The modelling of odour dispersion as a support tool for the improvements of high odours impact plants.

PubMed

Luciano, Antonella; Torretta, Vincenzo; Mancini, Giuseppe; Eleuteri, Andrea; Raboni, Massimo; Viotti, Paolo

2017-03-01

Two scenarios in terms of odour impact assessment were studied during the phase of upgrading of an existing waste treatment plant: CALPUFF was used for the simulation of odour dispersion. Olfactometric measures, carried out over different periods and different positions in the plant, were used for model calibration. Results from simulations were reported in terms of statistics of odour concentrations and isopleths maps of the 98th percentile of the hourly peak concentrations, as requested from the European legislation and standards. The excess perception thresholds and emissions were utilized to address the plant upgrade options. The hourly evaluation of odours was performed to determine the most impacting period of the day. An inverse application of the numerical simulation starting from defining the odour threshold at the receptor was made to allow the definition of the required abatement efficiency at the odours source location. Results from the proposed approach confirmed the likelihood to adopt odour dispersion modelling, not only in the authorization phase, but also as a tool for driving technical and managing actions in plant upgrade so to reduce impacts and improve the public acceptance. The upgrade actions in order to achieve the expected efficiency are reported as well.

A fluctuating plume dispersion model for the prediction of odour-impact frequencies from continuous stationary sources

NASA Astrophysics Data System (ADS)

Mussio, P.; Gnyp, A. W.; Henshaw, P. F.

A fluctuating plume dispersion model has been developed to facilitate the prediction of odour-impact frequencies in the communities surrounding elevated point sources. The model was used to predict the frequencies of occurrence of odours of various magnitudes for 1 h periods. In addition, the model predicted the maximum odour level. The model was tested with an extensive set of data collected in the residential areas surrounding the paint shop of an automotive assembly plant. Most of the perceived odours in the vicinity of the 64, 46 m high stacks ranged between 2 and 7 odour units and generally persisted for less than 30 s. Ninety-eight different field determinations of odour impact frequencies within 1 km of the plant were conducted during the course of the study. To simplify evaluation, the frequencies of occurrence of different odour levels were summed to give the total frequency of occurrence of all readily detectable (>2 OU) odours. The model provided excellent simulation of the total frequencies of occurrence where the odour was frequent (i.e . readily detectable more than 30% of the time). At lower frequencies of occurrence the model prediction was poor. The stability class did not seem to affect the model's ability to predict field frequency values. However, the model provided excellent predictions of the maximum odour levels without being sensitive to either stability class or distance from the source. Ninety-five percent of the predicted maximum values were within a factor of two of the measured field maximum values.

Development of an electronic nose for environmental odour monitoring.

PubMed

Dentoni, Licinia; Capelli, Laura; Sironi, Selena; Del Rosso, Renato; Zanetti, Sonia; Della Torre, Matteo

2012-10-25

Exhaustive odour impact assessment should involve the evaluation of the impact of odours directly on citizens. For this purpose it might be useful to have an instrument capable of continuously monitoring ambient air quality, detecting the presence of odours and also recognizing their provenance. This paper discusses the laboratory and field tests conducted in order to evaluate the performance of a new electronic nose, specifically developed for monitoring environmental odours. The laboratory tests proved the instrument was able to discriminate between the different pure substances being tested, and to estimate the odour concentrations giving correlation indexes (R2) of 0.99 and errors below 15%. Finally, the experimental monitoring tests conducted in the field, allowed us to verify the effectiveness of this electronic nose for the continuous detection of odours in ambient air, proving its stability to variable atmospheric conditions and its capability to detect odour peaks.

Odour and ammonia emissions from intensive poultry units in Ireland.

PubMed

Hayes, E T; Curran, T P; Dodd, V A

2006-05-01

Odour and ammonia emissions were measured from three broiler, two layer and two turkey houses in Ireland. The broiler units gave a large range of odour and ammonia emission rates depending on the age of the birds and the season. A considerable variation between the odour and ammonia emission rates was evident for the two layer units which may have been due to the different manure handling systems utilised in the houses. There was relatively little difference in the odour and ammonia emissions from the two turkey houses. As a precautionary principle, odour emission rates utilised in atmospheric dispersion models should use the maximum values for broilers and turkeys (1.22 and 10.5 ou(E) s(-1) bird(-1) respectively) and the mean value for the layers depending on the manure handling system used (0.47 or 1.35 ou(E) s(-1) bird(-1)).

Odour assessment in the vicinity of a pig-fatting farm using field inspections (EN 16841-1) and dispersion modelling

NASA Astrophysics Data System (ADS)

Oettl, Dietmar; Kropsch, Michael; Mandl, Michael

2018-05-01

The assessment of odour annoyance varies vastly among countries even within the European Union. Using so-called odour-hour frequencies offers the distinct possibility for either applying dispersion models or field inspections, both generally assumed to be equivalent. In this study, odour-hours based on field inspections according to the European standard EN 16841-1 (2017) in the vicinity of a pig-fattening farm have been compared with modelled ones using the Lagrangian particle model GRAL, which uses odour-concentration variances for computing odour hours as recently proposed by Oettl and Ferrero (2017). Using a threshold of 1 ou m-3 (ou = odour units) for triggering odour hours in the model, as prescribed by the German guideline for odour assessment, led to reasonable agreements between the two different methodologies. It is pointed out that the individual odour sensitivity of qualified panel members, who carry out field inspections, is of crucial importance for selecting a proper odour-hour model. Statistical analysis of a large number of data stemming from dynamic olfactometry (EN 13725, 2003), that cover a wide range of odorants, suggests that the prescribed method in Germany for modelling odour hours may likely result in an overestimation, and hence, equivalence with field inspections is not given. The dataset is freely available on request.

Reduction of odours in pilot-scale landfill biocovers.

PubMed

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

2014-04-01

Unpleasant odours generated from waste management facilities represent an environmental and societal concern. This multi-year study documented odour and total reduced sulfur (TRS) abatement in four experimental landfill biocovers installed on the final cover of the Saint-Nicéphore landfill (Canada). Performance was evaluated based on the reduction in odour and TRS concentrations between the raw biogas collected from a dedicated well and the emitted gases at the surface. Odour analyses were carried out by the sensorial technique of olfactometry, whereas TRS analyses followed the pulse fluorescence technique. The large difference of 2-5 orders of magnitude between raw biogas (average odour concentration=2,100,000OUm(-3)) and emitted gases resulted in odour removal efficiencies of close to 100% for all observations. With respect to TRS concentrations, abatement efficiencies were all greater than 95%, with values averaging 21,000ppb of eq. SO2 in the raw biogas. The influence of water infiltration on odour concentrations was documented and showed that lower odour values were obtained when the 48-h accumulated precipitation prior to sampling was higher. Copyright © 2014 Elsevier Ltd. All rights reserved.

Colour preferences influences odour learning in the hawkmoth, Macroglossum stellatarum

NASA Astrophysics Data System (ADS)

Balkenius, Anna; Kelber, Almut

2006-05-01

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

Female body odour is a potential cue to ovulation.

PubMed

Singh, D; Bronstad, P M

2001-04-22

Human body odours have been reported to influence female mate choice. Women prefer the odours of immunocompatible men and, during their fertile period, judge the body odours of men with symmetrical bodies--which is indicative of genetic quality--as sexy and pleasant. The reproductive success of men largely depends on mating with fertile women, but it is not known whether men can detect a woman's fertile period. We asked women who had regular menstrual cycles and who were not using hormonal contraceptives to wear a T-shirt for three consecutive nights during their late follicular (ovulatory) phase and another T-shirt during the luteal (non-ovulatory) phase of their menstrual cycle. Male raters judged the odours of T-shirts worn during the follicular phase as more pleasant and sexy than odours from T-shirts worn during the luteal phase. The odour differences between the follicular and luteal phases did not dissipate quickly over time as male raters were able to detect and judge follicular phase body odours as more pleasant and sexy than the odours from the luteal phase even after the T-shirts were kept at room temperature for one week. These findings suggest that ovulation may not be concealed and that men could use ovulation-linked odours in their mate selection.

Relative Contribution of Odour Intensity and Valence to Moral Decisions.

PubMed

Cecchetto, Cinzia; Rumiati, Raffaella Ida; Parma, Valentina

2017-01-01

Meta-analytic evidence showed that the chemical senses affect moral decisions. However, how odours impact on morality is currently unclear. Through a set of three studies, we assess whether and how odour intensity biases moral choices (Study 1a), its psychophysiological responses (Study 1b), as well as the behavioural and psychophysiological effects of odour valence on moral choices (Study 2). Study 1a suggests that the presence of an odour plays a role in shaping moral choice. Study 1b reveals that of two iso-pleasant versions of the same neutral odour, only the one presented sub-threshold (vs. supra-threshold) favours deontological moral choices, those based on the principle of not harming others even when such harm provides benefits. As expected, this odour intensity effect is tracked by skin conductance responses, whereas no difference in cardiac activity - proxy for the valence dimension - is revealed. Study 2 suggests that the same neutral odour presented sub-threshold increases deontological choices even when compared to iso-intense ambiguous odour, perceived as pleasant or unpleasant by half of the participants, respectively. Skin conductance responses, as expected, track odour pleasantness, but cardiac activity fails to do so. Results are discussed in the context of mechanisms alternative to disgust induction underlying moral choices.

