olfactory Bulb Model

    PubMed Central

    Zhou, Shanglin; Migliore, Michele; Yu, Yuguo

    2016-01-01

    Prior odor experience has a profound effect on the coding of new odor inputs by animals. The olfactory bulb, the first relay of the olfactory pathway, can substantially shape the representations of odor inputs. How prior odor experience affects the representation of new odor inputs in olfactory bulb and its underlying network mechanism are still unclear. Here we carried out a series of simulations based on a large-scale realistic mitral-granule network model and found that prior odor experience not only accelerated formation of the network, but it also significantly strengthened sparse responses in the mitral cell network while decreasing sparse responses in the granule cell network. This modulation of sparse representations may be due to the increase of inhibitory synaptic weights. Correlations among mitral cells within the network and correlations between mitral network responses to different odors decreased gradually when the number of prior training odors was increased, resulting in a greater decorrelation of the bulb representations of input odors. Based on these findings, we conclude that the degree of prior odor experience facilitates degrees of sparse representations of new odors by the mitral cell network through experience-enhanced inhibition mechanism. PMID:26903819

  4. Odors Discrimination by Olfactory Epithelium Biosensor

    NASA Astrophysics Data System (ADS)

    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.

  5. Natural gas odor level testing: Instruments and applications

    SciTech Connect

    Roberson, E.H.

    1995-12-01

    An odor in natural and LP gases is necessary. The statistics are overwhelming; when gas customers can smell a leak before the percentage of gas in air reaches a combustible mixture, the chances of an accident are greatly reduced. How do gas companies determine if there is sufficient odor reaching every gas customers home? Injection equipment is important. The rate and quality of odorant is important. Nevertheless, precision odorization alone does not guarantee that customers` homes always have gas with a readily detectable odor. To secure that goal, odor monitoring instruments are necessary.

  6. The Hydrodynamics and Odorant Transport Phenomena of Olfaction in the Hammerhead Shark

    NASA Astrophysics Data System (ADS)

    Rygg, Alex; Craven, Brent

    2013-11-01

    The hammerhead shark possesses a unique head morphology that is thought to facilitate enhanced olfactory performance. The olfactory organs, located at the distal ends of the cephalofoil, contain numerous lamellae that increase the surface area for olfaction. Functionally, for the shark to detect chemical stimuli, water-borne odors must reach the olfactory sensory epithelium that lines these lamellae. Thus, odorant transport from the aquatic environment to the sensory epithelium is the first critical step in olfaction. Here we investigate the hydrodynamics and odorant transport phenomena of olfaction in the hammerhead shark based on an anatomically-accurate reconstruction of the head and olfactory chamber from high-resolution micro-CT and MRI scans of a cadaver specimen. Computational fluid dynamics (CFD) simulations of water flow in the reconstructed model reveal the external and internal hydrodynamics of olfaction during swimming. Odorant transport in the olfactory organ is investigated using a multi-scale approach, whereby molecular dynamics (MD) simulations are used to calculate odorant partition coefficients that are subsequently utilized in macro-scale CFD simulations of odorant deposition. The hydrodynamic and odorant transport results are used to elucidate several important features of olfactory function in the hammerhead shark.

  7. Odor-taste interactions: effects of attentional strategies during exposure.

    PubMed

    Prescott, John; Johnstone, Victoria; Francis, Joanne

    2004-05-01

    Through repeated pairings with a tastant such as sucrose, odors are able to take on the tastant's qualities, e.g. by becoming more sweet smelling. When such odors are subsequently experienced with a sweet tastant in solution, the mixture is often given a higher sweetness rating than the tastant alone. Odor-induced taste enhancement appears to be sensitive to whether an odor-taste combination is viewed analytically as a set of discrete qualities, or synthetically as a flavor. The present research attempted to determine if adoption of these different perceptual approaches during co-exposure with sucrose would influence the extent to which an odor would become sweet smelling and subsequently enhance sweetness intensity. In Experiment 1, subjects received multiple exposures to mixtures of sucrose with low sweetness, low familiarity odors or, as a control, the odors and sucrose solutions separately. Two groups that received mixtures made intensity ratings that promoted either synthesis or analysis of the individual elements in the mixtures. The odors became sweeter smelling irrespective of group. Only adopting a synthetic strategy produced odors that enhanced sweetness in solution. However, these effects were also shown with a 'non-exposed' control odor. This could be accounted for if the single co-exposure with sucrose that all odors received in the pre-test was able to produce sweeter odors. A second experiment confirmed this prediction. Thus, while even a single co-exposure with sucrose is sufficient to produce a sweeter odor, the adoption of a synthetic perceptual strategy during the co-exposure is necessary to produce an odor that will enhance sweetness. These data are consistent with associative leaning accounts of how odors take on taste qualities and also support the interpretation that these effects reflect the central integration of odors and tastes into flavors.

  8. Maternal prefrontal cortex activation by newborn infant odors.

    PubMed

    Nishitani, Shota; Kuwamoto, Saori; Takahira, Asuka; Miyamura, Tsunetake; Shinohara, Kazuyuki

    2014-03-01

    Mothers are attracted by infant cues of a variety of different modalities. To clarify the possible neural mechanisms underlying maternal attraction to infant odor cues, we used near-infrared spectroscopy to examine prefrontal cortex (PFC) activity during odor detection tasks in which 19 mothers and 19 nulliparous females (nonmothers) were presented with infant or adult male odors. They were instructed to make a judgment about whether they smelled an odor during each task. We estimated the PFC activity by measuring the relative oxyhemoglobin (oxyHb) concentrations. The results showed that while detecting the infant odors, bilateral PFC activities were increased in mothers but not in nonmothers. In contrast, adult male odors activated the PFC similarly in mothers and nonmothers. These findings suggest that maternal activation of the PFC in response to infant odors explains a part of the neural mechanisms for maternal attraction to infant odors.

  9. Study of odor recorder using Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Miura, Tomohiro; Nakamoto, Takamichi; Moriizumi, Toyosaka

    It is necessary to determine the recipe of a target odor with sufficient accuracy to realize an odor recorder for recording and reproducing it. We studied the recipe measurement method of a target odor using a mass spectrometry. It was confirmed that the linear superposition was valid when the binary mixture of the apple-flavor components such as isobutyric acid and ethyl valerate was measured. The superposition of a mass spectrum pattern may enable the recipe determination of a multi-component odor easily. In this research, we succeeded in the recipe determinations of orange flavor made up of 14 component odors when its typical recipe, the equalized, the citral-enhanced and the citronellol-enhanced ones were measured.

  10. The typical MSW odorants identification and the spatial odorants distribution in a large-scale transfer station.

    PubMed

    Sun, Zhongtao; Cheng, Zhaowen; Wang, Luochun; Lou, Ziyang; Zhu, Nanwen; Zhou, Xuejun; Feng, Lili

    2017-03-01

    Odorants from municipal solid waste (MSW) were complex variable, and the screening of key offensive odorants was the prerequisite for odor control process. In this study, spatial odor emissions and environmental impacts were investigated based on a large-scale working waste transfer station (LSWTS) using waste container system, and a comprehensive odor characterization method was developed and applied in terms of the odor concentration (OC), theory odor concentration (TOC), total chemical concentration (TCC), and electric nose (EN). The detected odor concentration ranged from 14 to 28 (dimensionless), and MSW container showed the highest OC value of 28, EN of 78, and TCC of 35 (ppm) due to the accumulation of leachate and residual MSW. Ninety-two species odorants were identified, and H2S, NH3, benzene, styrene, ethyl acetate, and dichloromethane were the main contributors in the container, while benzene, m,p,x-xylene, butanone, acetone, isopropanol, and ethyl acetate were predominant in the compression surface (CS) and compression plant (CP). Side of roads (SR) and unload hall (UH) showed low odorous impact. Based on this odor list, 20 species of odor substances were screened for the priority control through the synthetic evaluation method, considering the odorants concentrations, toxicity, threshold values, detection frequency, saturated vapor pressure, and appeared frequency. Graphical abstract.

  11. Natural Variation in Odorant Recognition Among Odorant-Binding Proteins in Drosophila melanogaster

    PubMed Central

    Wang, Ping; Lyman, Richard F.; Mackay, Trudy F. C.; Anholt, Robert R. H.

    2010-01-01

    Chemical recognition is essential for survival and reproduction. Adaptive evolution has resulted in diverse chemoreceptor families, in which polymorphisms contribute to individual variation in chemosensation. To gain insights into the genetic determinants of individual variation in odorant recognition, we measured olfactory responses to two structurally similar odorants in a population of wild-derived inbred lines of Drosophila melanogaster. Odorant-binding proteins (OBPs) are the first components of the insect olfactory system to encounter odorants. Previously four single-nucleotide polymorphisms (SNPs) in the Obp99 group were associated with variation in olfactory responses to benzaldehyde. Here, we identify six different SNPs that are associated with variation in responses to a structurally similar odorant, acetophenone, in the same Obp genes. Five SNPs are in coding regions of Obp99b and Obp99d and one SNP is in the 3′-untranslated region of Obp99a (A610G). We found that the 610G allele is associated with higher response scores to acetophenone than the 610A allele, but with lower expression of Obp99a, suggesting that binding of acetophenone to Opb99a might limit rather than facilitate access to odorant receptors. Our results show that overlapping sets of OBPs contribute to odorant recognition for structurally similar odorants, but that different SNPs are associated with odorant-specific individual variation. Thus, dual olfactory recognition where OBPs regulate odorant access to receptors may enhance olfactory discrimination. PMID:20026676

  12. Balancing the robustness and efficiency of odor representations during learning

    PubMed Central

    Chu, Monica W.; Li, Wankun L.

    2016-01-01

    Summary For reliable stimulus identification, sensory codes have to be robust by including redundancy to combat noise, but redundancy sacrifices coding efficiency. To address how experience affects the balance between the robustness and efficiency of sensory codes, we probed odor representations in the mouse olfactory bulb during learning over a week, using longitudinal two-photon calcium imaging. When mice learned to discriminate between two dissimilar odorants, responses of mitral cell ensembles to the two odorants gradually became less discrete, increasing the efficiency. In contrast, when mice learned to discriminate between two very similar odorants, the initially overlapping representations of the two odorants became progressively decorrelated, enhancing the robustness. Qualitatively similar changes were observed when the same odorants were experienced passively, a condition that would induce implicit perceptual learning. These results suggest that experience adjusts odor representations to balance the robustness and efficiency depending on the similarity of the experienced odorants. PMID:27667005

  13. Identifying and tracking key odorants from cattle feedlots

    NASA Astrophysics Data System (ADS)

    Trabue, Steven; Scoggin, Kenwood; McConnell, Laura; Maghirang, Ronaldo; Razote, Edna; Hatfield, Jerry

    2011-08-01

    Odors from cattle feedlots can negatively affect air quality in local communities. Our objectives were the following: 1) identify key odor-causing compounds using odor activity values (OAVs) and gas chromatography-olfactometry (GC-O) techniques; 2) compare odor threshold values from published databases; and 3) track the movement of odors from a cattle feedlot to receptor community. Odorous compounds emitted from a cattle feedlot were sampled on-site, 250 m downwind and 3.2 km downwind using both sorbent tubes and denuders. Sorbent tubes were analyzed by both GC-MS and GC-MS-O and key odorants determined using both OAV and GC-Surface Nasal Impact Frequency (SNIF) analysis, while denuders were analyzed by ion chromatography. Odorant concentrations had a diurnal pattern with peak concentrations during early morning and late evening periods. Volatile fatty acids (VFAs) were the most abundant of the major odorants. Odorants with concentrations above their odor threshold values at the feedlot included amines, VFAs, phenol compounds, and indole compounds. Key odorants at the feedlot were VFAs and phenol compounds, but their relative importance diminished with downwind distance. Indole compounds, while not the key odorants at the feedlot, increased in relative importance downwind of the feedlot. In general, the odorous compounds identified by GC-SNIF and OAV as having fecal/manure nature were similar. GC-SNIF was the more sensitive analytical technique; it identified several compounds that may have contributed to the unpleasantness of the cattle feedlot odor, but its throughput was extremely low thereby limiting its usefulness. There is a need to improve field sampling devices and odor threshold databases to enhance understanding and confidence in evaluating odors.

  14. Sweating and Body Odor

    MedlinePlus

    Sweating and body odor Overview By Mayo Clinic Staff Sweating and body odor are facts of life for ... stress. Your body has two main types of sweat glands, and they produce two very different types ...

  15. Deconstructing multisensory enhancement in detection

    PubMed Central

    Pérez-Bellido, Alexis; Pereda-Baños, Alexandre; López-Moliner, Joan; Deco, Gustavo; Soto-Faraco, Salvador

    2014-01-01

    The mechanisms responsible for the integration of sensory information from different modalities have become a topic of intense interest in psychophysics and neuroscience. Many authors now claim that early, sensory-based cross-modal convergence improves performance in detection tasks. An important strand of supporting evidence for this claim is based on statistical models such as the Pythagorean model or the probabilistic summation model. These models establish statistical benchmarks representing the best predicted performance under the assumption that there are no interactions between the two sensory paths. Following this logic, when observed detection performances surpass the predictions of these models, it is often inferred that such improvement indicates cross-modal convergence. We present a theoretical analyses scrutinizing some of these models and the statistical criteria most frequently used to infer early cross-modal interactions during detection tasks. Our current analysis shows how some common misinterpretations of these models lead to their inadequate use and, in turn, to contradictory results and misleading conclusions. To further illustrate the latter point, we introduce a model that accounts for detection performances in multimodal detection tasks but for which surpassing of the Pythagorean or probabilistic summation benchmark can be explained without resorting to early cross-modal interactions. Finally, we report three experiments that put our theoretical interpretation to the test and further propose how to adequately measure multimodal interactions in audiotactile detection tasks. PMID:25520431

  16. Predicting Odor Perceptual Similarity from Odor Structure

    PubMed Central

    Weiss, Tali; Frumin, Idan; Khan, Rehan M.; Sobel, Noam

    2013-01-01

    To understand the brain mechanisms of olfaction we must understand the rules that govern the link between odorant structure and odorant perception. Natural odors are in fact mixtures made of many molecules, and there is currently no method to look at the molecular structure of such odorant-mixtures and predict their smell. In three separate experiments, we asked 139 subjects to rate the pairwise perceptual similarity of 64 odorant-mixtures ranging in size from 4 to 43 mono-molecular components. We then tested alternative models to link odorant-mixture structure to odorant-mixture perceptual similarity. Whereas a model that considered each mono-molecular component of a mixture separately provided a poor prediction of mixture similarity, a model that represented the mixture as a single structural vector provided consistent correlations between predicted and actual perceptual similarity (r≥0.49, p<0.001). An optimized version of this model yielded a correlation of r = 0.85 (p<0.001) between predicted and actual mixture similarity. In other words, we developed an algorithm that can look at the molecular structure of two novel odorant-mixtures, and predict their ensuing perceptual similarity. That this goal was attained using a model that considers the mixtures as a single vector is consistent with a synthetic rather than analytical brain processing mechanism in olfaction. PMID:24068899

  17. Resolution enhanced sound detecting apparatus

    NASA Technical Reports Server (NTRS)

    Kendall, J. M. (Inventor)

    1979-01-01

    An apparatus is described for enhancing the resolution of a sound detector of the type which includes an acoustic mirror for focusing sound from an object onto a microphone to enable the determination of the location from which the sound arises. The enhancement apparatus includes an enclosure which surrounds the space between the mirror and microphone, and contains a gas heavier than air, such as Freon, through which sound moves slower and therefore with a shorter wavelength than in air, so that a mirror of given size has greater resolving power. An acoustically transparent front wall of the enclosure which lies forward of the mirror, can include a pair of thin sheets with pressured air between them, to form an end of the region of heavy gas into a concave shape.

  18. Acoustic enhancement for photo detecting devices

    DOEpatents

    Thundat, Thomas G; Senesac, Lawrence R; Van Neste, Charles W

    2013-02-19

    Provided are improvements to photo detecting devices and methods for enhancing the sensitivity of photo detecting devices. A photo detecting device generates an electronic signal in response to a received light pulse. An electro-mechanical acoustic resonator, electrically coupled to the photo detecting device, damps the electronic signal and increases the signal noise ratio (SNR) of the electronic signal. Increased photo detector standoff distances and sensitivities will result.

  19. Predicting odor pleasantness with an electronic nose.

    PubMed

    Haddad, Rafi; Medhanie, Abebe; Roth, Yehudah; Harel, David; Sobel, Noam

    2010-04-15

    A primary goal for artificial nose (eNose) technology is to report perceptual qualities of novel odors. Currently, however, eNoses primarily detect and discriminate between odorants they previously "learned". We tuned an eNose to human odor pleasantness estimates. We then used the eNose to predict the pleasantness of novel odorants, and tested these predictions in naïve subjects who had not participated in the tuning procedure. We found that our apparatus generated odorant pleasantness ratings with above 80% similarity to average human ratings, and with above 90% accuracy at discriminating between categorically pleasant or unpleasant odorants. Similar results were obtained in two cultures, native Israeli and native Ethiopian, without retuning of the apparatus. These findings suggest that unlike in vision and audition, in olfaction there is a systematic predictable link between stimulus structure and stimulus pleasantness. This goes in contrast to the popular notion that odorant pleasantness is completely subjective, and may provide a new method for odor screening and environmental monitoring, as well as a critical building block for digital transmission of smell.

  20. Impaired odor perception in tank cleaners.

    PubMed

    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.

  1. Predicting Odor Pleasantness with an Electronic Nose

    PubMed Central

    Haddad, Rafi; Medhanie, Abebe; Roth, Yehudah; Harel, David; Sobel, Noam

    2010-01-01

    A primary goal for artificial nose (eNose) technology is to report perceptual qualities of novel odors. Currently, however, eNoses primarily detect and discriminate between odorants they previously “learned”. We tuned an eNose to human odor pleasantness estimates. We then used the eNose to predict the pleasantness of novel odorants, and tested these predictions in naïve subjects who had not participated in the tuning procedure. We found that our apparatus generated odorant pleasantness ratings with above 80% similarity to average human ratings, and with above 90% accuracy at discriminating between categorically pleasant or unpleasant odorants. Similar results were obtained in two cultures, native Israeli and native Ethiopian, without retuning of the apparatus. These findings suggest that unlike in vision and audition, in olfaction there is a systematic predictable link between stimulus structure and stimulus pleasantness. This goes in contrast to the popular notion that odorant pleasantness is completely subjective, and may provide a new method for odor screening and environmental monitoring, as well as a critical building block for digital transmission of smell. PMID:20418961

  2. An environmental nuisance: odor concentrated and transported by dust.

    PubMed

    Bottcher, R W

    2001-03-01

    Intensive swine production generates odorous emissions which flow from the buildings housing the animals. High ventilation rates bring in fresh air, remove heat and moisture and enhance pork productivity. Numerous compounds contribute to the uniquely offensive odors from swine facilities, including fatty acids, amines, aromatics and sulfur compounds. Dust particles, which originate predominantly from feces and feed, can adsorb and concentrate odorants in swine facilities. In addition, organic particles can decay and generate odorous compounds. Odorants can exist in much higher concentrations in the dust particles than in equivalent volumes of air. Thus, inhalation of odorous dust and deposition of the dust particles in the mucus overlying the olfactory mucosa are likely responsible for some odor-related complaints by swine farm neighbors. Accurate prediction of odor transport and dispersion downwind from swine farms may require models of dust dispersion and correlation between dust and odorant levels. Unfortunately, many approaches to estimating odor impact currently incorporate filtering of air to remove particulate matter before sensing by humans or electronic sensors. Accelerated progress in understanding this and other 'real world' odor control problems will require methodological innovations that allow quantification of odor in response to air streams containing vapor and particulate phases.

  3. Graded Encoding of Food Odor Value in the Drosophila Brain

    PubMed Central

    Beshel, Jennifer

    2013-01-01

    Odors are highly evocative, yet how and where in the brain odors derive meaning remains unknown. Our analysis of the Drosophila brain extends the role of a small number of hunger-sensing neurons to include food-odor value representation. In vivo two-photon calcium imaging shows the amplitude of food odor-evoked activity in neurons expressing Drosophila neuropeptide F (dNPF), the neuropeptide Y homolog, strongly correlates with food-odor attractiveness. Hunger elevates neural and behavioral responses to food odors only, although food odors that elicit attraction in the fed state also evoke heightened dNPF activity in fed flies. Inactivation of a subset of dNPF-expressing neurons or silencing dNPF receptors abolishes food-odor attractiveness, whereas genetically enhanced dNPF activity not only increases food-odor attractiveness but promotes attraction to aversive odors. Varying the amount of presented odor produces matching graded neural and behavioral curves, which can function to predict preference between odors. We thus demonstrate a possible motivationally scaled neural “value signal” accessible from uniquely identifiable cells. PMID:24089477

  4. Resolution-enhanced entanglement detection

    NASA Astrophysics Data System (ADS)

    Gessner, Manuel; Pezzè, Luca; Smerzi, Augusto

    2017-03-01

    We formulate a general family of entanglement criteria for multipartite states on arbitrary Hilbert spaces. Fisher information criteria compare the sensitivity to unitary rotations with the variances of suitable local observables. Generalized squeezing-type criteria provide lower bounds that are less stringent but require only measurements of second moments. The enhancement due to local access to the individual subsystems is studied in detail for the case of N spin-1 /2 particles. The discussed techniques can be readily implemented in current experiments with trapped ions in Paul traps and neutral atoms in optical lattices.

  5. Testing for odor discrimination and habituation in mice.

    PubMed

    Arbuckle, Erin P; Smith, Gregory D; Gomez, Maribel C; Lugo, Joaquin N

    2015-05-05

    This video demonstrates a technique to establish the presence of a normally functioning olfactory system in a mouse. The test helps determine whether the mouse can discriminate between non-social odors and social odors, whether the mouse habituates to a repeatedly presented odor, and whether the mouse demonstrates dishabituation when presented with a novel odor. Since many social behavior tests measure the experimental animal's response to a familiar or novel mouse, false positives can be avoided by establishing that the animals can detect and discriminate between social odors. There are similar considerations in learning tests such as fear conditioning that use odor to create a novel environment or olfactory cues as an associative stimulus. Deficits in the olfactory system would impair the ability to distinguish between contexts and to form an association with an olfactory cue during fear conditioning. In the odor habitation/dishabituation test, the mouse is repeatedly presented with several odors. Each odor is presented three times for two minutes. The investigator records the sniffing time directed towards the odor as the measurement of olfactory responsiveness. A typical mouse shows a decrease in response to the odor over repeated presentations (habituation). The experimenter then presents a novel odor that elicits increased sniffing towards the new odor (dishabituation). After repeated presentation of the novel odor the animal again shows habituation. This protocol involves the presentation of water, two or more non-social odors, and two social odors. In addition to reducing experimental confounds, this test can provide information on the function of the olfactory systems of new knockout, knock-in, and conditional knockout mouse lines.

  6. Odor Emotional Quality Predicts Odor Identification.

    PubMed

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

    2015-09-01

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

  7. Characterization of odor released during handling of swine slurry: Part I. Relationship between odorants and perceived odor concentrations

    NASA Astrophysics Data System (ADS)

    Blanes-Vidal, V.; Hansen, M. N.; Adamsen, A. P. S.; Feilberg, A.; Petersen, S. O.; Jensen, B. B.

    Odor emission from livestock production systems is a major nuisance in many rural areas. This study aimed at determining the major airborne chemical compounds responsible for the unpleasant odor perceived in swine facilities during slurry handling, and at proposing predictive models of odor concentration (OC) based on the concentrations of specific odorants in the air. A multivariate data analysis strategy involving principal components analysis and multiple linear regressions was implemented to analyze the relationships between concentration of 35 gases (measured by GC/MS or gas detection tubes), and the overall OC perceived by sensory analysis. The study compiled data on the concentration of odor and odorants, measured in the headspace of 24 unstored and stored slurry samples collected from three different types of production units on 8 commercial swine farms. Among all the measured constituents, OC was found to have the highest correlation with the sulfur containing compounds (i.e. hydrogen sulfide, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide). The concentration of hydrogen sulfide accounted for 68% of the variation in OC above the stirred slurry samples. The highest concentrations of volatile organic compounds were observed for phenols and indoles, which made a significant contribution to the overall OC when the slurry was fresh. The contribution of ammonia to the OC was only significant in the absence of hydrogen sulfide. The precision of predictive models of OC based on the concentration of specific odorants in the air was satisfactory ( R2 between 0.66 and 0.89). Hence, this study suggests that monitoring of specific odor compounds released from agitated swine slurry can be used to predict the concentration of odor perceived close to the source (e.g. at storage units), allowing the assessment of odor nuisance potentials.

  8. Odor composition analysis and odor indicator selection during sewage sludge composting

    PubMed Central

    Zhu, Yan-li; Zheng, Guo-di; Gao, Ding; Chen, Tong-bin; Wu, Fang-kun; Niu, Ming-jie; Zou, Ke-hua

    2016-01-01

    ABSTRACT On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography–mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index

  9. Odor Perception by Dogs: Evaluating Two Training Approaches for Odor Learning of Sniffer Dogs.

    PubMed

    Fischer-Tenhagen, Carola; Johnen, Dorothea; Heuwieser, Wolfgang; Becker, Roland; Schallschmidt, Kristin; Nehls, Irene

    2017-06-01

    In this study, a standardized experimental set-up with various combinations of herbs as odor sources was designed. Two training approaches for sniffer dogs were compared; first, training with a pure reference odor, and second, training with a variety of odor mixtures with the target odor as a common denominator. The ability of the dogs to identify the target odor in a new context was tested. Six different herbs (basil, St. John's wort, dandelion, marjoram, parsley, ribwort) were chosen to produce reference materials in various mixtures with (positive) and without (negative) chamomile as the target odor source. The dogs were trained to show 1 of 2 different behaviors, 1 for the positive, and 1 for the negative sample as a yes/no task. Tests were double blind with one sample presented at a time. In both training approaches, dogs were able to detect chamomile as the target odor in any presented mixture with an average sensitivity of 72% and a specificity of 84%. Dogs trained with odor mixture containing the target odor had more correct indications in the transfer task. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Odorant and pheromone receptors in insects.

    PubMed

    Ha, Tal Soo; Smith, Dean P

    2009-01-01

    Since the emergence of the first living cells, survival has hinged on the ability to detect and localize chemicals in the environment. Modern animal species ranging from insects to mammals express large odorant receptor repertoires to detect the structurally diverse array of volatile molecules important for survival. Despite the essential nature of chemical detection, there is surprising diversity in the signaling mechanisms that different species use for odorant detection. In vertebrates, odorant receptors are classical G-protein coupled, seven transmembrane receptors that activate downstream effector enzymes that, in turn, produce second messengers that open ion channels. However, recent work reveals that insects have adopted different strategies to detect volatile chemicals. In Drosophila, the odorant receptors, predicted to have seven transmembrane domains, have reversed membrane topology compared to classical G-protein coupled receptors. Furthermore, insect odorant receptors appear to form odorant-gated ion channels. Pheromone detection in insects is even more unusual, utilizing soluble, extracellular receptors that undergo conformational activation. These alternate olfactory signaling strategies are discussed in terms of receptor design principles.

  11. Characterizing odors from cattle feedlots with different odor techniques

    USDA-ARS?s Scientific Manuscript database

    Odors from cattle feedlots negatively affect local communities. The purpose of this study was to characterize odors and odorants using different odor sampling techniques. Odors were characterized with field olfactometers (Nasal Ranger®), sensory techniques (GC-O) and analytical techniques (sorbent t...

  12. Nanoassembled thin film gas sensors. III. Sensitive detection of amine odors using TiO2/poly(acrylic acid) ultrathin film quartz crystal microbalance sensors.

    PubMed

    Lee, Seung-Woo; Takahara, Naoki; Korposh, Sergiy; Yang, Do-Hyeon; Toko, Kiyoshi; Kunitake, Toyoki

    2010-03-15

    Quartz crystal microbalance (QCM) gas sensors based on the alternate adsorption of TiO(2) and polyacrilic acid (PAA) were developed for the sensitive detection of amine odors. Individual TiO(2) gel layers could be regularly assembled with a thickness of approximately 0.3 nm by the gas-phase surface sol-gel process (GSSG). The thickness of the poly(acrylic acid) (PAA) layer is dependent on its molecular weight, showing different thicknesses of approximately 0.4 nm for PAA(25) (Mw 250,000) and 0.6-0.8 nm for PAA(400) (Mw 4,000,000). The QCM sensors showed a linear response to ammonia in the concentration range 0.3-15 ppm, depending on the deposition cycle of the alternate TiO(2)/PAA layer. The ammonia binding is based on the acid-base interaction to the free carboxylic acid groups of PAA and the limit of detection (LOD) of the 20-cycle TiO(2)/PAA(400) film was estimated to be 0.1 ppm when exposed to ammonia. The sensor response was very fast and stable in a wide relative humidity (rH) range of 30-70%, showing almost the same frequency changes at a given concentration of ammonia. Sensitivity to n-butylamine and ammonia was higher than to pyridine, which is owing to the difference of molecular weight and basicity of the amine analytes. The alternate TiO(2)/PAA(400) films have a highly effective ability to capture amine odors, and the ambient ammonia concentration of 15 ppm could be condensed up to approximately 20,000 ppm inside the films.

  13. ß-Adrenoceptor Activation Enhances L-Type Calcium Channel Currents in Anterior Piriform Cortex Pyramidal Cells of Neonatal Mice: Implication for Odor Learning

    ERIC Educational Resources Information Center

    Ghosh, Abhinaba; Mukherjee, Bandhan; Chen, Xihua; Yuan, Qi

    2017-01-01

    Early odor preference learning occurs in one-week-old rodents when a novel odor is paired with a tactile stimulation mimicking maternal care. ß-Adrenoceptors and L-type calcium channels (LTCCs) in the anterior piriform cortex (aPC) are critically involved in this learning. However, whether ß-adrenoceptors interact directly with LTCCs in aPC…

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

    PubMed Central

    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

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

    PubMed

    Liu, Feng; Liu, Nannan

    2015-11-02

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

  16. Impairment of odor recognition and odor-induced emotions in type 1 myotonic dystrophy.

    PubMed

    Masaoka, Yuri; Kawamura, Mitsuru; Takeda, Akitoshi; Kobayakawa, Mutsutaka; Kuroda, Takeshi; Kasai, Hideyo; Tsuruya, Natsuko; Futamura, Akinori; Homma, Ikuo

    2011-10-10

    This study aimed to test whether type 1 myotonic dystrophy (DM1) patients who have a lower sensitivity to emotional facial expressions have an abnormal olfactory threshold or recognition level. We measured DM1 patients' performances in an olfactory acuity test and respiratory responses to odor stimuli, and compared their results to those of healthy controls (HCs). We found that DM1 patients exhibited a significantly reduced odor detection sensitivity compared with that in HCs. Three out of seven DM1 patients exhibited impaired odor recognition, while other four patients had significantly lower odor recognition compared with HCs. Even when patients were able to identify the type of odor, the levels of pleasantness they reported experiencing in response to a pleasant odor were significantly lower than those reported by HCs. These subjective data in DM1 patients were reflected in the respiratory responses (RRs). In the current study, one patient showed impairments in both odor detection and odor recognition. Abnormalities of the olfactory limbic areas might have been the cause of the olfactory impairments observed in the DM1 patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. The mouse eugenol odorant receptor: structural and functional plasticity of a broadly tuned odorant binding pocket.

    PubMed

    Baud, Olivia; Etter, Sylvain; Spreafico, Morena; Bordoli, Lorenza; Schwede, Torsten; Vogel, Horst; Pick, Horst

    2011-02-08

    Molecular interactions of odorants with their olfactory receptors (ORs) are of central importance for the ability of the mammalian olfactory system to detect and discriminate a vast variety of odors with a limited set of receptors. How a particular OR binds and distinguishes different odorant molecules remains largely unknown on a structural basis. Here we investigated this question for the mouse eugenol receptor (mOR-EG). By screening a large odorant library, we discovered a wide range of chemical structures activating the receptor in heterologous mammalian cells. Potent agonists comprise (i) benzene, (ii) cyclohexane, or (iii) polycyclic structures substituted with alcohol, aldehyde, keto, ether, or esterified carboxylic groups. To detect those amino acids within the receptor that are in contact with a particular bound odorant molecule, we investigated how distinct mOR-EG point mutants were activated by the different odorant agonists found for the wild-type receptor. We identified 11 amino acids as a part of the receptor's ligand binding pocket. Molecular modeling predicted 10 of these residues in transmembrane helices TM3-TM6 and one in the extracellular loop between TM2 and TM3. These amino acids participate in odorant binding with variable importance depending on the type of odorant, revealing functional "fingerprints" of ligand-receptor interactions.

  18. Ventilation/odor study, field study. Final report, Volume I

    SciTech Connect

    Duffee, R.A.; Jann, P.

    1981-04-01

    The results are presented of field investigations in schools, hospitals, and an office building on the relation between ventilation rate and odor within the buildings. The primary objective of the study was to determine: the reduction in ventilation rates that could be achieved in public buildings without causing adverse effects on odor; the sources of odor in public buildings; and the identity of the odorants. The variables of particular interest include: type of odor, occupant density, odorant identity and concentration, differences in impressions between occupants adapted to prevailing conditions and visitors, and the influence of temperature and humidity on both the generation and perception of common contaminants. Sensory odor measurements, chemical measurements, fresh air ventilation measurements, and acceptability evaluations via questionnaires were made. Sensory odor levels were found to be quite low in most buildings tested. A three-to-five-fold reduction in the fresh air ventilation in schools, hospitals, and office buildings can be achieved without significantly affecting perceived odor intensities or detectability. Tobacco smoking was found to be the most significant, pervasive contributor to interior odor level. Total hydrocarbon content of indoor air varies directly with ventilation rates; odor, however, does not. The complete set of reduced data are contained in Volume II. (LEW)

  19. Human fine body hair enhances ectoparasite detection.

    PubMed

    Dean, Isabelle; Siva-Jothy, Michael T

    2012-06-23

    Although we are relatively naked in comparison with other primates, the human body is covered in a layer of fine hair (vellus and terminal hair) at a relatively high follicular density. There are relatively few explanations for the evolutionary maintenance of this type of human hair. Here, we experimentally test the hypothesis that human fine body hair plays a defensive function against ectoparasites (bed bugs). Our results show that fine body hair enhances the detection of ectoparasites through the combined effects of (i) increasing the parasite's search time and (ii) enhancing its detection.

  20. Odor Landscapes in Turbulent Environments

    NASA Astrophysics Data System (ADS)

    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.

  1. Feasibility Study of Odor Biosensor Using Dissociate Neuronal Culture with Gene Expression of Ionotropic Odorant Receptors

    NASA Astrophysics Data System (ADS)

    Tanada, Norio; Sakurai, Takeshi; Mitsuno, Hidefumi; Bakkum, Douglas; Kanzaki, Ryohei; Takahashi, Hirokazu

    We propose a highly sensitive and real-time odor biosensor by expressing ionotropic odorant receptors of insects into dissociated cultures of neurons of rats. The odorant-gated ion channel structure of insect odorant receptor is expected to allow easy functional expression into cells. The neuronal dissociated cultures of rats have two significant advantages: a long lifetime comparable to rats, i.e., a few years; and amplification ability from weak ionic currents of odorant receptors into easily detectable action potentials of neurons. In the present work, in order to show the feasibility of the proposed sensor, we attempt to express the pheromone receptors of silkmoth, Bombyx mori, into cultured neurons of rats. We demonstrate that 10% of neuronal cells transfected using Lipofectamine successfully expressed pheromone receptors, and that these cells showed significant increase of calcium signals by 50% at the presentation of pheromone.

  2. Detectivity enhancement in THz electrooptical sampling

    SciTech Connect

    Ahmed, Saima; Savolainen, Janne; Hamm, Peter

    2014-01-15

    We demonstrate and discuss a simple scheme that significantly enhances the detectivity of THz electro-optical sampling by introducing a sequence of Brewster windows that increases the ellipticity of the probe beam. By varying the window material or the number of Brewster windows, the enhancement factor can be adjusted; we demonstrate an enhancement factor of ≈20 with four ZnSe Brewster windows. The scheme is particularly useful when very small THz fields are to be measured in connection with low-repetition rate amplified Ti:S laser systems.

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

    PubMed Central

    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 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 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 odor 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 individual’s own body odor

  4. Molecular determinants of odorant receptor function in insects.

    PubMed

    Ray, Anandasankar; van Naters, Wynand Goes; Carlson, John R

    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.

  5. Odor investigation of a Portland cement plant

    SciTech Connect

    Pleus, R.C.

    1998-12-31

    The main concern expressed by Smithville residents is whether the odors they were smelling during odor events were due to chemicals that could cause adverse health effects. Odors were allegedly emanating from the town`s Portland cement plant. The purpose of the study was to measure the ambient air for 20 reduced sulfur, 50 volatile organic compounds, and air samples for olfactometric analysis. Carbonyl sulfide was found to be at a concentration that could create a sense of odor and irritation. This sense of irritation may be due to a physiological response by the central nervous system, and is not associated with any known adverse effects. This physiological response could account for some or all of the irritation experienced by residents during odor events. Comparing chemical concentrations that were detected in air samples to standard and recognized guidelines for acceptable exposure, all measured concentrations were found to be well below the acceptable criteria. From these data the authors conclude that no acute or chronic adverse health effects are expected at the concentrations of the chemicals detected downwind of the cement plant, either routinely or during odor events.