Female body odour is a potential cue to ovulation.

PubMed Central

Singh, D.; Bronstad, P. M.

2001-01-01

Human body odours have been reported to influence female mate choice. Women prefer the odours of immunocompatible men and, during their fertile period, judge the body odours of men with symmetrical bodies--which is indicative of genetic quality--as sexy and pleasant. The reproductive success of men largely depends on mating with fertile women, but it is not known whether men can detect a woman's fertile period. We asked women who had regular menstrual cycles and who were not using hormonal contraceptives to wear a T-shirt for three consecutive nights during their late follicular (ovulatory) phase and another T-shirt during the luteal (non-ovulatory) phase of their menstrual cycle. Male raters judged the odours of T-shirts worn during the follicular phase as more pleasant and sexy than odours from T-shirts worn during the luteal phase. The odour differences between the follicular and luteal phases did not dissipate quickly over time as male raters were able to detect and judge follicular phase body odours as more pleasant and sexy than the odours from the luteal phase even after the T-shirts were kept at room temperature for one week. These findings suggest that ovulation may not be concealed and that men could use ovulation-linked odours in their mate selection. PMID:11345323

Homing pigeons only navigate in air with intact environmental odours: a test of the olfactory activation hypothesis with GPS data loggers.

PubMed

Gagliardo, Anna; Ioalè, Paolo; Filannino, Caterina; Wikelski, Martin

2011-01-01

A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation hypothesis proposes that odour perception is only needed to activate a navigational mechanism based on cues of another nature. Here we tested experimentally whether the perception of artificial odours is sufficient to allow pigeons to navigate, as expected from the olfactory activation hypothesis. We transported three groups of pigeons in air-tight containers to release sites 53 and 61 km from home in three different olfactory conditions. The Control group received natural environmental air; both the Pure Air and the Artificial Odour groups received pure air filtered through an active charcoal filter. Only the Artificial Odour group received additional puffs of artificial odours until release. We then released pigeons while recording their tracks with 1 Hz GPS data loggers. We also followed non-homing pigeons using an aerial data readout to a Cessna plane, allowing, for the first time, the tracking of non-homing homing pigeons. Within the first hour after release, the pigeons in both the Artificial Odour and the Pure Air group (receiving no environmental odours) showed impaired navigational performances at each release site. Our data provide evidence against an activation role of odours in navigation, and document that pigeons only navigate well when they perceive environmental odours.

Non-redundant coding of aversive odours in the main olfactory pathway

PubMed Central

Dewan, Adam; Pacifico, Rodrigo; Zhan, Ross; Rinberg, Dmitry; Bozza, Thomas

2013-01-01

Many species are critically dependent on olfaction for survival. In the main olfactory system of mammals, odours are detected by sensory neurons which express a large repertoire of canonical odorant receptors (ORs) and a much smaller repertoire of Trace Amine-Associated Receptors (TAARs)1–4. Odours are encoded in a combinatorial fashion across glomeruli in the main olfactory bulb, with each glomerulus corresponding to a different receptor5–7. The degree to which individual receptor genes contribute to odour perception is unclear. Here we show that genetic deletion of the olfactory TAAR gene family, or even a single TAAR gene, eliminates aversion that mice display to low concentrations of volatile amines and to the odour of predator urine. Our findings identify a role for the TAARs in olfaction, namely in the high-sensitivity detection of innately aversive odours. In addition, our data reveal that aversive amines are represented in a non-redundant fashion, and that individual main olfactory receptor genes can contribute significantly to odour perception. PMID:23624375

Continuous odour measurement from fattening pig units

NASA Astrophysics Data System (ADS)

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

2013-10-01

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

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

PubMed

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

2016-02-01

Beneficial health properties of garlic, as well as its most common adverse effect - distinctive breath odour - are well-known. In contrast, analogous research on the effect of garlic on axillary odour is currently missing. Here, in three studies varying in the amount and nature of garlic provided (raw garlic in study 1 and 2, garlic capsules in study 3), we tested the effect of garlic consumption on the quality of axillary odour. A balanced within-subject experimental design was used. In total, 42 male odour donors were allocated to either a "garlic" or "non-garlic" condition, after which they wore axillary pads for 12 h to collect body odour. One week later, the conditions were reversed. Odour samples were then judged for their pleasantness, attractiveness, masculinity and intensity by 82 women. We found no significant differences in ratings of any characteristics in study 1. However, the odour of donors after an increased garlic dosage was assessed as significantly more pleasant, attractive and less intense (study 2), and more attractive and less intense in study 3. Our results indicate that garlic consumption may have positive effects on perceived body odour hedonicity, perhaps due to its health effects (e.g., antioxidant properties, antimicrobial activity). Copyright © 2015 Elsevier Ltd. All rights reserved.

Mapping axillary microbiota responsible for body odours using a culture-independent approach.

PubMed

Troccaz, Myriam; Gaïa, Nadia; Beccucci, Sabine; Schrenzel, Jacques; Cayeux, Isabelle; Starkenmann, Christian; Lazarevic, Vladimir

2015-01-01

Human axillary odour is commonly attributed to the bacterial degradation of precursors in sweat secretions. To assess the role of bacterial communities in the formation of body odours, we used a culture-independent approach to study axillary skin microbiota and correlated these data with olfactory analysis. Twenty-four Caucasian male and female volunteers and four assessors showed that the underarms of non-antiperspirant (non-AP) users have significantly higher global sweat odour intensities and harboured on average about 50 times more bacteria than those of AP users. Global sweat odour and odour descriptors sulfury-cat urine and acid-spicy generally increased from the morning to the afternoon sessions. Among non-AP users, male underarm odours were judged higher in intensity with higher fatty and acid-spicy odours and higher bacterial loads. Although the content of odour precursors in underarm secretions varied widely among individuals, males had a higher acid: sulfur precursor ratio than females did. No direct correlations were found between measured precursor concentration and sweat odours. High-throughput sequencing targeting the 16S rRNA genes of underarm bacteria collected from 11 non-AP users (six females and five males) confirmed the strong dominance of the phyla Firmicutes and Actinobacteria, with 96% of sequences assigned to the genera Staphylococcus, Corynebacterium and Propionibacterium. The proportion of several bacterial taxa showed significant variation between males and females. The genera Anaerococcus and Peptoniphilus and the operational taxonomic units (OTUs) from Staphylococcus haemolyticus and the genus Corynebacterium were more represented in males than in females. The genera Corynebacterium and Propionibacterium were correlated and anti-correlated, respectively, with body odours. Within the genus Staphylococcus, different OTUs were either positively or negatively correlated with axillary odour. The relative abundance of five OTUs (three assigned to S. hominis and one each to Corynebacterium tuberculostearicum and Anaerococcus) were positively correlated with at least one underarm olfactory descriptor. Positive and negative correlations between bacterial taxa found at the phylum, genus and OTU levels suggest the existence of mutualism and competition among skin bacteria. Such interactions, and the types and quantities of underarm bacteria, affect the formation of body odours. These findings open the possibility of developing new solutions for odour control.

Field evaluation of natural human odours and the biogent-synthetic lure in trapping Aedes aegypti, vector of dengue and chikungunya viruses in Kenya.

PubMed

Owino, Eunice A; Sang, Rosemary; Sole, Catherine L; Pirk, Christian; Mbogo, Charles; Torto, Baldwyn

2014-09-23

Methods currently used in sampling adult Aedes aegypti, the main vector of dengue and chikungunya viruses are limited for effective surveillance of the vector and accurate determination of the extent of virus transmission during outbreaks and inter - epidemic periods. Here, we document the use of natural human skin odours in baited traps to improve sampling of adult Ae. aegypti in two different endemic areas of chikungunya and dengue in Kenya - Kilifi and Busia Counties. The chemistry of the volatiles released from human odours and the Biogent (BG)-commercial lure were also compared. Cotton socks and T-shirts were used to obtain natural human skin volatiles from the feet and trunk of three volunteers (volunteers 1 and 2 in Kilifi and volunteers 2 and 3 in Busia). Using Latin square design, we compared the efficacies of BG sentinel traps baited with carbon dioxide plus (a) no bait, (b) human feet volatiles, (c) human trunk volatiles each against (c) a control (Biogent commercial lure) at the two sites. Coupled gas chromatography-mass spectrometry (GC-MS) was used to identify and compare candidate attractants released by the commercial lure and human odours. Ae. aegypti captured in the trap baited with feet odours from volunteer 2 and trunk odours from the same volunteer were significantly higher than in the control trap in Busia and Kilifi respectively, [IRR = 5.63, 95% CI: 1.15 - 28.30, p = 0.030] and [IRR = 3.99, 95% CI: 0.95-16.69, p = 0.049]. At both sites, Ae. aegypti captures in traps baited with either the feet or trunk odours from volunteers 1 and 3 were not significantly different from the control. Major qualitative differences were observed between the chemical profiles of human odours and the commercial BG-lure. Aldehydes, fatty acids and ketones dominated human odour profiles, whereas the BG-lure released mainly hexanoic acid. Our results suggest that additional candidate attractants are present in human skin volatiles which can help to improve the efficacy of lures for trapping and surveillance of Ae. aegypti.

Rodents and humans are able to detect the odour of L-Lactate.

PubMed

Mosienko, Valentina; Chang, Andy J; Alenina, Natalia; Teschemacher, Anja G; Kasparov, Sergey

2017-01-01

L-Lactate (LL) is an essential cellular metabolite which can be used to generate energy. In addition, accumulating evidence suggests that LL is used for inter-cellular signalling. Some LL-sensitive receptors have been identified but we recently proposed that there may be yet another unknown G-protein coupled receptor (GPCR) sensitive to LL in the brain. Olfactory receptors (ORs) represent the largest family of GPCRs and some of them are expressed outside the olfactory system, including brain, making them interesting candidates for non-olfactory LL signalling. One of the "ectopically" expressed ORs, Olfr78 in mice (Olr59 in rats and OR51E2 in humans), reportedly can be activated by LL. This implies that both rodents and humans should be able to detect the LL odour. Surprisingly, this has never been demonstrated. Here we show that mice can detect the odour of LL in odour detection and habituation-dishabituation tasks, and discriminate it from peppermint and vanilla odours. Behaviour of the Olfr78 null mice and wildtype mice in odour detection task was not different, indicating that rodents are equipped with more than one LL-sensitive OR. Rats were also able to use the smell of LL as a cue in an odour-reward associative learning task. When presented to humans, more than 90% of participants detected a smell of LL in solution. Interestingly, LL was perceived differently than acetate or propionate-LL was preferentially reported as a pleasant sweet scent while acetate and propionate were perceived as repulsive sour/acid smells. Subjective perception of LL smell was different in men and women. Taken together, our data demonstrate that both rodents and humans are able to detect the odour of LL. Moreover, in mice, LL perception is not purely mediated by Olfr78. Discovery of further LL-sensitive OR might shed the light on their contribution to LL signalling in the body.

Evidence for partial overlap of male olfactory cues in lampreys

USGS Publications Warehouse

Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

2016-01-01

Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

Mother-infant skin-to-skin contact after delivery results in early recognition of own mother's milk odour.

PubMed

Mizuno, K; Mizuno, N; Shinohara, T; Noda, M

2004-12-01

To determine the effects of mother-infant skin-to-skin contact immediately after birth on infant recognition of their own mother's milk odour and breastfeeding duration until 1 y of age. Sixty healthy, full-term neonates were randomly assigned to group A with skin-to-skin contact and group B without. One and 4 d after birth, infant responses to the following odour stimuli were observed: own mother's milk, another mother's milk, formula, orange juice and distilled water. Infant facial action was videotaped and the frequency of mouthing movements was evaluated for each stimulus. Nutritional assessment, focused particularly on breastfeeding, was performed every 3 mo on participating infants. Statistical analysis comparing the frequency of mouthing movements with the aforementioned five different odour exposures was performed by ANOVA with Fisher's PLSD. Kaplan-Meier analysis with a log-rank test was used to compare breastfeeding rates between groups. Infants in both groups responded differently to mother's milk odour (either their own or another mother's milk) compared to the other stimuli on days 1 and 4. However, infants in group A demonstrated a larger difference in mouthing movements between their own and another mother's milk odour at 4 d of age (2.6 +/- 1.6) compared to infants in group B (0.9 +/- 2.0, p = 0.01). Infants in group A were breastfed an average of 1.9 mo longer than the others. Our study provides evidence that mother-infant skin-to-skin contact for more than 50 min immediately after birth results in enhanced infant recognition of their own mother's milk odour and longer breastfeeding duration.

Human body odour, symmetry and attractiveness.

PubMed Central

Rikowski, A; Grammer, K

1999-01-01

Several studies have found body and facial symmetry as well as attractiveness to be human mate choice criteria. These characteristics are presumed to signal developmental stability. Human body odour has been shown to influence female mate choice depending on the immune system, but the question of whether smell could signal general mate quality, as do other cues, was not addressed in previous studies. We compared ratings of body odour, attractiveness, and measurements of facial and body asymmetry of 16 male and 19 female subjects. Subjects wore a T-shirt for three consecutive nights under controlled conditions. Opposite-sex raters judged the odour of the T-shirts and another group evaluated portraits of the subjects for attractiveness. We measured seven bilateral traits of the subject's body to assess body asymmetry. Facial asymmetry was examined by distance measurements of portrait photographs. The results showed a significant positive correlation between facial attractiveness and sexiness of body odour for female subjects. We found positive relationships between body odour and attractiveness and negative ones between smell and body asymmetry for males only if female odour raters were in the most fertile phase of their menstrual cycle. The outcomes are discussed in the light of different male and female reproductive strategies. PMID:10380676

Decomposition Odour Profiling in the Air and Soil Surrounding Vertebrate Carrion

PubMed Central

2014-01-01

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

Decomposition odour profiling in the air and soil surrounding vertebrate carrion.

PubMed

Forbes, Shari L; Perrault, Katelynn A

2014-01-01

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

Characterisation of volatile organic compounds (VOCs) released by the composting of different waste matrices.

PubMed

Schiavon, Marco; Martini, Luca Matteo; Corrà, Cesare; Scapinello, Marco; Coller, Graziano; Tosi, Paolo; Ragazzi, Marco

2017-12-01

The complaints arising from the problem of odorants released by composting plants may impede the construction of new composting facilities, preclude the proper activity of existing facilities or even lead to their closure, with negative implications for waste management and local economy. Improving the knowledge on VOC emissions from composting processes is of particular importance since different VOCs imply different odour impacts. To this purpose, three different organic matrices were studied in this work: dewatered sewage sludge (M1), digested organic fraction of municipal solid waste (M2) and untreated food waste (M3). The three matrices were aerobically biodegraded in a bench-scale bioreactor simulating composting conditions. A homemade device sampled the process air from each treatment at defined time intervals. The samples were analysed for VOC detection. The information on the concentrations of the detected VOCs was combined with the VOC-specific odour thresholds to estimate the relative weight of each biodegraded matrix in terms of odour impact. When the odour formation was at its maximum, the waste gas from the composting of M3 showed a total odour concentration about 60 and 15,000 times higher than those resulting from the composting of M1 and M2, respectively. Ethyl isovalerate showed the highest contribution to the total odour concentration (>99%). Terpenes (α-pinene, β-pinene, p-cymene and limonene) were abundantly present in M2 and M3, while sulphides (dimethyl sulphide and dimethyl disulphide) were the dominant components of M1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Central mechanisms of odour object perception

PubMed Central

Gottfried, Jay A.

2013-01-01

The stimulus complexity of naturally occurring odours presents unique challenges for central nervous systems that are aiming to internalize the external olfactory landscape. One mechanism by which the brain encodes perceptual representations of behaviourally relevant smells is through the synthesis of different olfactory inputs into a unified perceptual experience — an odour object. Recent evidence indicates that the identification, categorization and discrimination of olfactory stimuli rely on the formation and modulation of odour objects in the piriform cortex. Convergent findings from human and rodent models suggest that distributed piriform ensemble patterns of olfactory qualities and categories are crucial for maintaining the perceptual constancy of ecologically inconstant stimuli. PMID:20700142

Detection of the dynamics of odour emissions from pig farms using dynamic olfactometry and an electronic odour sensor.

PubMed

Brose, G; Gallmann, E; Hartung, E; Jungbluth, T

2001-01-01

The dynamics of odour emissions from a pig house was investigated by olfactometry and using an electronic odour sensor. In addition, several suggested influencing factors on the odour emission were measured to get insight into the reasons for the fluctuation of the odour emission. Odour emission tended to increase over the fattening period f rom August to November 2000 by a factor of two to three, although temperature and air-flow rate decreased according to the seasons. Feeding caused a significant temporary rise in animal activity, dust and odour concentration resulting in an increase of odour emission. The sensor signals of an electronic odour sensor increased simultaneously and showed a good relation to the odour concentration. There is a promising potential of electronic odour sensors to detect the dynamic and the level of odour concentrations. Further investigation will be done, to ensure a standardised measuring protocol and to obtain a calibration of electronic odour sensor signals direct to odour concentrations.

Sniffer mice discriminate urine odours of patients with bladder cancer: A proof-of-principle study for non-invasive diagnosis of cancer-induced odours.

PubMed

Sato, Takaaki; Katsuoka, Yoji; Yoneda, Kimihiko; Nonomura, Mitsuo; Uchimoto, Shinya; Kobayakawa, Reiko; Kobayakawa, Ko; Mizutani, Yoichi

2017-11-07

Similar to fingerprints, humans have unique, genetically determined body odours. In case of urine, the odour can change due to variations in diet as well as upon infection or tumour formation. We investigated the use of mice in a manner similar to "sniffer dogs" to detect changes in urine odour in patients with bladder cancer. We measured the odour discrimination thresholds of mice in a Y-maze, using urine mixtures from patients with bladder cancer (Stage I) and healthy volunteers (dietary variations) as well as occult blood- or antibiotic drug metabolite-modulated samples. Threshold difference indicated that intensities of urinary olfactory cues increase in the following order: dietary variation < bladder cancer < occult blood < antibiotic drug metabolites. After training with patient urine mixtures, sniffer mice discriminated between urine odours of pre- and post-transurethral resection in individual patients with bladder cancer in an equal-occult blood diluted condition below the detection level of dietary variations, achieving a success rate of 100% (11/11). Furthermore, genetic ablation of all dorsal olfactory receptors elevated the discrimination thresholds of mice by ≥ 10 5 -fold. The marked reduction in discrimination sensitivity indicates an essential role of the dorsal olfactory receptors in the recognition of urinary body odours in mice.