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

    NASA Astrophysics Data System (ADS)

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

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

  7. Enhanced detection of glycoproteins in polyacrylamide gels.

    PubMed

    Muñoz, G; Marshall, S; Cabrera, M; Horvat, A

    1988-05-01

    A highly sensitive and simple method to enhance detection of glycoproteins resolved by either one- or two-dimensional polyacrylamide gel electrophoresis is described. The method is a modification of the procedure described by D. Fargeaud et al. (D. Fargeaud, J. C. Benoit, F. Kato, and G. Chappuis (1984) Arch. Virol. 80, 69-82) that uses concanavalin A conjugated with fluorescein isothyocyanate to detect the carbohydrate moiety of glycoproteins. Briefly, the electrophoresed gel is exposed to the fluorescent lectin, thoroughly washed, and sequentially transferred to 50% methanol in deionized water and to absolute methanol. The result is an abrupt dehydration of the gel which turns evenly white and stiff. At least a twofold enhancement of fluorescence is obtained as detected by exposing the treated gel to an appropriate uv source. The sensitivity of the procedure allows us to detect purified immunoglobulin molecules by their carbohydrate content in the range of 0.2 microgram of total protein. The specificity of the detection is demonstrated by a comparison with the corresponding polypeptide profile obtained by silver nitrate staining of the gel.

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

    PubMed Central

    Takahashi, Lorey K.

    2014-01-01

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

  9. Enhanced Propagating Surface Plasmon Signal Detection

    SciTech Connect

    Gong, Y.; Joly, Alan G.; El-Khoury, Patrick Z.; Hess, Wayne P.

    2016-12-21

    Overcoming the dissipative nature of propagating surface plasmons (PSPs) is pre-requisite to realizing functional plasmonic circuitry, in which large bandwidth signals can be manipulated over length scales far-below the diffraction limit of light. To this end, we report on a novel PSP enhanced signal detection technique achieved in an all-metallic substrate. We take advantage of two strategically spatio-temporally separated phase-locked femtosecond laser pulses, incident onto lithographically patterned PSP coupling structures. We follow PSP propagation with joint femtosecond temporal and nanometer spatial resolution in a time-resolved non-linear photoemission electron microscopy scheme. Initially, a PSP signal wave packet is launched from a hole etched into the silver surface from where it propagates through an open trench structure and is decoded through the use of a timed probe pulse. FDTD calculations demonstrate that PSP signal waves may traverse open trenches in excess of 10 microns in diameter, thereby allowing remote detection even through vacuum regions. This arrangement results in a 10X enhancement in photoemission relative to readout from the bare metal surface. The enhancement is attributed to an all-optical homodyne detection technique that mixes signal and reference PSP waves in a non-linear scheme. Larger readout trenches achieve higher readout levels, however reduced transmission through the trench limits the trench size to 6 microns for maximum readout levels. However, the use of an array of trenches increases the maximum enhancement to near 30X. The attainable enhancement factor may be harnessed to achieve extended coherent PSP propagation in ultrafast plasmonic circuitry.

  10. Homodyne detection for the enhancement of antibunching

    SciTech Connect

    Vyas, R.; Wang, C.; Singh, S.

    1996-09-01

    We propose a scheme based on homodyne detection for enhancing antibunching in second-harmonic generation and multiatom optical bistability. We show that depending on the reflectivity of the beam splitter, relative field strengths, and relative phase it is possible to achieve perfect antibunching in the superposed field. We also discuss other nonclassical effects exhibited by the superposed field and present curves to illustrate the behavior. {copyright} {ital 1996 The American Physical Society.}

  11. Odorant Receptor Sensitivity Modulation in Drosophila.

    PubMed

    Guo, Hao; Kunwar, Kishor; Smith, Dean

    2017-09-27

    The ability to modulate sensitivity in sensory systems is essential for useful information to be extracted from fluctuating stimuli in a wide range of background conditions. The mechanisms underlying sensitivity regulation in insect primary olfactory neurons are poorly understood. Here we reveal that dephosphorylation of Orco(S289) that occurs upon prolonged odor exposure is a mechanism underlying reduction in odorant sensitivity in Drosophila primary olfactory neurons in both sexes. Orco(S289A) mutants, unable to phosphorylate this position, have low intrinsic odorant sensitivity that is independent of altered expression or localization. A phosphomimetic allele, Orco(S289D) , has enhanced odorant sensitivity compared with wild-type controls. To explore the functional ramifications of this phosphorylation in vivo, we generated phospho-specific antiserum to Orco(S289) and show that phosphorylation at this residue is dynamically regulated by odorant exposure with concomitant modulation of odorant sensitivity. Orco(S289) is phosphorylated in the sensitized state, and odorant exposure triggers dephosphorylation and desensitization without altering receptor localization. We further show that dephosphorylation of Orco(S289) is triggered by neuronal activity, and not conformational changes in the receptor occurring upon ligand binding. Mutant flies unable to regulate Orco function through phosphorylation at S289 are defective for odor-guided behavior. These findings provide insight into the mechanisms underlying regulation of insect odorant receptors in vivoSIGNIFICANCE STATEMENT We have uncovered a mechanism underlying olfactory receptor sensitivity regulation in Drosophila The phosphorylation state of Orco (S289) is altered in an odorant-dependent manner and changes in phosphorylation affect receptor sensitivity without changing subcellular localization. We show that neuronal activity triggers the phosphorylation changes and that this phenomenon is important for odorant

  12. Enhanced photoacoustic detection using photonic crystal substrate

    SciTech Connect

    Zhao, Yunfei; Liu, Kaiyang; McClelland, John; Lu, Meng

    2014-04-21

    This paper demonstrates the enhanced photoacoustic sensing of surface-bound light absorbing molecules and metal nanoparticles using a one-dimensional photonic crystal (PC) substrate. The PC structure functions as an optical resonator at the wavelength where the analyte absorption is strong. The optical resonance of the PC sensor provides an intensified evanescent field with respect to the excitation light source and results in enhanced optical absorption by surface-immobilized samples. For the analysis of a light absorbing dye deposited on the PC surface, the intensity of photoacoustic signal was enhanced by more than 10-fold in comparison to an un-patterned acrylic substrate. The technique was also applied to detect gold nanorods and exhibited more than 40 times stronger photoacoustic signals. The demonstrated approach represents a potential path towards single molecule absorption spectroscopy with greater performance and inexpensive instrumentation.

  13. Prediction of odor from pig production based on chemical odorants.

    PubMed

    Hansen, Michael J; Adamsen, Anders Peter S; Pedersen, Poul; Feilberg, Anders

    2012-01-01

    The present work was performed to investigate the use of odorant measurements for prediction of odor concentration in facilities with growing-finishing pigs and to analyze the odorant composition in facilities with different floor and ventilation systems. Air was sampled in Nalophan bags, odor concentrations were measured by dilution-to-threshold olfactometry, and concentrations of odorants were measured by proton-transfer-reaction mass spectrometry (PTR-MS). Olfactometry and chemical analyses were synchronized to take place at identical time intervals after sampling. A principal component analysis revealed that different facilities for growing-finishing pigs can be distinguished based on the odorants. Pit ventilation comprising a small amount of the total ventilation air (10-20%) in facilities with both room and pit ventilation can be used to concentrate odorants, whereas the room ventilation contains lower concentrations of most odorants. A partial least squares regression model demonstrated that prediction of the odor concentration based on odorants measured by PTR-MS is feasible. Hydrogen sulfide, methanethiol, trimethylamine, and 4-methylphenol were identified as the compounds having the largest influence on the prediction of odor concentration, whereas carboxylic acids had no significant influence. In conclusion, chemical measurement of odorants by PTR-MS is an alternative for expressing the odor concentration in facilities with growing-finishing pigs that can be used to increase the understanding of odor from different types of facilities and improve the development of odor reduction technologies.

  14. Odorant-Binding Protein: Localization to Nasal Glands and Secretions

    NASA Astrophysics Data System (ADS)

    Pevsner, Jonathan; Sklar, Pamela B.; Snyder, Solomon H.

    1986-07-01

    An odorant-binding protein (OBP) was isolated from bovine olfactory and respiratory mucosa. We have produced polyclonal antisera to this protein and report its immunohistochemical localization to mucus-secreting glands of the olfactory and respiratory mucosa. Although OBP was originally isolated as a pyrazine binding protein, both rat and bovine OBP also bind the odorants [3H]methyldihydrojasmonate and 3,7-dimethyl-octan-1-ol as well as 2-isobutyl-3-[3H]methoxypyrazine. We detect substantial odorant-binding activity attributable to OBP in secreted rat nasal mucus and tears but not in saliva, suggesting a role for OBP in transporting or concentrating odorants.

  15. Analysis of Key Odorants in Roasted Green Tea

    NASA Astrophysics Data System (ADS)

    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.

  16. An enhanced Monte Carlo outlier detection method.

    PubMed

    Zhang, Liangxiao; Li, Peiwu; Mao, Jin; Ma, Fei; Ding, Xiaoxia; Zhang, Qi

    2015-09-30

    Outlier detection is crucial in building a highly predictive model. In this study, we proposed an enhanced Monte Carlo outlier detection method by establishing cross-prediction models based on determinate normal samples and analyzing the distribution of prediction errors individually for dubious samples. One simulated and three real datasets were used to illustrate and validate the performance of our method, and the results indicated that this method outperformed Monte Carlo outlier detection in outlier diagnosis. After these outliers were removed, the value of validation by Kovats retention indices and the root mean square error of prediction decreased from 3.195 to 1.655, and the average cross-validation prediction error decreased from 2.0341 to 1.2780. This method helps establish a good model by eliminating outliers. © 2015 Wiley Periodicals, Inc.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Odor Control Technology

    ERIC Educational Resources Information Center

    Turk, Amos; And Others

    1972-01-01

    Dispersion, chemical oxidation, and masking are reviewed as techniques primarily employed for odor control. Devices and systems, costs, and problems of measurement are considered in light of environmental agencies' efforts to curb smelly emissions. (BL)

  19. Odor Control Technology

    ERIC Educational Resources Information Center

    Turk, Amos; And Others

    1972-01-01

    Dispersion, chemical oxidation, and masking are reviewed as techniques primarily employed for odor control. Devices and systems, costs, and problems of measurement are considered in light of environmental agencies' efforts to curb smelly emissions. (BL)

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

    PubMed

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

    2010-06-09

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

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

    PubMed Central

    Rice, Somchai; Koziel, Jacek A.

    2015-01-01

    Volatile compounds emitted into headspace from illicit street drugs have been identified, but until now odor impact of these compounds have not been reported. Data in support of identification of these compounds and their odor impact to human nose are presented. In addition, data is reported on odor detection thresholds for canines highlighting differences with human ODTs and needs to address gaps in knowledge. New data presented here include: (1) compound identification, (2) gas chromatography (GC) column retention times, (3) mass spectral data, (4) odor descriptors from 2 databases, (5) human odor detection thresholds from 2 databases, (6) calculated odor activity values, and (7) subsequent ranking of compounds by concentration and ranking of compounds by odor impact (reported as calculated odor activity values). For further interpretation and discussion, see Rice and Koziel [1] and Rice [2]. PMID:26958621

  2. Now you like me, now you don't: impact of labels on odor perception.

    PubMed

    Manescu, Simona; Frasnelli, Johannes; Lepore, Franco; Djordjevic, Jelena

    2014-02-01

    Past research has shown that odor perception can be affected by how we label odors. The aim of this study was to expand on previous work by investigating the impact of labels on edibility, pleasantness, and intensity ratings as well as on reaction times when detecting labeled odors. We tested 50 subjects. Five odorants were administered, each with a positive and a negative label. Participants had to detect odors as fast as possible and then rate their edibility, pleasantness, and intensity. Because of a lack of fit, only 4 of the initial 5 odorants were analyzed. All odorants presented with positive labels were rated as being more edible than when they were presented with negative labels. Specifically, the effect was also seen for the 2 nonfood odorants suggesting an unbiased effect. All odorants presented with positive labels were rated as being more pleasant than when they were presented with negative labels. Labels also modulated intensity ratings and reaction times for some odors. In summary, odor labels affect pleasantness ratings and edibility perception. Although labels appear to also influence intensity ratings and reaction times, this seems to be a more complex relationship that could be modulated by additional factors such as odor valence, label fit, and possibly the edibility attributed to an odor or a label.

  3. Projection image enhancement for explosive detection systems

    NASA Astrophysics Data System (ADS)

    Yildiz, Yesna O.; Abraham, Douglas Q.; Agaian, Sos; Panetta, Karen

    2008-02-01

    Automated Explosive Detection Systems (EDS) utilizing Computed Tomography (CT) generate a series of 2-D projections from a series of X-ray scans OF luggage under inspection. 3-D volumetric images can also be generated from the collected data set. Extensive data manipulation of the 2-D and 3-D image sets for detecting the presence of explosives is done automatically by EDS. The results are then forwarded to human screeners for final review. The final determination as to whether the luggage contains an explosive and needs to be searched manually is performed by trained TSA (Transportation Security Administration) screeners following an approved TSA protocol. The TSA protocol has the screeners visually inspect the resulting images and the renderings from the EDS to determine if the luggage is suspicious and consequently should be searched manually. Enhancing those projection images delivers a higher quality screening, reduces screening time and also reduces the amount of luggage that needs to be manually searched otherwise. This paper presents a novel edge detection algorithm that is geared towards, though not exclusive to, automated explosive detection systems. The goal of these enhancements is to provide a higher quality screening process while reducing the overall screening time and luggage search rates. Accurately determining the location of edge pixels within 2-D signals, often the first step in segmentation and recognition systems indicates the boundary between overlapping objects in a luggage. Most of the edge detection algorithms such as Canny, Prewitt, Roberts, Sobel, and Laplacian methods are based on the first and second derivatives/difference operators. These operators detect the discontinuities in the differences of pixels. These approaches are sensitive to the presence of noise and could produce false edges in noisy images. Including large scale filters, may avoid errors generated by noise, but often simultaneously eliminating the finer edge details as

  4. Anomaly detection enhanced classification in computer intrusion detection

    SciTech Connect

    Fugate, M. L.; Gattiker, J. R.

    2002-01-01

    This report describes work with the goal of enhancing capabilities in computer intrusion detection. The work builds upon a study of classification performance, that compared various methods of classifying information derived from computer network packets into attack versus normal categories, based on a labeled training dataset. This previous work validates our classification methods, and clears the ground for studying whether and how anomaly detection can be used to enhance this performance, The DARPA project that initiated the dataset used here concluded that anomaly detection should be examined to boost the performance of machine learning in the computer intrusion detection task. This report investigates the data set for aspects that will be valuable for anomaly detection application, and supports these results with models constructed from the data. In this report, the term anomaly detection means learning a model from unlabeled data, and using this to make some inference about future data. Our data is a feature vector derived from network packets: an 'example' or 'sample'. On the other hand, classification means building a model from labeled data, and using that model to classify unlabeled (future) examples. There is some precedent in the literature for combining these methods. One approach is to stage the two techniques, using anomaly detection to segment data into two sets for classification. An interpretation of this is a method to combat nonstationarity in the data. In our previous work, we demonstrated that the data has substantial temporal nonstationarity. With classification methods that can be thought of as learning a decision surface between two statistical distributions, performance is expected to degrade significantly when classifying examples that are from regions not well represented in the training set. Anomaly detection can be seen as a problem of learning the density (landscape) or the support (boundary) of a statistical distribution so that

  5. An Odor Timer in Milk? Synchrony in the Odor of Milk Effluvium and Neonatal Chemosensation in the Mouse

    PubMed Central

    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

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

    PubMed

    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.

  7. Determination of urine-derived odorous compounds in a source separation sanitation system.

    PubMed

    Liu, Bianxia; Giannis, Apostolos; Chen, Ailu; Zhang, Jiefeng; Chang, Victor W C; Wang, Jing-Yuan

    2017-02-01

    Source separation sanitation systems have attracted more and more attention recently. However, separate urine collection and treatment could induce odor issues, especially in large scale application. In order to avoid such issues, it is necessary to monitor the odor related compounds that might be generated during urine storage. This study investigated the odorous compounds that emitted from source-separated human urine under different hydrolysis conditions. Batch experiments were conducted to investigate the effect of temperature, stale/fresh urine ratio and urine dilution on odor emissions. It was found that ammonia, dimethyl disulfide, allyl methyl sulfide and 4-heptanone were the main odorous compounds generated from human urine, with headspace concentrations hundreds of times higher than their respective odor thresholds. Furthermore, the high temperature accelerated urine hydrolysis and liquid-gas mass transfer, resulting a remarkable increase of odor emissions from the urine solution. The addition of stale urine enhanced urine hydrolysis and expedited odor emissions. On the contrary, diluted urine emitted less odorous compounds ascribed to reduced concentrations of odorant precursors. In addition, this study quantified the odor emissions and revealed the constraints of urine source separation in real-world applications. To address the odor issue, several control strategies are recommended for odor mitigation or elimination from an engineering perspective. Copyright © 2016. Published by Elsevier B.V.

  8. The influence of odor type on the discrimination and identification of odorants in multicomponent odor mixtures.

    PubMed

    Livermore, A; Laing, D G

    1998-11-15

    Using a limited set of odorants, previous studies have indicated that the ability of humans to discriminate and identify the components of olfactory mixtures is limited to approximately four. However, the ability to generalize these results may have been limited by specific neural or cognitive interactions among the particular odorants used. In the present experiment, 41 subjects examined the influence of odor type (different individual odorants), from two very different odor sets, on the perception of the components of complex mixtures. One set contained odors that were selected by an expert panel to blend well in mixtures (good blenders), whereas the other contained odors that blended poorly in mixtures (poor blenders). The stimuli were common, dissimilar odorants of equivalent, moderate intensity, each of which was a single chemical. A computer-controlled air dilution olfactometer delivered a single odorant or a mixture containing up to eight odorants. Although the poor blenders were more easily discriminated, this superiority was displayed within a narrow range, and the ability of subjects to identify mixture components with either odor set was limited to approximately four. The results indicate that, whereas odor type can alter which odorants will be perceived in a mixture, the limited capacity to discriminate mixture components is independent of the type of odorants. These findings are discussed in terms of their implications for olfactory coding.

  9. Attractiveness of fruit and flower odorants detected by olfactory receptor neurons in the fruit chafer Pachnoda marginata.

    PubMed

    Larsson, Mattias C; Stensmyr, Marcus C; Bice, Shannon B; Hansson, Bill S

    2003-05-01

    We studied the attraction of the African fruit chafer Pachnoda marginata Drury (Coleoptera: Scarabaeidae) to banana and 34 synthetic plant compounds previously shown to be detected by P. marginata olfactory receptor neurons. The behavioral studies were carried out in a two-choice olfactometer, where the attraction of beetles to lures and controls was monitored in 30-min intervals during whole days. Monitoring of the attraction over time gave additional information when comparing relative attractiveness of different compounds. Seventeen of the test compounds, primarily phenylic compounds, fruit esters, isovaleric acid, acetoin, and some floral or fruit terpenes, were attractive to P. marginata. Compounds showing no attractiveness included green leaf volatiles, lactones. and several alcohols, but also phenylic compounds and esters. One case of blend synergism was demonstrated, as well as some examples of sexual dimorphism in attraction. The significance of certain compounds and receptor neurons for olfactory-guided behavior of phytophagous scarabs is discussed.

  10. Odor detection thresholds and enantiomeric distributions of several 4-alkyl substituted gamma-lactones in Australian red wine.

    PubMed

    Cooke Née Brown, Rachel C; van Leeuwen, Katryna A; Capone, Dimitra L; Gawel, Richard; Elsey, Gordon M; Sefton, Mark A

    2009-03-25

    The individual enantiomers of gamma-octalactone (1), gamma-nonalactone (2), gamma-decalactone (3) and gamma-dodecalactone (4) have been synthesized. The (R) series of enantiomers was prepared from L-glutamic acid by a strategy involving deamination and reduction to (S)-5-oxo-2-tetrahydrofurancarboxaldehyde (S)-7. The different length side chains were introduced by a series of Wittig reactions, varying in the choice of phosphorane used. Hydrogenation then gave the final gamma-lactones 1-4. The (S) series of enantiomers was prepared in an analogous fashion beginning with d-glutamic acid. Aroma detection thresholds for all eight enantiomers were determined in a "bag in a box" dry red wine by the application of ASTM method E 679, employing a panel of 25 members. The lowest threshold determined was 8 microg/L for (R)-dodecalactone (4) while the highest threshold was 285 microg/L for (R)-nonalactone (2). With the exception of gamma-decalactone (3) there were statistically significant differences (at the 5% level) in aroma detection thresholds between the two enantiomers of the same lactone. A stable isotope method developed for quantification of the lactones 1-4 has been extended for use with chiral phase GC (Rt-betaDEXcst capillary column) allowing quantification of the individual enantiomers. The enantiomeric distribution of gamma-octalactone (1) and gamma-nonalactone (2) in seven botrytized wines and of 2 in a total of 34 red wines were thus determined; with few exceptions, the (R) enantiomer of gamma-nonalactone (2) was found to be more prevalent than its (S) counterpart in the dry red and botrytized white wines analyzed. The same was true for gamma-octalactone (1) in the botrytized white wines.

  11. Enhanced endoscopic detection of early colon cancer

    NASA Astrophysics Data System (ADS)

    Balachandar, Gowra; Trowers, Eugene A.

    1999-06-01

    Enhanced endoscopic detection of small flat adenomas is becoming increasingly important as they have a reported 14 percent incidence of dysplasia when compared with 5% incidence in polypod adenomas of the same size. These lesions even when invasive do not show up against the translucent surrounding mucosa making endoscopic detection difficult. Dye spraying with indigo carmine makes their morphology clear, with well-circumscribed borders. Dye spraying and magnifying endoscopes can be used to observe pit patterns on the surface of the bowel. Combining dye spraying and high-resolution video endoscopy demonstrates well the colorectal epithelial surface. Scanning immersion video endoscopy visualizes the epithelial surface of the colorectal mucosa by high-resolution endoscopy after filling the lumen with water. Endoscopic ultrasound can be used to see if the lesion is intramucosal or not and assess the depth of invasion if malignancy is presented. Laser induced fluorescence spectroscopy has the potential to detect colonic dysplasia in vivo. Combining such technologies with conventional colonoscopy can help in the surveillance of large areas of colonic mucosa for the presence of dysplasia. Guided biopsy can replace random biopsy based on information provided at the time of colonoscopic examination.

  12. Retronasal perception of odors.

    PubMed

    Hummel, Thomas

    2008-06-01

    Odors often produce different sensations when presented in front of the nose or intraorally, when eaten. It is a long-standing question whether these differences in sensations are due, for example, to the additional mechanical sensations elicited by the food in the mouth or additional odor release during mastication. To study this phenomenon in detail, a stimulation technique has been developed that allows controlled ortho- or retronasal presentation of odorous stimuli. Results from psychophysical, electrophysiological, and imaging studies suggest that there are clear differences in the perception of ortho- and retronasal stimuli. This 'duality of the sense of smell' is also observed in a clinical context where some patients exhibit good retronasal olfactory function with little or no orthonasal function left, and vice versa. The differences between ortho- and retronasal perception of odors are thought to be, at least partly, due to absorption of odors to the olfactory epithelium, which appears to differ in relation to the direction of the airflow across the olfactory epithelium.

  13. The Chilean Recluse Spider (Araneae: Sicariidae) Displays Behavioral Responses to Conspecific Odors, but Not to Several General Odorants.

    PubMed

    Calbiague, Victor Manuel; Olivares, Jesus; Olivares, Erick; Schmachtenberg, Oliver

    2017-09-01

    Spiders of the family Sicariidae pose a serious threat to affected populations, and Loxosceles laeta (Nicolet) is considered the most venomous species. Development of nontoxic olfaction-based spider repellents or traps is hindered by a current lack of knowledge regarding olfactory system function in arachnids. In the present study, general plant odorants and conspecific odors were tested for behavioral responses in L. laeta. Although general odorants triggered neither attraction nor aversion, conspecific odor of the opposite sex caused aversion in females, and attraction in males. These results support the presence of a specific olfactory system for the detection of conspecifics in L. laeta, but suggest the absence of a broadly tuned system for general odorant detection in this species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Detection of the Odor Signature of Ovarian Cancer using DNA-Decorated Carbon Nanotube Field Effect Transistor Arrays

    NASA Astrophysics Data System (ADS)

    Kehayias, Christopher; Kybert, Nicholas; Yodh, Jeremy; Johnson, A. T. Charlie

    Carbon nanotubes are low-dimensional materials that exhibit remarkable chemical and bio-sensing properties and have excellent compatibility with electronic systems. Here, we present a study that uses an electronic olfaction system based on a large array of DNA-carbon nanotube field effect transistors vapor sensors to analyze the VOCs of blood plasma samples collected from patients with malignant ovarian cancer, patients with benign ovarian lesions, and age-matched healthy subjects. Initial investigations involved coating each CNT sensor with single-stranded DNA of a particular base sequence. 10 distinct DNA oligomers were used to functionalize the carbon nanotube field effect transistors, providing a 10-dimensional sensor array output response. Upon performing a statistical analysis of the 10-dimensional sensor array responses, we showed that blood samples from patients with malignant cancer can be reliably differentiated from those of healthy control subjects with a p-value of 3 x 10-5. The results provide preliminary evidence that the blood of ovarian cancer patients contains a discernable volatile chemical signature that can be detected using DNA-CNT nanoelectronic vapor sensors, a first step towards a minimally invasive electronic diagnostic technology for ovarian cancer.

  15. Heterobimetallic Ru(II)-Eu(III) complex as chemodosimeter for selective biogenic amine odorants detection in fish sample.

    PubMed

    Chow, Cheuk-Fai; Kong, Hoi-Kuan; Leung, Shu-Wai; Chiu, Brenda K W; Koo, Chi-Kin; Lei, Elva N Y; Lam, Michael H W; Wong, Wing-Tak; Wong, Wai-Yeung

    2011-01-01

    Gaseous biogenic amines such as putrescine, spermidine, aniline, and trimethylamine are important biomolecules that play many crucial roles in metabolism and medical diagnostics. A chemodosimetric detection assay has been developed for those gaseous amines by Ru(II)-Eu(III) heterobimetallic complexes, K{[Ru(II)((t)Bubpy)(CN)(4)](2)Eu(III)(H(2)O)(4)} (where (t)Bubpy = 4,4'-di-tert-butyl-2,2'-bipyridine). Synthesis, X-ray crystal characterization, and spectroscopic properties of this Ru(II)-Eu(III) heterobimetallic complex were reported. Binding properties of the Ru(II)-Eu(III) complex with common gases revealed that this complex is very selective to gaseous amine molecules. Sensitivity of this complex toward the amines was found as ∼log k() = 4.5-4.8. Real time monitoring of gaseous biogenic amines was applied to real fish samples (Atlantic mackerel) by studying the spectrofluorimetric responses of the Ru(II)-Eu(III) complex toward different biogenic amine concentration. GC/MS studies were also used as a reference for the studies. A linear spectrofluorimetric response was found toward biogenic amine concentration in real fish samples. This complex was found to respond specifically to those biogenic amines down to 10 ppb.

  16. Selectivity of odorant receptors in insects

    PubMed Central

    Bohbot, Jonathan D.; Dickens, Joseph C.

    2012-01-01

    Insect olfactory receptors (ORs) detect chemicals, shape neuronal physiology, and regulate behavior. Although ORs have been categorized as “generalists” and “specialists” based on their ligand spectrum, both electrophysiological studies and recent pharmacological investigations show that ORs specifically recognize non-pheromonal compounds, and that our understanding of odorant-selectivity mirrors our knowledge of insect chemical ecology. As we are progressively becoming aware that ORs are activated through a variety of mechanisms, the molecular basis of odorant-selectivity and the corollary notion of broad-tuning need to be re-examined from a pharmacological and evolutionary perspective. PMID:22811659

  17. Plasmonically enhanced thermomechanical detection of infrared radiation.

    PubMed

    Yi, Fei; Zhu, Hai; Reed, Jason C; Cubukcu, Ertugrul

    2013-04-10

    Nanoplasmonics has been an attractive area of research due to its ability to localize and manipulate freely propagating radiation on the nanometer scale for strong light-matter interactions. Meanwhile, nanomechanics has set records in the sensing of mass, force, and displacement. In this work, we report efficient coupling between infrared radiation and nanomechanical resonators through nanoantenna enhanced thermoplasmonic effects. Using efficient conversion of electromagnetic energy to mechanical energy in this plasmo-thermomechanical platform with a nanoslot plasmonic absorber integrated directly on a nanobeam mechanical resonator, we demonstrate room-temperature detection of nanowatt level power fluctuations in infrared radiation. We expect our approach, which combines nanoplasmonics with nanomechanical resonators, to lead to optically controlled nanomechanical systems enabling unprecedented functionality in biomolecular and toxic gas sensing and on-chip mass spectroscopy.

  18. Suppression of Odorant Responses by Odorants in Olfactory Receptor Cells

    NASA Astrophysics Data System (ADS)

    Kurahashi, Takashi; Lowe, Graeme; Gold, Geoffrey H.

    1994-07-01

    Odorants activate an inward current in vertebrate olfactory receptor cells. Here it is shown, in receptor cells from the newt, that odorants can also suppress this current, by a mechanism that is distinct from inhibition and adaptation. Suppression provides a simple explanation for two seemingly unrelated phenomena: the anomalously long latency of olfactory transduction and the existence of an "off response" at the end of a prolonged stimulus. Suppression may influence the perception of odorants by masking odorant responses and by sharpening the odorant specificities of single cells.

  19. Cross-modal integration between odors and abstract symbols.

    PubMed

    Seo, Han-Seok; Arshamian, Artin; Schemmer, Kerstin; Scheer, Ingeborg; Sander, Thorsten; Ritter, Guido; Hummel, Thomas

    2010-07-12

    This study aimed to investigate the cross-modal association of an "abstract symbol," designed for representation of an odor, with its corresponding odor. First, to explore the associations of abstract symbols with odors, participants were asked to match 8 odors with 19 different abstract symbols (Experiment 1). Next, we determined whether congruent symbols could modulate olfactory perception and olfactory event-related potentials (ERPs) (Experiment 2). One of two odors (phenylethanol (PEA) or 1-butanol) was presented with one of three conditions (congruent or incongruent symbol, no-symbol), and participants were asked to rate odor intensity and pleasantness during olfactory ERP recordings. Experiment 1 demonstrated that certain abstract symbols could be paired with specific odors. In Experiment 2 congruent symbol enhanced the intensity of PEA compared to no-symbol presentation. In addition, the respective congruent symbol increased the pleasantness of PEA and the unpleasantness of 1-butanol. Finally, compared to the incongruent symbol, the congruent symbol produced significantly higher amplitudes and shorter latencies in the N1 peak of olfactory ERPs. In conclusion, our findings demonstrated that abstract symbols may be associated with specific odors. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Contrast enhancement of stimulus intermittency in a primary olfactory network and its behavioral significance

    PubMed Central

    Lei, Hong; Riffell, Jeffrey A; Gage, Stephanie L; Hildebrand, John G

    2009-01-01

    Background An animal navigating to an unseen odor source must accurately resolve the spatiotemporal distribution of that stimulus in order to express appropriate upwind flight behavior. Intermittency of natural odor plumes, caused by air turbulence, is critically important for many insects, including the hawkmoth, Manduca sexta, for odor-modulated search behavior to an odor source. When a moth's antennae receive intermittent odor stimulation, the projection neurons (PNs) in the primary olfactory centers (the antennal lobes), which are analogous to the olfactory bulbs of vertebrates, generate discrete bursts of action potentials separated by periods of inhibition, suggesting that the PNs may use the binary burst/non-burst neural patterns to resolve and enhance the intermittency of the stimulus encountered in the odor plume. Results We tested this hypothesis first by establishing that bicuculline methiodide reliably and reversibly disrupted the ability of PNs to produce bursting response patterns. Behavioral studies, in turn, demonstrated that after injecting this drug into the antennal lobe at the effective concentration used in the physiological experiments animals could no longer efficiently locate the odor source, even though they had detected the odor signal. Conclusions Our results establish a direct link between the bursting response pattern of PNs and the odor-tracking behavior of the moth, demonstrating the behavioral significance of resolving the dynamics of a natural odor stimulus in antennal lobe circuits. PMID:19232128

  1. Turning tryptophanase into odor-generating biosensors.

    PubMed

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

    2014-03-03

    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.

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

    PubMed

    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. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Simultaneous determination of "earthy-musty" odorous haloanisoles and their corresponding halophenols in water samples using solid-phase microextraction coupled to gas chromatography with electron-capture detection.

    PubMed

    Malleret, Laure; Dugay, José; Bruchet, Auguste; Hennion, Marie-Claire

    2003-05-30

    Certain haloanisoles present at trace levels cause a large part of earthy-musty off-flavor problems in drinking water. These potent odorous chemicals come mainly through biomethylation of their corresponding halopenols. To enable the investigation of both families of compounds, a method involving solid-phase microextraction (SPME) was developed and the main parameters governing SPME were optimized. This method allows the simultaneous quantification of haloanisoles and halophenols at levels ranging from 1 to 100 or 250 ng/l, with detection limits of about 0.5 ng/l and could be applied to potable as well as raw surface waters.

  4. A framework for identifying characteristic odor compounds in municipal wastewater effluent.

    PubMed

    Agus, Eva; Zhang, Lifeng; Sedlak, David L

    2012-11-15

    Municipal wastewater often contains trace amounts of organic compounds that can compromise aesthetics of drinking water and undermine public confidence if a small amount of effluent enters the raw water source of a potable water supply. To efficiently identify compounds responsible for odors in wastewater effluent, an analytical framework consisting of gas chromatography with mass spectrometry (GC-MS) and gas chromatography with olfactometry detection (GC-Olf) coupled with flavor profile analysis (FPA) was used to identify and monitor compounds that could affect the aesthetics of drinking water. After prioritizing odor peaks detected in wastewater effluent by GC-Olf, the odorous components were tentatively identified using retention indices, mass spectra and odor descriptors. Wastewater effluent samples were typically dominated by earthy-musty odors with additional odors in the amine, sulfidic and fragrant categories. 2,4,6-trichloroanisole (246TCA), geosmin and 2-methylisoborneol (2MIB) were the main sources of the earthy/musty odors in wastewater effluent. The other odors were attributable to a suite of compounds, which were detected in some but not all of the wastewater effluents at levels well in excess of their odor thresholds. In most cases, the identities of odorants were confirmed using authentic standards. The fate of these odorous compounds, including 2-pyrrolidone, methylnaphthalenes, vanillin and 5-hydroxyvanillin (5-OH-vanillin), should be considered in future studies of water systems that receive effluent from upstream sources. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. An olfactory cocktail party: figure-ground segregation of odorants in rodents.

    PubMed

    Rokni, Dan; Hemmelder, Vivian; Kapoor, Vikrant; Murthy, Venkatesh N

    2014-09-01

    In odorant-rich environments, animals must be able to detect specific odorants of interest against variable backgrounds. However, studies have found that both humans and rodents are poor at analyzing the components of odorant mixtures, suggesting that olfaction is a synthetic sense in which mixtures are perceived holistically. We found that mice could be easily trained to detect target odorants embedded in unpredictable and variable mixtures. To relate the behavioral performance to neural representation, we imaged the responses of olfactory bulb glomeruli to individual odors in mice expressing the Ca(2+) indicator GCaMP3 in olfactory receptor neurons. The difficulty of segregating the target from the background depended strongly on the extent of overlap between the glomerular responses to target and background odors. Our study indicates that the olfactory system has powerful analytic abilities that are constrained by the limits of combinatorial neural representation of odorants at the level of the olfactory receptors.

  6. Dried-bonito aroma components enhance salivary hemodynamic responses to broth tastes detected by near-infrared spectroscopy.

    PubMed

    Matsumoto, Tomona; Saito, Kana; Nakamura, Akio; Saito, Tsukasa; Nammoku, Takashi; Ishikawa, Masashi; Mori, Kensaku

    2012-01-25

    To elucidate the effects of aroma from dried bonito (katsuo-bushi) on broth tastes caused by the central integration of flavor, optical imaging of salivary hemodynamic responses was conducted using near-infrared spectroscopy (NIRS). A reconstituted dried bonito flavored broth produced a significantly larger hemodynamic response than the odorless broth taste solutions for 5 of the 10 panelists, who felt that the combination of the aroma with the tastes was congruent. In the remaining 5 panelists who felt the combination incongruent, the flavored broth did not cause the enhancement of response. Moreover, when the odor-active smoky parts were removed from the flavoring, the reconstituted flavoring did not enhance the response in the former five panelists. These results indicate that NIRS offers a sensitive method to detect the effect of specific congruent aroma components from dried-bonito broth on the taste-related salivary hemodynamic responses, dependent on the perceptual experience of the combination of aromas and tastes.

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

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

  9. Excretion and perception of a characteristic odor in urine after asparagus ingestion: a psychophysical and genetic study.

    PubMed

    Pelchat, Marcia Levin; Bykowski, Cathy; Duke, Fujiko F; Reed, Danielle R

    2011-01-01

    The urine of people who have recently eaten asparagus has a sulfurous odor, which is distinct and similar to cooked cabbage. Using a 2-alternative forced-choice procedure, we examined individual differences in both the production of the odorants and the perception of this asparagus odor in urine. We conclude that individual differences exist in both odorant production and odor perception. The biological basis for the inability to produce the metabolite in detectable quantities is unknown, but the inability to smell the odor is associated with a single nucleotide polymorphism (rs4481887) within a 50-gene cluster of olfactory receptors.

  10. Excretion and Perception of a Characteristic Odor in Urine after Asparagus Ingestion: a Psychophysical and Genetic Study

    PubMed Central

    Bykowski, Cathy; Duke, Fujiko F.; Reed, Danielle R.

    2011-01-01

    The urine of people who have recently eaten asparagus has a sulfurous odor, which is distinct and similar to cooked cabbage. Using a 2-alternative forced-choice procedure, we examined individual differences in both the production of the odorants and the perception of this asparagus odor in urine. We conclude that individual differences exist in both odorant production and odor perception. The biological basis for the inability to produce the metabolite in detectable quantities is unknown, but the inability to smell the odor is associated with a single nucleotide polymorphism (rs4481887) within a 50-gene cluster of olfactory receptors. PMID:20876394

  11. Behavioral reactions to novel food odors by intertidal hermit crabs.

    PubMed

    Tran, Mark V

    2015-04-01

    Novel food items represent important food resources for generalist scavengers, such as intertidal hermit crabs. For animals that rely heavily on olfaction to mediate foraging, their first encounters with novel food items come from the detection of novel food odors. Although crustaceans have been shown to possess sensory mechanisms for processing novel odors, little is known about the level of stimulus reinforcement needed to maintain behavioral responses to novel food odors upon subsequent exposures. In the context of foraging, reinforcement of a novel food odor comes from feeding on the novel food item after sensory detection of the food item. This study tested the behavioral responses of hermit crabs to a novel food odor over repeated exposures both with and without stimulus reinforcement. The results show that stimulus reinforcement is needed for the animals to maintain their baseline level of behavioral responses to the novel food odors. Animals that were allowed to feed on the novel food item after first exposure (reinforced treatment) maintained strong behavioral reactions to the novel food odor during subsequent exposures. The behavioral reactions of animals that were not allowed to feed on the novel food item after first exposure (unreinforced treatment) rapidly declined. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Olfactory fingerprints for major histocompatibility complex-determined body odors II: relationship among odor maps, genetics, odor composition, and behavior.

    PubMed

    Schaefer, Michele L; Yamazaki, Kunio; Osada, Kazumi; Restrepo, Diego; Beauchamp, Gary K

    2002-11-01

    The olfactory system detects small differences in the composition of natural odorants, made up of hundreds of molecules. Odorous quality is hypothetically represented by a combinatorial code: activation of distinct but overlapping subsets of olfactory receptors resulting in activation of a distinct subset of glomeruli in the main olfactory bulb (MOB). Here we show that modification of a single gene (the K gene of the major histocompatibility locus), which results in a subtle change in the odiferous quality of urine, causes a small but significant change in the composition of urine volatiles and consequently the evoked glomerular activation pattern in the MOB. The magnitude of disparity between urine-evoked glomerular activation patterns is predictive of the extent of (1) the genetic difference among the urine donors, (2) the difference in the chemical composition of urine, and (3) the odor detector's ability to discriminate. These data on natural odors are consistent with the combinatorial code hypothesis and identify subsets of glomeruli that are apt to play a significant role in mediating individual recognition.

  13. Health effects of indoor odorants.

    PubMed Central

    Cone, J E; Shusterman, D

    1991-01-01

    People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant odors (body odor), environmental tobacco smoke, volatile building materials, bio-odorants (particularly mold and animal-derived materials), air fresheners, deodorants, and perfumes. These are most often present as complex mixtures, making measurement of the total odorant problem difficult. There is no current method of measuring human body odor, other than by human panel studies of expert judges of air quality. Human body odors have been quantitated in terms of the "olf" which is the amount of air pollution produced by the average person. Another quantitative unit of odorants is the "decipol," which is the perceived level of pollution produced by the average human ventilated by 10 L/sec of unpolluted air or its equivalent level of dissatisfaction from nonhuman air pollutants. The standard regulatory approach, focusing on individual constituents or chemicals, is not likely to be successful in adequately controlling odorants in indoor air. Besides the current approach of setting minimum ventilation standards to prevent health effects due to indoor air pollution, a standard based on the olf or decipol unit might be more efficacious as well as simpler to measure. PMID:1821378

  14. Recognition on Maternal Axillary Odors by Infants.

    ERIC Educational Resources Information Center

    Cernoch, Jennifer M.; Porter, Richard H.

    1985-01-01

    Displaying no evidence of recognizing the axillary odors of their fathers, breastfed infants discriminated between their mother's axillary odor and odors produced by nonparturient or unfamiliar lactating females. Bottle-fed infants appeared unable to recognize the odor of their mother when presented along with odors from a nonparturient female or…

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

    PubMed

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

    2014-07-01

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

  16. Assessment of olfactory function and androstenone odor thresholds in humans with or without functional occlusion of the vomeronasal duct.

    PubMed

    Knecht, Michael; Lundström, Johan N; Witt, Martin; Hüttenbrink, Karl-Bernd; Heilmann, Stefan; Hummel, Thomas

    2003-12-01

    To obtain information on the possible role of the vomeronasal duct (VND) in odor perception and human pheromone detection, the present study investigated different aspects of olfactory function, including thresholds for androstenone in adults with or without detectable VNDs. The study also examined correlations between detection thresholds of androstenone odor and general olfactory function. Subjects' olfaction was assessed with tests for odor identification, odor discrimination, and phenyl ethyl alcohol odor threshold. Measurements were performed on 1 side only, with and without covering the VND. Subjects with or without detectable VNDs did not differ in olfactory sensitivity or androstenone odor thresholds. A small but significant correlation was found between detection thresholds of androstenone and general olfactory function. Finally, covering of the VND did not affect olfactory function or androstenone sensitivity. Results suggest that the human VND does not play a major role in sensitivity toward odorants or the perception of androstenone.

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

    PubMed

    Degl'Innocenti, Andrea; D'Errico, Anna

    2017-01-01

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

  18. Effects of Visual Priming on Taste-Odor Interaction

    PubMed Central

    van Beilen, Marije; Bult, Harold; Renken, Remco; Stieger, Markus; Thumfart, Stefan; Cornelissen, Frans; Kooijman, Valesca

    2011-01-01

    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. PMID:21969852

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

    PubMed

    van Beilen, Marije; Bult, Harold; Renken, Remco; Stieger, Markus; Thumfart, Stefan; Cornelissen, Frans; Kooijman, Valesca

    2011-01-01

    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.

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

    PubMed Central

    Degl’Innocenti, Andrea; D’Errico, Anna

    2017-01-01

    The odorant receptor genes, seven transmembrane receptor genes constituting the vastest mammalian gene multifamily, are expressed monogenically and monoallelicaly in each sensory neuron in the olfactory epithelium. This characteristic, often referred to as the one neuron–one receptor rule, is driven by mostly uncharacterized molecular dynamics, generally named odorant receptor gene choice. Much attention has been paid by the scientific community to the identification of sequences regulating the expression of odorant receptor genes within their loci, where related genes are usually arranged in genomic clusters. A number of studies identified transcription factor binding sites on odorant receptor promoter sequences. Similar binding sites were also found on a number of enhancers that regulate in cis their transcription, but have been proposed to form interchromosomal networks. Odorant receptor gene choice seems to occur via the local removal of strongly repressive epigenetic markings, put in place during the maturation of the sensory neuron on each odorant receptor locus. Here we review the fast-changing state of art for the study of regulatory features for odorant receptor genes. PMID:28270833

  1. Amino acid odorants stimulate microvillar sensory neurons.

    PubMed

    Lipschitz, David L; Michel, William C

    2002-03-01

    The olfactory epithelium (OE) of zebrafish is populated with ciliated and microvillar olfactory sensory neurons (OSNs). Whether distinct classes of odorants specifically activate either of these unique populations of OSNs is unknown. Previously we demonstrated that zebrafish OSNs could be labeled in an activity-dependent fashion by amino acid but not bile acid odorants. To determine which sensory neuron type was stimulated by amino acid odorants, we labeled OSNs using the ion channel permeant probe agmatine (AGB) and analyzed its distribution with conventional light- and electron-microscope immunocytochemical techniques. Approximately 7% of the sensory epithelium was labeled by AGB exposure alone. Following stimulation with one of the eight amino acids tested, the proportion of labeled epithelium increased from 9% for histidine to 19% for alanine; amino acid stimulated increases in labeling of 2-12% over control labeling. Only histidine failed to stimulate a significant increase in the proportion of labeled OSNs compared to control preparations. Most amino acid sensitive OSNs were located superficially in the epithelium and immuno-electron microscopy demonstrated that the labeled OSNs were predominantly microvillar. Large numbers of nanogold particles (20-60 per 1.5 microm(2)) were associated with microvillar olfactory sensory neurons (MSNs), while few such particles (<15 per 1.5 microm(2)) were observed over ciliated olfactory sensory neurons (CSNs), supporting cells (SCs) and areas without tissue, such as the lumen above the OE. Collectively, these findings indicate that microvillar sensory neurons are capable of detecting amino acid odorants.

  2. Hazardous Odor Recognition by CMAC Based Neural Networks.

    PubMed

    Bucak, Ihsan Ömür; Karlık, Bekir

    2009-01-01

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

  3. Odor sensing for robot guidance

    NASA Astrophysics Data System (ADS)

    Deveza, Reimundo; Thiel, David; Russell, Andrew; Mackay-Sim, Alan

    1994-06-01

    There is no generally applicable technique for finding the position of an autonomous mobile robot operating in an unstructured or varying environment. This article describes a project to investigate the use of short-lived navigational markers consisting of olfactory chemicals to guide mobile robots and to help them search and explore efficiently. Such a method of laying a trail to mark the path of a robot provides differential navigational information relative to the starting point and starting direction. Many insects employ olfactory cues as navigation aids and to improve their efficiency when searching for food. Three scenarios are proposed in which navigational markers can be of assistance to a mobile robot. The design and characteristics of an adsorbed mass olfactory sensor are described. This sensor was designed to be mounted on a mobile robot and is suitable for detecting and tracking olfactory chemicals. The performance of this sensor is described together with preliminary results of using it to track an odor trail.

  4. Functional Characterization of Odorant Receptors

    DTIC Science & Technology

    1994-02-07

    94 IFINAL REPORT 9/1/92-11/30/93 4. TITLE AND SUBTITLE S. FUNDING NUMBERS Functional Characterization of Odorant Receptors DAAL03-92-G-0390 6. AUTHOR(S...characterization of odorant receptors have developed in two directions. One direction is concerned with the characterization of the ligand specificity of... receptor have been replaced by the equivalent regions of odorant receptor 1-15 (Buck and Axel, 1991), thus forming a chimaeric seven transmembrane domain

  5. Complex Odor from Plants under Attack: Herbivore's Enemies React to the Whole, Not Its Parts

    PubMed Central

    van Wijk, Michiel; de Bruijn, Paulien J. A.; Sabelis, Maurice W.

    2011-01-01

    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. PMID:21765908

  6. Odor compounds in waste gas emissions from agricultural operations and food industries.

    PubMed

    Rappert, S; Müller, R

    2005-01-01

    In the last decades, large-scale agricultural operations and food industries have increased. These operations generate numerous types of odors. The reduction of land areas available for isolation of agricultural and food processing industrial operations from the public area and the increase in sensitivity and demand of the general public for a clean and pleasant environment have forced all of these industries to control odor emissions and toxic air pollutants. To develop environmentally sound, sustainable agricultural and food industrial operations, it is necessary to integrate research that focuses on modern analytical techniques and latest sensory technology of measurement and evaluation of odor and pollution, together with a fundamental knowledge of factors that are the basic units contributing to the production of odor and pollutants. Without a clear understanding of what odor is, how to measure it, and where it originates, it will be difficult to control the odor. The present paper reviews the available information regarding odor emissions from agricultural operations and food industries by giving an overview about odor problems, odor detection and quantification, and identifying the sources and the mechanisms that contribute to the odor emissions. Finally, ways of reducing or controlling the odor problem are discussed.

  7. Identification of Candidate Odorant Receptors in Asian Corn Borer Ostrinia furnacalis

    PubMed Central

    Yang, Bin; Ozaki, Katsuhisa; Ishikawa, Yukio; Matsuo, Takashi

    2015-01-01

    In lepidopteran insects, odorant receptors are involved in the perception of sex pheromones and general odorants. In the Asian corn borer, Ostrinia furnacalis, although several pheromone receptors have been identified, no general odorant receptor has been reported. In this study, an RNA sequencing analysis was carried out to identify the whole repertoire of the odorant receptors expressed in the antennae of O. furnacalis. Among 12 million reads obtained from the antennae of male and female moths, 52 candidate odorant receptors were identified, including 45 novel ones. Expression levels of candidate odorant receptors were estimated by read mapping and quantitative reverse transcription PCR. These analyses confirmed that the expression of the previously identified pheromone receptors was highly male biased. In contrast, none of the newly identified odorant receptors showed male-biased expression. Three of the newly identified odorant receptors showed female-biased expression. Two of them were the most highly expressed odorant receptors in the female antennae, suggesting that they may be involved in the detection of odorants important for the induction of female-specific behaviors such as oviposition site selection. In addition, candidate genes of 21 ionotropic receptors, 5 gustatory receptors, 2 sensory neuron membrane proteins, and 26 odorant degrading enzymes were identified. Our results provide a basis for further analysis of the chemosensory system in the Ostrinia species. PMID:25803580

  8. Metal Nanostructures for Detection and Imaging Enhancements

    DTIC Science & Technology

    2011-01-03

    source spectrum, is delivered into a pig adipose sample. OCT is a widely used optical imaging technique for the diagnoses of many diseases [27-29... Fahr , C. Rockstuhl, and F. Lederer, “Engineering the randomness for enhanced absorption in solar cells,” Appl. Phys. Lett. 92, 171114 (2008). 7. T...Rockstuhl, S. Fahr , and F. Lederer, “Absorption enhancement in solar cells by localized plasmon polaritons,” J. Appl. Phys. 104, 123102 (2008). 31. A

  9. Enhanced detection of infectious airborne influenza virus.

    PubMed

    Blachere, Francoise M; Cao, Gang; Lindsley, William G; Noti, John D; Beezhold, Donald H

    2011-09-01

    Current screening methodologies for detecting infectious airborne influenza virus are limited and lack sensitivity. To increase the sensitivity for detecting infectious influenza virus in an aerosol sample, the viral replication assay was developed. With this assay, influenza virus is first amplified by replication in Madin-Darby canine kidney (MDCK) cells followed by detection with quantitative PCR (qPCR). Spanning a 20-h replication period, matrix gene expression levels from infectious virus were measured at several time points using qPCR and found to exponentially increase. Compared with the traditional culture-based viral plaque assay, the viral replication assay resulted in a 4.6 × 10(5) fold increase in influenza virus detection. Furthermore, viral replication assay results were obtained in half the time of the viral plaque assay. To demonstrate that the viral replication assay is capable of detecting airborne influenza virus, dilute preparations of strain A/WS/33 were loaded into a nebulizer, aerosolized within a calm-air settling chamber and subsequently collected using NIOSH Two-Stage Bioaerosol Samplers. At the most diluted concentration corresponding to a chicken embryo infectious dose 50% endpoint (CEID(50)) of 2.8E+02/ml, the viral replication assay was able to detect infectious influenza virus that was otherwise undetectable by viral plaque assay. The results obtained demonstrate that the viral replication assay is highly sensitive at detecting infectious influenza virus from aerosol samples. Published by Elsevier B.V.

  10. Bio-Inspired Odor Source Localization

    DTIC Science & Technology

    2011-07-01

    1 Distribution A: Approved for Public Release; Distribution Unlimited Bio -Inspired Odor Source Localization Bio -Inspired Odor Source Localization...2011 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Bio -Inspired Odor Source Localization 5a. CONTRACT NUMBER 5b. GRANT...Distribution Unlimited Bio -Inspired Odor Source Localization Why study odor tracking? • Engineer odor tracking systems – Gas leaks – Hazardous waste

  11. Distant Odors: Identifying Key Odors Associated With Cattle Feedlots Downwind

    USDA-ARS?s Scientific Manuscript database

    The National Research Council identified odors as the most significant animal emission at the local level and has highlighted the need for the development of standardized protocols for sampling and analysis of odors. To date, however, little progress has been made on identifying sampling and analys...

  12. LIBS plasma enhancement for standoff detection applications

    NASA Astrophysics Data System (ADS)

    Killinger, Dennis K.; Allen, Susan D.; Waterbury, Robert D.; Stefano, Chris; Dottery, Edwin L.

    2008-04-01

    We have used a simultaneous 10.6 micron CO II laser pulse to enhance the Laser Induced Breakdown Spectroscopy (LIBS) emission from a 1.064 micron Nd:YAG laser induced plasma on a hard target. The enhancement factor was found to be one or two orders of magnitude, depending upon the emission lines observed and the target composition. The output energy of the 5 ns Nd:YAG laser pulse was about 50 mJ and was focused to a 1 mm diameter spot to produce breakdown. The CO II laser pulse (100 ns spike, 5 microsec tail) had a similar energy density on target (0.06 J/mm2). Timing overlap of the two laser pulses within 1 microsecond was important for enhancement to be observed. Enhancement of neutral atomic emission was usually on the order of 5-20X, while enhancement of ionized species tended to be higher, 10-200X. We attribute the increase in both the atmospheric components and the +1 and +2 ionic emission to heating of the Nd:YAG plasma by the coincident CO II laser. Such inverse bremsstrahlung absorption of CO II laser radiation by the free electrons of plasma is well known. We are conducting additional studies to better quantify the effects of laser beam mode, pulse-to-pulse jitter, temporal pulse shaping, and optimization of these parameters for different LIBS target compositions.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Neural Sensitivity to Odorants in Deprived and Normal Olfactory Bulbs

    PubMed Central

    Rodríguez, Francisco B.; Huerta, Ramón; Aylwin, Maria de la Luz

    2013-01-01

    Early olfactory deprivation in rodents is accompanied by an homeostatic regulation of the synaptic connectivity in the olfactory bulb (OB). However, its consequences in the neural sensitivity and discrimination have not been elucidated. We compared the odorant sensitivity and discrimination in early sensory deprived and normal OBs in anesthetized rats. We show that the deprived OB exhibits an increased sensitivity to different odorants when compared to the normal OB. Our results indicate that early olfactory stimulation enhances discriminability of the olfactory stimuli. We found that deprived olfactory bulbs adjusts the overall excitatory and inhibitory mitral cells (MCs) responses to odorants but the receptive fields become wider than in the normal olfactory bulbs. Taken together, these results suggest that an early natural sensory stimulation sharpens the receptor fields resulting in a larger discrimination capability. These results are consistent with previous evidence that a varied experience with odorants modulates the OB's synaptic connections and increases MCs selectivity. PMID:23580211

  15. Unsupervised abnormality detection using saliency and Retinex based color enhancement.

    PubMed

    Deeba, Farah; Mohammed, Shahed K; Bui, Francis M; Wahid, Khan A

    2016-08-01

    An efficient and automated abnormality detection method can significantly reduce the burden of screening of the enormous visual information resulting from capsule endoscopic procedure. As a pre-processing stage, color enhancement could be useful to improve the image quality and the detection performance. Therefore, in this paper, we have proposed a two-stage automated abnormality detection algorithm. In the first stage, an adaptive color enhancement method based on Retinex theory is applied on the endoscopic images. In the second stage, an efficient salient region detection algorithm is applied to detect the clinically significant regions. The proposed algorithm is applied on a dataset containing images with diverse pathologies. The algorithm can successfully detect a significant percentage of the abnormal regions. From our experiment, it was evident that color enhancement method improves the performance of abnormality detection. The proposed algorithm can achieve a sensitivity of 97.33% and specificity of 79%, higher than state-of-the-art performance.

  16. Source-water odor during winter in the Yellow River area of China: Occurrence and diagnosis.

    PubMed

    Li, Xia; Yu, Jianwei; Guo, Qingyuan; Su, Ming; Liu, Tingting; Yang, Min; Zhao, Yu

    2016-11-01

    Yellow River source water has long suffered from odor problems in winter. In this study, odor characteristics, potential odorants, and algae in the source water of six cities (Lanzhou, Yinchuan, Hohhot, Zhengzhou, Jinan and Dongying) along the Yellow River were determined in winter (February to March 2014). According to flavor profile analysis (FPA), moderate to strong fishy odors occurred in all cities, except for Lanzhou. At the same time, mild earthy/musty odors and septic/swampy odors were also detected. The strong fishy odor (FPA intensity, 8.5) in Yinchuan was attributed to the abnormal growth of Dinobryon (cell density, 5.7 × 10(4) cells/mL), while the fishy odors in Hohhot, Zhengzhou, Jinan, and Dongying might be caused by Melosira and Cyclotella, Cryptomonas, Dinobryon, and Synedra, respectively. Unsaturated aldehydes, which have been reported to cause fishy odors, were not detected in all samples. However, some saturated aldehydes, including hexanal, heptanal, nonanal, decanal, and benzaldehyde, were detected with a total concentration range of 690 ng/L to 2166 ng/L, and might have partly contributed to the fishy odors. In addition, 2-MIB (5.77-21.12 ng/L) and geosmin (2.26-9.73 ng/L) were responsible for the earthy/musty odors in the Yellow River source waters, and dimethyl disulfide (648.2 ng/L) was responsible for the rancid/swampy odor (FPA intensity, 8.0) episode in Yinchuan. This is a comprehensive study reporting on the occurrence and possible reasons for the odor issues in the Yellow River source water during winter.

  17. Infrared-enhanced TV for fire detection

    NASA Technical Reports Server (NTRS)

    Hall, J. R.

    1978-01-01

    Closed-circuit television is superior to conventional smoke or heat sensors for detecting fires in large open spaces. Single TV camera scans entire area, whereas many conventional sensors and maze of interconnecting wiring might be required to get same coverage. Camera is monitored by person who would trip alarm if fire were detected, or electronic circuitry could process camera signal for fully-automatic alarm system.

  18. Development of a smell identification test using a novel stick-type odor presentation kit.

    PubMed

    Saito, Sachiko; Ayabe-Kanamura, Saho; Takashima, Yasuhiro; Gotow, Naomi; Naito, Naomi; Nozawa, Takashi; Mise, Miyako; Deguchi, Yuichi; Kobayakawa, Tatsu

    2006-05-01

    The odor identification is strongly influenced by the social and cultural factors; therefore, the odorants used in a smell identification test should be familiar to the test population. In addition, the device used in the test is desired to be simply handled and retain odor quality over time. We developed a novel stick-type odor presentation kit that consists of microcapsules of odorant incorporated into stable cream and the smell identification test using it. Thirteen odorants were selected to be familiar to the test population. In the test, we used two identification methods: one was a modified forced-choice paradigm with "detectable but not recognizable" and "no smell detected" added as choices and the other was a two-step identification paradigm where the participant first selected one of eight odor categories and then chose the specific odor name from the selected category. We verified the performance of the odor stick and the test by stability, using a test-retest paradigm, comparing this test with another smell test, and testing Japanese people from a range of age groups. We conclude that this kit is a useful odor presentation device, and the test using it works effectively as a smell identification test.

  19. Odorant-binding protein: localization to nasal glands and secretions.

    PubMed Central

    Pevsner, J; Sklar, P B; Snyder, S H

    1986-01-01

    An odorant-binding protein (OBP) was isolated from bovine olfactory and respiratory mucosa. We have produced polyclonal antisera to this protein and report its immunohistochemical localization to mucus-secreting glands of the olfactory and respiratory mucosa. Although OBP was originally isolated as a pyrazine binding protein, both rat and bovine OBP also bind the odorants [3H]methyldihydrojasmonate and 3,7-dimethyl-octan-1-ol as well as 2-isobutyl-3-[3H]methoxypyrazine. We detect substantial odorant-binding activity attributable to OBP in secreted rat nasal mucus and tears but not in saliva, suggesting a role for OBP in transporting or concentrating odorants. Images PMID:3523479

  20. Olfactory receptor cells respond to odors in a tissue and semiconductor hybrid neuron chip.

    PubMed

    Liu, Qingjun; Ye, Weiwei; Hu, Ning; Cai, Hua; Yu, Hui; Wang, Ping

    2010-12-15

    Olfactory systems of human beings and animals have the abilities to sense and distinguish varieties of odors. In this study, a bioelectronic nose was constructed by fixing biological tissues onto the surface of light-addressable potentiometric sensor (LAPS) to mimic human olfaction and realize odor differentiation. The odorant induced potentials on tissue-semiconductor interface was analyzed by sensory transduction theory and sheet conductor model. The extracellular potentials of the receptor cells in the olfactory epithelium were detected by LAPS. Being stimulated by different odorants, such as acetic acid and butanedione, olfactory epithelium activities were analyzed on basis of local field potentials and presented different firing modes. The signals fired in different odorants could be distinguished into different clusters by principal component analysis (PCA). Therefore, with cellular populations well preserved, the epithelium tissue and LAPS hybrid system will be a promising neuron chip of olfactory biosensors for odor detecting. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Identification and Quantitation of Potent Odorants in Spearmint Oils.

    PubMed

    Kelley, Lauren E; Cadwallader, Keith R

    2017-01-17

    Potent odorants in Native spearmint, Scotch spearmint, and Macho mint oils were determined by the combined use of gas chromatography-olfactometry (GCO), gas chromatography-mass spectrometry (GC-MS), and aroma extract dilution analysis (AEDA). Of the 85 odorants detected, (R)-(-)-carvone was the most potent odorant in all three spearmint oils. Additional predominant odorants in all spearmint oils included eugenol, ethyl (S)-(+)-2-methylbutanoate, (E)-β-damascenone, and (3E,5Z)-1,3,5-undecatriene. Forty-six compounds were quantitated using various methods, including 19 by gas chromatography with flame ionization detection (GC-FID), 20 by stable isotope dilution analysis (SIDA), and 14 by GCO dilution analysis. Concentrations were used to calculate the odor activity values (OAVs) for predominant odorants in the oils. Among the compounds quantitated, those with the highest OAVs were (R)-(-)-carvone, 1,8-cineole, (E,Z)-2,6-nonadienal, (E)-β-damascenone, and (3E,5Z)-1,3,5-undecatriene.

  2. Hyperspectral anomaly detection using enhanced global factors

    NASA Astrophysics Data System (ADS)

    Paciencia, Todd J.; Bauer, Kenneth W.

    2016-05-01

    Dimension reduction techniques have become one popular unsupervised approach used towards detecting anomalies in hyperspectral imagery. Although demonstrating promising results in the literature on specific images, these methods can become difficult to directly interpret and often require tuning of their parameters to achieve high performance on a specific set of images. This lack of generality is also compounded by the need to remove noise and atmospheric absorption spectral bands from the image prior to detection. Without a process for this band selection and to make the methods adaptable to different image compositions, performance becomes difficult to maintain across a wider variety of images. Here, we present a framework that uses factor analysis to provide a robust band selection and more meaningful dimension reduction with which to detect anomalies in the imagery. Measurable characteristics of the image are used to create an automated decision process that allows the algorithm to adjust to a particular image, while maintaining high detection performance. The framework and its algorithms are detailed, and results are shown for forest, desert, sea, rural, urban, anomaly-sparse, and anomaly-dense imagery types from different sensors. Additionally, the method is compared to current state-of-the-art methods and is shown to be computationally efficient.

  3. Evaluation of the representativeness of the odor of cooked mussel extracts and the relationship between sensory descriptors and potent odorants.

    PubMed

    Le Guen, S; Prost, C; Demaimay, M

    2001-03-01

    The representativeness of the odor of mussel extract was assessed after each step of the distillation-extraction-concentration process. Results showed that the whole process was convenient for cooked mussels, but the extract was representative only when it was reincorporated into a suitable matrix such as water. Sensory and gas chromatography-olfactometry (GC-O) analyses were then performed on representative extracts of wild and bouchot mussels. Most of the sensory attributes were related to odors detected during olfactometry. Methional and (Z)-4-heptenal were two of the most potent odorants of mussels and, thus, were identified as the major contributors to the characteristic boiled potato-like odor of cooked mussels distinguished during sensory analysis. The sulfury note, highlighted for wild mussels during sensory analysis, could be linked to dimethyl disulfide, which was significantly more perceived in wild mussels by GC-O. Dimethyl disulfide could then be considered to be a characteristic compound of wild mussels.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Odorants for Surveillance and Control of the Asian Citrus Psyllid (Diaphorina citri)

    PubMed Central

    Coutinho-Abreu, Iliano V.; Forster, Lisa; Guda, Tom; Ray, Anandasankar

    2014-01-01

    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. PMID:25347318

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

    PubMed

    Coutinho-Abreu, Iliano V; Forster, Lisa; Guda, Tom; Ray, Anandasankar

    2014-01-01

    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. 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%. 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.

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

    PubMed Central

    Elsharif, Shaimaa A.; Banerjee, Ashutosh; Buettner, Andrea

    2015-01-01

    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. PMID:26501053

  8. Narcolepsy and odor: preliminary report.

    PubMed

    Dominguez-Ortega, L; Díaz-Gállego, E; Pozo, F; Cabrera García-Armenter, S; Serrano Comino, M; Dominguez-Sanchez, E

    2013-10-01

    This study has been carried out to test the clinical hypothesis of personal smell as a hint to the diagnosis of narcoleptic patients. Sweat samples from narcoleptic and healthy controls were tested independently by two trained dogs and their positive or negative detection compared to the gold standard diagnosis for narcolepsy. Neither trainer nor dog knew the source of the sample selected or its placement in the search device. Twelve narcoleptic patients, both sexes and various ages, recruited from April 2011 to June 2012 and diagnosed according to standard criteria, through their clinical records and nocturnal polysomnography plus multiple sleep latency test, made up the patient group. The control group was made up of 22 healthy volunteer without sleep disorders, both sexes and various ages. Sweat samples from both patients and controls were collected following the same protocol to avoid contamination, and tested independently by two trained dogs. Eleven narcoleptic were detected positive by the dogs while only three controls. It seems that narcoleptic patients have a distinct typical odor that trained dogs can detect. The development of olfactory test could be a useful method in the screening of narcolepsy while opens a new research area. Copyright © 2013 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  9. Odor and odorous chemical emissions from animal buildings: Part 2. Odor emissions

    USDA-ARS?s Scientific Manuscript database

    This study was an add-on project to the National Air Emissions Monitoring Study (NAEMS) and focused on comprehensive measurement of odor emissions considering variations in seasons, animal types and olfactometry laboratories. Odor emissions from four of 14 NEAMS sites with nine barns/rooms (two dair...

  10. Odor and odorous chemical emissions from animal buildings: Part 2 - odor emissions

    USDA-ARS?s Scientific Manuscript database

    This study was an add-on project to the National Air Emissions Monitoring Study (NAEMS) and focused on comprehensive measurement of odor emissions. Odor emissions from two animal species (dairy and swine) from four sites with nine barns/rooms (two dairy barns in Wisconsin, two dairy barns and two sw...

  11. Odor and odorous chemical emissions from animal buildings: Part 6.Odor activity value

    USDA-ARS?s Scientific Manuscript database

    There is a growing concern with air and odor emissions from agricultural facilities. A supplementary research project was conducted to complement the U.S. National Air Emissions Monitoring Study (NAEMS). The overall goal of the project was to establish odor and chemical emission factors for animal...

  12. Toward an Objective Enhanced-V Detection Algorithm

    NASA Technical Reports Server (NTRS)

    Brunner, Jason; Feltz, Wayne; Moses, John; Rabin, Robert; Ackerman, Steven

    2007-01-01

    The area of coldest cloud tops above thunderstorms sometimes has a distinct V or U shape. This pattern, often referred to as an "enhanced-V' signature, has been observed to occur during and preceding severe weather in previous studies. This study describes an algorithmic approach to objectively detect enhanced-V features with observations from the Geostationary Operational Environmental Satellite and Low Earth Orbit data. The methodology consists of cross correlation statistics of pixels and thresholds of enhanced-V quantitative parameters. The effectiveness of the enhanced-V detection method will be examined using Geostationary Operational Environmental Satellite, MODerate-resolution Imaging Spectroradiometer, and Advanced Very High Resolution Radiometer image data from case studies in the 2003-2006 seasons. The main goal of this study is to develop an objective enhanced-V detection algorithm for future implementation into operations with future sensors, such as GOES-R.

  13. Odor analysis of decomposing buried human remains

    SciTech Connect

    Vass, Arpad Alexander; Smith, Rob R; Thompson, Cyril V; Burnett, Michael N; Dulgerian, Nishan; Eckenrode, Brian A

    2008-01-01

    This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the 'odor signatures' unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  14. Odor analysis of decomposing buried human remains.

    PubMed

    Vass, Arpad A; Smith, Rob R; Thompson, Cyril V; Burnett, Michael N; Dulgerian, Nishan; Eckenrode, Brian A

    2008-03-01

    This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the "odor signatures" unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  15. Thresholds for odor and nasal pungency.

    PubMed

    Cometto-Muñiz, J E; Cain, W S

    1990-11-01

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

  16. Organic compounds in office environments - sensory irritation, odor, measurements and the role of reactive chemistry.

    PubMed

    Wolkoff, P; Wilkins, C K; Clausen, P A; Nielsen, G D

    2006-02-01

    Abstract Sensory irritation and odor effects of organic compounds in indoor environments are reviewed. It is proposed to subdivide volatile organic compounds (VOCs) into four categories: (i) chemically non-reactive, (ii) chemically 'reactive', (iii) biologically reactive (i.e. form chemical bonds to receptor sites in mucous membranes) and (iv) toxic compounds. Chemically non-reactive VOCs are considered non-irritants at typical indoor air levels. However, compounds with low odor thresholds contribute to the overall perception of the indoor air quality. Reported sensory irritation may be the result of odor annoyance. It appears that odor thresholds for many VOCs probably are considerably lower than previously reported. This explains why many building materials persistently are perceived as odorous, although the concentrations of the detected organic compounds are close to or below their reported odor thresholds. Ozone reacts with certain alkenes to form a gas and aerosol phase of oxidation products, some of which are sensory irritants. However, all of the sensory irritating species have not yet been identified and whether the secondary aerosols (ultrafine and fine particles) contribute to sensory irritation requires investigation. Low relative humidity may exacerbate the sensory irritation impact. Practical Implications Certain odors, in addition to odor annoyance, may result in psychological effects and distraction from work. Some building materials continually cause perceivable odors, because the odor thresholds of the emitted compounds are low. Some oxidation products of alkenes (e.g. terpenes) may contribute to eye and airway symptoms under certain conditions and low relative humidity.

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

    PubMed

    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.

  18. Neural correlates of odor learning in the honeybee antennal lobe.

    PubMed

    Denker, Michael; Finke, Robert; Schaupp, Frank; Grün, Sonja; Menzel, Randolf

    2010-01-01

    Extracellular spiking activity and local field potentials (LFP) were recorded via tetrodes at the output of the antennal lobe (AL) in the honeybee brain during olfactory conditioning. Odors induce reliable rate responses that consist of either phasic-tonic responses, or complex responses with odor-specific profiles. In addition, odors evoke consistent responses of LFP oscillations in the 50-Hz band during the phasic ON-response to odor stimulation, and variable LFP responses at other frequency bands during the sustained response. A principal component analysis of the ensemble activity during differential conditioning consistently indicates the largest changes in response to the learned odor (conditioned stimulus; CS+). Relative LFP power increases for CS+ in the 15-40-Hz frequency band during the sustained response, and decreases for frequencies above 45 Hz. To quantify the relationship between these population responses given by the ensemble spiking activity and LFP, we show that for CS+ the learning-related changes in the degree of the phase-locked spiking activity correlate with the power changes in the corresponding frequency bands. Our results indicate associative plasticity in the AL of the bee leading to both enhancement and decrease of neuronal response rates. LFP power changes and the correlated changes in the locking between spikes and LFP at different frequencies observed for the learned odor serve as further evidence for a learning-induced restructuring of temporal ensemble representations.

  19. Odor and pheromone sensing via chemoreceptors.

    PubMed

    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.

  20. Surface enhanced vibrational spectroscopy for the detection of explosives

    NASA Astrophysics Data System (ADS)

    Büttner, Fritjof; Hagemann, Jan; Wellhausen, Mike; Funke, Sebastian; Lenth, Christoph; Rotter, Frank; Gundrum, Lars; Plachetka, Ulrich; Moormann, Christian; Strube, Moritz; Walte, Andreas; Wackerbarth, Hainer

    2013-10-01

    A detector which can detect a broad range of explosives without false alarms is urgently needed. Vibrational spectroscopy provides specific spectral information about molecules enabling the identification of analytes by their "fingerprint" spectra. The low detection limit caused by the inherent weak Raman process can be increased by the Surface Enhanced Raman (SER) effect. This is particularly attractive because it combines low detection limits with high information content for establishing molecular identity. Based on SER spectroscopy we have constructed a modular detection system. Here, we want to show a combination of SER spectroscopy and chemometrics to distinguish between chemically similar substances. Such an approach will finally reduce the false alarm rate. It is still a challenge to determine the limit of detection of the analyte on a SER substrate or its enhancement factor. For physisorbed molecules we have applied a novel approach. By this approach the performance of plasmonic substrates and Surface Enhanced Raman Scattering (SERS) enhancement of explosives can be evaluated. Moreover, novel nanostructured substrates for surface enhanced IR absorption (SEIRA) spectroscopy will be presented. The enhancement factor and a limit of detection are estimated.