Odour perception in chronic renal disease.

PubMed

Griep, M I; Van der Niepen, P; Sennesael, J J; Mets, T F; Massart, D L; Verbeelen, D L

1997-10-01

The sense of smell plays an important role in the quality of life. Many studies have shown a declining odour perception in the elderly, as well as in subjects in poor health or nutritional state. Considering the high prevalence of poor nutritional state in renal disease and the importance of odour perception in nutrition and health, the relationship between renal function, nutritional state, and odour perception is explored in this study. A total of 101 patients with chronic renal failure participated in the study. Thirty-eight haemodialysis patients (mean age = 64.3 years) were evaluated both before and after dialysis. Sixteen patients on peritoneal dialysis treatment (mean age = 64.0 years), 28 transplanted patients (mean age = 53.5 years, mean creatinine clearance = 64.0 ml/min) and 19 patients with varying degrees of renal insufficiency were also included (mean age = 63.7 years, mean creatinine clearance = 29.5 ml/min). Patients with cognitive deficits or upper respiratory airway diseases were excluded. A validated objective procedure was used to measure odour perception, by determining the detection threshold for isoamyl acetate (banana odour) as the lowest detectable odour concentration. Healthy control persons had significantly lower odour thresholds compared to patients on peritoneal (P = 0.001) and haemodialysis (P = 0.002). No significant difference was observed in odour perception between patients on peritoneal and haemodialysis (P = 0.779) and for patients on haemodialysis before and after a dialysis session. Transplanted patients had significantly better odour perception compared to matched patients on dialysis (P < 0.001). Odour perception of transplanted patients and matched healthy control persons was similar (P = 0.81). In patients with varying degrees of renal insufficiency, including healthy controls and transplanted patients, a significant positive correlation was found between odour perception and creatinine clearance (P = 0.02). A significant negative correlation was found between odour perception and serum concentration of urea (P < 0.001), serum phosphorus (P = 0.022) and protein catabolic rate (P < 0.05). Other parameters measuring nutritional status (albumin, BMI) were not correlated with odour perception. Our results show that the ability to smell is severely impaired in patients with chronic renal failure and is related to the degree of renal impairment and the degree of accumulation of uraemic toxins. After renal transplantation, patients have a normal odour perception, indicating the capacity of the olfactory system to recover once the concentration of uraemic toxins remains below a critical threshold. Acute removal of uraemic toxins by dialysis does not correct olfactory disturbances, suggesting a long lasting effect of uraemia on olfactory function.

Pleasant and unpleasant odour-face combinations influence face and odour perception: An event-related potential study.

PubMed

Cook, Stephanie; Kokmotou, Katerina; Soto, Vicente; Fallon, Nicholas; Tyson-Carr, John; Thomas, Anna; Giesbrecht, Timo; Field, Matt; Stancak, Andrej

2017-08-30

Odours alter evaluations of concurrent visual stimuli. However, neural mechanisms underlying the effects of congruent and incongruent odours on facial expression perception are not clear. Moreover, the influence of emotional faces on odour perception is not established. We investigated the effects of one pleasant and one unpleasant odour paired with happy and disgusted faces, on subjective ratings and ERP responses to faces. Participants rated the pleasantness of happy and disgusted faces that appeared during 3s pleasant or unpleasant odour pulses, or without odour. Odour pleasantness and intensity ratings were recorded in each trial. EEG was recorded continuously using a 128-channel system. Happy and disgusted faces paired with pleasant and unpleasant odour were rated as more or less pleasant, respectively, compared to the same faces presented in the other odour conditions. Odours were rated as more pleasant when paired with happy faces, and unpleasant odour was rated more intense when paired with disgusted faces. Unpleasant odour paired with disgusted faces also decreased inspiration. Odour-face interactions were evident in the N200 and N400 components. Our results reveal bi-directional effects of odours and faces, and suggest that odour-face interactions may be represented in ERP components. Pairings of unpleasant odour and disgusted faces resulted in stronger hedonic ratings, ERP changes, increased odour intensity ratings and respiratory adjustment. This finding likely represents heightened adaptive responses to multimodal unpleasant stimuli, prompting appropriate behaviour in the presence of danger. Copyright © 2017. Published by Elsevier B.V.

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

PubMed Central

Stevenson, Philip C.; Belmain, Steven R.

2016-01-01

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

Predation-related odours reduce oviposition in a herbivorous mite.

PubMed

Choh, Yasuyuki; Uefune, Masayoshi; Takabayashi, Junji

2010-01-01

When adult females of the herbivorous mite, Tetranychus urticae, were exposed to the predatory mite, Phytoseiulus persimilis, they laid fewer eggs than females that had not been exposed to P. persimilis when transferred onto a new leaf patch. However, when T. urticae females were exposed to either products of P. persimilis or artificially damaged conspecific eggs on a leaf patch, the number of T. urticae eggs on a new leaf patch did not differ significantly from the control. The reduced oviposition was neither due to the feeding activity on the leaf patch with P. persimilis nor to that on the new leaf patch. There was also no significant difference between the number of T. urticae eggs produced on a new leaf patch following exposure to the odours of a neighbouring leaf patch where there had previously been either P. persimilis or T. urticae adults. However, female T. urticae that had been exposed to odours from neighbouring leaf patches on which both T. urticae and P. persimilis had been placed produced significantly fewer eggs on a new leaf patch than those that had not been exposed to such odours. Neither odours from neighbouring intact leaf patches on which T. urticae eggs were preyed on by P. persimilis, nor odours from a neighbouring Parafilm patch on which T. urticae was preyed on by P. persimilis affected the oviposition of T. urticae. These data suggest that the presence of T. urticae, P. persimilis and a leaf patch are needed for the emission of odours to reduce oviposition in T. urticae.

An odorant congruent with a colour cue is selectively perceived in an odour mixture.

PubMed

Arao, Mari; Suzuki, Maya; Katayama, Jun'ich; Akihiro, Yagi

2012-01-01

Odour identification can be influenced by colour cues. This study examined the mechanism underlying this colour context effect. We hypothesised that a specific odour component congruent with a colour would be selectively perceived in preference to another odour component in a binary odour mixture. We used a ratio estimation method under two colour conditions, a binary odour mixture (experiment 1) and single chemicals presented individually (experiment 2). Each colour was congruent with one of the odour components. Participants judged the perceived mixture ratio in each odour container on which a colour patch was pasted. An influence of colour was not observed when the odour stimulus did not contain the odour component congruent with the colour (experiment 2); however, the odour component congruent with the colour was perceived as more dominant when the odour stimulus did contain the colour-congruent odorant (experiment 1). This pattern indicates that a colour-congruent odour component is selectively perceived in an odour mixture. This finding suggests that colours can enhance the perceptual representation of the colour-associated component in an odour mixture.

Responses of antennal olfactory receptors in the yellow fever mosquito Aedes aegypti to human body odours.

PubMed

Pappenberger, B; Geier, M; Boeckh, J

1996-01-01

Recent behavioural studies have demonstrated that human body odours which female Aedes aegypti find attractive exert their effects as complex mixtures of synergistically acting components. We have attempted to clarify the sensory mechanisms underlying the perception of these complex host odours by studying the responses of sensory cells underneath the A3-type sensilla of the mosquito antenna to both a human skin wash extract and the extract's active chromatographic fractions. The reaction patterns show that the host stimuli elicit responses from several types of receptor cells in a typical across-fibre pattern mode. It seems as if this is another case where the essential message in a biologically significant odour consists of a complex pattern of compounds that is encoded in an according complex response pattern by a cooperating set of primary sensory neurons of different odour specificities.

Neonicotinoid-induced impairment of odour coding in the honeybee

PubMed Central

Andrione, Mara; Vallortigara, Giorgio; Antolini, Renzo; Haase, Albrecht

2016-01-01

Exposure to neonicotinoid pesticides is considered one of the possible causes of honeybee (Apis mellifera) population decline. At sublethal doses, these chemicals have been shown to negatively affect a number of behaviours, including performance of olfactory learning and memory, due to their interference with acetylcholine signalling in the mushroom bodies. Here we provide evidence that neonicotinoids can affect odour coding upstream of the mushroom bodies, in the first odour processing centres of the honeybee brain, i.e. the antennal lobes (ALs). In particular, we investigated the effects of imidacloprid, the most common neonicotinoid, in the AL glomeruli via in vivo two-photon calcium imaging combined with pulsed odour stimulation. Following acute imidacloprid treatment, odour-evoked calcium response amplitude in single glomeruli decreases, and at the network level the representations of different odours are no longer separated. This demonstrates that, under neonicotinoid influence, olfactory information might reach the mushroom bodies in a form that is already incorrect. Thus, some of the impairments in olfactory learning and memory caused by neonicotinoids could, in fact, arise from the disruption in odor coding and olfactory discrimination ability of the honey bees. PMID:27905515

Behavioural development of conspecific odour preferences in bank voles, Clethrionomys glareolus.

PubMed

Kruczek, Malgorzata; Golas, Aniela

2003-08-29

Biological odours of conspecifics are known to have strong influences on behavioural interaction in bank voles Clethrionomys glareolus. This experiment tested two hypotheses. (1) Olfactory cues from familiar and unfamiliar mature opposite-sex conspecifics differ in their attractiveness to males and females, and their behavioural reactions change with age. (2) A genetically based mechanism is involved in female recognition of kin.In a two-choice preference test, prepubertal males and females were more attracted to familiar than to unfamiliar odours of opposite-sex conspecifics, as manifested by more time spent sniffing familiar voles. As the young reached sexual maturity they shifted their odour preferences. Mature males and females preferred the novel odour of unrelated opposite-sex conspecifics to that of relatives. The results of experiments testing the second hypothesis indicate that females use a genetically based mechanism to recognise their kin. Young and mature females were able to recognise the odour of their biological but socially unknown fathers, and showed the same pattern of behaviour as females in previous experiments.The possible biological functions of kin recognition in bank voles are discussed.

Analyses of odours from concentrated animal feeding operations: A review

NASA Astrophysics Data System (ADS)

Guffanti, P.; Pifferi, V.; Falciola, L.; Ferrante, V.

2018-02-01

Concentrated Animal Feeding Operations (CAFOs) are widely present all over the world due to the high population demand for food and products of animal origin. However, they have generated several environmental concerns, including odour nuisance, which affects people health and quality of life. Odours from livestock are a very complex mixtures of molecules and their analytical investigation is highly demanding. Many works have been published regarding the study of odours from CAFOs, using different techniques and technologies to face the issue. Thus, the aim of this review paper is to summarize all the ways to study odours from CAFOs, starting from the sampling methods and then treating in general the principles of Dynamic Olfactometry, Gas Chromatography coupled with Mass Spectrometry and Electronic Noses. Finally, a deep literature summary of Gas Chromatography coupled with Mass Spectrometry and Electronic Noses applied to odours coming from poultry, dairy and swine feeding operations is reported. This work aims to make some order in this field and it wants to help future researchers to deal with this environmental problem, constituting a state-of-the-art in this field.

Item-specific proactive interference in olfactory working memory.

PubMed

Moss, Andrew; Miles, Christopher; Elsley, Jane; Johnson, Andrew

2018-04-01

We examine item-specific olfactory proactive interference (PI) effects and undertake comparisons with verbal and non-verbal visual stimuli. Using a sequential recent-probes task, we show no evidence for PI with hard-to-name odours (Experiment 1). However, verbalisable odours do exhibit PI effects (Experiment 2). These findings occur despite above chance performance and similar serial position functions across both tasks. Experiments 3 and 4 apply words and faces, respectively, to our modified procedure, and show that methodological differences cannot explain the null finding in Experiment 1. The extent to which odours exhibit analogous PI effects to that of other modalities is, we argue, contingent on the characteristics of the odours employed.

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

PubMed Central

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

2015-01-01

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

Different Ways to Apply a Measurement Instrument of E-Nose Type to Evaluate Ambient Air Quality with Respect to Odour Nuisance in a Vicinity of Municipal Processing Plants

PubMed Central

Szulczyński, Bartosz; Wasilewski, Tomasz; Wojnowski, Wojciech; Majchrzak, Tomasz; Dymerski, Tomasz; Namieśnik, Jacek; Gębicki, Jacek

2017-01-01

This review paper presents different ways to apply a measurement instrument of e-nose type to evaluate ambient air with respect to detection of the odorants characterized by unpleasant odour in a vicinity of municipal processing plants. An emphasis was put on the following applications of the electronic nose instruments: monitoring networks, remote controlled robots and drones as well as portable devices. Moreover, this paper presents commercially available sensors utilized in the electronic noses and characterized by the limit of quantification below 1 ppm v/v, which is close to the odour threshold of some odorants. Additionally, information about bioelectronic noses being a possible alternative to electronic noses and their principle of operation and application potential in the field of air evaluation with respect to detection of the odorants characterized by unpleasant odour was provided. PMID:29156597

Different Ways to Apply a Measurement Instrument of E-Nose Type to Evaluate Ambient Air Quality with Respect to Odour Nuisance in a Vicinity of Municipal Processing Plants.

PubMed

Szulczyński, Bartosz; Wasilewski, Tomasz; Wojnowski, Wojciech; Majchrzak, Tomasz; Dymerski, Tomasz; Namieśnik, Jacek; Gębicki, Jacek

2017-11-19

This review paper presents different ways to apply a measurement instrument of e-nose type to evaluate ambient air with respect to detection of the odorants characterized by unpleasant odour in a vicinity of municipal processing plants. An emphasis was put on the following applications of the electronic nose instruments: monitoring networks, remote controlled robots and drones as well as portable devices. Moreover, this paper presents commercially available sensors utilized in the electronic noses and characterized by the limit of quantification below 1 ppm v / v , which is close to the odour threshold of some odorants. Additionally, information about bioelectronic noses being a possible alternative to electronic noses and their principle of operation and application potential in the field of air evaluation with respect to detection of the odorants characterized by unpleasant odour was provided.

Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites.

PubMed

Aratchige, N S; Lesna, I; Sabelis, M W

2004-01-01

Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract predatory mites (Neoseiulus cucumeris). Since our aim was to demonstrate such odours and not their relevance under soil conditions, the experiments were carried out using a classic Y-tube olfactometer in which the predators moved on a Y-shaped wire in open air. We found that food-deprived female predators can discriminate between odours from infested bulbs and odours from uninfested bulbs or artificially wounded bulbs. No significant difference in attractiveness to predators was found between clean bulbs and bulbs either wounded 30 min or 3 h before the experiment. These results indicate that it may not be simply the wounding of the bulbs, but rather the feeding by rust mites, which causes the bulb to release odours that attract N. cucumeris. Since bulbs are belowground plant structures, the olfactometer results demonstrate the potential for odour-mediated interactions in the soil. However, their importance in the actual soil medium remains to be demonstrated.

Evaluation of two counterflow traps for testing behaviour-mediating compounds for the malaria vector Anopheles gambiae s.s. under semi-field conditions in Tanzania

PubMed Central

Schmied, Wolfgang H; Takken, Willem; Killeen, Gerry F; Knols, Bart GJ; Smallegange, Renate C

2008-01-01

Background Evaluation of mosquito responses towards different trap-bait combinations in field trials is a time-consuming process that can be shortened by experiments in contained semi-field systems. Possible use of the BG Sentinel (BGS) trap to sample Anopheles gambiae s.s. was evaluated. The efficiency of this trap was compared with that of the Mosquito Magnet-X (MM-X) trap, when baited with foot odour alone or combinations of foot odour with carbon dioxide (CO2) or lemongrass as behaviour-modifying cues. Methods Female An. gambiae s.s. were released in an experimental flight arena that was placed in a semi-field system and left overnight. Catch rates for the MM-X and BGS traps were recorded. Data were analysed by fitting a generalized linear model to the (n+1) transformed catches. Results Both types of traps successfully captured mosquitoes with all odour cues used. When the BGS trap was tested against the MM-X trap in a choice assay with foot odour as bait, the BGS trap caught about three times as many mosquitoes as the MM-X trap (P = 0.002). Adding CO2 (500 ml/min) to foot odour increased the number of mosquitoes caught by 268% for the MM-X (P < 0.001) and 34% (P = 0.051) for the BGS trap, compared to foot odour alone. When lemongrass leaves were added to foot odour, mosquito catches were reduced by 39% (BGS, P < 0.001) and 38% (MM-X, P = 0.353), respectively. Conclusion The BGS trap shows high potential for field trials due to its simple construction and high catch rate when baited with human foot odour only. However, for rapid screening of different baits in a contained semi-field system, the superior discriminatory power of the MM-X trap is advantageous. PMID:18980669

Effect of Biological Relatedness on Perfume Selection for Others: Preliminary Evidence.

PubMed

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

2017-01-01

People tend to choose perfumes to complement their body odour. As kin share some body odour qualities, their ability to select complementary perfumes for relatives might be higher compared with selection for nonrelatives. We tested this in two studies, comparing selection of a perfume for a target man by himself and by either a familiar but unrelated individual (girlfriend; Study 1) or a relative (sister; Study 2). Target men applied the two perfumes (own or other's choice) to their axillae and then wore cotton pads for 12 hr. Collected perfume-body odour blends and perfumes alone were assessed by rater panels. In Study 1, the blends were rated as nominally more pleasant when body odours were mixed with the perfumes selected by girlfriends compared with those selected by target men themselves. In Study 2, body odours mixed with perfumes selected by sisters were rated significantly more attractive than those mixed with perfumes selected by target men. No significant differences were found for attractiveness and pleasantness ratings when perfumes were rated alone, suggesting that it was the resulting blends that were uniquely different. Our results indicate that sisters might be particularly tuned to select suitable perfumes for their siblings.

Correlation between odour concentration and odour intensity from exposure to environmental odour

NASA Astrophysics Data System (ADS)

Yusoff, Syafinah; Qamaruz Zaman, Nastaein

2017-08-01

The encroachment of industries, agricultural activities and husbandries to the community area had been a major concern of late, especially in regards to the escalating reports of odour nuisances. A study was performed with the objective of establishing correlation between odour concentration and odour intensity, as an improved method to determine odour nuisances in the community. Universiti Sains Malaysia Engineering Campus was chosen as the study location, due to its vicinity to several odour sources including paper mill, palm oil mill and poultry farm. The odour survey was based on VDI 3940, to determine the level of odour intensity with the corresponding odour concentration measured using an infield olfactometer. The correlation between both methods shows a significant correlation by using Pearson Correlation with a level of confidence of 99.9 percent. The graph plotted between intensity and concentration shows the R2 value of 0.40 which indicated a good correlation between both methods, despite having a high variance and low in consistency. Therefore, this study concludes that the determination of odour concentration should be complemented with odour intensity in order to recognize the true impact of odour nuisance in a community.