  1. Metallic Nanomaterials for Sensitivity Enhancement of Fluorescence Detection

    PubMed Central

    Goldys, Ewa M.; Xie, Fang

    2008-01-01

    Utrasensitive detection of trace analytes by fluorescence benefits for fluorescence amplifying substrates. We review here our recent work concerned with understanding of enhancement mechanisms and formation of three such substrates: silver fractals, silver coated gold nanoparticles deposited on glass and fluorescence enhancing gold colloids. PMID:27879741

  2. Readily implemented enhanced sinusoid detection in noise

    SciTech Connect

    Lindsay, K.V.

    1992-03-05

    Significant efforts have been devoted, spanning many years, to the problem of sinusoid detection in noise. Many of these efforts have produced superb, yet complex, algorithms which may be difficult to use for a wide segment of the Digital Signal Processing (DSP) community. This paper presents a simple, easily implemented and high effective method which solves this problem. This method severely degrades non-sinusoidal noise while leaving the embedded sinusoid(s) relatively undisturbed. The algorithm, simply put, exploits the difference between the net effect of integration and differentiation of sinusoids versus the effect of these operations on random noise and other signal sequences. The cross-correlation of sine wave with its differentiated (and/or integrated) self is quite high. Conversely, the cross-reduction of a noise sequence with its differentiated (and/or integrated) self is much lower. Therefore, it is reasonable to assume that for sequences consisting of a sinusoid in noise, significant signal-to-noise-ratios (SNRs) in the correlation results are achievable using a combination of differentiation (and/or integration) and cross-correlation operations on such sequences. This technique has been applied to actual Doppler radar data, as well as to synthesized data, with excellent improvement in signal detection capability. 4 refs.

  3. Effect of information about odor on causal ascriptions for illness.

    PubMed

    Williams, C W; Lees-Haley, P R

    1997-10-01

    The effect of information about detection of an odor on causal ascriptions for illness was investigated. In four different scenarios perceptions regarding the cause of a hypothetical symptomatic experience were compared for events described with and without an odor. Participants (N = 106) were asked to imagine themselves becoming ill after engaging in several common experiences, including pumping gasoline at a service station. In two scenarios participants read that they smelled an offensive odor while pumping the gasoline whereas in two other scenarios no information about an odor was provided. Further, information about gasoline described with or without odor was presented either early or late in the stimulus paragraphs. All participants then responded to questions including an open-ended question asking them to make causal attributions for their illness. Participants in the odor-suggested group ascribed the cause of illness more frequently to gasoline and perceived the probability of other potential causes as lower than did participants in the nonodor suggested group. Findings suggest that peoples' implicit theories about toxicity contain causal connections between malodorous stimuli and illness. The implications of implicit theories for perception of illness are discussed.

  4. Bias of Tedlar bags in the measurement of agricultural odorants.

    PubMed

    Trabue, Steven L; Anhalt, Jennifer C; Zahn, James A

    2006-01-01

    Odor regulations typically specify the use of dynamic dilution olfactometery (DDO) as a method to quantify odor emissions, and Tedlar bags are the preferred holding container for grab samples. This study was conducted to determine if Tedlar bags affect the integrity of sampled air from animal operations. Air samples were collected simultaneously in both Tedlar bags and Tenax thermal desorption tubes. Sample sources originated from either a hydrocarbon-free air tank, dynamic headspace chamber (DHC), or swine-production facility, and were analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). Several background contaminants were identified from Tedlar bags, which included the odorous compounds N,N-dimethyl acetamide (DMAC), acetic acid, and phenol. Samples from the DHC demonstrated that recovery of malodor compounds was dependent on residence time in the Tedlar bag with longer residence time leading to lower recovery. After 24 h of storage, recovery of C3-C6 volatile fatty acids (VFA) averaged 64%, 4-methylphenol and 4-ethylphenol averaged 10%, and indole and 3-methylindole were below the detection limits of GC-MS-O. The odor activity value (OAV) of grab samples collected in Tedlar bags were 33 to 65% lower following 24 h of storage. These results indicate that significant odorant bias occurs when using Tedlar bags for the sampling of odors from animal production facilities.

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

    PubMed Central

    Gonzalez-Kristeller, Daniela C.; do Nascimento, João B. P.; Galante, Pedro A. F.; Malnic, Bettina

    2015-01-01

    Olfaction plays a critical role in several aspects of the human life. Odorants are detected by hundreds of odorant receptors (ORs) which belong to the superfamily of G protein-coupled receptors. These receptors are expressed in the olfactory sensory neurons of the nose. The information provided by the activation of different combinations of ORs in the nose is transmitted to the brain, leading to odorant perception and emotional and behavioral responses. There are ~400 intact human ORs, and to date only a small percentage of these receptors (~10%) have known agonists. The determination of the specificity of the human ORs will contribute to a better understanding of how odorants are discriminated by the olfactory system. In this work, we aimed to identify human specific ORs, that is, ORs that are present in humans but absent from other species, and their corresponding agonists. To do this, we first selected 22 OR gene sequences from the human genome with no counterparts in the mouse, rat or dog genomes. Then we used a heterologous expression system to screen a subset of these human ORs against a panel of odorants of biological relevance, including foodborne aroma volatiles. We found that different types of odorants are able to activate some of these previously uncharacterized human ORs. PMID:25784876

  6. Compost odor control using high carbon wood ash.

    PubMed

    Rosenfeld, P E; Grey, M A; Suffet, I H

    2004-01-01

    A pilot study on the feasibility of using high carbon wood ash to control composting odor emissions was conducted at a green material composting facility. The study's treatments consisted of adding 0%, 12.5%, and 25% high carbon wood ash by volume to green-material compost feedstock in three separate windrows. The wood ash has properties similar to activated carbon with an active surface area of 105 square metres per gram on a dry weight basis. The odorant emission data suggest that the higher percentage wood ash treatment results in the most effective control of most compost odors and that wood ash provides effective treatment of volatile fatty acids and some aldehydes and ketones. The 25% wood ash treatment resulted in more effective treatment of odors for a longer time period than the 12.5% treatment. Acetaldehyde had the highest concentration in the control (14,000 times its odor threshold concentration), was reduced by high carbon ash by over 97% but remained 386 times its reported odor threshold concentration after 14 days. Ethyl mecaptan and ammonia were produced in the process and were also over their reported human detection limits.

  7. [Dispersion and analysis of odor pollution in landfill area under the enclosed operation condition].

    PubMed

    Lu, Peng; Wu, Shi-Xing; Dai, Zhi-Feng; Zhang, Xiao-Hui; Su, Zhao-Hui; Zhou, Xiao-Fei; Dai, Zhan-Guo; Lu, Xu-Fei; Zheng, Bin; Shen, Kai; Wei, Pan-Ming

    2013-03-01

    Odor pollution of landfill site is a serious problem accompanied with the urbanization process that influences city life. Generally, odor emission points in landfill boundary are detected by experience, but the pollution intensity, distribution and variation in the scope of landfill boundary are difficulty to describe. In this research, odor emission points were disclosed with equal odor concentration curves that were delineated using electric nose and GPS instrument. The leakage of landfill gas and exhaust emission from biogas incineration torch was the main cause of the odor pollution in landfill area. Gas production evaluation suggested that the improvement of landfill gas consumption is the key point to control the odor pollution at the landfill site.

  8. A comparison of methods for the assessment of odor impacts on air quality: Field inspection (VDI 3940) and the air dispersion model CALPUFF

    NASA Astrophysics Data System (ADS)

    Ranzato, Laura; Barausse, Alberto; Mantovani, Alice; Pittarello, Alberto; Benzo, Maurizio; Palmeri, Luca

    2012-12-01

    Unpleasant odors are a major cause of public complaints concerning air quality and represent a growing social problem in industrialized countries. However, the assessment of odor pollution is still regarded as a difficult task, because olfactory nuisance can be caused by many different chemical compounds, often found in hard-to-detect concentrations, and the perception of odors is influenced by subjective thresholds; moreover, the impact of odor sources on air quality is mediated by complex atmospheric dispersion processes. The development of standardized assessment approaches to odor pollution and proper international regulatory tools are urgently needed. In particular, comparisons of the methodologies commonly used nowadays to assess odor impacts on air quality are required. Here, we assess the olfactory nuisance caused by an anaerobic treatment plant for municipal solid waste by means of two alternative techniques: the field inspection procedure and the atmospheric dispersion model CALPUFF. Our goal was to compare rigorously their estimates of odor nuisance, both qualitatively (spatial extent of odor impact) and quantitatively (intensity of odor nuisance). To define the impact of odors, we referred to the German standards, based on the frequency of odor episodes in terms of odor hours. We report a satisfying, although not perfect agreement between the estimates provided by the two techniques. For example, they assessed similar spatial extents of odor pollution, but different frequencies of odor episodes in locations where the odor nuisance was highest. The comparison highlights strengths and weaknesses for both approaches. CALPUFF is a cheaper methodology which can be used predictively, but fugitive emissions are difficult to model reliably, because of uncertainty regarding timing, location and emission rate. Field inspection takes into account the role of human perception, but unlike the model it does not always characterize precisely the extent of the odor

  9. Detection for processing history of seam insertion and contrast enhancement

    NASA Astrophysics Data System (ADS)

    Li, Jianwei; Zhao, Yao; Ni, Rongrong

    2014-11-01

    With the development of manipulations techniques of digital images, digital image forensic technology is becoming more and more necessary. However, the determination of processing history of multi-operation is still a challenge problem. In this paper, we improve the traditional seam insertion algorithm, and propose corresponding detection method. Then an algorithm that focuses on detecting the processing history of seam insertion and contrast enhancement is proposed, which can be widely used in practical image forgery. Based on comprehensive analysis, we have discovered the inherent relationship between seam insertion and contrast enhancement. Different orders of processing make different impacts on images. By using the newly proposed algorithm, both contrast enhancement followed by seam insertion and seam insertion followed by contrast enhancement can be detected correctly. Plenty of experiments have been implemented to prove the accuracy.

  10. Sonoclot(®)-based method to detect iron enhanced coagulation.

    PubMed

    Nielsen, Vance G; Henderson, Jon

    2016-07-01

    Thrombelastographic methods have been recently introduced to detect iron mediated hypercoagulability in settings such as sickle cell disease, hemodialysis, mechanical circulatory support, and neuroinflammation. However, these inflammatory situations may have heme oxygenase-derived, coexistent carbon monoxide present, which also enhances coagulation as assessed by the same thrombelastographic variables that are affected by iron. This brief report presents a novel, Sonoclot-based method to detect iron enhanced coagulation that is independent of carbon monoxide influence. Future investigation will be required to assess the sensitivity of this new method to detect iron mediated hypercoagulability in clinical settings compared to results obtained with thrombelastographic techniques.

  11. Enhanced sensitivity for hyperspectral infrared chemical detection

    SciTech Connect

    Jacobson, P. L.; Petrin, R. R.; Koskelo, A. C.; Quick, C. R.; Romero, J. J.

    2001-01-01

    The sensitivity of imaging, hyperspectral, passive remote sensors in the long-wavelength infrared (LWIR) spectral region is currently limited by the ability to achieve an accurate, time-invariant, pixel-to-pixel calibration of the elements composing the Focal Plane Array (FPA). Pursuing conventional techniques to improve the accuracy of the calibration will always be limited by the trade-off between the time required to collect calibration data of improved precision and the drift in the pixel response that occurs on a timescale comparable to the calibration time. This paper will present the results from a study of a method to circumvent these problems. Improvements in detection capability can be realized by applying a quick, repetitive dither of the field of view (FOV) of the imager (by a small angular amount), so that radiance/spectral differences between individual target areas can be measured by a single FPA pixel. By performing this difference measurement repetitively both residual differences in the pixel-to-pixel calibration and l/f detector drift noise can effectively be eliminated. In addition, variations in the atmosphere and target scene caused by the motion of the sensor platform will cause signal drifts that this technique would be able to remove. This method allows improvements in sensitivity that could potentially scale as the square root of the observation time.

  12. Factors Influencing Odor Sensitivity in the Dog

    DTIC Science & Technology

    1974-10-01

    and Discussion 22 PART iI: RELATION BETWEEN PROGESTERONE LEVELS AND FZRFL.PRANCE OF F• MALE RATS 01. AN ODOR DETECTION TASK 25 Method 26 Results ard...curves for c-ionone in three male human subjects(4.5. x 10 9 moles/cm3 refers to the mean detection threshold).Eac’t point on the curve is the mean (+ SE...Subjects. Two female and one male German Shepherd were used. One female was about three years old at the start of the experiments while the other dogs were

  13. Preservation of Essential Odor-Guided Behaviors and Odor-Based Reversal Learning after Targeting Adult Brain Serotonin Synthesis

    PubMed Central

    Carlson, Kaitlin S.

    2016-01-01

    Abstract The neurotransmitter serotonin (5-HT) is considered a powerful modulator of sensory system organization and function in a wide range of animals. The olfactory system is innervated by midbrain 5-HT neurons into both its primary and secondary odor-processing stages. Facilitated by this circuitry, 5-HT and its receptors modulate olfactory system function, including odor information input to the olfactory bulb. It is unknown, however, whether the olfactory system requires 5-HT for even its most basic behavioral functions. To address this question, we established a conditional genetic approach to specifically target adult brain tryptophan hydroxylase 2 (Tph2), encoding the rate-limiting enzyme in brain 5-HT synthesis, and nearly eliminate 5-HT from the mouse forebrain. Using this novel model, we investigated the behavior of 5-HT–depleted mice during performance in an olfactory go/no-go task. Surprisingly, the near elimination of 5-HT from the forebrain, including the olfactory bulbs, had no detectable effect on the ability of mice to perform the odor-based task. Tph2-targeted mice not only were able to learn the task, but also had levels of odor acuity similar to those of control mice when performing coarse odor discrimination. Both groups of mice spent similar amounts of time sampling odors during decision-making. Furthermore, odor reversal learning was identical between 5-HT–depleted and control mice. These results suggest that 5-HT neurotransmission is not necessary for the most essential aspects of olfaction, including odor learning, discrimination, and certain forms of cognitive flexibility. PMID:27896310

  14. An enhanced stream mining approach for network anomaly detection

    NASA Astrophysics Data System (ADS)

    Bellaachia, Abdelghani; Bhatt, Rajat

    2005-03-01

    Network anomaly detection is one of the hot topics in the market today. Currently, researchers are trying to find a way in which machines could automatically learn both normal and anomalous behavior and thus detect anomalies if and when they occur. Most important applications which could spring out of these systems is intrusion detection and spam mail detection. In this paper, the primary focus on the problem and solution of "real time" network intrusion detection although the underlying theory discussed may be used for other applications of anomaly detection (like spam detection or spy-ware detection) too. Since a machine needs a learning process on its own, data mining has been chosen as a preferred technique. The object of this paper is to present a real time clustering system; we call Enhanced Stream Mining (ESM) which could analyze packet information (headers, and data) to determine intrusions.

  15. Comparison of odor-active volatile compounds of fresh and smoked salmon.

    PubMed

    Varlet, Vincent; Knockaert, Camille; Prost, Carole; Serot, Thierry

    2006-05-03

    The odorant volatile compounds of raw salmon and smoked salmon have been investigated by two gas chromatography-olfactometry methods (frequency detection and odorant intensity) and gas chromatography-mass spectrometry. After simultaneous steam distillation-solvent extraction with diethyl ether and the recovery of the aromatic extract in ethanol, qualitative olfactometric characterization and identification followed by a quantitative assessment of the odorant volatile compounds were carried out. The origin of many odorant compounds of smoked salmon can be attributed to wood smoke. Another part of smoked salmon aroma is due either to the odorant compounds of the raw fish flesh or to an evolution of fish flesh aroma thanks to the smoking process conditions. Forty-nine odorant compounds have been identified in fresh salmon and 74 in smoked salmon. Carbonyl compounds, such as heptanal or (E,Z)-2,6-nonadienal, show a high detection frequency and odorant intensity in unsmoked fish, giving the flesh its typical fishy odor. For smoked salmon, phenolic compounds, such as cresol or guaiacol, and furanic compounds seem to be responsible for the smoked odor.

  16. Mice with a “Monoclonal” Nose: Perturbations in an Olfactory Map Impair Odor Discrimination

    PubMed Central

    Fleischmann, Alexander; Shykind, Benjamin M.; Sosulski, Dara L.; Franks, Kevin M.; Glinka, Meredith E.; Mei, Dan Feng; Sun, Yonghua; Kirkland, Jennifer; Mendelsohn, Monica; Albers, Mark W.; Axel, Richard

    2009-01-01

    SUMMARY The recognition of odors is accomplished in the sensory epithelium where individual olfactory neurons express only one of 1,300 odorant receptor genes. Neurons expressing a given receptor project to two spatially invariant glomeruli in the olfactory bulb such that each odor elicits a distinct and sparse pattern of glomerular activity. We have altered the neural representation of odors in the brain by generating a mouse with a “monoclonal nose” in which greater than 95% of the sensory neurons express a single odorant receptor, M71. As a consequence, the frequency of sensory neurons expressing endogenous receptor genes is reduced twenty-fold. We observe that these mice can smell but odor discrimination and performance in associative olfactory learning tasks are impaired. However, these mice cannot detect the M71 ligand acetophenone despite the observation that virtually all sensory neurons and glomeruli are activated by this odor. The M71 transgenic mice readily detect other odors in the presence of acetophenone. These observations have implications for how receptor activation in the periphery is represented in the brain and how these representations encode odors. PMID:19109912

  17. Congruent sound can modulate odor pleasantness.

    PubMed

    Seo, Han-Seok; Lohse, Franziska; Luckett, Curtis R; Hummel, Thomas

    2014-03-01

    This study aimed to determine 1) whether certain background sounds can be matched with specific odors and 2) whether the background sounds can increase pleasantness for their congruent odors. In Experiment 1, congruent sounds increased odor pleasantness, but not odor intensity, significantly more than incongruent sounds. Experiment 2 demonstrated that certain background sounds can be paired with specific odors. For example, cinnamon, clove, and orange odors were rated significantly more congruent with a Christmas carol compared with the sound of brushing teeth and/or the beach sound. The congruent sounds increased odor pleasantness significantly more than incongruent sounds. Similarly, the congruent sound-induced odor pleasantness was observed in Experiment 3. As participants judged the pair of odor and sound to be more congruent, they rated the odor significantly more pleasant. Congruent sound assisted participants in identifying and in being familiar with the odor, thereby leading to an increase in odor pleasantness. However, the congruent sound-induced odor pleasantness was not obtained in all odors. In conclusion, this study provides new empirical evidence that pleasantness ratings for odors can increase in the presence of their congruent sounds.

  18. Odorization of combustible hydrocarbon gases

    SciTech Connect

    Yoshida, T.; Katz, I.; Warren, C. B.; Wiener, C.

    1984-12-11

    Described is a warning agent for the odorization of gaseous hydrocarbon fuels based on mixtures of at least one of the compounds, 2-methooxy-3-isobutyl pyrazine and 4-methyl-4-mercapto-2-pentanone with a monomercaptan or a sulfide.

  19. Odorization in a small town

    SciTech Connect

    1997-04-01

    This application for Low Volume Odorization leads to the proactive town of Berwick, LA, located in the bayous 120 miles southeast of New Orleans. Like many municipal systems, Berwick provides distribution for electric, water and gas for its 4,800 residents. As with many small distribution systems, Berwick was operating a wick odorizor at its city gate station, which received its supply gas from a river crossing. After experiencing several barge accidents that interrupted the gas supply to the city gate, Berwick decided to build a new city gate station with a gas supply delivery from a new direction, thus improving its reliability. With that decision, the next question they asked was whether to continue with a wick method odorization system or integrate state-of-the-art methods in the odorization program. The company investigated electronic odorization as an alternative. The paper discusses system changes and system performance.

  20. Photonic crystal enhanced fluorescence for early breast cancer biomarker detection.

    PubMed

    Cunningham, Brian T; Zangar, Richard C

    2012-08-01

    Photonic crystal surfaces offer a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics. Through the complementary processes of photonic crystal enhanced excitation and enhanced extraction, a periodic dielectric-based nanostructured surface can simultaneously increase the electric field intensity experienced by surface-bound fluorophores and increase the collection efficiency of emitted fluorescent photons. Through the ability to inexpensively fabricate photonic crystal surfaces over substantial surface areas, they are amenable to single-use applications in biological sensing, such as disease biomarker detection in serum. In this review, we will describe the motivation for implementing high-sensitivity, multiplexed biomarker detection in the context of breast cancer diagnosis. We will summarize recent efforts to improve the detection limits of such assays though the use of photonic crystal surfaces. Reduction of detection limits is driven by low autofluorescent substrates for photonic crystal fabrication, and detection instruments that take advantage of their unique features.

  1. Enhanced urinalysis in the detection of asymptomatic bacteriuria in pregnancy.

    PubMed

    Aigere, E O S; Okusanya, B O; Eigbefoh, J O; Okome, G B O

    2013-01-01

    Detection and treatment of asymptomatic bacteriuria (ASB) in pregnancy is important to avert the attendant maternal and fetal morbidity. Other than urine culture, no other screening test is unequivocal. The use of enhanced urinalysis test to detect ASB in pregnancy was investigated. This was a prospective observational study which compared enhanced urinalysis with dipstick tests and urine culture. Clean catch midstream urine specimen was collected from 150 consecutive asymptomatic pregnant women. Tests of validity were used for comparison. Enhanced urinalysis detected bacteriuria as much as urine culture (4% vs. 4.7%). Itwas 57.1% sensitive and 98.6% specific. It had a false negative rate of 42.9% and was 96.7% accurate when compared to urine culture. Enhanced urinalysis took 1-2 hours to be done and required skills to use the microscope and was more expensive than dipstick urinalysis. The accuracy of enhanced urinalysis and its ability to detect ASB as much as urine culture connotes that it can be used to detect asymptomatic bacteriuria in pregnancy albeit only in secondary and tertiary health centres because of the cost and technicality involved.

  2. Neonatal Responsiveness to the Odor of Amniotic and Lacteal Fluids: A Test of Perinatal Chemosensory Continuity.

    ERIC Educational Resources Information Center

    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…

  3. Retronasal odor of dried bonito stock induces umami taste and improves the palatability of saltiness.

    PubMed

    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.

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

    PubMed Central

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

    2013-01-01

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

  5. Unexpected plant odor responses in a moth pheromone system

    PubMed Central

    Rouyar, Angéla; Deisig, Nina; Dupuy, Fabienne; Limousin, Denis; Wycke, Marie-Anne; Renou, Michel; Anton, Sylvia

    2015-01-01

    Male moths rely on olfactory cues to find females for reproduction. Males also use volatile plant compounds (VPCs) to find food sources and might use host-plant odor cues to identify the habitat of calling females. Both the sex pheromone released by conspecific females and VPCs trigger well-described oriented flight behavior toward the odor source. Whereas detection and central processing of pheromones and VPCs have been thought for a long time to be highly separated from each other, recent studies have shown that interactions of both types of odors occur already early at the periphery of the olfactory pathway. Here we show that detection and early processing of VPCs and pheromone can overlap between the two sub-systems. Using complementary approaches, i.e., single-sensillum recording of olfactory receptor neurons, in vivo calcium imaging in the antennal lobe, intracellular recordings of neurons in the macroglomerular complex (MGC) and flight tracking in a wind tunnel, we show that some plant odorants alone, such as heptanal, activate the pheromone-specific pathway in male Agrotis ipsilon at peripheral and central levels. To our knowledge, this is the first report of a plant odorant with no chemical similarity to the molecular structure of the pheromone, acting as a partial agonist of a moth sex pheromone. PMID:26029117

  6. Could contrast-enhanced CT detect STEMI prior to electrocardiogram?

    PubMed

    Sabbagh, Chadi; Rahi, Mayda; Baz, Maria; Haddad, Fadi; Helwe, Omar; Aoun, Noel; Ibrahim, Tony; Abdo, Lynn

    2015-01-01

    We present here a case in which contrast-enhanced computed tomography (CT) was the first diagnostic tool to detect myocardial hypoperfusion in a patient with atypical symptoms and normal electrocardiogram (ECG) on admission. An ST-segment elevation was detected thereafter on a second ECG realized several minutes after CT with raised troponin levels. Percutaneous coronary intervention was performed after failure of thrombolysis and confirmed occlusion of the left anterior descending artery. Further studies are needed to evaluate the role of high-resolution contrast-enhanced CT with or without coronary angiography in the workup of suspected myocardial infarction in the setting of a normal ECG.

  7. The relationship between chemical concentration and odor activity value explains the inconsistency in making a comprehensive surrogate scent training tool representative of illicit drugs.

    PubMed

    Rice, Somchai; Koziel, Jacek A

    2015-12-01

    This report highlights the importance of an individual chemical's odor impact in the olfactory identification of marijuana, cocaine, and heroin. There are small amounts of highly odorous compounds present in headspace of these drugs, with very low odor detection thresholds, that are more likely responsible for contributing to the overall odor of these drugs. Previous reports of the most abundant compounds in headspace can mislead researchers when dealing with whole odor of these drugs. Surrogate scent formulations, therefore, must match the odor impact of key compounds and not just the chemical abundance of compounds. The objective of this study was to compare odorous volatile organic compounds (VOCs) emitted from illicit drug samples of marijuana, cocaine, and heroin to surrogate smell formulations using simultaneous sensory (via human olfaction) and chemical analyses. Use of solid phase microextraction (SPME) allowed VOCs in drug headspace to be extracted and pre-concentrated on site, and analyzed by multidimensional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O). Use of MDGC-MS-O allowed for further separation of odorous compounds and simultaneous detection by the human nose of the separate odor parts that make up the total aroma of these drugs. The compounds most abundant in headspace were not the most odor impactful when ranked by odor activity values (OAVs) (defined as ratio of concentration to odor detection threshold, ODT). There were no apparent correlations between concentrations and OAVs. A 1g marijuana surrogate lacked in odor active acids, aldehydes, ethers, hydrocarbons, N-containing, and S-containing VOCs and was overabundant in odor active alcohols and aromatics compared with real marijuana. A 1g cocaine surrogate was overabundant in odor active alcohols, aldehydes, aromatics, esters, ethers, halogenates, hydrocarbons, ketones and N-containing compounds compared with real. A 1g heroin surrogate should contain less odor active acids

  8. Interplay between sniffing and odorant sorptive properties in the rat

    PubMed Central

    Rojas-Líbano, Daniel; Kay, Leslie M.

    2012-01-01

    For decades it has been known that the olfactory sensory epithelium can act like a chromatograph, separating odorants based on their air-mucus sorptive properties (Mozell and Jagodowicz, 1973). It has been hypothesized that animals could take advantage of this property, modulating sniffing behavior to manipulate airflow and thereby direct odorant molecules to the portions of the olfactory epithelium where they are best detected (Schoenfeld and Cleland, 2005). We report here a test of this hypothesis in behaving rats, monitoring respiratory activity through diaphragm EMG, which allowed us to estimate nasal airflow. In our test rats had to detect either low-sorption (LS) or high-sorption (HS) monomolecular odorant targets from the same stimulus set of six binary odor mixtures. We found that it is more difficult for rats to detect LS than HS targets. Even though sniffing bouts are the same duration for each group (approximately 500 ms), sniffing longer and using more inhalations results in better performance for rats assigned to detect LS targets. LS-detecting rats also increase the duration of individual inhalations (81 msec for LS- vs. 69 msec for HS-detecting rats) and sniff at lower frequencies (7.8 Hz for LS- vs. 8.6 Hz for HS-detecting rats) when learning to sense the target. When LS-detecting rats do discriminate well, they do so with lower airflow, more sniffs and lower frequency sniffing than HS-detecting counterparts. These data show that rats adjust sniff strategies as a function of odorant sorptiveness and provide support for the chromatographic and zonation hypotheses. PMID:23115193

  9. Measurement of biosolids compost odor emissions from a windrow, static pile, and biofilter.

    PubMed

    Rosenfeld, Paul; Grey, Mark; Sellew, Paul

    2004-01-01

    A pilot study was conducted to compare odor emissions from a windrow process and an aerated static pile and to determine the odor reduction efficiency of a pilot two-phase biofilter for odor control of biosolids composting. Chemical compounds identified as responsible for odors from biosolids composting include ammonia, dimethyl disulfide, carbon disulfide, formic acid, acetic acid, and sulfur dioxide (or carbonyl sulfide). Aeration was found to reduce the concentration of ammonia, formic acid, and acetic acid by 72, 57, and 11%, respectively, compared with a nearby windrow, while dimethyl sulfide, carbon disulfide, and sulfur dioxide (or carbonyl sulfide) concentrations were below detection limits. Using dilution-to-threshold olfactometry, aeration followed by biofiltration was found to reduce the odor from biosolids composting by 98%. Biofiltration also altered the character of odor emissions from biosolids composting, producing a less offensive odor with an earthy character. Biofiltration was found to reduce the concentration of ammonia, dimethyl disulfide, carbon disulfide, formic acid, acetic acid, and sulfur dioxide (or carbonyl sulfide) by 99, 90, 32, 100, 34, and 100%, respectively. The concentrations of those odorants were estimated to be 3700, 110000, 26,37,5, and 1.2 times reported human detection limits before the two-phase biofilter, respectively, and 42,9600,18,0,3, and 0 times human detection limits after the biofilter, respectively.

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

    PubMed

    Cometto-Muñiz, J E; Hernández, S M

    1990-04-01

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

  11. Identification of the main odor-active compounds in musts from French and Romanian hybrids by three olfactometric methods.

    PubMed

    Serot, T; Prost, C; Visan, L; Burcea, M

    2001-04-01

    Three olfactometric methods (frequency of detection, time--intensity method, and aroma extract dilution analysis) were used to evaluate the main odorants of three musts obtained from French--Romanian hybrids (Valerien, Admira, and Brumariu). The three methods allow detection of the same odor-active compounds. The results obtained from these methods were closely related. Nineteen odor-active compounds were detected, and 13 were identified. The three methods showed the importance of an unidentified compound with a grape and grape juice aroma note in the three musts. Among the other compounds, 3-hexen-1-al, (E,Z)-2,6-nonadien-1-ol, and 1-ccten-3-one seemed to contribute actively to the odor of Valerien must. 3-(Methylthio)propanal and hexanal were contributors to the Admira and Brumariu odor. Phenylacetaldehyde was one of the main odor-active compounds in must from Admira.

  12. Olfactory speed - Temporal odor processing of paired stimuli.

    PubMed

    Schriever, V A; Frenzel, C; Wernecke, S; Croy, I; Valder, C; Hummel, T

    2015-06-04

    Compared to other senses, temporal perception of odors seems fairly slow. In addition it has been shown in previous studies that even not consciously perceived odors could influence our behavior. Aim of the current study therefore was to study the interstimulus interval (ISI) length, which is necessary between two repetitive stimuli to be able to perceive them separately. The additional aim focused on observing central odor processing of not perceived odorous stimuli. The study was divided into three parts. In each part healthy, normosmic volunteers were included. In part I and II stimulus pairs (CO2, H2S, orange and phenyl ethyl alcohol (PEA)) were presented to the subjects via a computer-controlled olfactometer with short ISI of 0.6-9s. The decision whether one or two stimuli were perceived was recorded. In addition the influence of odor valence, trigeminallity and concentrations was observed. In part III olfactory event-related potentials (OERPs) to perceived and not-perceived odors were recorded. The two stimuli of a stimulus pair were perceived separately more often with increasing ISI length. This increase was significant until an ISI between the stimuli of 4s. Odor intensity, pleasantness, trigeminallity and sex had no major influence on this. In addition we were able to observe that OERPs are less often detected in response to not perceived olfactory stimuli. However, the presence of OERP in response to not perceived stimuli in more than half of the cases indicated that even not perceived stimuli are centrally processed. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2006-04-01

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

  14. Light-weight analyzer for odor recognition

    DOEpatents

    Vass, Arpad A; Wise, Marcus B

    2014-05-20

    The invention provides a light weight analyzer, e.g., detector, capable of locating clandestine graves. The detector utilizes the very specific and unique chemicals identified in the database of human decompositional odor. This detector, based on specific chemical compounds found relevant to human decomposition, is the next step forward in clandestine grave detection and will take the guess-work out of current methods using canines and ground-penetrating radar, which have historically been unreliable. The detector is self contained, portable and built for field use. Both visual and auditory cues are provided to the operator.

  15. Longer latency of sensory response to intravenous odor injection predicts olfactory neural disorder

    PubMed Central

    Kikuta, Shu; Matsumoto, Yu; Kuboki, Akihito; Nakayama, Tsuguhisa; Asaka, Daiya; Otori, Nobuyoshi; Kojima, Hiromi; Sakamoto, Takashi; Akinori, Kashio; Kanaya, Kaori; Ueha, Rumi; Kagoya, Ryoji; Nishijima, Hironobu; Toma-Hirano, Makiko; Kikkawa, Yayoi; Kondo, Kenji; Tsunoda, Koichi; Miyaji, Tempei; Yamaguchi, Takuhiro; Kataoka, Kazunori; Mori, Kensaku; Yamasoba, Tatsuya

    2016-01-01

    A near loss of smell may result from conductive and/or neural olfactory disorders. However, an olfactory test to selectively detect neural disorders has not been established. We investigated whether onset latency of sensory response to intravenous odor injection can detect neural disorders in humans and mice. We showed that longer preoperative onset latency of odor recognition to intravenous odor in patients with chronic rhinosinusitis predicted worse recovery of olfactory symptoms following sinus surgery. The onset latency of the olfactory sensory neuron (OSN) response to intravenous odor using synaptopHluorin signals from OSN axon terminals was delayed in mice with reduced numbers of OSNs (neural disorder) but not with increased mucus or blocked orthonasal pathways (conductive disorders). Moreover, the increase in onset latency correlated with the decrease in mature OSN numbers. Longer onset latency to intravenous odor injection is a useful biomarker for presence and severity of olfactory disorders with neural etiology. PMID:27734933

  16. Sparse representation-based ECG signal enhancement and QRS detection.

    PubMed

    Zhou, Yichao; Hu, Xiyuan; Tang, Zhenmin; Ahn, Andrew C

    2016-12-01

    Electrocardiogram (ECG) signal enhancement and QRS complex detection is a critical preprocessing step for further heart disease analysis and diagnosis. In this paper, we propose a sparse representation-based ECG signal enhancement and QRS complex detection algorithm. Unlike traditional Fourier or wavelet transform-based methods, which use fixed bases, the proposed algorithm models the ECG signal as the superposition of a few inner structures plus additive random noise, where these structures (referred to here as atoms) can be learned from the input signal or a training set. Using these atoms and their properties, we can accurately approximate the original ECG signal and remove the noise and other artifacts such as baseline wandering. Additionally, some of the atoms with larger kurtosis values can be modified and used as an indication function to detect and locate the QRS complexes in the enhanced ECG signals. To demonstrate the robustness and efficacy of the proposed algorithm, we compare it with several state-of-the-art ECG enhancement and QRS detection algorithms using both simulated and real-life ECG recordings.

  17. Comodulation Enhances Signal Detection via Priming of Auditory Cortical Circuits

    PubMed Central

    Sollini, Joseph

    2016-01-01

    Acoustic environments are composed of complex overlapping sounds that the auditory system is required to segregate into discrete perceptual objects. The functions of distinct auditory processing stations in this challenging task are poorly understood. Here we show a direct role for mouse auditory cortex in detection and segregation of acoustic information. We measured the sensitivity of auditory cortical neurons to brief tones embedded in masking noise. By altering spectrotemporal characteristics of the masker, we reveal that sensitivity to pure tone stimuli is strongly enhanced in coherently modulated broadband noise, corresponding to the psychoacoustic phenomenon comodulation masking release. Improvements in detection were largest following priming periods of noise alone, indicating that cortical segregation is enhanced over time. Transient opsin-mediated silencing of auditory cortex during the priming period almost completely abolished these improvements, suggesting that cortical processing may play a direct and significant role in detection of quiet sounds in noisy environments. SIGNIFICANCE STATEMENT Auditory systems are adept at detecting and segregating competing sound sources, but there is little direct evidence of how this process occurs in the mammalian auditory pathway. We demonstrate that coherent broadband noise enhances signal representation in auditory cortex, and that prolonged exposure to noise is necessary to produce this enhancement. Using optogenetic perturbation to selectively silence auditory cortex during early noise processing, we show that cortical processing plays a crucial role in the segregation of competing sounds. PMID:27927950

  18. Asphaltene detection using surface enhanced Raman scattering (SERS).

    PubMed

    Alabi, O O; Edilbi, A N F; Brolly, C; Muirhead, D; Parnell, J; Stacey, R; Bowden, S A

    2015-04-28

    Surface enhanced Raman spectroscopy using a gold substrate and excitation at 514 nm can detect sub parts per million quantities of asphaltene and thereby petroleum. This simple format and sensitivity make it transformative for applications including sample triage, flow assurance, environmental protection and analysis of unique one of a kind materials.

  19. Nanostructured Surfaces and Detection Instrumentation for Photonic Crystal Enhanced Fluorescence

    PubMed Central

    Chaudhery, Vikram; George, Sherine; Lu, Meng; Pokhriyal, Anusha; Cunningham, Brian T.