A new intelligent electronic nose system for measuring and analysing livestock and poultry farm odours.

PubMed

Pan, Leilei; Yang, Simon X

2007-12-01

This paper introduces a new portable intelligent electronic nose system developed especially for measuring and analysing livestock and poultry farm odours. It can be used in both laboratory and field. The sensor array of the proposed electronic nose consists of 14 gas sensors, a humidity sensor, and a temperature sensor. The gas sensors were especially selected for the main compounds from the livestock farm odours. An expert system called "Odour Expert" was developed to support researchers' and farmers' decision making on odour control strategies for livestock and poultry operations. "Odour Expert" utilises several advanced artificial intelligence technologies tailored to livestock and poultry farm odours. It can provide more advanced odour analysis than existing commercially available products. In addition, a rank of odour generation factors is provided, which refines the focus of odour control research. Field experiments were conducted downwind from the barns on 14 livestock and poultry farms. Experimental results show that the predicted odour strengths by the electronic nose yield higher consistency in comparison to the perceived odour intensity by human panel. The "Odour Expert" is a useful tool for assisting farmers' odour management practises.

Cannabinoids increase conditioned ultrasonic vocalisations and cat odour avoidance in rats: strain differences in drug-induced anxiety.

PubMed

Arnold, Jonathon C; Dielenberg, Robert A; McGregor, Iain S

2010-10-23

Genetic disposition modulates the psychoactive effects of cannabis. Cannabinoids have a greater impact on brain regions that subserve anxiety in Wistar compared to Lewis strain rats. Here we aim to show that this correlates with strain differences in cannabinoid-induced anxiety-related behaviour. Lewis and Wistar rats were administered vehicle or the synthetic cannabinoid receptor agonist, CP 55,940 (10, 25 and 50μg/kg) before testing in the conditioned ultrasonic vocalization (USV), cat odour avoidance or open area avoidance models. Animals were placed in a chamber in which they had previously received footshock. Wistar but not Lewis rats re-exposed under the influence of all CP 55,940 doses emitted significantly more USVs than vehicle-treated rats. In the cat odour avoidance model, rats were exposed to cat odour and given the opportunity to hide in a small box. In Wistar but not Lewis rats, 50μg/kg of CP 55,940 magnified hiding behaviour promoted by cat odour exposure. Animals were also tested in the open area avoidance model which occurred in the same arena as the predatory avoidance model but without cat odour. In Wistar, but not Lewis rats, 25 and 50μg/kg of CP 55,940 increased the avoidance of the open space. CP 55,940 increased anxiety-related behaviour in Wistar rats but not Lewis rats providing a model to dissect the genetic basis of cannabinoid-induced anxiety. We show for the first time that cannabinoids magnify conditioned USVs and cat odour avoidance behaviour dependent on the strain being tested. Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.

Simultaneous odour-face presentation strengthens hedonic evaluations and event-related potential responses influenced by unpleasant odour.

PubMed

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

2018-04-13

Odours alter evaluations of concurrently presented visual stimuli, such as faces. Stimulus onset asynchrony (SOA) is known to affect evaluative priming in various sensory modalities. However, effects of SOA on odour priming of visual stimuli are not known. The present study aimed to analyse whether subjective and cortical activation changes during odour priming would vary as a function of SOA between odours and faces. Twenty-eight participants rated faces under pleasant, unpleasant, and no-odour conditions using visual analogue scales. In half of trials, faces appeared one-second after odour offset (SOA 1). In the other half of trials, faces appeared during the odour pulse (SOA 2). EEG was recorded continuously using a 128-channel system, and event-related potentials (ERPs) to face stimuli were evaluated using statistical parametric mapping (SPM). Faces presented during unpleasant-odour stimulation were rated significantly less pleasant than the same faces presented one-second after offset of the unpleasant odour. Scalp-time clusters in the late-positive-potential (LPP) time-range showed an interaction between odour and SOA effects, whereby activation was stronger for faces presented simultaneously with the unpleasant odour, compared to the same faces presented after odour offset. Our results highlight stronger unpleasant odour priming with simultaneous, compared to delayed, odour-face presentation. Such effects were represented in both behavioural and neural data. A greater cortical and subjective response during simultaneous presentation of faces and unpleasant odour may have an adaptive role, allowing for a prompt and focused behavioural reaction to a concurrent stimulus if an aversive odour would signal danger, or unwanted social interaction. Copyright © 2018 Elsevier B.V. All rights reserved.

Flatulence on airplanes: just let it go.

PubMed

Pommergaard, Hans C; Burcharth, Jakob; Fischer, Anders; Thomas, William E G; Rosenberg, Jacob

2013-02-15

Flatus is natural and an invariable consequence of digestion, however at times it creates problems of social character due to sound and odour. This problem may be more significant on commercial airplanes where many people are seated in limited space and where changes in volume of intestinal gases, due to altered cabin pressure, increase the amount of potential flatus. Holding back flatus on an airplane may cause significant discomfort and physical symptoms, whereas releasing flatus potentially presents social complications. To avoid this problem we humbly propose that active charcoal should be embedded in the seat cushion, since this material is able to neutralise the odour. Moreover active charcoal may be used in trousers and blankets to emphasise this effect. Other less practical or politically correct solutions to overcome this problem may be to restrict access of flatus-prone persons from airplanes, by using a methane breath test or to alter the fibre content of airline meals in order to reduce its flatulent potential. We conclude that the use of active charcoal on airlines may improve flight comfort for all passengers.

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

PubMed

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

2016-08-01

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

Perceptual and Neural Olfactory Similarity in Honeybees

PubMed Central

Sandoz, Jean-Christophe

2005-01-01

The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones) and in their carbon-chain length (from six to nine carbons).The results obtained by presentation of a total of 16 × 16 odour pairs show that (i) all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii) generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii) for some odour pairs, cross-generalisation between odorants was asymmetric; (iv) a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v) perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours. PMID:15736975

Odour recognition by male hamsters: discrimination of the hormonal state of females by odour from vaginal secretions.

PubMed

Steel, E

1985-05-01

Male hamsters were tested for their interest in females on different days of the oestrous cycle. Behaviour of males toward novel females was measured and (after exposure to vaginal secretion) towards females that matched or did not match that vaginal odour. Because pro-oestrous (day 4) females lay trails of vaginal secretion and will become receptive within a few hours, it was predicted that males would show more interest in day 4 than in other dioestrous females. While males showed no preference for novel, pro-oestrous females over dioestrous females, after pre-exposure to odour, their response to females was determined by the cycle day of the vaginal secretion to which they had been exposed. Males pre-exposed to vaginal odour from females carrying large implants of oestrogen preferred to spend more time with females who matched that vaginal odour than mismatching females and to sniff them more. This preference was not seen if the females carried small oestrogen implants or had no replacement oestrogen. This suggests that pro-oestrous females (who are known to have high circulating levels of oestrogen) can, by means of their scent-marking behaviour, attract and keep males nearby until they become receptive.

Rats track odour trails accurately using a multi-layered strategy with near-optimal sampling.

PubMed

Khan, Adil Ghani; Sarangi, Manaswini; Bhalla, Upinder Singh

2012-02-28

Tracking odour trails is a crucial behaviour for many animals, often leading to food, mates or away from danger. It is an excellent example of active sampling, where the animal itself controls how to sense the environment. Here we show that rats can track odour trails accurately with near-optimal sampling. We trained rats to follow odour trails drawn on paper spooled through a treadmill. By recording local field potentials (LFPs) from the olfactory bulb, and sniffing rates, we find that sniffing but not LFPs differ between tracking and non-tracking conditions. Rats can track odours within ~1 cm, and this accuracy is degraded when one nostril is closed. Moreover, they show path prediction on encountering a fork, wide 'casting' sweeps on encountering a gap and detection of reappearance of the trail in 1-2 sniffs. We suggest that rats use a multi-layered strategy, and achieve efficient sampling and high accuracy in this complex task.

Indoor Air Quality and Thermal Comfort in School Buildings

NASA Astrophysics Data System (ADS)

Juhásová Šenitková, Ingrid

2017-12-01

This paper presents results to thermal comfort and environment quality questions in 21 school building rooms. Results show that about 80% of the occupants expressed satisfaction with their thermal comfort in only 11% of the buildings surveyed. Air quality scores were somewhat higher, with 26% of buildings having 80% or occupant satisfaction. With respect to thermal comfort and air quality performance goals set out by standards, most buildings appear to be falling far short. Occupant surveys offer a means to systematically measure this performance, and also to provide diagnostic information for building designers and operators. The odours from building materials as well as human odours were studied by field measurement. The odour intensity and indoor air acceptability were assessed by a sensory panel. The concentrations of total volatile organic compounds and carbon dioxide were measured. The odours from occupancy and building materials were studied under different air change rate. The case study of indoor air acceptability concerning to indoor odours and its effect on perceived air quality are also presented in this paper.