    2013-01-01

    Photonic crystal (PC) surfaces have been demonstrated as a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics and life science research. PCs can be engineered to support optical resonances at specific wavelengths at which strong electromagnetic fields are utilized to enhance the intensity of surface-bound fluorophore excitation. Meanwhile, the leaky resonant modes of PCs can be used to direct emitted photons within a narrow range of angles for more efficient collection by a fluorescence detection system. The multiplicative effects of enhanced excitation combined with enhanced photon extraction combine to provide improved signal-to-noise ratios for detection of fluorescent emitters, which in turn can be used to reduce the limits of detection of low concentration analytes, such as disease biomarker proteins. Fabrication of PCs using inexpensive manufacturing methods and materials that include replica molding on plastic, nano-imprint lithography on quartz substrates result in devices that are practical for single-use disposable applications. In this review, we will describe the motivation for implementing high-sensitivity fluorescence detection in the context of molecular diagnosis and gene expression analysis though the use of PC surfaces. Recent efforts to improve the design and fabrication of PCs and their associated detection instrumentation are summarized, including the use of PCs coupled with Fabry-Perot cavities and external cavity lasers. PMID:23624689

  20. Nanostructured surfaces and detection instrumentation for photonic crystal enhanced fluorescence.

    PubMed

    Chaudhery, Vikram; George, Sherine; Lu, Meng; Pokhriyal, Anusha; Cunningham, Brian T

    2013-04-26

    Photonic crystal (PC) surfaces have been demonstrated as a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics and life science research. PCs can be engineered to support optical resonances at specific wavelengths at which strong electromagnetic fields are utilized to enhance the intensity of surface-bound fluorophore excitation. Meanwhile, the leaky resonant modes of PCs can be used to direct emitted photons within a narrow range of angles for more efficient collection by a fluorescence detection system. The multiplicative effects of enhanced excitation combined with enhanced photon extraction combine to provide improved signal-to-noise ratios for detection of fluorescent emitters, which in turn can be used to reduce the limits of detection of low concentration analytes, such as disease biomarker proteins. Fabrication of PCs using inexpensive manufacturing methods and materials that include replica molding on plastic, nano-imprint lithography on quartz substrates result in devices that are practical for single-use disposable applications. In this review, we will describe the motivation for implementing high-sensitivity fluorescence detection in the context of molecular diagnosis and gene expression analysis though the use of PC surfaces. Recent efforts to improve the design and fabrication of PCs and their associated detection instrumentation are summarized, including the use of PCs coupled with Fabry-Perot cavities and external cavity lasers.

  1. Pulse Onset Detection using Neighbor Pulse-Based Signal Enhancement

    PubMed Central

    Xu, Peng; Bergsneider, Marvin; Hu, Xiao

    2008-01-01

    Detecting onsets of cardiovascular pulse wave signals is an important prerequisite for successfully conducting various analysis tasks involving the concept of pulse wave velocity. However, pulse onsets are frequently influenced by inherent noise and artifacts in signals continuously acquired in a clinical environment. The present work proposed and validated a neighbor pulse-based signal enhancement algorithm for reducing error in the detected pulse onset locations from noise-contaminated pulsatile signals. Pulse onset was proposed to be detected using the first principal component extracted from three adjacent pulses. This algorithm was evaluated using test signals constructed by mixing arterial blood pressure, cerebral blood flow velocity and intracranial pressure pulses recorded from neurosurgical patients with white noise of various levels. The results showed that the proposed pulse enhancement algorithm improved (p < 0.05) pulse onset detection according to all three different onset definitions and for all three types of pulsatile signals as compared to results without using the pulse enhancement. These results suggested that the proposed algorithm could help achieve robustness in pulse onset detection and facilitate pulse wave analysis using clinical recordings. PMID:18632299

  2. Entanglement enhanced thermometry in the detection of the Unruh effect

    NASA Astrophysics Data System (ADS)

    Tian, Zehua; Wang, Jieci; Jing, Jiliang; Dragan, Andrzej

    2017-02-01

    We show how the use of entanglement can enhance the precision of the detection of the Unruh effect with an accelerated probe. We use a two-level atom interacting relativistically with a quantum field as the probe, and treat it as an open quantum system to derive the master equation governing its evolution. By means of quantum state discrimination, we detect the accelerated motion of the atom by examining its time evolving state. It turns out that the optimal strategy for the detection of the Unruh effect, to which the accelerated atom is sensitive, involves letting the atom-thermometer equilibrate with the thermal bath. However, introducing initial entanglement between the detector and an external degree of freedom leads to an enhancement of the sensitivity of the detector. Also, the maximum precision is attained within finite time, before equilibration takes place.

  3. Extraordinary sensitivity enhancement by metasurfaces in terahertz detection of antibiotics

    NASA Astrophysics Data System (ADS)

    Xie, Lijuan; Gao, Weilu; Shu, Jie; Ying, Yibin; Kono, Junichiro

    2015-03-01

    We have detected trace amounts of molecules of antibiotics (kanamycin sulfate) dispersed on metasurfaces with terahertz (THz) spectroscopy. Utilizing the extraordinary optical transmission resonance of an array of square-shaped slits on a silicon substrate at ~0.3 THz, we were able to monitor varying concentrations of kanamycin sulfate as low as ~100 picogram/L. In contrast, the lowest detectable concentration of kanamycin sulfate on silicon without any metallic structure was ~1 gram/L. This dramatic ~1010 times enhancement of sensitivity is due to the near-field enhancement of THz electric fields by the metamaterial structure. This result thus demonstrates the power and usefulness of metamaterial-assisted THz spectroscopy in trace molecular detection for biological and chemical sensing as well as for food product quality and safety inspection and control.

  4. Extraordinary sensitivity enhancement by metasurfaces in terahertz detection of antibiotics

    PubMed Central

    Xie, Lijuan; Gao, Weilu; Shu, Jie; Ying, Yibin; Kono, Junichiro

    2015-01-01

    We have detected trace amounts of molecules of antibiotics (kanamycin sulfate) dispersed on metasurfaces with terahertz (THz) spectroscopy. Utilizing the extraordinary optical transmission resonance of an array of square-shaped slits on a silicon substrate at ~0.3 THz, we were able to monitor varying concentrations of kanamycin sulfate as low as ~100 picogram/L. In contrast, the lowest detectable concentration of kanamycin sulfate on silicon without any metallic structure was ~1 gram/L. This dramatic ~1010 times enhancement of sensitivity is due to the near-field enhancement of THz electric fields by the metamaterial structure. This result thus demonstrates the power and usefulness of metamaterial-assisted THz spectroscopy in trace molecular detection for biological and chemical sensing as well as for food product quality and safety inspection and control. PMID:25728144

  5. Site-Selective Surface-Enhanced Raman Detection of Proteins.

    PubMed

    Matteini, Paolo; Cottat, Maximilien; Tavanti, Francesco; Panfilova, Elizaveta; Scuderi, Mario; Nicotra, Giuseppe; Menziani, Maria Cristina; Khlebtsov, Nikolai; de Angelis, Marella; Pini, Roberto

    2017-01-24

    Strategies for protein detection via surface-enhanced Raman spectroscopy (SERS) currently exploit the formation of randomly generated hot spots at the interfaces of metal colloidal nanoparticles, which are clustered together by intrusive chemical or physical processes in the presence of the target biomolecule. We propose a different approach based on selective and quantitative gathering of protein molecules at regular hot spots generated on the corners of individual silver nanocubes in aqueous medium at physiological pH. Here, the protein, while keeping its native configuration, experiences an intense local E-field, which boosts SERS efficiency and detection sensitivity. Uncontrolled signal fluctuations caused by variable molecular adsorption to different particle areas or inside clustered nanoparticles are circumvented. Advanced electron microscopy analyses and computational simulations outline a strategy relying on a site-selective mechanism with superior Raman signal enhancement, which offers the perspective of highly controlled and reproducible routine SERS detection of proteins.

  6. Proposed Objective Odor Control Test Methodology for Waste Containment

    NASA Technical Reports Server (NTRS)

    Vos, Gordon

    2010-01-01

    The Orion Cockpit Working Group has requested that an odor control testing methodology be proposed to evaluate the odor containment effectiveness of waste disposal bags to be flown on the Orion Crew Exploration Vehicle. As a standardized "odor containment" test does not appear to be a matter of record for the project, a new test method is being proposed. This method is based on existing test methods used in industrial hygiene for the evaluation of respirator fit in occupational settings, and takes into consideration peer reviewed documentation of human odor thresholds for standardized contaminates, industry stardnard atmostpheric testing methodologies, and established criteria for laboratory analysis. The proposed methodology is quantitative, though it can readily be complimented with a qualitative subjective assessment. Isoamyl acetate (IAA - also known at isopentyl acetate) is commonly used in respirator fit testing, and there are documented methodologies for both measuring its quantitative airborne concentrations. IAA is a clear, colorless liquid with a banana-like odor, documented detectable smell threshold for humans of 0.025 PPM, and a 15 PPB level of quantation limit.

  7. Nanocellulose-Zeolite Composite Films for Odor Elimination.

    PubMed

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

    2015-07-08

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

  8. Odor and odorous chemical emissions from animal buildings: Part 3. Chemical emissions

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to measure the long-term odor emissions and corresponding concentrations and emissions of 20 odorous volatile organic compounds (VOCs). This study was an add-on study to the National Air Emission Monitoring Study (NAEMS). Odor and odorous gas measurements at four NAEM...

  9. Odor and odorous chemical emissions from animal buildings: Part 3 - chemical emissions

    USDA-ARS?s Scientific Manuscript database

    This study was an add-on study to the National Air Emission Monitoring Study (NAEMS). The objective of this study was to measure odor emissions and corresponding concentrations and emissions of target odorous gases. Odor and odorous gas measurements at four NAEMS sites (dairy barns in Wisconsin-WI5B...

  10. Offensive odorants released from stormwater catch basins (SCB) in an urban area.

    PubMed

    Kabir, Ehsanul; Kim, Ki-Hyun; Ahn, Ji-Won; Hong, One-Feel; Chang, Y-S

    2010-09-01

    The potent role of stormwater catch basins (SCB) as a source of malodor in urban areas has been recognized because of its active involvement in the production and release of diverse odorants. Here, the status of odor pollution was investigated from two types of SCBs (i.e., wet and dry systems) by measuring a list of offensive odorants (i.e., reduced sulfur compounds (RSC), carbonyl compounds, nitrogenous, volatile organic compounds (VOCs), and fatty acids). Samples from those SCB systems were collected three times a day for five non-consecutive days. According to our study, H(2)S recorded consistently the highest mean values of 2554 ppb (wet) and 699 ppb (dry system) among all major offensive odorants. In contrast, the most prevalent VOCs were distinguished between methyl ethyl ketone (250 ppb in dry SCB) and toluene (32.8 ppb in wet SCB). In general, most odorants tend to exhibit relative enhancement in the afternoon, regardless of SCB types. If the concentration values of each odorant are converted into odor intensity (OI), the RSC group was identified as the key components of odor formation in SCB. If the OI values of each individual component are bound to yield sum of odor intensity (SOI), their values for wet and dry system were 4.99 and 4.25, respectively. In light of the fact that SCBs can serve as a potential odor source in urban areas, it should be managed and maintained properly to suppress the propagation of odor into the surrounding environments. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. 46 CFR 76.15-60 - Odorizing units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

  13. 46 CFR 76.15-60 - Odorizing units.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

  14. 46 CFR 76.15-60 - Odorizing units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

  15. 46 CFR 95.15-60 - Odorizing units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

  16. Ultrasensitive surface-enhanced Raman scattering detection in common fluids

    PubMed Central

    Yang, Shikuan; Dai, Xianming; Stogin, Birgitt Boschitsch; Wong, Tak-Sing

    2016-01-01

    Detecting target analytes with high specificity and sensitivity in any fluid is of fundamental importance to analytical science and technology. Surface-enhanced Raman scattering (SERS) has proven to be capable of detecting single molecules with high specificity, but achieving single-molecule sensitivity in any highly diluted solutions remains a challenge. Here we demonstrate a universal platform that allows for the enrichment and delivery of analytes into the SERS-sensitive sites in both aqueous and nonaqueous fluids, and its subsequent quantitative detection of Rhodamine 6G (R6G) down to ∼75 fM level (10−15 mol⋅L−1). Our platform, termed slippery liquid-infused porous surface-enhanced Raman scattering (SLIPSERS), is based on a slippery, omniphobic substrate that enables the complete concentration of analytes and SERS substrates (e.g., Au nanoparticles) within an evaporating liquid droplet. Combining our SLIPSERS platform with a SERS mapping technique, we have systematically quantified the probability, p(c), of detecting R6G molecules at concentrations c ranging from 750 fM (p > 90%) down to 75 aM (10−18 mol⋅L−1) levels (p ≤ 1.4%). The ability to detect analytes down to attomolar level is the lowest limit of detection for any SERS-based detection reported thus far. We have shown that analytes present in liquid, solid, or air phases can be extracted using a suitable liquid solvent and subsequently detected through SLIPSERS. Based on this platform, we have further demonstrated ultrasensitive detection of chemical and biological molecules as well as environmental contaminants within a broad range of common fluids for potential applications related to analytical chemistry, molecular diagnostics, environmental monitoring, and national security. PMID:26719413

  17. Olfactometric determination of the most potent odor-active compounds in salmon muscle (Salmo salar) smoked by using four smoke generation techniques.

    PubMed

    Varlet, Vincent; Serot, Thierry; Cardinal, Mireille; Knockaert, Camille; Prost, Carole

    2007-05-30

    The volatile compounds of salmon fillets smoked according to four smoked generation techniques (smoldering, thermostated plates, friction, and liquid smoke) were investigated. The main odor-active compounds were identified by gas chromatography coupled with olfactometry and mass spectrometry. Only the odorant volatile compounds detected by at least six judges (out of eight) were identified as potent odorants. Phenolic compounds and guaiacol derivatives were the most detected compounds in the olfactometric profile whatever the smoking process and could constitute the smoky odorant skeleton of these products. They were recovered in the aromatic extracts of salmon smoked by smoldering and by friction, which were characterized by 18 and 25 odor-active compounds, respectively. Furannic compounds were more detected in products smoked with thermostated plates characterized by 26 odorants compounds. Finally, the 27 odorants of products treated with liquid smoke were significantly different from the three others techniques applying wood pyrolysis because pyridine derivatives and lipid oxidation products were perceived in the aroma profile.

  18. Ultrasound enhanced detection of individual meningococcal serogroups by latex immunoassay

    PubMed Central

    Sobanski, M A; Vince, R; Biagini, G A; Cousins, C; Guiver, M; Gray, S J; Kaczmarski, E B; Coakley, W T

    2002-01-01

    Aims: To examine A, C, Y, and W135 Neisseria meningitidis serogroup characterisation by ultrasonic standing wave enhanced latex agglutination tests (USELATs) of clinical samples. In addition, to determine USELAT enhancement of detection sensitivity for the individual antigens compared with conventional card latex agglutination tests (LATs). Methods: Wellcogen (Abbott Murex), Slidex meningite kit 5 (bioMerieux), and Pastorex (Sanofi) kits and beads coated in house with antibodies to Y and to W135 alone were tested. Positive control antigens consisted of A and C polysaccharide preparations and the Pastorex Y/W135 kit sample. The limiting concentrations of antigen detection were determined by USELAT and by LAT. Thirty five clinical samples (plasma), previously characterised by the polymerase chain reaction (PCR) and culture, were tested by USELAT and, when sample volume allowed, by LAT. Results: USELAT enhancement of control antigen detection ranged from 16 to 128 fold for the different latex systems. Enhancements for the different control antigens were comparable between kits. USELAT tests of clinical (A/C/Y/W135) samples (n = 15) with the Wellcogen (A/C/Y/W135) and Slidex meningite (A/C/Y/W135) kits showed comparable specificities. A set (n = 22) of Y and W135 samples gave 18, 19, and 17 positive results for Wellcogen (A/C/Y/W135), Pastorex (A/C/Y/W135), and in house beads (Y/W135), respectively. Positive USELAT PCR and culture results were concordant. A typical sensitivity for the commercial kits was 80% (Wellcogen). Conclusions: USELAT identified serogroups for 80% of samples, whereas LATs identified only 40%. The USELAT detection of the A, C, Y, and W135 antigen serogroups showed comparable enhancement for the kits tested. The commercial availability of latex beads coated with antibody to the Y and W135 serogroups would expedite their identification. PMID:11825922

  19. Advances in image enhancement in colonoscopy for detection of adenomas.

    PubMed

    Matsuda, Takahisa; Ono, Akiko; Sekiguchi, Masau; Fujii, Takahiro; Saito, Yutaka

    2017-05-01

    High-quality colonoscopy is mandatory to prevent adenoma recurrence and colorectal cancer. In the past few years, technical advances have been developed with the purpose of improving adenoma detection rate (ADR), one of the most important validated colonoscopy quality benchmarks. Several techniques or devices are used to optimize visualization: observation techniques; add-on devices; auxiliary imaging devices; colonoscopes with increased field of view; and colonoscopes with an integrated inflatable reusable balloon. Image-enhanced endoscopy (IEE) facilitates the detection and characterization of polyps and especially nonpolypoid colorectal neoplasms. Indigo carmine is the most frequently used dye in colonoscopy as it deposits in depressed areas, improving detection of flat and depressed lesions. Virtual chromoendoscopy has emerged as an effective contrast enhancement technology without the limitation of preparing dyes and applying them through the colonoscope working channel. Narrow-band imaging (NBI) enhances the capillary pattern and surface of the mucosa using optical filters, and second-generation NBI provides a twofold brighter image than the previous system, yielding promising ADR results. Moreover, a second-generation blue laser imaging system, LASEREO, has been reported to improve not only polyp detection rate but also ADR, becoming a promising IEE modality. Herein, we describe technical advances in colonoscopy imaging and their effect on ADR.

  20. Enhancement of visual motion detection thresholds in early deaf people.

    PubMed

    Shiell, Martha M; Champoux, François; Zatorre, Robert J

    2014-01-01

    In deaf people, the auditory cortex can reorganize to support visual motion processing. Although this cross-modal reorganization has long been thought to subserve enhanced visual abilities, previous research has been unsuccessful at identifying behavioural enhancements specific to motion processing. Recently, research with congenitally deaf cats has uncovered an enhancement for visual motion detection. Our goal was to test for a similar difference between deaf and hearing people. We tested 16 early and profoundly deaf participants and 20 hearing controls. Participants completed a visual motion detection task, in which they were asked to determine which of two sinusoidal gratings was moving. The speed of the moving grating varied according to an adaptive staircase procedure, allowing us to determine the lowest speed necessary for participants to detect motion. Consistent with previous research in deaf cats, the deaf group had lower motion detection thresholds than the hearing. This finding supports the proposal that cross-modal reorganization after sensory deprivation will occur for supramodal sensory features and preserve the output functions.

  1. Impact of ambient odors on food intake, saliva production and appetite ratings.

    PubMed

    Proserpio, Cristina; de Graaf, Cees; Laureati, Monica; Pagliarini, Ella; Boesveldt, Sanne

    2017-03-01

    The aim of this study was to investigate the effect of ambient odor exposure on appetite, salivation and food intake. 32 normal-weight young women (age: 21.4±5.3year; BMI: 21.7±1.9kg/m(2)) attended five test sessions in a non-satiated state. Each participant was exposed to ambient odors (chocolate, beef, melon and cucumber), in a detectable but mild concentration, and to a control condition (no-odor exposure). During each condition, at different time points, participants rated appetite for 15 food products, and saliva was collected. After approximately 30min, ad libitum intake was measured providing a food (chocolate rice, high-energy dense product) that was congruent with one of the odors they were exposed to. A significant odor effect on food intake (p=0.034) and salivation (p=0.017) was found. Exposure to odors signaling high-energy dense products increased food intake (243.97±22.84g) compared to control condition (206.94±24.93g; p=0.03). Consistently, salivation was increased significantly during chocolate and beef exposure (mean: 0.494±0.050g) compared to control condition (0.417±0.05g; p=0.006). Even though odor exposure did not induce specific appetite for congruent products (p=0.634), appetite scores were significantly higher during odor exposure (p<0.0001) compared to the no-odor control condition and increased significantly over time (p=0.010). Exposure to food odors seems to drive behavioral and physiological responses involved in eating behavior, specifically for odors and foods that are high in energy density. This could have implications for steering food intake and ultimately influencing the nutritional status of people.

  2. CONTROLLING ODOROUS EMISSIONS FROM IRON FOUNDRIES

    EPA Science Inventory

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

  3. CONTROLLING ODOROUS EMISSIONS FROM IRON FOUNDRIES

    EPA Science Inventory

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

  4. Carbohydrate-conditioned odor preferences in rats.

    PubMed

    Lucas, F; Sclafani, A

    1995-06-01

    The effectiveness of odor cues to support nutrient-conditioned flavor preferences in rats was studied. When the rats drank fluid, the CS+ odor was paired with intragastric (IG) infusions of Polycose, and the CS- odor with IG water. In Experiment 1, rats trained with almond and anise odors presented with plain drinking water failed to acquire a CS+ odor preference. In contrast, rats in Experiment 2 formed a strong aversion to anise (or almond) paired with lithium chloride, which indicated that the odors were distinguishable to the rats. Experiment 3 showed that providing unique tastes (bitter or sour) in combination with the odors during training potentiated odor conditioning. The rats displayed a strong preference for the odor+taste CS+ and for the odor component alone. Experiment 4 showed that with another pair of odor (peppermint and vanilla), CS+ preferences could be conditioned in the absence of taste cues during training. These results demonstrate that rats can acquire strong nutrient-conditioned odor preferences.

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

    PubMed

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

    2014-05-01

    Exposure to palatable food odors influences appetite responses, either promoting or inhibiting food intake. Possibly, food odors are appetizing after a short exposure (of circa 1-3 min), but become satiating over time (circa 10-20 min). To investigate the effect of odor exposure on general appetite and sensory-specific appetite (SSA) over time. In a cross-over study, 21 unrestrained women (age: 18-45 years; BMI: 18.5-25 kg m(-2)) were exposed for 20 min to eight different odor types: five food odors, two nonfood odors and no-odor. All odors were distributed in a test room at suprathreshold levels. General appetite, SSA and salivation were measured over time. All food odors significantly increased general appetite and SSA, compared with the no-odor condition. The nonfood odors decreased general appetite. All effects did not change over time during odor exposure. Savory odors increased the appetite for savory foods, but decreased appetite for sweet foods, and vice versa after exposure to sweet odors. Neither food odors nor nonfood odors affected salivation. Palatable food odors were appetizing during and after odor exposure and did not become satiating over a 20-min period. Food odors had a large impact on SSA and a small impact on general appetite. Moreover, exposure to food odors increased the appetite for congruent foods, but decreased the appetite for incongruent foods. It may be hypothesized that, once the body is prepared for intake of a certain food with a particular macronutrient composition, it is unfavorable to consume foods that are very different from the cued food.

  6. Key Odorants Regulate Food Attraction in Drosophila melanogaster.

    PubMed

    Giang, Thomas; He, Jianzheng; Belaidi, Safaa; Scholz, Henrike

    2017-01-01

    In insects, the search for food is highly dependent on olfactory sensory input. Here, we investigated whether a single key odorant within an odor blend or the complexity of the odor blend influences the attraction of Drosophila melanogaster to a food source. A key odorant is defined as an odorant that elicits a difference in the behavioral response when two similar complex odor blends are offered. To validate that the observed behavioral responses were elicited by olfactory stimuli, we used olfactory co-receptor Orco mutants. We show that within a food odor blend, ethanol functions as a key odorant. In addition to ethanol other odorants might serve as key odorants at specific concentrations. However, not all odorants are key odorants. The intensity of the odor background influences the attractiveness of the key odorants. Increased complexity is only more attractive in a concentration-dependent range for single compounds in a blend. Orco is necessary to discriminate between two similarly attractive odorants when offered as single odorants and in food odor blends, supporting the importance of single odorant recognition in odor blends. These data strongly indicate that flies use more than one strategy to navigate to a food odor source, depending on the availability of key odorants in the odor blend and the alternative odor offered.

  7. Key Odorants Regulate Food Attraction in Drosophila melanogaster

    PubMed Central

    Giang, Thomas; He, Jianzheng; Belaidi, Safaa; Scholz, Henrike

    2017-01-01

    In insects, the search for food is highly dependent on olfactory sensory input. Here, we investigated whether a single key odorant within an odor blend or the complexity of the odor blend influences the attraction of Drosophila melanogaster to a food source. A key odorant is defined as an odorant that elicits a difference in the behavioral response when two similar complex odor blends are offered. To validate that the observed behavioral responses were elicited by olfactory stimuli, we used olfactory co-receptor Orco mutants. We show that within a food odor blend, ethanol functions as a key odorant. In addition to ethanol other odorants might serve as key odorants at specific concentrations. However, not all odorants are key odorants. The intensity of the odor background influences the attractiveness of the key odorants. Increased complexity is only more attractive in a concentration-dependent range for single compounds in a blend. Orco is necessary to discriminate between two similarly attractive odorants when offered as single odorants and in food odor blends, supporting the importance of single odorant recognition in odor blends. These data strongly indicate that flies use more than one strategy to navigate to a food odor source, depending on the availability of key odorants in the odor blend and the alternative odor offered. PMID:28928642

  8. Optogenetic Stimulation of Lateral Amygdala Input to Posterior Piriform Cortex Modulates Single-Unit and Ensemble Odor Processing.

    PubMed

    Sadrian, Benjamin; Wilson, Donald A

    2015-01-01

    Olfactory information is synthesized within the olfactory cortex to provide not only an odor percept, but also a contextual significance that supports appropriate behavioral response to specific odor cues. The piriform cortex serves as a communication hub within this circuit by sharing reciprocal connectivity with higher processing regions, such as the lateral entorhinal cortex and amygdala. The functional significance of these descending inputs on piriform cortical processing of odorants is currently not well understood. We have employed optogenetic methods to selectively stimulate lateral and basolateral amygdala (BLA) afferent fibers innervating the posterior piriform cortex (pPCX) to quantify BLA modulation of pPCX odor-evoked activity. Single unit odor-evoked activity of anesthetized BLA-infected animals was significantly modulated compared with control animal recordings, with individual cells displaying either enhancement or suppression of odor-driven spiking. In addition, BLA activation induced a decorrelation of odor-evoked pPCX ensemble activity relative to odor alone. Together these results indicate a modulatory role in pPCX odor processing for the BLA complex. This interaction could contribute to learned changes in PCX activity following associative conditioning, as well as support alternate patterns of odor processing that are state-dependent.

  9. Principles of odor coding and a neural network for odor discrimination.

    PubMed Central

    Schild, D

    1988-01-01

    A concept of olfactory coding is proposed. It describes the stimulus responses of all receptor cells by the use of vector spaces. The morphological convergence pattern between receptor cells and glomeruli is given in the same vector space as the receptor cell activities. The overall input of a glomerulus follows as the scalar product of the receptor cell activity vector and the vector of the glomerulus' convergence pattern. The proposed coding concept shows how the network of the olfactory bulb succeeds in discriminating odors with high selectivity. It is concluded that sets of mitral cells coding similar odors work very much in the way of mutually inhibited matched filters. This solves one main problem both in olfaction as well as real-time odor detection by an artificial nose, i.e., how the fairly low degree of selectivity of receptor cells or sensors is overcome by the neural network following the receptor stage. The formal description of olfactory coding suggests that quality perception which is invariant under concentration shifts is accomplished by an associative memory in the olfactory bulb. PMID:3233263

  10. Efficacy of using multiple open-path Fourier transform infrared (OP-FTIR) spectrometers in an odor emission episode investigation at a semiconductor manufacturing plant.

    PubMed

    Tsao, Yung-Chieh; Wu, Chang-Fu; Chang, Pao-Erh; Chen, Shin-Yu; Hwang, Yaw-Huei

    2011-08-01

    This study evaluated the efficacy of simultaneously employing three open-path Fourier transform infrared (OP-FTIR) spectrometers with 3-day consecutive monitoring, using an odor episode as an example. The corresponding monitoring paths were allocated among the possible emission sources of a semiconductor manufacturing plant and the surrounding optoelectronic and electronic-related factories, which were located in a high-tech industrial park. There was a combined total odor rate of 43.9% for the three monitoring paths, each comprised of 736 continuous 5-minute monitoring records and containing detectable odor compounds, such as ammonia, ozone, butyl acetate, and propylene glycol monomethyl ether acetate (PGMEA). The results of the logistic regression model indicated that the prevailing south wind and the OP-FTIR monitoring path closest to the emission source in down-wind direction resulted in a high efficacy for detecting odorous samples with odds ratios (OR) of 3.8 (95% confidence interval (CI): 2.9-5.0) and 5.1 (95% CI: 3.6-7.2), respectively. Meanwhile, the odds ratio for detecting ammonia odorous samples was 7.5 for Path II, which was downwind closer to the possible source, as compared to Path III, downwind far away from the possible source. PGMEA could not be monitored at Path II but could be at Path III, indicating the importance of the monitoring path and flow ejection velocities inside the stacks on the monitoring performance of OP-FTIR. Besides, an odds ratio of 5.1 for odorous sample detection was obtained with south prevailing wind comprising 65.0% of the monitoring time period. In general, it is concluded that OP-FTIR operated with multiple paths simultaneously shall be considered for investigation on relatively complicated episodes such as emergency of chemical release, multiple-source emission and chemical monitoring for odor in a densely populated plant area to enhance the efficacy of OP-FTIR monitoring. Copyright © 2011 Elsevier B.V. All rights

  11. Treatment of odor by a seashell biofilter at a wastewater treatment plant.

    PubMed

    Abraham, Samantha; Joslyn, Scott; Suffet, I H Mel

    2015-10-01

    Biofilters are becoming an increasingly popular treatment device for odors and other volatiles found at wastewater treatment plants. A seashell media based biofilter was installed in April 2011 at Lake Wildwood Wastewater Treatment Plant located in Penn Valley, California. It was sampled seasonally to examine its ability to treat odorous compounds found in the air above the anaerobic equalization basin at the front end of the plant and to examine the properties of the biofilter and its recirculating water system. The odor profile method sensory panels found mainly sulfide odors (rotten eggs and rotten vegetable) and some fecal odors. This proved to be a useful guidance tool for selecting the required types of chemical sampling. The predominant odorous compounds found were hydrogen sulfide, methyl mercaptan and dimethyl sulfide. These compounds were effectively removed by the biofilter at greater than 99% removal efficiency therein reducing the chemical concentrations to below their odor thresholds. Aldehydes found in the biofilter were below odor thresholds but served as indicators of biological activity. Gas chromatography with mass spectrometry and gas chromatography with sensory detection showed the presence of dimethyl disulfide and dimethyl trisulfide as well, but barely above their respective odor thresholds. The neutrality of the pH of the recirculating water was variable depending on conditions in the biofilter, but a local neutral pH was found in the shells themselves. Other measurements of the recirculating water indicated that the majority of the bio-activity takes place in the first stage of the biofilter. All measurements performed suggest that this seashell biofilter is successful at removing odors found at Lake Wildwood. This study is an initial examination into the mechanism of the removal of odorous compounds in a seashell biofilter. This paper presents a thorough examination of a seashell media biofilter, a sustainable treatment technology used to

  12. Preference for human body odors is influenced by gender and sexual orientation.

    PubMed

    Martins, Yolanda; Preti, George; Crabtree, Christina R; Runyan, Tamar; Vainius, Aldona A; Wysocki, Charles J

    2005-09-01

    Human body odor may contribute to selection of partners. If so, sexual orientation may influence preference for and perhaps production of human body odors. In a test of these hypotheses, heterosexual and homosexual males and females made two-alternative forced-choice preference judgments for body odors obtained from other heterosexual and homosexual males and females. Subjects chose between odors from (a) heterosexual males and gay males, (b) heterosexual males and heterosexual females, (c) heterosexual females and lesbians, and (d) gay males and lesbians. Results indicate that differences in body odor are detected and responded to on the basis of, in part, an individual's gender and sexual orientation. Possible mechanisms underlying these findings are discussed.

  13. Changes in brain cholecystokinin and anxiety-like behavior following exposure of mice to predator odor.

    PubMed

    Hebb, A L O; Zacharko, R M; Dominguez, H; Laforest, S; Gauthier, M; Levac, C; Drolet, G

    2003-01-01

    Exposure of CD-1 mice to a familiar environment lined with clean shavings (control odor) as well as a familiar environment lined with soiled rat shavings (predator odor) induced anxiety in the light/dark box. Mice exposed to the familiar environment or predator odor displayed decreased latency to enter the dark chamber of the light/dark box and spent less time in the light portion of the apparatus relative to home-caged mice. Mice exposed to the familiar environment lined with clean shavings or predator odor displayed elevated cholecystokinin mRNA levels from the ventral tegmental area, medial and basolateral nuclei of the amygdala relative to home-caged mice. Exposure of CD-1 mice to 2, 5 or 10 min of predator odor increased acoustic startle relative to mice merely exposed to the familiar environment lined with clean shavings at protracted intervals. Mice exposed to the familiar environment lined with clean shavings did not exhibit enhanced startle relative to home-caged mice. Exaggerated startle reactivity was in evidence immediately, 24, and 48 h following a 5-min exposure of mice to predator odor. In contrast, a 10-min exposure of mice to predator odor produced an oscillating pattern of enhanced startle evident during the immediate and 48-h post-stressor intervals only. However, when the startle stimulus was withheld 1 h following odor presentation, mice exhibited enhanced startle patterns reminiscent of the 5-min exposure. The 2-min exposure of mice to predator odor produced a delayed onset of enhanced startle observed at the 168-h test interval only. Potential anxiogenic influences of mesocorticolimbic cholecystokinin availability as well as the time course and underlying neuronal substrates of long-term behavioral disturbances as a result of psychogenic stressor manipulations are discussed. Copyright 2003 IBRO

  14. Plasmon resonance enhanced mechanical detection of ligand binding

    SciTech Connect

    Ariyaratne, Amila; Zocchi, Giovanni

    2015-01-05

    Small molecule binding to the active site of enzymes typically modifies the mechanical stiffness of the enzyme. We exploit this effect, in a setup which combines nano-mechanics and surface plasmon resonance (SPR) enhanced optics, for the label free detection of ligand binding to an enzyme. The large dynamic range of the signal allows to easily obtain binding curves for small ligands, in contrast to traditional SPR methods which rely on small changes in index of refraction. Enzyme mechanics, assessed by nano-rheology, thus emerges as an alternative to electronic and spin resonances, assessed by traditional spectroscopies, for detecting ligand binding.

  15. Evaluation of Food Freshness and Locality by Odor Sensor

    NASA Astrophysics Data System (ADS)

    Koike, Takayuki; Shimada, Koji; Kamimura, Hironobu; Kaneki, Noriaki

    The aim of this study was to investigate whether food freshness and locality can be classified using a food evaluation system consisting four SnO2-semiconductor gas sensors and a solid phase column, into which collecting aroma materials. The temperature of sensors was periodically changed to be in unsteady state and thus, the sensor information was increased. The parameters (in quefrency band) were extracted from sensor information using cepstrum analysis that enable to separate superimposed information on sinusoidal wave. The quefrency was used as parameters for principal component and discriminant analyses (PCA and DCA) to detect food freshness and food localities. We used three kinds of strawberries, people can perceive its odors, passed from one to three days after harvest, and kelps and Ceylon tea, people are hardly to perceive its odor, corrected from five areas as sample. Then, the deterioration of strawberries and localities of kelps and Ceylon teas were visually evaluated using the numerical analyses. While the deteriorations were classified using PCA or DCA, the localities were classified only by DCA. The findings indicate that, although odorant intensity influenced the method detecting food quality, the quefrency obtained from odorant information using cepstrum analysis were available to detect the difference in the freshness and the localities of foods.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  17. Detection with Enhanced Energy Windowing Phase I Report

    SciTech Connect

    Bass, David A.; Enders, Alexander L.

    2016-12-01

    This document reviews the progress of Phase I of the Detection with Enhanced Energy Windowing (DEEW) project. The DEEW project is the implementation of software incorporating an algorithm which reviews data generated by radiation portal monitors and utilizes advanced and novel techniques for detecting radiological and fissile material while not alarming on Naturally Occurring Radioactive Material. Independent testing indicated that the Enhanced Energy Windowing algorithm showed promise at reducing the probability of alarm in the stream of commerce compared to existing algorithms and other developmental algorithms, while still maintaining adequate sensitivity to threats. This document contains a brief description of the project, instructions for setting up and running the applications, and guidance to help make reviewing the output files and source code easier.

  18. Detection of volatile organic compounds using surface enhanced Raman scattering

    SciTech Connect

    Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C

    2012-03-22

    The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.

  19. Characterization of typical potent odorants in cola-flavored carbonated beverages by aroma extract dilution analysis.

    PubMed

    Lorjaroenphon, Yaowapa; Cadwallader, Keith R

    2015-01-28

    The aroma-active compounds in typical cola-flavored carbonated beverages were characterized using gas chromatography-olfactometry and gas chromatography-mass spectrometry. The potent odorants in the top three U.S. brands of regular colas were identified by aroma extract dilution analysis (AEDA). Among the numerous odorants identified, eugenol (spicy, clovelike, sweet) and coumarin (sweet, herbaceous) were predominant in all colas. Other predominant odorants in at least one brand included guaiacol (smoky) and linalool (floral, sweet), while 1,8-cineole (minty, eucalyptus-like) was a moderately potent odorant in all colas. Determination of the enantiomeric compositions indicated that (R)-(-)-linalool (34.5%) was a more potent odorant than the (S)-(+)-enantiomer (65.6%) due to its much lower odor detection threshold. In addition, lemon-lime and cooling attributes determined by sensory descriptive analysis had the highest odor intensities among the eight sensory descriptors. The aroma profiles of the three colas were in good agreement with the potent odorants identified by AEDA.