Inbreeding affects sexual signalling in males but not females of Tenebrio molitor.

PubMed

Pölkki, Mari; Krams, Indrikis; Kangassalo, Katariina; Rantala, Markus J

2012-06-23

In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours.

Inbreeding affects sexual signalling in males but not females of Tenebrio molitor

PubMed Central

Pölkki, Mari; Krams, Indrikis; Kangassalo, Katariina; Rantala, Markus J.

2012-01-01

In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours. PMID:22237501

Schismatoglottis and Apoballis (Araceae: Schismatoglottideae): A new example for the significance of pollen morphology in Araceae systematics

PubMed Central

Ulrich, Silvia; Hesse, Michael; Bröderbauer, David; Wong, Sin Yeng; Boyce, Peter C.

2016-01-01

Pollen characters in Araceae accord well with recent DNA-based phylogenies, and here we provide a new example of “compass needle” quality in Araceae on the basis of two closely related genera, Schismatoglottis and Apoballis. All investigated Schismatoglottis pollen is psilate (smooth pollen surface) with calcium crystals covering the pollen surface. By contrast, pollen of species transferred to recently resurrected Apoballis (Apoballis acuminatissima and A. mutata) is distinctively echinate (spiny). A unique layer covers the endexine of Schismatoglottis, and the whole pollen surface of Apoballis. Our findings strongly suggest that “Schismatoglottis” species with echinate pollen fall into the genus Apoballis. Moreover, all schismatoglottid taxa perform spathe movements during anthesis to control the movement of pollinators. The spathe movements of Apoballis acuminatissima clearly differ from those known in Schismatoglottis species, and indeed are so far unique for the entire family. This, together with differences in floral odour is strongly suggestive of differences in pollination ecology between the genera Schismatoglottis and Apoballis. PMID:28904408

Different cerebral connectivity of obese and lean children studied with fMRI

NASA Astrophysics Data System (ADS)

Anaya Moreno, Maryan A.; Hernández López, Javier M.; Hidalgo Tobón, Silvia; Dies Suarez, Pilar; Barragán Pérez, Eduardo; De Celis Alonso, Benito

2014-11-01

In this work we studied the different fMRI brain activations and connections between normal weighted (NW) and obese (OB) infants for different types of food odours. A total of 30 right handed volunteers (infants 8.4±2 years) of both sexes were studied. Infants were divided in two group, one with BMI between 19 and 24 kg/m2 and the other with BMI over 30 kg/m2. The first part of this project consisted of a study in which fMRI BOLD activations to pleasant, neutral and healthy food was performed on both groups. Cerebellum regions were found to be more active in the NW group over the OB when presented with odour cues. OB volunteers in contrast showed larger activations in cingulate cortex structures than their NW counterparts when presented with food odours. The second part of this study performed connectivity studies (ROI to ROI) comparing both groups for each smell. The NW group presented for the onion smell a strong reward anticipation connection between the gustatory cortex and the cingulate cortex which the OB group did not have. In contrast the OB group presented strong orbitofrontal connections (decision making) with gustatory and somatosensory cortex when stimulated with the chocolate odour which the NW did not present. We can conclude that clear differences in fMRI BOLD activation as well as connectivity between the OB and NW groups were found. This points at a very different processing mechanisms of odour cues in infants. To our knowledge this study has never been performed before on infants.

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

PubMed

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

2016-07-15

Odour emissions from meat chicken sheds can at times cause odour impacts on surrounding communities. Litter is seen as the primary source of this odour. Formation and emission of odour from meat chicken litter during the grow-out period are influenced by various factors such as litter conditions, the environment, microbial activity, properties of the odorous gases and management practices. Odour emissions vary spatially and temporally. This variability has made it challenging to understand how specific litter conditions contribute to odour emissions from the litter and production sheds. Existing knowledge on odorants, odour formation mechanisms and emission processes that contribute to odour emissions from litter are reviewed. Litter moisture content and water thermodynamics (i.e. water activity, Aw) are also examined as factors that contribute to microbial odour formation, physical litter conditions and the exchange of individual odorant gases at the air-water interface. Substantial opportunities exist for future research on litter conditions and litter formation mechanisms and how these contribute to odour emissions. Closing this knowledge gap will improve management strategies that intercept and interfere with odour formation and emission processes leading to an overall reduction in the potential to cause community impacts. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Odour intensity learning in fruit flies

PubMed Central

Yarali, Ayse; Ehser, Sabrina; Hapil, Fatma Zehra; Huang, Ju; Gerber, Bertram

2009-01-01

Animals' behaviour towards odours depends on both odour quality and odour intensity. While neuronal coding of odour quality is fairly well studied, how odour intensity is treated by olfactory systems is less clear. Here we study odour intensity processing at the behavioural level, using the fruit fly Drosophila melanogaster. We trained flies by pairing a MEDIUM intensity of an odour with electric shock, and then, at a following test phase, measured flies' conditioned avoidance of either this previously trained MEDIUM intensity or a LOWer or a HIGHer intensity. With respect to 3-octanol, n-amylacetate and 4-methylcyclohexanol, we found that conditioned avoidance is strongest when training and test intensities match, speaking for intensity-specific memories. With respect to a fourth odour, benzaldehyde, on the other hand, we found no such intensity specificity. These results form the basis for further studies of odour intensity processing at the behavioural, neuronal and molecular level. PMID:19586944

A review of odour impact criteria in selected countries around the world.

PubMed

Brancher, Marlon; Griffiths, K David; Franco, Davide; de Melo Lisboa, Henrique

2017-02-01

Exposure to environmental odour can result in annoyance, health effects and depreciation of property values. Therefore, many jurisdictions classify odour as an atmospheric pollutant and regulate emissions and/or impacts from odour generating activities at a national, state or municipal level. In this work, a critical review of odour regulations in selected jurisdictions of 28 countries is presented. Individual approaches were identified as: comparing ambient air odour concentration and individual chemicals statistics against impact criteria (maximum impact standard); using fixed and variable separation distances (separation distance standard); maximum emission rate for mixtures of odorants and individual chemical species (maximum emission standard); number of complaints received or annoyance level determined via community surveys (maximum annoyance standard); and requiring use of best available technologies (BAT) to minimize odour emissions (technology standard). The comparison of model-predicted odour concentration statistics against odour impact criteria (OIC) is identified as one of the most common tools used by regulators to evaluate the risk of odour impacts in planning stage assessments and is also used to inform assessment of odour impacts of existing facilities. Special emphasis is given to summarizing OIC (concentration percentile and threshold) and the manner in which they are applied. The way short term odour peak to model time-step mean (peak-to-mean) effects is also captured. Furthermore, the fundamentals of odorant properties, dimensions of nuisance odour, odour sampling and analysis methods and dispersion modelling guidance are provided. Common elements of mature and effective odour regulation frameworks are identified and an integrated multi-tool strategy is recommended. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

Nimmermark, S

2001-01-01

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

Odour concentration affects odour identity in honeybees

PubMed Central

Wright, Geraldine A; Thomson, Mitchell G.A; Smith, Brian H

2005-01-01

The fact that most types of sensory stimuli occur naturally over a large range of intensities is a challenge to early sensory processing. Sensory mechanisms appear to be optimized to extract perceptually significant stimulus fluctuations that can be analysed in a manner largely independent of the absolute stimulus intensity. This general principle may not, however, extend to olfaction; many studies have suggested that olfactory stimuli are not perceptually invariant with respect to odour intensity. For many animals, absolute odour intensity may be a feature in itself, such that it forms a part of odour identity and thus plays an important role in discrimination alongside other odour properties such as the molecular identity of the odorant. The experiments with honeybees reported here show a departure from odour-concentration invariance and are consistent with a lower-concentration regime in which odour concentration contributes to overall odour identity and a higher-concentration regime in which it may not. We argue that this could be a natural consequence of odour coding and suggest how an ‘intensity feature’ might be useful to the honeybee in natural odour detection and discrimination. PMID:16243694

The Sound and the Fury—Bees Hiss when Expecting Danger

PubMed Central

Galizia, C. Giovanni

2015-01-01

Honey bees are important model systems for the investigation of learning and memory and for a better understanding of the neuronal basics of brain function. Honey bees also possess a rich repertoire of tones and sounds, from queen piping and quacking to worker hissing and buzzing. In this study, we tested whether the worker bees’ sounds can be used as a measure of learning. We therefore conditioned honey bees aversively to odours in a walking arena and recorded both their sound production and their movement. Bees were presented with two odours, one of which was paired with an electric shock. Initially, the bees did not produce any sound upon odour presentation, but responded to the electric shock with a strong hissing response. After learning, many bees hissed at the presentation of the learned odour, while fewer bees hissed upon presentation of another odour. We also found that hissing and movement away from the conditioned odour are independent behaviours that can co-occur but do not necessarily do so. Our data suggest that hissing can be used as a readout for learning after olfactory conditioning, but that there are large individual differences between bees concerning their hissing reaction. The basis for this variability and the possible ecological relevance of the bees’ hissing remain to be investigated. PMID:25747702

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

PubMed

Zhao, Yan; Lu, Wenjing; Wang, Hongtao

2015-12-30

Odour pollution caused by municipal solid waste is a public concern. This study quantitatively evaluated the concentration, environmental impacts, and olfaction of volatile trace compounds released from a waste transfer station. Seventy-six compounds were detected, and ethanol presented the highest releasing rate and ratio of 14.76 kg/d and 12.30 g/t of waste, respectively. Life cycle assessment showed that trichlorofluoromethane and dichlorodifluoromethane accounted for more than 99% of impact potentials to global warming and approximately 70% to human toxicity (non-carcinogenic). The major contributor for both photochemical ozone formation and ecotoxicity was ethanol. A detection threshold method was also used to evaluate odour pollution. Five compounds including methane thiol, hydrogen sulphide, ethanol, dimethyl disulphide, and dimethyl sulphide, with dilution multiples above one, were considered the critical compounds. Methane thiol showed the highest contribution to odour pollution of more than 90%, as indicated by its low threshold. Comparison of the contributions of the compounds to different environmental aspects indicated that typical pollutants varied based on specific evaluation targets and therefore should be comprehensively considered. This study provides important information and scientific methodology to elucidate the impacts of odourant compounds to the environment and odour pollution. Copyright © 2015 Elsevier B.V. All rights reserved.