  20. Experimental Demonstration of Masking Phenomena between Competing Odorants via an Air Dilution Sensory Test

    PubMed Central

    Kim, Ki-Hyun

    2010-01-01

    To simulate the occurrence of masking phenomena with the aid of an air dilution sensory (ADS) test, two types of odorant mixtures were prepared: (1) M2 with two individual odorants [H2S and acetaldehyde (AA)] and (2) M6 with six individual odorants (H2S and five aldehydes). The test results derived for samples containing single individual odorants at a wide range of concentrations are initially used to define the empirical relationship between the dilution-to-threshold (D/T) ratio and odor intensity (OI) scaling. Based on these relationships, the D/T ratios were estimated for each odorant with the same intensity as the synthetic mixture. The relative contribution of each odorant to such mixture is then assessed by comparing the estimated and measured D/T values. This stepwise test confirmed the dominance of certain compounds at a given OI rating. In the case of M2, H2S showed sensitive detection at high OI range, while AA did so at low end. The pattern of a competing relationship is also seen consistently from M6 between AA (low) and iso-valeraldehyde (IA: high OI range). The overall results thus suggest that the masking phenomena between strong odorants should proceed under competing relationships, if released at the same time. PMID:22163603

  1. Odor-Specific Loss of Smell Sensitivity with Age as Revealed by the Specific Sensitivity Test.

    PubMed

    Seow, Yi-Xin; Ong, Peter K C; Huang, Dejian

    2016-07-01

    The perception of odor mixtures plays an important role in human food intake, behavior, and emotions. Decline of smell acuity with normal aging could impact food perception and preferences at various ages. However, since the landmark Smell Survey by National Geographic, little has been elucidated on differences in the onset and extent of loss in olfactory sensitivity toward single odorants. Here, using the Specific Sensitivity test, we show the onset and extent of loss in both identification and detection thresholds of odorants with age are odorant-specific. Subjects of Chinese descent in Singapore (186 women, 95 men), aged 21-80 years, were assessed for olfactory sensitivity of 10 odorants from various odor groups. Notably, subjects in their 70s required 179 times concentration of rose-like odorant (2-phenylethanol) than subjects in the 20s, while thresholds for onion-like 2-methyloxolane-3-thiol only differed by 3 times between the age groups. In addition, identification rate for 2-phenylethanol was negatively correlated with age throughout adult life whereas mushroom-like oct-1-en-3-ol was equally identified by subjects across all ages. Our results demonstrated the girth of differentiated olfactory loss due to normal ageing, which potentially affect overall perception and preferences of odor mixtures with age. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Transplant Antennae and Host Brain Interact to Shape Odor Perceptual Space in Male Moths

    PubMed Central

    Lee, Seong-Gyu; Poole, Kathy; Linn, Charles E.; Vickers, Neil J.

    2016-01-01

    Behavioral responses to odors rely first upon their accurate detection by peripheral sensory organs followed by subsequent processing within the brain’s olfactory system and higher centers. These processes allow the animal to form a unified impression of the odor environment and recognize combinations of odorants as single entities. To investigate how interactions between peripheral and central olfactory pathways shape odor perception, we transplanted antennal imaginal discs between larval males of two species of moth Heliothis virescens and Heliothis subflexa that utilize distinct pheromone blends. During metamorphic development olfactory receptor neurons originating from transplanted discs formed connections with host brain neurons within olfactory glomeruli of the adult antennal lobe. The normal antennal receptor repertoire exhibited by males of each species reflects the differences in the pheromone blends that these species employ. Behavioral assays of adult transplant males revealed high response levels to two odor blends that were dissimilar from those that attract normal males of either species. Neurophysiological analyses of peripheral receptor neurons and central olfactory neurons revealed that these behavioral responses were a result of: 1. the specificity of H. virescens donor olfactory receptor neurons for odorants unique to the donor pheromone blend and, 2. central odor recognition by the H. subflexa host brain, which typically requires peripheral receptor input across 3 distinct odor channels in order to elicit behavioral responses. PMID:26816291

  3. Representativeness of extracts of offset paper packaging and analysis of the main odor-active compounds.

    PubMed

    Landy, Pascale; Nicklaus, Sophie; Sémon, Etienne; Mielle, Patrick; Guichard, Elisabeth

    2004-04-21

    Packagings often carry odors due to the support and printing inks. The aim of the investigation was to define a representative solvent-free extract of paper-based packaging materials printed by the offset process, for the identification of the odor-causing volatile compounds. Static headspace and solid-phase microextraction were the two applied extraction methods. Representativeness tests showed that the odor of the PDMS fiber extract gave satisfying odor similarities with the original packaging. The sample incubation was performed at 40 degrees C for 30 min, whereas the extraction time was 3 min at 40 degrees C. Extracts of both the nonprinted and printed papers of different batches were analyzed by gas chromatography-olfactometry. 4-Phenylcyclohexene was identified as the most potent compound contributing to the latex-like odor of the nonprinted paper. Among the 13 major odorants identified by mass spectrometry, 10 were aldehydes and ketones generated by oxidation of the printing ink resins. The ratio of odorants to interferences was too low for a possible detection of the key odorants by nonseparative techniques such as sensor arrays.

  4. US-inflation in a differential odor-conditioning paradigm is not robust: relevance for medically unexplained symptoms.

    PubMed

    Devriese, Stephan; De Peuter, Steven; Van Diest, Ilse; Van de Woestijne, Karel P; Van den Bergh, Omer

    2006-12-01

    Reported somatic symptoms without clear relation to physiological processes are studied. A learning paradigm was used with two odors (CSs) and the inhalation of CO(2)-enriched air (US), while measuring symptom levels and respiratory behavior. After paring one odor with the CO(2)-enriched air and the other odor with air, half of the participants received a US-inflation manipulation (information manipulation and enhanced US). Subsequently, all participants received both odors with air (test). A difference between the odor previously paired with CO(2)-enriched air and the odor previously paired with air was found for the symptom measure, US-expectancy ratings, and, to a lesser extent, for respiratory volume. No differences, however, were found between the group receiving the US-inflation manipulation and a group not receiving this manipulation. The results indicate that, despite a successful learning of reported symptoms, US-inflation does not seem to be robust.

  5. Magnetic resonance cholangiopancreatography image enhancement for automatic disease detection.

    PubMed

    Logeswaran, Rajasvaran

    2010-07-28

    To sufficiently improve magnetic resonance cholangiopancreatography (MRCP) quality to enable reliable computer-aided diagnosis (CAD). A set of image enhancement strategies that included filters (i.e. Gaussian, median, Wiener and Perona-Malik), wavelets (i.e. contourlet, ridgelet and a non-orthogonal noise compensation implementation), graph-cut approaches using lazy-snapping and Phase Unwrapping MAxflow, and binary thresholding using a fixed threshold and dynamic thresholding via histogram analysis were implemented to overcome the adverse characteristics of MRCP images such as acquisition noise, artifacts, partial volume effect and large inter- and intra-patient image intensity variations, all of which pose problems in application development. Subjective evaluation of several popular pre-processing techniques was undertaken to improve the quality of the 2D MRCP images and enhance the detection of the significant biliary structures within them, with the purpose of biliary disease detection. The results varied as expected since each algorithm capitalized on different characteristics of the images. For denoising, the Perona-Malik and contourlet approaches were found to be the most suitable. In terms of extraction of the significant biliary structures and removal of background, the thresholding approaches performed well. The interactive scheme performed the best, especially by using the strengths of the graph-cut algorithm enhanced by user-friendly lazy-snapping for foreground and background marker selection. Tests show promising results for some techniques, but not others, as viable image enhancement modules for automatic CAD systems for biliary and liver diseases.

  6. Body Odor (For Young Men)

    MedlinePlus

    Young Men's Health http://youngmenshealthsite.org/guides/body-odor/ ≡ Menu Ask Us Health Guides Quizzes Parents About Us Donate ... wear sneakers without socks? Tweets by @YoungMensHealth Young Men’s Health (YMH) is produced by the Division of ...

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Sedative effects of the jasmine tea odor and (R)-(-)-linalool, one of its major odor components, on autonomic nerve activity and mood states.

    PubMed

    Kuroda, Kyoko; Inoue, Naohiko; Ito, Yuriko; Kubota, Kikue; Sugimoto, Akio; Kakuda, Takami; Fushiki, Tohru

    2005-10-01

    We investigated the effects of the odor of jasmine tea on autonomic nerve activity and mood states in a total of 24 healthy volunteers. We used the odor of jasmine tea at the lowest concentration that could be detected by each subject but that did not elicit any psychological effects. R-R intervals and the POMS test were measured before and after inhalation of the odors for 5 min. Both jasmine tea and lavender odors at perceived similar intensity caused significant decreases in heart rate and significant increases in spectral integrated values at high-frequency component in comparison with the control (P < 0.05). In the POMS tests, these odors produced calm and vigorous mood states. We also examined the effects of (R)-(-)-linalool, one of its major odor components, at the same concentration as in the tea, and (S)-(+)-linalool. Only (R)-(-)-linalool elicited a significant decrease in heart rate (P < 0.05) and an increase in high-frequency component in comparison with the controls, and produced calm and vigorous mood states. Thus, the low intensity of jasmine tea odor has sedative effects on both autonomic nerve activity and mood states, and (R)-(-)-linalool, one of its components, can mimic these effects.

  9. Chemical characterization of odors due to some industrial and urban facilities in Izmir, Turkey

    NASA Astrophysics Data System (ADS)

    Dincer, Faruk; Muezzinoglu, Aysen

    The relationship between odor concentrations (olfactometry) and chemical concentrations (gas chromatography-mass spectrometry, GC-MS) was studied for the odorous air compositions of a rendering plant, a sanitary landfill and an industrial area with large petroleum and petrochemical industries. Samples taken from the university campus located in a non-industrial and non-urban area were also studied for several organic components for comparison. Ambient air samples were taken into special bags by using an odor sampling device designed for field sampling of odors. In the laboratory odorous chemicals in the samples were transferred into adsorbent tubes and analyzed using a combination of thermal desorption and GC-MS. Results point to different characteristics of the odorous gases and air in and around the urban and industrial sources. Among the 64 specific compounds studied, 49 volatile organic compounds (VOCs) were detected in rendering plant, 53 VOCs were detected in sanitary landfill and 44 VOCs were detected in petroleum and petrochemical industries. The compounds measured in the odorous gas composition are the alkanes, alkenes, carbonyls, arenes, chlorinated and other halogenated compounds and organic chlorides as well as the volatile fatty acids.

  10. Biochemistry and genetics of taste- and odor-producing cyanobacteria.

    PubMed

    Watson, Susan B; Monis, Paul; Baker, Peter; Giglio, Steven

    2016-04-01

    Cyanobacteria are one of the principal sources of volatile organic compounds (VOCs) which cause offensive taste and odor (T&O) in drinking and recreational water, fish, shellfish and other seafood. Although non-toxic to humans, these T&O compounds severely undermine public trust in these commodities, resulting in substantial costs in treatment, and lost revenue to drinking water, aquaculture, food and beverage and tourist/hospitality industries. Mitigation and control have been hindered by the complexity of the communities and processes which produce and modify T&O events, making it difficult to source-track the major producer(s) and the factors governing VOC production and fate. Over the past decade, however, advances in bioinformatics, enzymology, and applied detection technologies have greatly enhanced our understanding of the pathways, the enzymes and the genetic coding for some of the most problematic VOCs produced by cyanobacteria. This has led to the development of tools for rapid and sensitive detection and monitoring for the VOC production at source, and provided the basis for further diagnostics of endogenous and exogenous controls. This review provides an overview of current knowledge of the major cyanobacterial VOCs, the producers, the biochemistry and the genetics and highlight the current applications and further research needs in this area. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Odor processing in multiple chemical sensitivity.

    PubMed

    Hillert, Lena; Musabasic, Vildana; Berglund, Hans; Ciumas, Carolina; Savic, Ivanka

    2007-03-01

    Multiple chemical sensitivity (MCS) is characterized by somatic distress upon exposure to odors. As in other idiopathic environmental intolerances, the mechanisms behind the reported hypersensitivity are unknown. Using the advantage of the well-defined trigger (odor), we investigated whether subjects with MCS could have an increased odor-signal response in the odor-processing neuronal circuits. Positron emission tomography (PET) activation studies with several different odorants were carried out in 12 MCS females and 12 female controls. Activation was defined as a significant increase in regional cerebral blood flow (rCBF) during smelling of the respective odorant compared to smelling of odorless air. The study also included online measurements of respiratory frequency and amplitude and heart rate variations by recording of R wave intervals (RR) on the surface electrocardiogram. The MCS subjects activated odor-processing brain regions less than controls, despite the reported, and physiologically indicated (decreased RR interval) distress. In parallel, they showed an odorant-related increase in activation of the anterior cingulate cortex and cuneus-precuneus. Notably, the baseline rCBF was normal. Thus, the abnormal patterns were observed only in response to odor signals. Subjects with MCS process odors differently from controls, however, without signs of neuronal sensitization. One possible explanation for the observed pattern of activation in MCS is a top-down regulation of odor-response via cingulate cortex.

  12. Molecularly Imprinted Filtering Adsorbents for Odor Sensing

    PubMed Central

    Shinohara, Sho; Chiyomaru, You; Sassa, Fumihiro; Liu, Chuanjun; Hayashi, Kenshi

    2016-01-01

    Versatile odor sensors that can discriminate among huge numbers of environmental odorants are desired in many fields, including robotics, environmental monitoring, and food production. However, odor sensors comparable to an animal’s nose have not yet been developed. An animal’s olfactory system recognizes odor clusters with specific molecular properties and uses this combinatorial information in odor discrimination. This suggests that measurement and clustering of odor molecular properties (e.g., polarity, size) using an artificial sensor is a promising approach to odor sensing. Here, adsorbents composed of composite materials with molecular recognition properties were developed for odor sensing. The selectivity of the sensor depends on the adsorbent materials, so specific polymeric materials with particular solubility parameters were chosen to adsorb odorants with various properties. The adsorption properties of the adsorbents could be modified by mixing adsorbent materials. Moreover, a novel molecularly imprinted filtering adsorbent (MIFA), composed of an adsorbent substrate covered with a molecularly imprinted polymer (MIP) layer, was developed to improve the odor molecular recognition ability. The combination of the adsorbent and MIP layer provided a higher specificity toward target molecules. The MIFA thus provides a useful technique for the design and control of adsorbents with adsorption properties specific to particular odor molecules. PMID:27886070

  13. Alert odor from skin gland in deer.

    PubMed

    Müller-Schwarze, D; Altieri, R; Porter, N

    1984-12-01

    Black-tailed deer (Odocoileus hemionus columbianus) discharge an odor from the metatarsal (MT) gland, located on the hindleg, when disturbed or alarmed. Freely moving, captive deer were exposed to the MT odor by means of a remote-release apparatus. Responses by males and females to MT odor from both sexes were recorded with a coding system and a video camera. When the odor was present, females became more alert and left the site more often than in the presence of control odors, odorless air, or deer urine. It is concluded that the MT secretion provides an alert signal, placing the odor into the class of alarm pheromones. There is no evidence that the closely related white-tailed deer,O. virginianus, possesses this alert (or alarm) odor system to the same degree.

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

    PubMed Central

    Degl'Innocenti, Andrea

    2016-01-01

    Background 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. Aim 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. Procedures 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. Results 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

  15. Ultraviolet Resonant Raman Enhancements in the Detection of Explosives

    SciTech Connect

    Short Jr., Billy Joe

    2009-06-01

    Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (non-resonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, however, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided ~2000-fold enhancement at 244 nm and ~800-fold improvement at 229 nm while PETN showed a maximum of ~25-fold at 244 nm and ~190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as !4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

  16. Nasal pungency, odor, and eye irritation thresholds for homologous acetates.

    PubMed

    Cometto-Muñiz, J E; Cain, W S

    1991-08-01

    We measured detection thresholds for nasal pungency (in anosmics), odor (in normosmics) and eye irritation employing a homologous series of acetates: methyl through octyl acetate, decyl and dodecyl acetate. All anosmics reliably detected the series up to heptyl acetate. Only the anosmics without smell since birth (congenital) reliably detected octyl acetate, and only one congenital anosmic detected decyl and dodecyl acetate. Anosmics who lost smell from head trauma proved to be selectively less sensitive. As expected, odor thresholds lay well below pungency thresholds. Eye irritation thresholds for selected acetates came close to nasal pungency thresholds. All three types of thresholds decreased logarithmically with carbon chain length, as previously seen with homologous alcohols and as seen in narcotic and toxic phenomena. Results imply that nasal pungency for these stimuli rests upon a physical, rather than chemical, interaction with susceptible mucosal structures. When expressed as thermodynamic activity, nasal pungency thresholds remain remarkably constant within and across the homologous series of acetates and alcohols.

  17. A “Misfit” Theory of Spontaneous Conscious Odor Perception (MITSCOP): reflections on the role and function of odor memory in everyday life

    PubMed Central

    Köster, Egon P.; Møller, Per; Mojet, Jozina

    2014-01-01

    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. PMID:24575059

  18. The relation between modeled odor exposure from livestock farming and odor annoyance among neighboring residents.

    PubMed

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

    2016-04-01

    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 may affect the relation. In this study, we (1) investigated the relation between modeled odor exposure and odor annoyance; (2) investigated whether other factors can affect this relation; and (3) compared our dose-response relation to a dose-response relation established in a previous study carried out in the Netherlands, more than 10 years ago, in order to investigate changes in odor perception and appreciation over time. We used data from 582 respondents who participated in a questionnaire survey among neighboring residents of livestock farms in the south of the Netherlands. Odor annoyance was established by two close-ended questions in a questionnaire; odor exposure was estimated using the Stacks dispersion model. The results of our study indicate a statistically significant and positive relation between modeled odor exposure and reported odor annoyance from livestock farming (OR 1.92; 95 % CI 1.53-2.41). Furthermore, age, asthma, education and perceived air pollution in the environment are all related to odor annoyance, although they hardly affect the relation between estimated livestock odor exposure and reported odor annoyance. We also found relatively more odor annoyance reported among neighboring residents than in a previous study conducted in the Netherlands. We found a strong relation between modeled odor exposure and odor annoyance. However, due to some uncertainties and small number of studies on this topic, further research and replication of results is recommended.

  19. Study of the volatile compounds and odor-active compounds of dry-cured Iberian ham extracted by SPME.

    PubMed

    del Pulgar, José Sánchez; García, Carmen; Reina, Raquel; Carrapiso, Ana I

    2013-06-01

    The volatile compounds and the most odor-active compounds of dry-cured Iberian ham were investigated by extracting them using a solid phase microextraction technique with a 2 cm Carboxen/PDMS/DVB fiber. The detection frequency method was applied to estimate the potential contribution of each compound to the odor of hams. Twenty-one volatile compounds were tentatively identified for the first time in dry-cured ham by gas chromatography-mass spectrometry, and eight in dry-cured Iberian ham. Gas chromatography-olfactometry allowed the identification for the first time of six compounds not previously reported as odorants of Iberian ham, and also two odorants were newly identified in dry-cured ham. According to the detection frequency method, the most odor active compounds found were 3-methylbutanoic acid (dirty sock-like smelling), hexanal (cut grass-like odor), 3-methylbutanal (sweaty and bitter almond-like odor), 2-methyl-3-furanthiol (toasted nuts-like odor) and 1-octen-3-one (mushroom-like odor).

  20. Effects of crystalline amino acid supplementation to the diet on odor from pig manure.

    PubMed

    Le, P D; Aarnink, A J A; Jongbloed, A W; van der Peet Schwering, C M C; Ogink, N W M; Verstegen, M W A

    2007-03-01

    The objective of this study was to determine the effects of specific crystalline AA supplementation to a diet on odor emission, odor intensity, odor hedonic tone, and ammonia emission from pig manure, and on manure characteristics (pH; ammonia N; total nitrogen; sulfurous, indolic, and phenolic compounds; and VFA concentrations). An experiment was conducted with growing pigs (n = 18) in a randomized complete block design, with 3 treatments in 6 blocks. Treatment groups were (1) a 15%-CP basal diet with 3 times the requirement of sulfur-containing AA (14.2 g/kg of diet, as-fed basis); (2) the basal diet with 2 times the requirement of Trp and Phe+Tyr (2.9 and 20.4 g/kg of diet, respectively, as-fed basis); and (3) the basal diet with AA supplementation to levels sufficient for maximum protein gain. Pigs with an initial BW of 41.2 +/- 0.8 kg were individually penned in partly slatted floor pens and offered a daily feed allowance of 2.8 times the maintenance requirement for NE (293 kJ/kg of BW(0.75)). Feed was mixed with water at 1:2.5 (wt/wt). Feces and urine of each pig was allowed to accumulate in separate manure pits under the slatted floor. After an adaptation period of 2 wk, and after cleaning the manure pits, manure was subsequently collected. In wk 5 of the collection period, separate samples were collected directly from each manure pit for odor, ammonia, and manure composition analyses. Air samples were analyzed for odor concentration and for hedonic tone and odor intensity above the odor detection threshold. Results showed that supplementing crystalline S-containing AA in surplus of the requirement increased odor emission (P < 0.001) and odor intensity (P < 0.05) and reduced odor hedonic tone (P < 0.05) from the air above the manure pits. Supplementing crystalline Trp, Tyr, and Phe in surplus of the recommended requirements did not affect odor emission, odor intensity, or odor hedonic tone. Regardless of dietary treatment, all pigs had similar performance

  1. Monitoring of odor compounds produced by solid waste treatment plants with diffusive samplers.

    PubMed

    Bruno, P; Caselli, M; de Gennaro, G; Solito, M; Tutino, M

    2007-01-01

    Nuisance caused by odors is one of the most important problems for waste management plants. To control an odor nuisance, it must first be quantified. The analytical difficulties in odor measurements are related to the high number of volatile components (belonging to several chemical classes), above all when the concentration is lower than the detection limit of the technique used for the measurement. In this work, 2-butanone, alpha-pinene, tetrachloroethylene, dimethyldisulfide, beta-pinene, limonene, phenol and benzoic acid are determined, because they are representative of some important classes of compounds with higher odor impact. The compounds are sampled with thermal desorbable radial diffusive samplers Radiello containing Tenax cartridges. The analytical repeatability and the complete thermal desorption of the cartridges were verified for each odor compound; the relative standard deviations for repeated samples and the recovery percentage were, respectively, less than 7% and about 97% for all compounds. The measurements of the linearity of sampling showed no systematic difference according to the collection period. The comparison between the odor threshold and the limit of detection demonstrated that this method is reliable for the recognition and quantification of odor compounds, allowing Public Administration to impose legal limits and the control agencies to verify them.

  2. An olfactory cocktail party: figure-ground segregation of odorants in rodents

    PubMed Central

    Rokni, Dan; Hemmelder, Vivian; Kapoor, Vikrant; Murthy, Venkatesh N.

    2014-01-01

    In odorant-rich environments, animals must be able to detect specific odorants of interest against variable backgrounds. However, several studies have suggested that both humans and rodents are very poor at analyzing the components of odorant mixtures, leading to the idea that olfaction is a synthetic sense in which mixtures are perceived holistically. We have developed a behavioral task to directly measure the ability of mice to perceive mixture components and found that mice can be easily trained to detect target odorants embedded in unpredictable and variable mixtures. We imaged the responses of olfactory bulb glomeruli to the individual odors used in the task in mice expressing the Ca++ indicator GCaMP3 in olfactory receptor neurons. By relating behavioral performance to the glomerular response patterns, we found that the difficulty of segregating the target from the background was strongly dependent on the extent of overlap between the representations of the target and the background odors by olfactory receptors. Our study indicates that the olfactory system has powerful analytic abilities that are constrained by the limits of combinatorial neural representation of odorants at the level of the olfactory receptors. PMID:25086608

  3. [Clinical usefulness of odor stick identification test for patients with olfactory disturbance].

    PubMed

    Miwa, Takaki; Furukawa, Mitsuru; Tsukatani, Toshiaki; Ikeno, Sachiko; Yata, Tsuyoshi; Horikawa, Isao; Deguchi, Yuichi; Saito, Sachiko

    2004-10-01

    The odor stick identification test for Japanese (OSITJ) is the latest in measuring olfactory identification. It consists of 13 odorants familiar to the Japanese population. We studied the relationship between the Japanese standard olfactory test (T & T olfactometer) and the OSITJ in 182 patients with olfactory disturbance. The identification ratio in 2 of OSITJ tests using 13 odorants was correlated significantly negatively with the detection and recognition threshold measured by the T & T olfactometer. A high correlation between identification ratio and olfactory thresholds was maintained even when the number of odorants in the OSITJ was reduced to 2. For each odorant used, the identification ratio correlated significantly with olfactory thresholds. Results from the OSITJ provide a measure of the degree of olfactory deficit because the ratio of correct answers obtained by the OSITJ decreased gradually with of the severity of olfactory disturbance. Compared to the T & T olfactometer, the OSITJ has several advantages for use in the clinic. These include minimal odor pollution of the test room, simplicity of use, and shorter clinical time needed to administer the test. The OSITJ may be ideal for use in screening due to the minimum number of odorants needed. In conclusion, the OSITJ is useful for detecting and evaluating olfactory disturbance in Japanese people.

  4. [Discrimination of Coptidis Rhizoma and its processed products by odor objectify].

    PubMed

    Xu, Min; Yang, Shi-Long; Zhang, Chao; Wan, Jun; Wu, Na; Li, Xin-Yi; Huang, Qin-Wan; Zhou, Xia; Wu, Chin-Jie

    2015-01-01

    Different processed products of Coptidis Rhizoma have its unique odor, which is an important assessment index for pro- cessed products identification of Coptidis Rhizoma. Objectify odor as an entry point in this study, an electronic nose technology was used, and a suitable method for Coptidis Rhizoma measurement was built firstly. Then different processed products of Coptidis Rhizoma were detected by the method built. Finally, different processed products were identified by combining with chemometrics based on the objective odor information obtained. Electronic nose detection indicated that a significant difference in odor between different processed products was performed. Coptidis Rhizoma processed or not can be distinguished based on statistical quality control (SQC) and soft independent modeling of class analogy (SIMCA). Principle component analysis (PCA) model showed that Coptidis Rhizoma and its various processed products discriminated obviously. In addition, in order to identify the processed products of Coptidis Rhizoma, a correct recognition rate of 100% was acquired by discriminant factor analysis (DFA) , and the initial identification rate and cross-validation recognition rate of linear discriminant analysis (LDA) is 100%, 94.4% respectively. In conclusion, differentiationin odor of different processed Coptidis Rhizoma was performed by the electronic nose technology used, and different products Coptidis Rhizoma were dis- criminated by combining with chemometrics. This research can be a reference for objective identification in odor of traditional Chinese medicine, and is good for the inheritance and development of traditional experience in odor identification.

  5. Development of a portable odorant test instrument. Final report, October 15, 1981-April 15, 1983

    SciTech Connect

    Grain, C.F.; Oberholtzer, J.E.

    1983-04-25

    The report describes the results of a laboratory program in which the feasibility of using solid-state semiconductor detectors to measure odorant levels in natural gas was studied. One type of sensor which employed a catalyst composed of the mixed oxides of lanthanum, strontium and cobalt in a Perovskite crystal structure could detect low-ppm concentration of sulfur-containing odorants at odorant-to-methane ratios typical of those found in odorized natural gas. A second sensor which used a thin film of pure tin oxide could also detect odorants in relatively high concentrations of methane but it was not as selective for odorant vs. methane as was the Perovskite material. Odorants commonly used by the gas industry were prepared as mixtures in cylinders of pressurized methane, certified at 50 ppm. Prepared sensors were placed in a glass test chamber of a dynamic flow system and exposed to concentration levels which varied from 1-50 ppm while operating over a temperature range from 190 C to 340 C.

  6. Impact prediction by looming visual stimuli enhances tactile detection.

    PubMed

    Cléry, Justine; Guipponi, Olivier; Odouard, Soline; Wardak, Claire; Ben Hamed, Suliann

    2015-03-11

    From an ecological point of view, approaching objects are potentially more harmful than receding objects. A predator, a dominant conspecific, or a mere branch coming up at high speed can all be dangerous if one does not detect them and produce the appropriate escape behavior fast enough. And indeed, looming stimuli trigger stereotyped defensive responses in both monkeys and human infants. However, while the heteromodal somatosensory consequences of visual looming stimuli can be fully predicted by their spatiotemporal dynamics, few studies if any have explored whether visual stimuli looming toward the face predictively enhance heteromodal tactile sensitivity around the expected time of impact and at its expected location on the body. In the present study, we report that, in addition to triggering a defensive motor repertoire, looming stimuli toward the face provide the nervous system with predictive cues that enhance tactile sensitivity on the face. Specifically, we describe an enhancement of tactile processes at the expected time and location of impact of the stimulus on the face. We additionally show that a looming stimulus that brushes past the face also enhances tactile sensitivity on the nearby cheek, suggesting that the space close to the face is incorporated into the subjects' body schema. We propose that this cross-modal predictive facilitation involves multisensory convergence areas subserving the representation of a peripersonal space and a safety boundary of self.

  7. Moving object detection and background enhancement for thalamic visual prostheses.

    PubMed

    Abolfotuh, Hossam H; Jawwad, Amr; Abdullah, Bassem; Mahdi, Hani M K; Eldawlatly, Seif

    2016-08-01

    Visual prostheses open the door of hope to restore functional vision for the blind. One of the main challenges facing their development is the limited number of electrodes used in the stimulation process which limits the resolution of the perceived images. To improve the perception, the useful features in the scene need to be enhanced while the other features should be suppressed to achieve better resolution. This paper introduces an image processing method to enhance three main features detectable by the natural visual pathway; namely the contrast, the motion and the edges. It then reduces the size of the image into an activity matrix used to generate the electric stimulation for the electrodes array. We compared the proposed method to four other image processing strategies in terms of the quality of the resulting image in addition to the perceived image using a simulation of prosthetic vision. Results demonstrate that the proposed method outperforms the other techniques in both aspects.

  8. Assessment of mass detection performance in contrast enhanced digital mammography

    NASA Astrophysics Data System (ADS)

    Carton, Ann-Katherine; de Carvalho, Pablo M.; Li, Zhijin; Dromain, Clarisse; Muller, Serge

    2015-03-01

    We address the detectability of contrast-agent enhancing masses for contrast-agent enhanced spectral mammography (CESM), a dual-energy technique providing functional projection images of breast tissue perfusion and vascularity using simulated CESM images. First, the realism of simulated CESM images from anthropomorphic breast software phantoms generated with a software X-ray imaging platform was validated. Breast texture was characterized by power-law coefficients calculated in data sets of real clinical and simulated images. We also performed a 2-alternative forced choice (2-AFC) psychophysical experiment whereby simulated and real images were presented side-by-side to an experienced radiologist to test if real images could be distinguished from the simulated images. It was found that texture in our simulated CESM images has a fairly realistic appearance. Next, the relative performance of human readers and previously developed mathematical observers was assessed for the detection of iodine-enhancing mass lesions containing different contrast agent concentrations. A four alternative-forced-choice (4 AFC) task was designed; the task for the model and human observer was to detect which one of the four simulated DE recombined images contained an iodineenhancing mass. Our results showed that the NPW and NPWE models largely outperform human performance. After introduction of an internal noise component, both observers approached human performance. The CHO observer performs slightly worse than the average human observer. There is still work to be done in improving model observers as predictors of human-observer performance. Larger trials could also improve our test statistics. We hope that in the future, this framework of software breast phantoms, virtual image acquisition and processing, and mathematical observers can be beneficial to optimize CESM imaging techniques.

  9. Magnetic resonance cholangiopancreatography image enhancement for automatic disease detection

    PubMed Central

    Logeswaran, Rajasvaran

    2010-01-01

    AIM: To sufficiently improve magnetic resonance cholangiopancreatography (MRCP) quality to enable reliable computer-aided diagnosis (CAD). METHODS: A set of image enhancement strategies that included filters (i.e. Gaussian, median, Wiener and Perona-Malik), wavelets (i.e. contourlet, ridgelet and a non-orthogonal noise compensation implementation), graph-cut approaches using lazy-snapping and Phase Unwrapping MAxflow, and binary thresholding using a fixed threshold and dynamic thresholding via histogram analysis were implemented to overcome the adverse characteristics of MRCP images such as acquisition noise, artifacts, partial volume effect and large inter- and intra-patient image intensity variations, all of which pose problems in application development. Subjective evaluation of several popular pre-processing techniques was undertaken to improve the quality of the 2D MRCP images and enhance the detection of the significant biliary structures within them, with the purpose of biliary disease detection. RESULTS: The results varied as expected since each algorithm capitalized on different characteristics of the images. For denoising, the Perona-Malik and contourlet approaches were found to be the most suitable. In terms of extraction of the significant biliary structures and removal of background, the thresholding approaches performed well. The interactive scheme performed the best, especially by using the strengths of the graph-cut algorithm enhanced by user-friendly lazy-snapping for foreground and background marker selection. CONCLUSION: Tests show promising results for some techniques, but not others, as viable image enhancement modules for automatic CAD systems for biliary and liver diseases. PMID:21160667

  10. Do ambient urban odors evoke basic emotions?

    PubMed Central

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

    2013-01-01

    Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman's (Ekman et al., 1983) basic emotions happiness, surprise, anger, fear, sadness, and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles/bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate, and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response (SCR) varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the SCR and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles/bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics. PMID:24860522

  11. Elaborated Odor Test for Extended Exposure

    NASA Technical Reports Server (NTRS)

    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.

  12. Do ambient urban odors evoke basic emotions?

    PubMed

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

    2014-01-01

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

  13. Depth resolution enhancement in double-detection optical scanning holography.

    PubMed

    Ou, Haiyan; Poon, Ting-Chung; Wong, Kenneth K Y; Lam, Edmund Y

    2013-05-01

    We propose an optical scanning holography system with enhanced axial resolution using two detections at different depths. By scanning the object twice, we can obtain two different sets of Fresnel zone plates to sample the same object, which in turn provides more information for the sectional image reconstruction process. We develop the computation algorithm that makes use of such information, solving a constrained optimization problem using the conjugate gradient method. Simulation results show that this method can achieve a depth resolution up to 1 μm.

  14. A comparative study of odor identification and odor discrimination deficits in Parkinson's disease.

    PubMed

    Boesveldt, Sanne; Verbaan, Dagmar; Knol, Dirk L; Visser, Martine; van Rooden, Stephanie M; van Hilten, Jacobus J; Berendse, Henk W

    2008-10-30

    The aim of this study was to compare the characteristics of odor discrimination and odor identification deficits in a large population of patients with Parkinson's disease (PD) and to determine which of these olfactory tests best distinguishes between patients with PD and control subjects. Olfactory performance was assessed in 404 patients with PD and 150 controls, using the odor identification and discrimination parts of the Sniffin' Sticks battery. Mean identification and discrimination scores in patients with PD were significantly lower than in controls. Linear regression analysis using a 95% confidence interval revealed that, relative to the performance of controls, 65.0% of patients with PD had an impairment in odor identification, whereas 42.1% of patients were impaired on the odor discrimination task. ROC curves revealed a higher sensitivity and specificity for odor identification than for odor discrimination in separating patients from controls. In patients with PD, odor discrimination performance decreased with increasing disease duration, whereas odor identification was not correlated with disease stage or duration. In PD, odor identification is more frequently impaired than odor discrimination and allows a better discrimination between patients and controls. Although an odor identification deficit is generally believed to be independent of disease progression, the impairment in odor discrimination appears to increase with disease duration.

  15. Image enhancement using thermal-visible fusion for human detection

    NASA Astrophysics Data System (ADS)

    Zaihidee, Ezrinda Mohd; Hawari Ghazali, Kamarul; Zuki Saleh, Mohd

    2017-09-01

    An increased interest in detecting human beings in video surveillance system has emerged in recent years. Multisensory image fusion deserves more research attention due to the capability to improve the visual interpretability of an image. This study proposed fusion techniques for human detection based on multiscale transform using grayscale visual light and infrared images. The samples for this study were taken from online dataset. Both images captured by the two sensors were decomposed into high and low frequency coefficients using Stationary Wavelet Transform (SWT). Hence, the appropriate fusion rule was used to merge the coefficients and finally, the final fused image was obtained by using inverse SWT. From the qualitative and quantitative results, the proposed method is more superior than the two other methods in terms of enhancement of the target region and preservation of details information of the image.

  16. Detecting Chemically Modified DNA Bases Using Surface Enhanced Raman Spectroscopy.

    PubMed

    Barhoumi, Aoune; Halas, Naomi J

    2011-12-15

    Post-translational modifications of DNA- changes in the chemical structure of individual bases that occur without changes in the DNA sequence- are known to alter gene expression. They are believed to result in frequently deleterious phenotypic changes, such as cancer. Methylation of adenine, methylation and hydroxymethylation of cytosine, and guanine oxidation are the primary DNA base modifications identified to date. Here we show it is possible to use surface enhanced Raman spectroscopy (SERS) to detect these primary DNA base modifications. SERS detection of modified DNA bases is label-free and requires minimal additional sample preparation, reducing the possibility of additional chemical modifications induced prior to measurement. This approach shows the feasibility of DNA base modification assessment as a potentially routine analysis that may be further developed for clinical diagnostics.

  17. Nuisance Odors: Is there a Concern - 12340

    SciTech Connect

    Brounstein, Robert A.

    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

  18. Use of thermal desorption gas chromatography-olfactometry/mass spectrometry for the comparison of identified and unidentified odor active compounds emitted from building products containing linseed oil.

    PubMed

    Clausen, P A; Knudsen, H N; Larsen, K; Kofoed-Sørensen, V; Wolkoff, P; Wilkins, C K

    2008-11-14

    The emission of odor active volatile organic compounds (VOCs) from a floor oil based on linseed oil, the linseed oil itself and a low-odor linseed oil was investigated by thermal desorption gas chromatography combined with olfactometry and mass spectrometry (TD-GC-O/MS). The oils were applied to filters and conditioned in the micro emission cell, FLEC, for 1-3days at ambient temperature, an air exchange rate of 26.9h(-1) and a 30% relative humidity. These conditions resulted in dynamic headspace concentrations and composition of the odor active VOCs that may be similar to real indoor setting. Emission samples for TD-GC-O/MS analysis from the FLEC were on Tenax TA. Although many volatile VOCs were detected by MS, only the odor active VOCs are reported here. In total, 142 odor active VOCs were detected in the emissions from the oils. About 50 of the odor active VOCs were identified or tentatively identified by GC-MS. While 92 VOCs were detected from the oil used in the floor oil, only 13 were detected in the low-odor linseed oil. The major odor active VOCs were aldehydes and carboxylic acids. Spearmen rank correlation of the GC-O profiles showed that the odor profile of the linseed oil likely influenced the odor profile of the floor oil based on this linseed oil.

  19. The broadly tuned odorant receptor OR1A1 is highly selective for 3-methyl-2,4-nonanedione, a key food odorant in aged wines, tea, and other foods.

    PubMed

    Geithe, Christiane; Noe, Franziska; Kreissl, Johanna; Krautwurst, Dietmar

    2016-12-04

    Key food odorants are the most relevant determinants by which we detect, recognize, and hedonically evaluate the aroma of foods and beverages. Odorants are detected by our chemical sense of olfaction, comprising a set of approximately 400 different odorant receptor types. However, the specific receptor activity patterns representing the aroma percepts of foods or beverages, as well as the key food odorant agonist profiles of single-odorant receptors, are largely unknown. We aimed to establish comprehensive key food odorant agonist profiles of 2 unrelated, broadly tuned receptors, OR1A1 and OR2W1, that had been associated thus far with mostly non-key food odorants and shared some of these agonists. By screening both receptors against 190 key food odorants in a cell-based luminescence assay, we identified 14 and 18 new key food odorant agonists for OR1A1 and OR2W1, respectively, with 3-methyl-2,4-nonanedione emerging as the most potent agonist for OR1A1 by 3 orders of magnitude, with a submicromolar half maximal effective concentration. 3-Methyl-2,4-nonanedione has been associated with a prune note in oxidized wine and is an aroma determinant in tea and apricots. Further screening against the entire set of 391 human odorant receptors revealed that 30 or 300 μmol/L 3-methyl-2,4-nonanedione activated only 1 receptor, OR1A1, suggesting a unique role of OR1A1 for the most sensitive detection of this key food odorant in wine, tea, and other food matrices.

  20. Sensitive Carbohydrate Detection using Surface Enhanced Raman Tagging

    PubMed Central

    Vangala, Karthikeshwar; Yanney, Michael; Hsiao, Cheng-Te; Wu, Wells W.; Shen, Rong-Fong; Zou, Sige; Sygula, Andrzej; Zhang, Dongmao

    2010-01-01

    Glycomic analysis is an increasingly important field in biological and biomedical research as glycosylation is one of the most important protein post-translational modifications. We have developed a new technique to detect carbohydrates using surface enhanced Raman spectroscopy (SERS) by designing and applying a Rhodamine B derivative as the SERS tag. Using a reductive amination reaction, the Rhodamine-based tag (RT) was successfully conjugated to three model carbohydrates (glucose, lactose and glucuronic acid). SERS detection limits obtained with 632 nm HeNe laser were ~1 nM in concentration for all the RT-carbohydrate conjugates and ~10 fmol in total sample consumption. The dynamic range of the SERS method is about 4 orders of magnitude, spanning from 1 nM to 5 µM. Ratiometric SERS quantification using isotope-substituted SERS internal references also allows comparative quantifications of carbohydrates labeled with RT and deuterium/hydrogen substituted RT tags, respectively. In addition to enhancing the SERS detection of the tagged carbohydrates, the Rhodamine tagging facilitates fluorescence and mass spectrometric detection of carbohydrates. Current fluorescence sensitivity of RT-carbohydrates is ~ 3 nM in concentration while the mass spectrometry (MS) sensitivity is about 1 fmol that was achieved with linear ion trap electrospray ionization (ESI)-MS instrument. Potential applications that take advantage of the high SERS, fluorescence and MS sensitivity of this SERS tagging strategy are discussed for practical glycomic analysis where carbohydrates may be quantified with a fluorescence and SERS technique, and then identified with ESI-MS techniques. PMID:21082777

  1. Odor frequency and odor annoyance. Part I: assessment of frequency, intensity and hedonic tone of environmental odors in the field.

    PubMed

    Sucker, Kirsten; Both, Ralf; Bischoff, Michael; Guski, Rainer; Winneke, Gerhard

    2008-05-01

    Odors can be evaluated as being pleasant or unpleasant (hedonic tone), but this differentiation was not incorporated into environmental odor regulation. In order to study the hedonic-induced modification of dose-response associations for community odor annoyance a pertinent field study was conducted. This paper covers the first step, namely the development and validation of a standardized human observation strategy for the direct quantification of the frequency, intensity, and hedonic tone of environmental odors in the field. Grids with equidistant observation points were located around six industrial odor sources, two with pleasant (sweets, rusk bakery), two with neutral (textile production, seed oil production), and two with unpleasant odor emissions (fat refinery, cast iron production). These points were visited by trained observers, screened for normal olfaction and reliable performance, in a systematic fashion for an observation time of 10 min duration. Exposure-related information from the observers in terms of frequency, intensity (six-point scale) and hedonic tone (nine-point scale) were compared to that of 1,456 residents using the same rating scales. Residents evaluated the industrial odors more intense and more unpleasant than the panelists. Furthermore, for the residents only negative relations between odor intensity and hedonic tone were found while for the observer pleasant odor became more pleasant with increasing intensity. Instead of three classes of industrial odors, namely pleasant, neutral and unpleasant, the responses allowed only for two odor classes, namely pleasant and not pleasant, the latter also covering the neutral category. The developed methodology has been shown to yield valid information about odor exposure in the field. With regard to different application settings the discrepancies between external observers and affected residents are discussed in terms of different information processing strategies, namely stimulus-based (bottom

  2. Androstadienone odor thresholds in adolescents.

    PubMed

    Hummel, Thomas; Krone, Franziska; Lundström, Johan N; Bartsch, Oliver

    2005-03-01

    A sex-related difference in olfactory sensitivity to androstenone has been reported to occur during adolescence. More males than females exhibited anosmia to androstenone, or an increase in androstenone threshold with age. The current study addressed the question whether similar, sexually dimorphic effects of aging over puberty can also be found for androstadienone. A total of 102 subjects participated (36 females, 66 males). Similar to previous investigations, subjects were divided into a group of 47 individuals with a mean age of 13.3 years, defined as pre/peri-pubertal, and a group of 55 subjects with a mean age of 17.1 years, defined as post-pubertal. All subjects underwent tests for verbal abilities, general olfactory function, and measurements of androstadienone thresholds. The study provided the following major results: (1) Male subjects exhibited higher androstadienone sensitivity in the pre/peri-pubertal group as compared to the post-pubertal group. This difference was not observed in female subjects. Correspondingly, a negative correlation between age and androstadienone sensitivity was found for male subjects, but not for female subjects. (2) In contrast to this sex-specific change of the androstadienone odor threshold, verbal skills and odor identification abilities increased with age in all subjects regardless of their sex. In conclusion, the present observations confirm previous research on sex-differentiated effects of aging during puberty on sensitivity towards odorous steroids. While the underlying causes are unknown, it may be hypothesized that the decreased sensitivity could result from the increased endogenous levels of androstadienone in male subjects. Future studies should include both steroid and non-steroid odorants to further explore these age-related changes.

  3. The function of bilateral odor arrival time differences in olfactory orientation of sharks.

    PubMed

    Gardiner, Jayne M; Atema, Jelle

    2010-07-13

    The direction of an odor signal source can be estimated from bilateral differences in signal intensity and/or arrival time. The best-known examples of the use of arrival time differences are in acoustic orientation. For chemoreception, animals are believed to orient by comparing bilateral odor concentration differences, turning toward higher concentrations. However, time differences should not be ignored, because odor plumes show chaotic intermittency, with the concentration variance several orders of magnitude greater than the concentration mean. We presented a small shark species, Mustelus canis, with carefully timed and measured odor pulses directly into their nares. They turned toward the side stimulated first, even with delayed pulses of higher concentration. This is the first conclusive evidence that under seminatural conditions and without training, bilateral time differences trump odor concentration differences. This response would steer the shark into an odor patch each time and thereby enhance its contact with the plume, i.e., a stream of patches. Animals with more widely spaced nares would be able to resolve smaller angles of attack at higher swimming speeds, a feature that may have contributed to the evolution of hammerhead sharks. This constitutes a novel steering algorithm for tracking odor plumes.

  4. Major Odorants Released as Urinary Volatiles by Urinary Incontinent Patients

    PubMed Central

    Pandey, Sudhir Kumar; Kim, Ki-Hyun; Choi, Si On; Sa, In Young; Oh, Soo Yeon

    2013-01-01

    In this study, volatile urinary components were collected using three different types of samples from patients suffering from urinary incontinence (UI): (1) urine (A); (2) urine + non-used pad (B); and (3) urine + used pad (C). In addition, urine + non-used pad (D) samples from non-patients were also collected as a reference. The collection of urinary volatiles was conducted with the aid of a glass impinger-based mini-chamber method. Each of the four sample types (A through D) was placed in a glass impinger and incubated for 4 hours at 37 °C. Ultra pure air was then passed through the chamber, and volatile urine gas components were collected into Tedlar bags at the other end. These bag samples were then analyzed for a wide range of VOCs and major offensive odorants (e.g., reduced sulfur compounds (RSCs), carbonyls, trimethylamine (TMA), ammonia, etc.). Among the various odorants, sulfur compounds (methanethiol and hydrogen sulfide) and aldehydes (acetaldehyde, butylaldehyde, and isovaleraldehyde) were detected above odor threshold and predicted to contribute most effectively to odor intensity of urine incontinence. PMID:23823973

  5. Major odorants released as urinary volatiles by urinary incontinent patients.

    PubMed

    Pandey, Sudhir Kumar; Kim, Ki-Hyun; Choi, Si On; Sa, In Young; Oh, Soo Yeon

    2013-07-03

    In this study, volatile urinary components were collected using three different types of samples from patients suffering from urinary incontinence (UI): (1) urine (A); (2) urine + non-used pad (B); and (3) urine + used pad (C). In addition, urine + non-used pad (D) samples from non-patients were also collected as a reference. The collection of urinary volatiles was conducted with the aid of a glass impinger-based mini-chamber method. Each of the four sample types (A through D) was placed in a glass impinger and incubated for 4 hours at 37 °C. Ultra pure air was then passed through the chamber, and volatile urine gas components were collected into Tedlar bags at the other end. These bag samples were then analyzed for a wide range of VOCs and major offensive odorants (e.g., reduced sulfur compounds (RSCs), carbonyls, trimethylamine (TMA), ammonia, etc.). Among the various odorants, sulfur compounds (methanethiol and hydrogen sulfide) and aldehydes (acetaldehyde, butylaldehyde, and isovaleraldehyde) were detected above odor threshold and predicted to contribute most effectively to odor intensity of urine incontinence.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Chemical Identification of "Maternal Signature Odors" in Rat.

    PubMed

    Sreng, Leam; Temime-Roussel, Brice; Wortham, Henri; Mourre, Christiane

    2016-12-22

    Newborn altricial mammals need just after birth to locate their mother's nipples for suckling. In this precocious behavior, including for the human baby, maternal odor via the olfactory process plays a major role. Maternal odor emitted by lactating females or by amniotic fluid (AF) attracts pups, but the chemical identity of this attractant has not yet been elucidated. Here, using behavioral tests and gas chromatography coupled with mass spectrometry (GC-MS) techniques, we show that AF extracts from rat pregnant female, nipples, ventral skin, milk, and nest extracts of mother contained 3-6 active substances. AF extracts contained 3 active compounds: ethylbenzene, benzaldehyde, and benzyl alcohol, and their mixture in similar proportions to those found in AF extracts, in a ratio, respectively, of 1:1:12 (700 ng), attracts pups as putative maternal attractant substances (MAS). These 3 AF substances have already been identified in milk, nipples, ventral wash, and nest extracts of mother, but not in feces. Moreover, anethole flavor incorporated in pregnant rat and mother's diet is also detected in AF, nipples, milk, and nest extracts and the pups are attracted to anethole odor, but not in the case of the no-anethole pups. MAS, combined with diet flavors present in the AF bath, represent olfactory signals as "maternal signature odors" (MSO) that are learned by fetus and pups. These findings open the way to improved understanding of the neurobiology of early olfactory learning and of the importance of evolutionarily conserved survival behavior in many mammal species.

  8. Odor sampling: techniques and strategies for the estimation of odor emission rates from different source types.

    PubMed

    Capelli, Laura; Sironi, Selena; Del Rosso, Renato

    2013-01-15

    Sampling is one of the main issues pertaining to odor characterization and measurement. The aim of sampling is to obtain representative information on the typical characteristics of an odor source by means of the collection of a suitable volume fraction of the effluent. The most important information about an emission source for odor impact assessment is the so-called Odor Emission Rate (OER), which represents the quantity of odor emitted per unit of time, and is expressed in odor units per second (ou∙s-1). This paper reviews the different odor sampling strategies adopted depending on source type. The review includes an overview of odor sampling regulations and a detailed discussion of the equipment to be used as well as the mathematical considerations to be applied to obtain the OER in relation to the sampled source typology.

  9. Odor Sampling: Techniques and Strategies for the Estimation of Odor Emission Rates from Different Source Types

    PubMed Central

    Capelli, Laura; Sironi, Selena; Rosso, Renato Del

    2013-01-01

    Sampling is one of the main issues pertaining to odor characterization and measurement. The aim of sampling is to obtain representative information on the typical characteristics of an odor source by means of the collection of a suitable volume fraction of the effluent. The most important information about an emission source for odor impact assessment is the so-called Odor Emission Rate (OER), which represents the quantity of odor emitted per unit of time, and is expressed in odor units per second (ou·s−1). This paper reviews the different odor sampling strategies adopted depending on source type. The review includes an overview of odor sampling regulations and a detailed discussion of the equipment to be used as well as the mathematical considerations to be applied to obtain the OER in relation to the sampled source typology. PMID:23322098

  10. [Study on odor control using wood vinegars].

    PubMed

    Takahara, Y; Katoh, K; Inaba, R; Iwata, H

    1993-01-01

    The effectiveness of wood vinegars reducing or eliminating offensive odors, associated with cattle breeding, was studied. The results obtained were as follows: 1. Analyzed were 0.7-7.2% acetic acid and 0.5-1.8% methyl alcohol as main contents. 2. Gaseous odorants, such as ammonia, trimethylamine, n-butyric acid were almost eliminated through absorption using 1-20% wood vinegar solutions. 3. The same gaseous odorants, mentioned above, when confined to an airtight vessel, were eliminated in a short time by adding a little volume of wood vinegars to it. The effect was maintained for 2 weeks. 4. A sensory test was performed to evaluate the degree of deodorization, such as odor intensity and odor acceptability. Results showed that wood vinegars have a good deodorant effect on the offensive odors.

  11. An odor flux model for cattle feedlots

    SciTech Connect

    Ormerod, R.J.

    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.

  12. Radial localization of odors by human newborns.

    PubMed

    Rieser, J; Yonas, A; Wikner, K

    1976-09-01

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

  13. Receptor arrays optimized for natural odor statistics

    PubMed Central

    Zwicker, David; Murugan, Arvind; 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 arrays. PMID:27102871

  14. Normalized Neural Representations of Complex Odors

    PubMed Central

    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 the processing in the olfactory bulb, 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. Comparing these predictions to experiments will help us to understand the role of global inhibition in shaping normalized odor representations in the olfactory bulb. PMID:27835696

  15. Comparison of odorant specificity of two human olfactory receptors from different phylogenetic classes and evidence for antagonism.

    PubMed

    Sanz, Guenhaël; Schlegel, Claire; Pernollet, Jean-Claude; Briand, Loïc

    2005-01-01

    Humans are able to detect and discriminate myriads of odorants using only several hundred olfactory receptors (ORs) classified in two major phylogenetic classes representing ORs from aquatic (class I) and terrestrial animals (class II). Olfactory perception results in a combinatorial code, in which one OR recognizes multiple odorants and different odorants are recognized by different combinations of ORs. Moreover, recent data suggest that odorants could also behave as antagonists for other ORs, thus making the combinatorial coding more complex. Here we describe the odorant repertoires of two human ORs belonging to class I and class II, respectively. For this purpose, we set up an assay based on calcium imaging in which 100 odorants were screened using air-phase odorant stimulation at physiological doses. We showed that the human class I OR52D1 is functional, exhibiting a narrow repertoire related to that of its orthologous murine OR, demonstrating than this human class I OR is not an evolutionary relic. The class II OR1G1 was revealed to be broadly tuned towards odorants of 9-10 carbon chain length, with diverse functional groups. The existence of antagonist odorants for the class II OR was also demonstrated. They are structurally related to the agonists, with shorter carbon chain length.

  16. High Sensitivity Surface Enhanced Raman Scattering Detection of Tryptophan

    NASA Astrophysics Data System (ADS)

    Kandakkathara, Archana

    Raman spectroscopy has the capability of providing detailed information about molecular structure, but the extremely small cross section of Raman scattering prevents this technique from applications requiring high sensitivity. Surface enhanced Raman scattering (SERS) on the other hand provides strongly increased Raman signal from molecules attached to metallic nanostructures. SERS is thus a promising technique for high sensitivity analytical applications. One particular area of interest is the application of such techniques for the analysis of the composition of biological cells. However, there are issues which have to be addressed in order to make SERS a reliable technique such as the optimization of conditions for any given analyte, understanding the kinetic processes of binding of the target molecules to the nanostructures and understanding the evolution and coagulation of the nanostructures, in the case of colloidal solutions. The latter processes introduce a delay time for the observation of maximum enhancement factors which must be taken into account for any given implementation of SERS. In the present thesis the goal was to develop very sensitive SERS techniques for the measurement of biomolecules of interest for analysis of the contents of cells. The techniques explored could be eventually be applicable to microfluidic systems with the ultimate goal of analyzing the molecular constituents of single cells. SERS study of different amino acids and organic dyes were performed during the course of this thesis. A high sensitivity detection system based on SERS has been developed and spectrum from tryptophan (Trp) amino acid at very low concentration (10-8 M) has been detected. The concentration at which good quality SERS spectra could be detected from Trp is 4 orders of magnitude smaller than that previously reported in literature. It has shown that at such low concentrations the SERS spectra of Trp are qualitatively distinct from the spectra commonly reported in

  17. Factors Influencing Odor Sensitivity in the Dog

    DTIC Science & Technology

    1975-10-01

    U.S. DEPARTMENT OF COMMERCE Natsual Techuical Imfwmatmi Suuwie AD-A024 267 FACTORS INFLUENCING ODOR SENSITIVITY IN THE DOG PENNSYLVANIA UNIVERSITY...PREPARED FOR AIR FORCE OFFICE OF SCIENTIFIC RESEARCH OCTOBER 1975 138097 FACTORS INFLUENCING ODOR SENSITIVITY IN THE DOG Final report - October, 1975...Subtitle) S. TYPE OF REPORT 6 PERIOD COVERED FACTORS INFLUENCING ODOR SENSITIVITY IN FIP.1 Scientific Report TlE DOG "Ś. PERFORMING ORG. REPORT NUMBER 7

  18. 2-Nonenal newly found in human body odor tends to increase with aging.

    PubMed

    Haze, S; Gozu, Y; Nakamura, S; Kohno, Y; Sawano, K; Ohta, H; Yamazaki, K

    2001-04-01

    Human body odor consists of various kinds of odor components. Here, we have investigated the changes in body odor associated with aging. The body odor of subjects between the ages of 26 and 75 was analyzed by headspace gas chromatography/mass spectrometry. 2-Nonenal, an unsaturated aldehyde with an unpleasant greasy and grassy odor, was detected only in older subjects (40 y or older). Furthermore, analysis of skin surface lipids revealed that omega7 unsaturated fatty acids and lipid peroxides also increased with aging and that there were positive correlations between the amount of 2-nonenal in body odor and the amount of omega7 unsaturated fatty acids or lipid peroxides in skin surface lipids. 2-Nonenal was generated only when omega7 unsaturated fatty acids were degraded by degradation tests in which some main components of skin surface lipids were oxidatively decomposed using lipid peroxides as initiator of an oxidative chain reaction. The results indicate that 2-nonenal is generated by the oxidative degradation of omega7 unsaturated fatty acids, and suggest that 2-nonenal may be involved in the age-related change of body odor.

  19. Odor-active constituents in fresh pineapple (Ananas comosus [L.] Merr.) by quantitative and sensory evaluation.

    PubMed

    Tokitomo, Yukiko; Steinhaus, Martin; Büttner, Andrea; Schieberle, Peter

    2005-07-01

    By application of aroma extract dilution analysis (AEDA) to an aroma distillate prepared from fresh pineapple using solvent-assisted flavor evaporation (SAFE), 29 odor-active compounds were detected in the flavor dilution (FD) factor range of 2 to 4,096. Quantitative measurements performed by stable isotope dilution assays (SIDA) and a calculation of odor activity values (OAVs) of 12 selected odorants revealed the following compounds as key odorants in fresh pineapple flavor: 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDF; sweet, pineapple-like, caramel-like), ethyl 2-methylpropanoate (fruity), ethyl 2-methylbutanoate (fruity) followed by methyl 2-methylbutanoate (fruity, apple-like) and 1-(E,Z)-3,5-undecatriene (fresh, pineapple-like). A mixture of these 12 odorants in concentrations equal to those in the fresh pineapple resulted in an odor profile similar to that of the fresh juice. Furthermore, the results of omission tests using the model mixture showed that HDF and ethyl 2-methylbutanoate are character impact odorants in fresh pineapple.

  20. Dissecting the signaling mechanisms underlying recognition and preference of food odors.

    PubMed

    Harris, Gareth; Shen, Yu; Ha, Heonick; Donato, Alessandra; Wallis, Samuel; Zhang, Xiaodong; Zhang, Yun

    2014-07-09

    Food is critical for survival. Many animals, including the nematode Caenorhabditis elegans, use sensorimotor systems to detect and locate preferred food sources. However, the signaling mechanisms underlying food-choice behaviors are poorly understood. Here, we characterize the molecular signaling that regulates recognition and preference between different food odors in C. elegans. We show that the major olfactory sensory neurons, AWB and AWC, play essential roles in this behavior. A canonical Gα-protein, together with guanylate cyclases and cGMP-gated channels, is needed for the recognition of food odors. The food-odor-evoked signal is transmitted via glutamatergic neurotransmission from AWC and through AMPA and kainate-like glutamate receptor subunits. In contrast, peptidergic signaling is required to generate preference between different food odors while being dispensable for the recognition of the odors. We show that this regulation is achieved by the neuropeptide NLP-9 produced in AWB, which acts with its putative receptor NPR-18, and by the neuropeptide NLP-1 produced in AWC. In addition, another set of sensory neurons inhibits food-odor preference. These mechanistic logics, together with a previously mapped neural circuit underlying food-odor preference, provide a functional network linking sensory response, transduction, and downstream receptors to process complex olfactory information and generate the appropriate behavioral decision essential for survival.

  1. Developing hexanal as an odor reference standard for sensory analysis of drinking water.

    PubMed

    Omür-Ozbek, Pinar; Dietrich, Andrea M

    2008-05-01

    There are many analytical and sensory methods to analyze drinking water for flavor and off-flavors before it reaches consumers. Flavor profile analysis (FPA) is one of the most comprehensive methods. A well-trained panel is essential for FPA and although taste standards are well established, FPA training lacks an odor reference standard. In search of an odor reference standard, four different panel groups were trained and tested for n-hexanal at various concentrations (1-1000 microg/L) over 14 months. The Weber-Fechner plots for n-hexanal showed a linear and overlapping relationship for all panels. Analytical measurements demonstrated that the headspace concentration of n-hexanal was constant after 5 sniffs at 45 degrees C and it remained constant during FPA sessions for up to 4 h. The panelists liked the grassy odor of n-hexanal, which did not result in fatigue, and testing demonstrated that approximately 95% of the population can detect n-hexanal's odor. n-Hexanal is proposed as an odor reference standard for FPA training to define odor intensities because it is chemically stable, follows Weber-Fechner law, mimics grassy odors found in drinking water, and was acceptable to the human panelists.

  2. Dissecting the Signaling Mechanisms Underlying Recognition and Preference of Food Odors

    PubMed Central

    Harris, Gareth; Shen, Yu; Ha, Heonick; Donato, Alessandra; Wallis, Samuel; Zhang, Xiaodong

    2014-01-01

    Food is critical for survival. Many animals, including the nematode Caenorhabditis elegans, use sensorimotor systems to detect and locate preferred food sources. However, the signaling mechanisms underlying food-choice behaviors are poorly understood. Here, we characterize the molecular signaling that regulates recognition and preference between different food odors in C. elegans. We show that the major olfactory sensory neurons, AWB and AWC, play essential roles in this behavior. A canonical Gα-protein, together with guanylate cyclases and cGMP-gated channels, is needed for the recognition of food odors. The food-odor-evoked signal is transmitted via glutamatergic neurotransmission from AWC and through AMPA and kainate-like glutamate receptor subunits. In contrast, peptidergic signaling is required to generate preference between different food odors while being dispensable for the recognition of the odors. We show that this regulation is achieved by the neuropeptide NLP-9 produced in AWB, which acts with its putative receptor NPR-18, and by the neuropeptide NLP-1 produced in AWC. In addition, another set of sensory neurons inhibits food-odor preference. These mechanistic logics, together with a previously mapped neural circuit underlying food-odor preference, provide a functional network linking sensory response, transduction, and downstream receptors to process complex olfactory information and generate the appropriate behavioral decision essential for survival. PMID:25009271

  3. The consequence of fetal ethanol exposure and adolescent odor re-exposure on the response to ethanol odor in adolescent and adult rats.

    PubMed

    Eade, Amber M; Sheehe, Paul R; Molina, Juan C; Spear, Norman E; Youngentob, Lisa M; Youngentob, Steven L

    2009-01-15

    An epidemiologic predictive relationship exists between fetal ethanol exposure and the likelihood for adolescent use. Further, an inverse relationship exists between the age of first experience and the probability of adult abuse. Whether and how the combined effects of prenatal and adolescent ethanol experiences contribute to this progressive pattern remains unknown. Fetal ethanol exposure directly changes the odor attributes of ethanol important for both ethanol odor preference behavior and ethanol flavor perception. These effects persist only to adolescence. Here we tested whether adolescent ethanol odor re-exposure: (Experiment 1) augments the fetal effect on the adolescent behavioral response to ethanol odor; and/or (Experiment 2) perpetuates previously observed adolescent behavioral and neurophysiological responses into adulthood. Pregnant rats received either an ethanol or control liquid diet. Progeny (observers) experienced ethanol odor in adolescence via social interaction with a peer (demonstrators) that received an intragastric infusion of either 1.5 g/kg ethanol or water. Social interactions were scored for the frequency that observers followed their demonstrator. Whole-body plethysmography evaluated the unconditioned behavioral response of observers to ethanol odor in adolescence (P37) or adulthood (P90). The olfactory epithelium of adults was also examined for its neural response to five odorants, including ethanol. Experiment 1: Relative to fetal or adolescent exposure alone, adolescent re-exposure enhanced the behavioral response to ethanol odor in P37 animals. Compared to animals with no ethanol experience, rats receiving a single experience (fetal or adolescent) show an enhanced, yet equivalent, ethanol odor response. Fetal ethanol experience also increased olfactory-guided following of an intoxicated peer. Experiment 2: Combined exposure yielded persistence of the behavioral effects only in adult females. We found no evidence for persistence of

  4. Volatile sulfur compounds responsible for an offensive odor of the flat-head, Calliurichthys doryssus.

    PubMed

    Shiomi, K; Noguchi, A; Yamanaka, H; Kikuchi, T; Iida, H

    1982-01-01

    1. The volatiles of a flat-head, Calliurichthys doryssus, which gives out a characteristic offensive odor in living time, were analyzed by gas chromatography. 2. A large quantity of volatile sulfur compounds was detected in the flat-head; of which methyl mercaptan and/or dimethyl disulfide were judged to be responsible for the offensive odor. 3. The contents of methyl mercaptan and dimethyl disulfide were much higher in skin than in muscle and viscera.

  5. Cross-cultural color-odor associations.

    PubMed

    Levitan, Carmel A; Ren, Jiana; Woods, Andy T; Boesveldt, Sanne; Chan, Jason S; McKenzie, Kirsten J; Dodson, Michael; Levin, Jai A; Leong, Christine X R; van den Bosch, Jasper 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., 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.

  6. Body odor similarity in noncohabiting twins.

    PubMed

    Roberts, S Craig; Gosling, L Morris; Spector, Tim D; Miller, Paul; Penn, Dustin J; Petrie, Marion

    2005-10-01

    There is currently considerable interest in biometric approaches using human odor as a marker of disease or genetic individuality. Body odor is also thought to be used during mate choice to select genetically compatible mates. The idea that body odor reveals information about both genetic identity and genetic similarity is most readily tested by examining odor in twin pairs. However, although this idea can be traced back 130 years to Francis Galton in 1875, most studies using dogs fail to control for shared environmental effects associated with cohabitation. Here we show that odors of identical twins (but not dizygotic twins) can be matched by human sniffers at rates better than chance, even when the twins are living apart. In addition, matching frequencies for identical twin odors were not significantly different from those for duplicate odors from the same individual. These results indicate an important genetic influence on body odor and the potential for developing technologies for human odor printing in relation to underlying genotype.

  7. Cross-Cultural Color-Odor Associations

    PubMed Central

    Levitan, Carmel A.; Ren, Jiana; Woods, Andy T.; Boesveldt, Sanne; Chan, Jason S.; McKenzie, Kirsten J.; Dodson, Michael; Levin, Jai A.; Leong, Christine X. R.; van den Bosch, Jasper 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., 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. PMID:25007343

  8. Human olfactory receptor responses to odorants

    PubMed Central

    Mainland, Joel D; Li, Yun R; Zhou, Ting; Liu, Wen Ling L; Matsunami, Hiroaki

    2015-01-01

    Although the human olfactory system is capable of discriminating a vast number of odors, we do not currently understand what chemical features are encoded by olfactory receptors. In large part this is due to a paucity of data in a search space covering the interactions of hundreds of receptors with billions of odorous molecules. Of the approximately 400 intact human odorant receptors, only 10% have a published ligand. Here we used a heterologous luciferase assay to screen 73 odorants against a clone library of 511 human olfactory receptors. This dataset will allow other researchers to interrogate the combinatorial nature of olfactory coding. PMID:25977809

  9. Unpleasant odors increase aversion to monetary losses.

    PubMed

    Stancak, Andrej; Xie, Yuxin; Fallon, Nicholas; Bulsing, Patricia; Giesbrecht, Timo; Thomas, Anna; Pantelous, Athanasios A

    2015-04-01

    Loss aversion is the tendency to prefer avoiding losses over acquiring gains of equal nominal values. Unpleasant odors not only influence affective state but have also been shown to activate brain regions similar to those mediating loss aversion. Therefore, we hypothesized a stronger loss aversion in a monetary gamble task if gambles were associated with an unpleasant as opposed to pleasant odor. In thirty human subjects, unpleasant (methylmercaptan), pleasant (jasmine), and neutral (clean air) odors were presented for 4 s. At the same time, uncertain gambles offering an equal chance of gain or loss of a variable amount of money, or a prospect of an assured win were displayed. One hundred different gambles were presented three times, each time paired with a different odor. Loss aversion, risk aversion, and logit sensitivity were evaluated using non-linear fitting of individual gamble decisions. Loss aversion was larger when prospects were displayed in the presence of methylmercaptan compared to jasmine or clean air. Moreover, individual differences in changes in loss aversion to the unpleasant as compared to pleasant odor correlated with odor pleasantness but not with odor intensity. Skin conductance responses to losses during the outcome period were larger when gambles were associated with methylmercaptan compared to jasmine. Increased loss aversion while perceiving an unpleasant odor suggests a dynamic adjustment of loss aversion toward greater sensitivity to losses. Given that odors are biological signals of hazards, such adjustment of loss aversion may have adaptive value in situations entailing threat or danger.

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

    ERIC Educational Resources Information Center

    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…

  11. Usefulness of curry odorant of odor stick identification test for Japanese in olfactory impairment screening.

    PubMed

    Shiga, Hideaki; Toda, Hideki; Kobayakawa, Tatsu; Saito, Sachiko; Hirota, Kyoko; Tsukatani, Toshiaki; Furukawa, Mitsuru; Miwa, Takaki

    2009-06-01

    The curry odorant of the odor stick identification test for Japanese (OSIT-J) is useful in screening for olfactory impairment in Japanese subjects. The present study was designed to determine the most useful odorant of the OSIT-J in screening for olfactory impairment in Japanese subjects. We studied olfactory impairment screening with the OSIT-J in 83 participants (49 male, 34 female; average age 50 years) in an executive check-up at NTT West Kanazawa Hospital. Olfactory discrimination acuity was evaluated with three odorants of the OSIT-J (rose, curry, and sweaty-smelling clothes), each known to be significantly correlated with the assessment of the Japanese standard olfaction test (T&T olfactometer). Those participants who did not score full marks in tests with the three odors were assessed with another nine odorants of the OSIT-J. The positive predictive value was 100% in the screening with the curry odorant. In 38 participants who did not identify all three odors correctly, the identification of the curry odor was significantly correlated with the scores for all 12 odors (p<0.005). Identification of the curry odor was not significantly correlated with identification of the menthol odor of OSIT-J.

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

    ERIC Educational Resources Information Center

    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…

  13. 17β-estradiol enhances memory duration in the main olfactory bulb in CD-1 mice.

    PubMed

    Dillon, T Samuel; Fox, Laura C; Han, Crystal; Linster, Christiane

    2013-12-01

    Rodents rely heavily on odor detection, discrimination, and memory to locate food, find mates, care for pups, and avoid predators. Estrogens have been shown to increase memory retention in rodents performing spatial memory and object placement tasks. Here we evaluate the extent to which 17β-estradiol modulates memory formation and duration in the olfactory system. Adult CD-1 mice were gonadectomized and given either systemic 17β-estradiol replacement, local 17β-estradiol in the main olfactory bulb, or no replacement. Before performing the behavioral task the mice were given saline or PHTPP (an estrogen receptor β [ER-β] antagonist) via bilateral infusion into the main olfactory bulb. As the beta-type estrogen receptor (ER-β) is more abundant than the alpha-type estrogen receptor in the murine main olfactory bulb, the current study focuses on 17β-estradiol and its interactions with ERβ. Habituation, a simple, nonassociative learning task in which an animal is exposed to the same odor over successive presentations, was used to evaluate the animals' ability to detect odors and form an olfactory memory. To evaluate memory duration, we added a final trial of intertrial interval time (30 or 60 min) in which we presented the habituated odor. Neither surgical nor drug manipulation affected the ability of mice to detect or habituate to an odor. After habituation, gonadectomized 17β-estradiol-treated mice retained memory of an odor for 30 min, whereas non-estradiol-treated, 17β-estradiol+ERβ antagonist (PHTPP), and untreated male mice did not remember an odor 30 min after habituation. The results show that both systemic and local bulbar infusions of 17β-estradiol enhance odor memory duration in mice.

  14. Odor as an aid to chemical safety: odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution.

    PubMed

    Amoore, J E; Hautala, E

    1983-12-01

    The body of information in this paper is directed to specialists in industrial health and safety, and air and water pollution, who need quantitative data on the odor thresholds of potentially hazardous chemical vapors and gases. The literature, largely unorganized, has been reviewed for 214 compounds and condensed into tables based on consistent units. Data on the volatility, solubility, ionization and water-air distribution ratio at 25 degrees C are included. From the currently recommended threshold limit value (TLV), a safe dilution factor and an odor safety factor are calculated for each compound. The equivalent data are presented for both air and water dilutions of the chemicals. Available data are summarized on the variability of odor sensitivities in the population, and the increased odor concentrations that are required to elicit responses from persons whose attention is distracted, or who are sleeping. This information is reduced to calibration charts that may be used to estimate the relative detectability, warning potential and rousing capacity of the odorous vapors. Each compound has been assigned a letter classification, from A to E, to indicate the margin of safety, if any, that may be afforded by the odor of the compound as a warning that its threshold limit value is being exceeded.

  15. The value of an odor-quality-wheel classification scheme for wastewater treatment plants.

    PubMed

    Suffet, I H Mel; Burlingame, G A; Rosenfeld, P E; Bruchet, A

    2004-01-01

    Each odorant possesses a unique odor signature (i.e. odor character or quality, odor threshold and chemical concentration). This paper develops an initial understanding of how the volatile odorous chemicals and their relative concentrations produced are related to the total odor quality from the process by their odor threshold concentrations and odor signatures.

  16. Optical extinction monitor using cw cavity enhanced detection.

    PubMed

    Kebabian, Paul L; Robinson, Wade A; Freedman, Andrew

    2007-06-01

    We present details of an apparatus capable of measuring optical extinction (i.e., scattering and/or absorption) with high precision and sensitivity. The apparatus employs one variant of cavity enhanced detection, specifically cavity attenuated phase shift spectroscopy, using a near-confocal arrangement of two high reflectivity (R approximately 0.9999) mirrors in tandem with an enclosed cell 26 cm in length, a light emitting diode (LED), and a vacuum photodiode detector. The square wave modulated light from the LED passes through the absorption cell and is detected as a distorted wave form which is characterized by a phase shift with respect to the initial modulation. The amount of that phase shift is a function of fixed instrument properties-cell length, mirror reflectivity, and modulation frequency-and of the presence of a scatterer or absorber (air, particles, trace gases, etc.) within the cell. The specific implementation reported here employs a blue LED; the wavelength and spectral bandpass of the measurement are defined by the use of an interference filter centered at 440 nm with a 20 nm wide bandpass. The monitor is enclosed within a standard 19 in. rack-mounted instrumentation box, weighs 10 kg, and uses 70 W of electrical power including a vacuum pump. Measurements of the phase shift induced by Rayleigh scattering from several gases (which range in extinction coefficient from 0.4-32 Mm(-1)) exhibit a highly linear dependence (r(2)=0.999 97) when plotted as the co-tangent of the phase shift versus the expected extinction. Using heterodyne demodulation techniques, we demonstrate a detection limit of 0.04 Mm(-1) (4 x 10(-10) cm(-1)) (2sigma) in 10 s integration time and a base line drift of less than +/-0.1 Mm(-1) over a 24 h period. Detection limits decrease as the square root of integration time out to approximately 150 s.

  17. Spontaneous Rapid Odor Source Localization Behavior Requires Interhemispheric Communication.

    PubMed

    Esquivelzeta Rabell, José; Mutlu, Kadir; Noutel, João; Martin Del Olmo, Pamela; Haesler, Sebastian

    2017-05-22

    Navigation, finding food sources, and avoiding danger critically depend on the identification and spatial localization of airborne chemicals. When monitoring the olfactory environment, rodents spontaneously engage in active olfactory sampling behavior, also referred to as exploratory sniffing [1]. Exploratory sniffing is characterized by stereotypical high-frequency respiration, which is also reliably evoked by novel odorant stimuli [2, 3]. To study novelty-induced exploratory sniffing, we developed a novel, non-contact method for measuring respiration by infrared (IR) thermography in a behavioral paradigm in which novel and familiar stimuli are presented to head-restrained mice. We validated the method by simultaneously performing nasal pressure measurements, a commonly used invasive approach [2, 4], and confirmed highly reliable detection of inhalation onsets. We further discovered that mice actively orient their nostrils toward novel, previously unexperienced, smells. In line with the remarkable speed of olfactory processing reported previously [3, 5, 6], we find that mice initiate their response already within the first sniff after odor onset. Moreover, transecting the anterior commissure (AC) disrupted orienting, indicating that the orienting response requires interhemispheric transfer of information. This suggests that mice compare odorant information obtained from the two bilaterally symmetric nostrils to locate the source of the novel odorant. We further demonstrate that asymmetric activation of the anterior olfactory nucleus (AON) is both necessary and sufficient for eliciting orienting responses. These findings support the view that the AON plays an important role in the internostril difference comparison underlying rapid odor source localization. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Carbon Nanotube-based microelectrodes for enhanced detection of neurotransmitters

    NASA Astrophysics Data System (ADS)

    Jacobs, Christopher B.

    Fast-scan cyclic voltammetry (FSCV) is one of the common techniques used for rapid measurement of neurotransmitters in vivo. Carbon-fiber microelectrodes (CFMEs) are typically used for neurotransmitter detection because of sub-second measurement capabilities, ability to measure changes in neurotransmitter concentration during neurotransmission, and the small size electrode diameter, which limits the amount of damage caused to tissue. Cylinder CFMEs, typically 50 -- 100 microm long, are commonly used for in vivo experiments because the electrode sensitivity is directly related to the electrode surface area. However the length of the electrode can limit the spatial resolution of neurotransmitter detection, which can restrict experiments in Drosophila and other small model systems. In addition, the electrode sensitivity toward dopamine and serotonin detection drops significantly for measurements at rates faster than 10 Hz, limiting the temporal resolution of CFMEs. While the use of FSCV at carbon-fiber microelectrodes has led to substantial strides in our understanding of neurotransmission, techniques that expand the capabilities of CFMEs are crucial to fully maximize the potential uses of FSCV. This dissertation introduces new methods to integrate carbon nanotubes (CNT) into microelectrodes and discusses the electrochemical enhancements of these CNT-microelectrodes. The electrodes are specifically designed with simple fabrication procedures so that highly specialized equipment is not necessary, and they utilize commercially available materials so that the electrodes could be easily integrated into existing systems. The electrochemical properties of CNT modified CFMEs are characterized using FSCV and the effect of CNT functionalization on these properties is explored in Chapter 2. For example, CFME modification using carboxylic acid functionalized CNTs yield about a 6-fold increase in dopamine oxidation current, but modification with octadecylamine CNTs results in a

  19. Simultaneous sampling of flow and odorants by crustaceans can aid searches within a turbulent plume.

    PubMed

    Pravin, Swapnil; Reidenbach, Matthew A

    2013-12-03

    Crustaceans such as crabs, lobsters and crayfish use dispersing odorant molecules to determine the location of predators, prey, potential mates and habitat. Odorant molecules diffuse in turbulent flows and are sensed by the olfactory organs of these animals, often using a flicking motion of their antennules. These antennules contain both chemosensory and mechanosensory sensilla, which enable them to detect both flow and odorants during a flick. To determine how simultaneous flow and odorant sampling can aid in search behavior, a 3-dimensional numerical model for the near-bed flow environment was created. A stream of odorant concentration was released into the flow creating a turbulent plume, and both temporally and spatially fluctuating velocity and odorant concentration were quantified. The plume characteristics show close resemblance to experimental measurements within a large laboratory flume. Results show that mean odorant concentration and it's intermittency, computed as dc/dt, increase towards the plume source, but the temporal and spatial rate of this increase is slow and suggests that long measurement times would be necessary to be useful for chemosensory guidance. Odorant fluxes measured transverse to the mean flow direction, quantified as the product of the instantaneous fluctuation in concentration and velocity, v'c', do show statistically distinct magnitude and directional information on either side of a plume centerline over integration times of <0.5 s. Aquatic animals typically have neural responses to odorant and velocity fields at rates between 50 and 500 ms, suggesting this simultaneous sampling of both flow and concentration in a turbulent plume can aid in source tracking on timescales relevant to aquatic animals.

  20. Simultaneous Sampling of Flow and Odorants by Crustaceans can Aid Searches within a Turbulent Plume

    PubMed Central

    Pravin, Swapnil; Reidenbach, Matthew A.

    2013-01-01

    Crustaceans such as crabs, lobsters and crayfish use dispersing odorant molecules to determine the location of predators, prey, potential mates and habitat. Odorant molecules diffuse in turbulent flows and are sensed by the olfactory organs of these animals, often using a flicking motion of their antennules. These antennules contain both chemosensory and mechanosensory sensilla, which enable them to detect both flow and odorants during a flick. To determine how simultaneous flow and odorant sampling can aid in search behavior, a 3-dimensional numerical model for the near-bed flow environment was created. A stream of odorant concentration was released into the flow creating a turbulent plume, and both temporally and spatially fluctuating velocity and odorant concentration were quantified. The plume characteristics show close resemblance to experimental measurements within a large laboratory flume. Results show that mean odorant concentration and it's intermittency, computed as dc/dt, increase towards the plume source, but the temporal and spatial rate of this increase is slow and suggests that long measurement times would be necessary to be useful for chemosensory guidance. Odorant fluxes measured transverse to the mean flow direction, quantified as the product of the instantaneous fluctuation in concentration and velocity, v′c′, do show statistically distinct magnitude and directional information on either side of a plume centerline over integration times of <0.5 s. Aquatic animals typically have neural responses to odorant and velocity fields at rates between 50 and 500 ms, suggesting this simultaneous sampling of both flow and concentration in a turbulent plume can aid in source tracking on timescales relevant to aquatic animals. PMID:24300599

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

    PubMed

    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.

  2. Rapid Brightness Variations as a Tool to Enhance Satellite Detectability

    NASA Astrophysics Data System (ADS)

    Laas-Bourez, Myrtille; Klotz, Alain; Ducrotte, Etienne; Boer, Michel; Blanchet, Gwendoline

    2009-03-01

    To preserve the space environment for future generations and ensure the safety of space missions, we have to improve our knowledge of the debris at all altitudes. Since 2004, we have started to observe and study satellites and debris on the geostationary orbit. We use a network of robotic telescopes called TAROT (Télescopes Action Rapide pour les Objets Transitoires - Rapid Action Telescope for Transient Objects) which are located in France and Chile. This system processes the data in real time. Its wide field of view is useful for detection, systematic survey and to follow both catalogued and uncatalogued objects. The TAROTs are 25 cm telescopes with a wide field of view of 1.86deg x 1.86deg. It can detect objects up to 17th magnitude with an integration time of 30 seconds, corresponding to an object of 50cm in the geostationary belt with a 0.2 albedo. Tiny debris are also dangerous for space mission and satellites. To detect them, we need either to increase the TAROT sensitivity or to observe them in optimal light conditions.Last year we detected very important magnitude variations from several geostationary satellites during observations close to equinoxes. The brightness of a geostationary satellite evolves during the night and during the year, depending on the angle between the observer, the satellite and the sun. Geostationary satellites will be brighter near March 1st and of October 10th, at their exit of the shade. In this period the sun crosses the equatorial plan of the Earth, the enlightened surface will reach a maximum during a limited periods of time (about 30 minutes), provoking a short, bright flash. This phenomenon is used in two ways: first, it allows to detect smaller objects, which are usually below the detection limit, enhancing the sensitivity of the survey. Secondly, for longer objects the light curve during and outside the °ash contains information on the object intrinsic geometry and reflectivity. In this paper we discuss how the various

  3. Efficient control of odors and VOC emissions via activated carbon technology.

    PubMed

    Mohamed, Farhana; Kim, James; Huang, Ruey; Nu, Huong Ton; Lorenzo, Vlad

    2014-07-01

    This research study was undertaken to enhance the efficiency and economy of carbon scrubbers in controlling odors and volatile organic compounds (VOCs) at the wastewater collection and treatment facilities of the Bureau of Sanitation, City of Los Angeles. The butane activity and hydrogen sulfide breakthrough capacity of activated carbon were assessed. Air streams were measured for odorous gases and VOCs and removal efficiency (RE) determined. Carbon towers showed average to excellent removal of odorous compounds, VOCs, and siloxanes; whereas, wet scrubbers demonstrated good removal of odorous compounds but low to negative removal of VOCs. It was observed that the relative humidity and empty bed contact time are one of the most important operating parameters of carbon towers impacting the pollutant RE. Regular monitoring of activated carbon and VOCs has resulted in useful information on carbon change-out frequency, packing recommendations, and means to improve performance of carbon towers.

  4. The role of algae and cyanobacteria in the production and release of odorants in water.

    PubMed

    Lee, Jechan; Rai, Prabhat Kumar; Jeon, Young Jae; Kim, Ki-Hyun; Kwon, Eilhann E

    2017-08-01

    This review covers literatures pertaining to algal and cyanobacterial odor problems that have been published over the last five decades. Proper evaluation of algal and cyanobacterial odors may help establish removal strategies for hazardous metabolites while enhancing the recyclability of water. A bloom of microalgae is a sign of an anthropogenic disturbance in aquatic systems and can lead to diverse changes in ecosystems along with increased production of odorants. In general, because algal and cyanobacterial odors vary in chemistry and intensity according to blooming pattern, it is necessary to learn more about the related factors and processes (e.g., changes due to differences in taxa). This necessitates systematic and transdisciplinary approaches that require the cooperation of chemists, biologists, engineers, and policy makers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Functional brain networks during picture encoding and recognition in different odor contexts.

    PubMed

    Reichert, J L; Ninaus, M; Schuehly, W; Hirschmann, C; Bagga, D; Schöpf, V

    2017-08-30

    Contextual odors can serve as retrieval cues when applied during encoding and recall/recognition of information. To investigate the neuronal basis of these observations, we collected functional MRI data while participants (n=51) performed an encoding and recognition memory task during which odors (congruent: CO or incongruent: IO) were presented as contextual cues. Recognition performance was not influenced by odor, but there was increased activation in the piriform cortex during successful encoding in the CO group, possibly indicating enhanced retrieval of information previously integrated with an olfactory percept. Moreover, group-independent component analysis revealed a stronger task-modulation of subcortical networks for IO versus CO during the recognition task, pointing to differences in olfactory processing. These observations provide a deeper understanding of the involvement of functional neuronal networks in memory tasks and a basis for further evaluation of the impact of odor contexts. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Evidence for a bacterial mechanism for group-specific social odors among hyenas.

    PubMed

    Theis, Kevin R; Schmidt, Thomas M; Holekamp, Kay E

    2012-01-01

    Symbiotic microbes can benefit their animal hosts by enhancing the diversity of communication signals available to them. The fermentation hypothesis for chemical recognition posits that 1) fermentative bacteria in specialized mammalian scent glands generate odorants that mammals co-opt to communicate with one another, and 2) that variation in scent gland odors is due to underlying variation in the structure of bacterial communities within scent glands. For example, group-specific social odors are suggested to be due to members of the same social group harboring more similar bacterial communities in their scent glands than do members of different social groups. We used 16S rRNA gene surveys to show that 1) the scent secretions of spotted hyenas are densely populated by fermentative bacteria whose closest relatives are well-documented odor producers, and that 2) these bacterial communities are more similar among hyenas from the same social group than among those from different groups.

  7. Image animation for theme enhancement and change detection. [LANDSAT 1

    NASA Technical Reports Server (NTRS)

    Evans, W. E.

    1976-01-01

    Animated displays are useful in enhancing subtle temporally related changes in scenes viewed by satellites capable of providing repetitive coverage. The detectability of fixed features is also improved through the help of the powerful visual integration process. To expedite the process of assembling and displaying well-registered, time-lapse sequences and to provide means for making quantitative measurements of radiances, displacements, and areas, an electronic satellite image analysis console was constructed. During the LANDSAT-1 program, this equipment was applied to the needs of a number of earth resource investigators with interests principally related to dynamic hydrology. The measurement of the areal extent of snow cover within defined drainage basins is discussed as a representative applications example.

  8. Method and apparatus for enhanced detection of toxic agents

    DOEpatents

    Greenbaum, Elias; Rodriguez, Jr., Miguel; Wu, Jie Jayne; Qi, Hairong

    2013-10-01

    A biosensor based detection of toxins includes enhancing a fluorescence signal by concentrating a plurality of photosynthetic organisms in a fluid into a concentrated region using biased AC electro-osmosis. A measured photosynthetic activity of the photosynthetic organisms is obtained in the concentrated region, where chemical, biological or radiological agents reduce a nominal photosynthetic activity of the photosynthetic organisms. A presence of the chemical, biological and/or radiological agents or precursors thereof, is determined in the fluid based on the measured photosynthetic activity of the concentrated plurality of photosynthetic organisms. A lab-on-a-chip system is used for the concentrating step. The presence of agents is determined from feature vectors, obtained from processing a time dependent signal using amplitude statistics and/or time-frequency analysis, relative to a control signal. A linear discriminant method including support vector machine classification (SVM) is used to identify the agents.

  9. Image animation for theme enhancement and change detection. [LANDSAT 1

    NASA Technical Reports Server (NTRS)

    Evans, W. E.

    1976-01-01

    Animated displays are useful in enhancing subtle temporally related changes in scenes viewed by satellites capable of providing repetitive coverage. The detectability of fixed features is also improved through the help of the powerful visual integration process. To expedite the process of assembling and displaying well-registered, time-lapse sequences and to provide means for making quantitative measurements of radiances, displacements, and areas, an electronic satellite image analysis console was constructed. During the LANDSAT-1 program, this equipment was applied to the needs of a number of earth resource investigators with interests principally related to dynamic hydrology. The measurement of the areal extent of snow cover within defined drainage basins is discussed as a representative applications example.

  10. Network community-detection enhancement by proper weighting

    NASA Astrophysics Data System (ADS)

    Khadivi, Alireza; Ajdari Rad, Ali; Hasler, Martin

    2011-04-01

    In this paper, we show how proper assignment of weights to the edges of a complex network can enhance the detection of communities and how it can circumvent the resolution limit and the extreme degeneracy problems associated with modularity. Our general weighting scheme takes advantage of graph theoretic measures and it introduces two heuristics for tuning its parameters. We use this weighting as a preprocessing step for the greedy modularity optimization algorithm of Newman to improve its performance. The result of the experiments of our approach on computer-generated and real-world data networks confirm that the proposed approach not only mitigates the problems of modularity but also improves the modularity optimization.

  11. Numerical modeling of turbulent and laminar airflow and odorant transport during sniffing in the human and rat nose.

    PubMed

    Zhao, Kai; Dalton, Pamela; Yang, Geoffery C; Scherer, Peter W

    2006-02-01

    Human sniffing behavior usually involves bouts of short, high flow rate inhalation (>300 ml/s through each nostril) with mostly turbulent airflow. This has often been characterized as a factor enabling higher amounts of odorant to deposit onto olfactory mucosa than for laminar airflow and thereby aid in olfactory detection. Using computational fluid dynamics human nasal cavity models, however, we found essentially no difference in predicted olfactory odorant flux (g/cm2 s) for turbulent versus laminar flow for total nasal flow rates between 300 and 1000 ml/s and for odorants of quite different mucosal solubility. This lack of difference was shown to be due to the much higher resistance to lateral odorant mass transport in the mucosal nasal airway wall than in the air phase. The simulation also revealed that the increase in airflow rate during sniffing can increase odorant uptake flux to the nasal/olfactory mucosa but lower the cumulative total uptake in the olfactory region when the inspired air/odorant volume was held fixed, which is consistent with the observation that sniff duration may be more important than sniff strength for optimizing olfactory detection. In contrast, in rats, sniffing involves high-frequency bouts of both inhalation and exhalation with laminar airflow. In rat nose odorant uptake simulations, it was observed that odorant deposition was highly dependent on solubility and correlated with the locations of different types of receptors.

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

    PubMed Central

    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

  13. Association of Odor Thresholds and Responses in Cerebral Blood Flow of the Prefrontal Area during Olfactory Stimulation in Patients with Multiple Chemical Sensitivity

    PubMed Central

    Uchiyama, Iwao; Tanigawa, Mari; Bamba, Ikuko; Azuma, Michiyo; Takano, Hirohisa; Yoshikawa, Toshikazu; Sakabe, Kou

    2016-01-01

    Multiple chemical sensitivity (MCS) is a disorder characterized by nonspecific and recurrent symptoms from various organ systems associated with exposure to low levels of chemicals. Patients with MCS process odors differently than controls do. Previously, we suggested that this odor processing was associated with increased regional cerebral blood flow (rCBF) in the prefrontal area during olfactory stimulation using near-infrared spectroscopic (NIRS) imaging. The aim of this study was to investigate the association of odor thresholds and changes in rCBF during olfactory stimulation at odor threshold levels in patients with MCS. We investigated changes in the prefrontal area using NIRS imaging and a T&T olfactometer during olfactory stimulation with two different odorants (sweet and fecal) at three concentrations (zero, odor recognition threshold, and normal perceived odor level) in 10 patients with MCS and six controls. The T&T olfactometer threshold test and subjective assessment of irritating and hedonic odors were also performed. The results indicated that the scores for both unpleasant and pungent odors were significantly higher for those for sweet odors at the normal perceived level in patients with MCS than in controls. The brain responses at the recognition threshold (fecal odor) and normal perceived levels (sweet and fecal odors) were stronger in patients with MCS than in controls. However, significant differences in the odor detection and recognition thresholds and odor intensity score between the two groups were not observed. These brain responses may involve cognitive and memory processing systems during past exposure to chemicals. Further research regarding the cognitive features of sensory perception and memory due to past exposure to chemicals and their associations with MCS symptoms is needed. PMID:27936122

  14. Association of Odor Thresholds and Responses in Cerebral Blood Flow of the Prefrontal Area during Olfactory Stimulation in Patients with Multiple Chemical Sensitivity.

    PubMed

    Azuma, Kenichi; Uchiyama, Iwao; Tanigawa, Mari; Bamba, Ikuko; Azuma, Michiyo; Takano, Hirohisa; Yoshikawa, Toshikazu; Sakabe, Kou

    2016-01-01

    Multiple chemical sensitivity (MCS) is a disorder characterized by nonspecific and recurrent symptoms from various organ systems associated with exposure to low levels of chemicals. Patients with MCS process odors differently than controls do. Previously, we suggested that this odor processing was associated with increased regional cerebral blood flow (rCBF) in the prefrontal area during olfactory stimulation using near-infrared spectroscopic (NIRS) imaging. The aim of this study was to investigate the association of odor thresholds and changes in rCBF during olfactory stimulation at odor threshold levels in patients with MCS. We investigated changes in the prefrontal area using NIRS imaging and a T&T olfactometer during olfactory stimulation with two different odorants (sweet and fecal) at three concentrations (zero, odor recognition threshold, and normal perceived odor level) in 10 patients with MCS and six controls. The T&T olfactometer threshold test and subjective assessment of irritating and hedonic odors were also performed. The results indicated that the scores for both unpleasant and pungent odors were significantly higher for those for sweet odors at the normal perceived level in patients with MCS than in controls. The brain responses at the recognition threshold (fecal odor) and normal perceived levels (sweet and fecal odors) were stronger in patients with MCS than in controls. However, significant differences in the odor detection and recognition thresholds and odor intensity score between the two groups were not observed. These brain responses may involve cognitive and memory processing systems during past exposure to chemicals. Further research regarding the cognitive features of sensory perception and memory due to past exposure to chemicals and their associations with MCS symptoms is needed.

  15. Enhanced electrochemical detection of quercetin by Natural Deep Eutectic Solvents.

    PubMed

    Gomez, Federico José Vicente; Espino, Magdalena; de Los Angeles Fernandez, María; Raba, Julio; Silva, María Fernanda

    2016-09-14

    New trends in analytical chemistry encourage the development of smart techniques and methods aligned with Green Chemistry. In this sense, Natural Deep Eutectic Solvents represents an excellent opportunity as a new generation of green solvents. In this work a new application for them has been proposed and demonstrated. These solvents were synthesized by combinations of inexpensive and natural components like, Glucose, Fructose, Citric acid and Lactic acid. The different natural solvents were easily prepared and added to buffer solution in different concentrations, allowing the enhancement of electrochemical detection of an important representative antioxidant like quercetin (QR) with improved signal up to 380%. QR is a ubiquitous flavonoid widespread in plants and food of plant origin. The proposed method using phosphate buffer with a eutectic mixture of Citric acid, Glucose and water in combination with carbon screen printed electrodes exhibited a good analytical performance. Detection and quantification limits were of 7.97 and 26.3 nM respectively; and repeatability with %RSDs of 1.41 and 7.49 for peak potential and intensity respectively. In addition, it has proved to be faster, greener and cheaper than other sensors and chromatographic methods available with the additional advantage of being completely portable. Furthermore, the obtained results demonstrated that the proposed method is able for the determination of QR in complex food samples.

  16. Enhancing Time-Series Detection Algorithms for Automated Biosurveillance

    PubMed Central

    Burkom, Howard; Xing, Jian; English, Roseanne; Bloom, Steven; Cox, Kenneth; Pavlin, Julie A.

    2009-01-01

    BioSense is a US national system that uses data from health information systems for automated disease surveillance. We studied 4 time-series algorithm modifications designed to improve sensitivity for detecting artificially added data. To test these modified algorithms, we used reports of daily syndrome visits from 308 Department of Defense (DoD) facilities and 340 hospital emergency departments (EDs). At a constant alert rate of 1%, sensitivity was improved for both datasets by using a minimum standard deviation (SD) of 1.0, a 14–28 day baseline duration for calculating mean and SD, and an adjustment for total clinic visits as a surrogate denominator. Stratifying baseline days into weekdays versus weekends to account for day-of-week effects increased sensitivity for the DoD data but not for the ED data. These enhanced methods may increase sensitivity without increasing the alert rate and may improve the ability to detect outbreaks by using automated surveillance system data. PMID:19331728

  17. Enhancing time-series detection algorithms for automated biosurveillance.

    PubMed

    Tokars, Jerome I; Burkom, Howard; Xing, Jian; English, Roseanne; Bloom, Steven; Cox, Kenneth; Pavlin, Julie A

    2009-04-01

    BioSense is a US national system that uses data from health information systems for automated disease surveillance. We studied 4 time-series algorithm modifications designed to improve sensitivity for detecting artificially added data. To test these modified algorithms, we used reports of daily syndrome visits from 308 Department of Defense (DoD) facilities and 340 hospital emergency departments (EDs). At a constant alert rate of 1%, sensitivity was improved for both datasets by using a minimum standard deviation (SD) of 1.0, a 14-28 day baseline duration for calculating mean and SD, and an adjustment for total clinic visits as a surrogate denominator. Stratifying baseline days into weekdays versus weekends to account for day-of-week effects increased sensitivity for the DoD data but not for the ED data. These enhanced methods may increase sensitivity without increasing the alert rate and may improve the ability to detect outbreaks by using automated surveillance system data.

  18. Detection Of Biochips By Raman And Surface Enhanced Raman Spectroscopies

    NASA Astrophysics Data System (ADS)

    Kantarovich, Keren; Tsarfati, Inbal; Gheber, Levi A.; Haupt, Karsten; Bar, Ilana

    2010-08-01

    Biochips constitute a rapidly increasing research field driven by the versatility of sensing devices and the importance of their applications in the bioanalytical field, drug development, environmental monitoring, food analysis, etc. Common strategies used for creating biochips and for reading them have extensive limitations, motivating development of miniature biochips and label-free formats. To achieve these goals we combined the nano fountain pen method, for printing microscale features with Raman spectroscopy or surface enhanced Raman spectroscopy (SERS) for reading droplets of synthetic receptors. These receptors include molecularly imprinted polymers (MIPs), which are obtained by polymerization of suitable functional and cross-linking monomers around molecular templates. MIPs are characterized by higher physical and chemical stability than biomacromolecules, and therefore are potentially very suitable as recognition elements for biosensors, or biochips. The monitored bands in the Raman and SERS spectra could be related to the taken up compound, allowing direct detection of the template, i.e., the β-blocking drug propranolol in the imprinted droplets, as well as imaging of individual and multiple dots in an array. This study shows that the combination of nanolithography techniques with SERS might open the possibility of miniaturized arrayed MIP sensors with label-free, specific and quantitative detection.

  19. The Odor Awareness Scale: a new scale for measuring positive and negative odor awareness.

    PubMed

    Smeets, Monique A M; Schifferstein, Hendrik N J; Boelema, Sarai R; Lensvelt-Mulders, Gerty

    2008-10-01

    The Odor Awareness Scale (OAS) is a questionnaire designed to assess individual differences in awareness of odors in the environment. The theory that odor awareness can be distinguished in awareness of negative (to be avoided) odors and positive (to be approached) odors was tested using confirmatory factor analysis (CFA) on the 34-item questionnaire after completion by 525 respondents. CFA (after deletion of 2 items) showed good fit of the 2-factor theory, resulting in a positive awareness subscale (11 items, Cronbach's alpha = .77) and a negative awareness subscale (21 items, Cronbach's alpha = .80). Furthermore, reports of sickness from environmental odors were correlated with the negative odor awareness factor, not the positive odor awareness factor. Respondents scoring high on the overall sum score of the OAS showed significantly better olfactory performance on an odor perception test battery than respondents with a low score. These results suggest a causal relation between awareness of potentially negative odors, olfactory performance and experiencing health effects from environmental odor exposure, that warrants further investigation.

  20. Perceptual blending in odor mixtures depends on the nature of odorants and human olfactory expertise.

    PubMed

    Barkat, S; Le Berre, E; Coureaud, G; Sicard, G; Thomas-Danguin, T

    2012-02-01

    Our olfactory system is confronted with complex mixtures of odorants, often recognized as single entities due to odor blending (e.g., coffee). In contrast, we are also able to discriminate odors from complex mixtures (e.g., off-odors). Therefore, the olfactory system is able to engage either configural or elemental processes when confronted with mixtures. However, the rules that govern the involvement of these processes during odor perception remain poorly understood. In our first experiment, we examined whether simple odorant mixtures (binary/ternary) could elicit configural perception. Twenty untrained subjects were asked to evaluate the odor typicality of mixtures and their constituents. The results revealed a significant increase in odor typicality in some but not all mixtures as compared with the single components, which suggest that perceptual odor blending can occur only in specific mixtures (configural processing). In our second experiment, we tested the hypothesis that general olfactory expertise can improve elemental perception of mixtures. Thirty-two trained subjects evaluated the odor typicality of the stimuli presented during the first experiment, and their responses were compared with those obtained from the untrained panelists. The results support the idea that general training with odors increases the elemental perception of binary and ternary blending mixtures.

  1. Characterization of odorants in inflatable aquatic toys and swimming learning devices-which substances are causative for the characteristic odor and potentially harmful?

    PubMed

    Wiedmer, Christoph; Velasco-Schön, Cristina; Buettner, Andrea

    2017-06-01

    Based on the observation of intense and offensive smells in the product group of aquatic toys, four representative products were exemplarily chosen and sensorially characterized by an expert panel. Panellists reported mostly almond- and rubber-like notes for three of the four samples, whereas the smell of the fourth sample was dominated by organic solvent-associated notes such as "nail polish-like." To elucidate the molecular reasons of these smells, we isolated the volatile fraction of the product by solvent extraction and high vacuum distillation, and identified the main odorants by aroma extract dilution analysis (AEDA), followed by one- and two-dimensional gas chromatography, with parallel mass spectrometric and olfactometric detection. Additionally, the materials of the samples were identified by means of differential scanning calorimetry (DSC), attenuated total reflectance spectroscopy (ATR-spectroscopy), and Beilstein halogen test. Between 32 and 46 odors could be detected in each sample by means of AEDA, whereby five to 13 of these compounds were detectable with by far the highest dilution factors, and were found to primarily correlate with the smells of the respective products. Focussing the subsequent identification on these causative substances led to the successful identification of the majority of these odorants. Among them were several mono- or di-unsaturated carbonyl compounds and their epoxidized derivatives, which are typical odorous artefacts from fatty acid oxidation, but also odor-active organic solvents such as cyclohexanone, isophorone, and phenol.

  2. Reverse-flow apparatus for enhanced colorimetric detection of bacteriuria.

    PubMed Central

    Wallis, C; Melnick, J L

    1984-01-01

    The reverse-flow apparatus is a new device for enhancing the detection of bacteria in urine. Bacteria are trapped onto a customized filter, and the pigments, crystals, and other interfering substances in the urine pass through the filter and are discarded. The bacteria are backflushed and are recovered as a concentrate, and the concentrate is then processed through the previously described colorimetric bacteriuria detection device. A total of 1,000 urine samples were obtained from randomly selected patients and were cultured on agar. Upon enumeration of the colonies, 160 urine samples were shown to contain more than 10(5) CFU/ml. In the bacteriuria detection device, 150 urine samples could not be processed (pigmenters and cloggers), and of the 850 urine samples processed, 127 were culture positive for 10(5) CFU/ml or greater, and 150 urine samples contained between 10(4) and 10(5) CFU/ml. At 10(5) CFU/ml, there were 140 false-positives and 14 false-negatives. When duplicate urine samples were processed through and concentrated by our new reverse-flow apparatus, all samples, including the above pigmenters and cloggers, could be tested in the bacteriuria detection device. The 150 unprocessable samples described above yielded 33 additional bacteria-positive urines, 23 at the 10(5)-CFU/ml cutoff and 10 at the 10(4)-to-10(5)-CFU/ml cutoff. There were 105 false-positives at 10(5) CFU/ml and only 2 false-negatives at the same level of bacteria. At 10(4) to 10(5) CFU/ml there was only 1% false-positive and 4% false-negative. The reverse-flow apparatus allows greater specificity and sensitivity in the rapid bacteriuria test. Urine containing 10(4) CFU/ml or more can now be detected with a 96% sensitivity in a total processing time of less than 2 min. Images PMID:6392325

  3. 46 CFR 58.16-25 - Odorization.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Odorization. 58.16-25 Section 58.16-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-25 Odorization. (a)...

  4. 46 CFR 58.16-25 - Odorization.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Odorization. 58.16-25 Section 58.16-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-25 Odorization. (a)...

  5. 46 CFR 58.16-25 - Odorization.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Odorization. 58.16-25 Section 58.16-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-25 Odorization. (a)...

  6. 46 CFR 58.16-25 - Odorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Odorization. 58.16-25 Section 58.16-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-25 Odorization. (a)...

  7. 46 CFR 58.16-25 - Odorization.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Odorization. 58.16-25 Section 58.16-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-25 Odorization. (a)...

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

    ERIC Educational Resources Information Center

    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…

  9. Functional Neuronal Processing of Human Body Odors

    PubMed Central

    Lundström, Johan N.; Olsson, Mats J.

    2013-01-01

    Body odors carry informational cues of great importance for individuals across a wide range of species, and signals hidden within the body odor cocktail are known to regulate several key behaviors in animals. For a long time, the notion that humans may be among these species has been dismissed. We now know, however, that each human has a unique odor signature that carries information related to his or her genetic makeup, as well as information about personal environmental variables, such as diet and hygiene. Although a substantial number of studies have investigated the behavioral effects of body odors, only a handful have studied central processing. Recent studies have, however, demonstrated that the human brain responds to fear signals hidden within the body odor cocktail, is able to extract kin specific signals, and processes body odors differently than other perceptually similar odors. In this chapter, we provide an overview of the current knowledge of how the human brain processes body odors and the potential importance these signals have for us in everyday life. PMID:20831940

  10. Functional neuronal processing of human body odors.

    PubMed

    Lundström, Johan N; Olsson, Mats J

    2010-01-01

    Body odors carry informational cues of great importance for individuals across a wide range of species, and signals hidden within the body odor cocktail are known to regulate several key behaviors in animals. For a long time, the notion that humans may be among these species has been dismissed. We now know, however, that each human has a unique odor signature that carries information related to his or her genetic makeup, as well as information about personal environmental variables, such as diet and hygiene. Although a substantial number of studies have investigated the behavioral effects of body odors, only a handful have studied central processing. Recent studies have, however, demonstrated that the human brain responds to fear signals hidden within the body odor cocktail, is able to extract kin specific signals, and processes body odors differently than other perceptually similar odors. In this chapter, we provide an overview of the current knowledge of how the human brain processes body odors and the potential importance these signals have for us in everyday life. Copyright © 2010 Elsevier Inc. All rights reserved.

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

    ERIC Educational Resources Information Center

    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…

  12. Characterization and analysis of diesel exhaust odor

    SciTech Connect

    Shala, F.J.

    1983-01-01

    An instrumental method known as the Diesel Odor Analysis System or DOAS, has been developed at A.D. Little, Inc. for measuring diesel exhaust odor. It was of interest to determine which compound or compounds in the oxygenated fraction of the exhaust were primarily responsible for the odor correlation as developed at A.D. Little, Inc. This was accomplished by observing how the measurement of the exhaust odor intensity and number of chemical constituents of the oxygenate fraction were changing with respect to the odor values as measured by the DOAS. Benzaldehyde was found to give the best correlation (R = 0.98) with odor. A quantitative relationship between exhaust odor as measured by the total intensity of aroma (TIA) and the benzaldehyde concentration (B) in ppm in the exhaust is given by: TIA = 1.11 log/sub 10/(B) + 4.10. This correlation was supported by results obtained from two other diesel engine exhaust sources. A methyl benzaldehyde isomer also yielded a good correlation (R = 0.90) with odor. Air to fuel ratio correlations were determined for the tentatively identified compounds, cinnamaldehyde (R = 0.94) and a C2-benzaldehyde isomer (R = 0.94).

  13. Odorous urine following asparagus ingestion in man.

    PubMed

    Mitchell, S C; Waring, R H; Land, D; Thorpe, W V

    1987-04-15

    The production of odorous urine after the ingestion of asparagus has been shown to occur in 43% of 800 volunteers investigated. This characteristic is reproducible over a 12-month-period and has been shown to remain with individuals for virtually a lifetime. Family studies suggest that the ability to produce the odorous urine is inherited as an autosomal dominant trait.

  14. Age-Related Changes in Odor Discrimination

    ERIC Educational Resources Information Center

    Stevenson, Richard J.; Mahmut, Mehmet; Sundqvist, Nina

    2007-01-01

    Odor naming and recognition memory are poorer in children than in adults. This study explored whether such differences might result from poorer discriminative ability. Experiment 1 used an oddity test of discrimination with familiar odors on 6-year-olds, 11-year-olds, and adults. Six-year-olds were significantly poorer at discrimination relative…

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

    PubMed

    Shimemura, Takahiro; Fujita, Kazuhisa; Kashimori, Yoshiki

    2016-09-01

    Taste perception is significantly affected by other sensory modalities such as vis