The sound and the fury--bees hiss when expecting danger.

PubMed

Wehmann, Henja-Niniane; Gustav, David; Kirkerud, Nicholas H; Galizia, C Giovanni

2015-01-01

Honey bees are important model systems for the investigation of learning and memory and for a better understanding of the neuronal basics of brain function. Honey bees also possess a rich repertoire of tones and sounds, from queen piping and quacking to worker hissing and buzzing. In this study, we tested whether the worker bees' sounds can be used as a measure of learning. We therefore conditioned honey bees aversively to odours in a walking arena and recorded both their sound production and their movement. Bees were presented with two odours, one of which was paired with an electric shock. Initially, the bees did not produce any sound upon odour presentation, but responded to the electric shock with a strong hissing response. After learning, many bees hissed at the presentation of the learned odour, while fewer bees hissed upon presentation of another odour. We also found that hissing and movement away from the conditioned odour are independent behaviours that can co-occur but do not necessarily do so. Our data suggest that hissing can be used as a readout for learning after olfactory conditioning, but that there are large individual differences between bees concerning their hissing reaction. The basis for this variability and the possible ecological relevance of the bees' hissing remain to be investigated.

The Odour of Sex: Sex-Related Differences in Volatile Compound Composition among Barn Swallow Eggs Carrying Embryos of Either Sex

PubMed Central

Costanzo, Alessandra; Panseri, Sara; Giorgi, Annamaria; Romano, Andrea; Caprioli, Manuela; Saino, Nicola

2016-01-01

Avian communication has been traditionally believed to be mainly mediated by visual and auditory channels. However, an increasing number of studies are disclosing the role of olfaction in the interaction of birds with their social environment and with other species, as well as in other behaviors such as nest recognition, food location and navigation. Olfaction has also been suggested to play a role in parent-offspring communication not only in the post- but also in the pre-hatching period. Volatile compounds produced during embryogenesis and passively released through the eggshell pores may indeed represent the only cue at parents’ disposal to assess offspring quality, including the sex composition of their clutch before hatching. In turn, sex identification before hatching may mediate adaptive strategies of allocation to either sex. In the present study, we analyzed odour composition of barn swallow eggs incubated in their nest in order to identify any sex-related differences in volatile compounds emitted. For the first time in any bird species, we also investigated whether odour composition is associated with relatedness. The evidence of differences in odour composition among eggs containing embryos of either sex indicates that parents have a cue to identify their brood sex composition even before hatching which can be used to modulate their behavior accordingly. Moreover, odour similarity within nests may represent the prerequisite for kin recognition in this species. PMID:27851741

Biological complexity and adaptability of simple mammalian olfactory memory systems.

PubMed

Brennan, P; Keverne, E B

2015-03-01

Chemosensory systems play vital roles in the lives of most mammals, including the detection and identification of predators, as well as sex and reproductive status and the identification of individual conspecifics. All of these capabilities require a process of recognition involving a combination of innate (kairomonal/pheromonal) and learned responses. Across very different phylogenies, the mechanisms for pheromonal and odour learning have much in common. They are frequently associated with plasticity of GABA-ergic feedback at the initial level of processing the chemosensory information, which enhances its pattern separation capability. Association of odourant features into an odour object primarily involves anterior piriform cortex for non-social odours. However, the medial amygdala appears to be involved in both the recognition of social odours and their association with chemosensory information sensed by the vomeronasal system. Unusually not only the sensory neurons themselves, but also the GABA-ergic interneurons in the olfactory bulb are continually being replaced, with implications for the induction and maintenance of learned chemosensory responses. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

The relative importance of olfaction and vision in a diurnal and a nocturnal hawkmoth.

PubMed

Balkenius, Anna; Rosén, Wenqi; Kelber, Almut

2006-04-01

Nectar-feeding animals can use vision and olfaction to find rewarding flowers and different species may give different weight to the two sensory modalities. We have studied how a diurnal or nocturnal lifestyle affects the weight given to vision and olfaction. We tested naïve hawkmoths of two species in a wind tunnel, presenting an odour source and a visual stimulus. Although the two species belong to the same subfamily of sphingids, the Macroglossinae, their behaviour was quite different. The nocturnal Deilephila elpenor responded preferably to the odour while the diurnal Macroglossum stellatarum strongly favoured the visual stimulus. Since a nocturnal lifestyle is ancestral for sphingids, the diurnal species, M. stellatarum, has evolved from nocturnal moths that primarily used olfaction. During bright daylight visual cues may have became more important than odour.

Variant discovery in the sheepmeat odour and flavour in javanese fat tailed sheep using RNA sequencing

NASA Astrophysics Data System (ADS)

Abuzahra, M. A. M.; Jakaria; Listyarini, K.; Furqon, A.; Sumantri, C.; Uddin, M. J.; Gunawan, A.

2018-05-01

High-throughput RNA sequencing (RNA-Seq) reveals new challenges for the detection of transcriptome variants (SNPs) in different tissues and species. The aims of this study was to characterize a SNP discovery analysis in the sheep meat odour and flavour transcriptome using RNA-Seq. Six liver samples from divergent sheep meat odour and flavour were analyzed using the Illumina Genome Hiseq 2500 Analyzer. The SNP detection analysis revealed 142 SNPs in sheep meat samples, and a large number of those corresponded to differences between high and low sheep meat odour and flavour ovis genome assembly OAR v4.0. Among them, about 90.4% of genes had multiple polymorphisms within 12 genes (JAML, ANGPTL8, LOC101103463, SEPW1, SCN5A, LOC101113036, DOCK6, GTSE1, KIF12, KCTD17, KANK2, CYP2A6). Several of the SNPs (JAML, CYP2A6, SEPW1, and KIF12) found in this study could be included as suitable markers in genotyping platforms to perform association analyses in commercial populations and apply genomic selection protocols in the sheep meat production.

Insulin effects on honeybee appetitive behaviour.

PubMed

Mengoni Goñalons, Carolina; Guiraud, Marie; de Brito Sanchez, María Gabriela; Farina, Walter M

2016-10-01

Worker honeybees (Apis mellifera) carry out multiple tasks throughout their adult lifespan. It has been suggested that the insulin/insulin-like signalling pathway participates in regulating behavioural maturation in eusocial insects. Insulin signalling increases as the honeybee worker transitions from nurse to food processor to forager. As behavioural shifts require differential usage of sensory modalities, our aim was to assess insulin effects on olfactory and gustatory responsiveness as well as on olfactory learning in preforaging honeybee workers of different ages. Adults were reared in the laboratory or in the hive. Immediately after being injected with insulin or vehicle (control), and focusing on the proboscis extension response, bees were tested for their spontaneous response to odours, sucrose responsiveness and ability to discriminate odours through olfactory conditioning. Bees injected with insulin have higher spontaneous odour responses. Sucrose responsiveness and odour discrimination are differentially affected by treatment according to age: whereas insulin increases gustatory responsiveness and diminishes learning abilities of younger workers, it has the opposite effect on older bees. In summary, insulin can improve chemosensory responsiveness in young workers, but also worsens their learning abilities to discriminate odours. The insulin signalling pathway is responsive in young workers, although they are not yet initiating outdoor activities. Our results show strong age-dependent effects of insulin on appetitive behaviour, which uncover differences in insulin signalling regulation throughout the honeybee worker's adulthood. © 2016. Published by The Company of Biologists Ltd.

Diversification and spatial structuring in the mutualism between Ficus septica and its pollinating wasps in insular South East Asia.

PubMed

Rodriguez, Lillian Jennifer; Bain, Anthony; Chou, Lien-Siang; Conchou, Lucie; Cruaud, Astrid; Gonzales, Regielene; Hossaert-McKey, Martine; Rasplus, Jean-Yves; Tzeng, Hsy-Yu; Kjellberg, Finn

2017-08-29

Interspecific interactions have long been assumed to play an important role in diversification. Mutualistic interactions, such as nursery pollination mutualisms, have been proposed as good candidates for diversification through co-speciation because of their intricate nature. However, little is known about how speciation and diversification proceeds in emblematic nursery pollination systems such as figs and fig wasps. Here, we analyse diversification in connection with spatial structuring in the obligate mutualistic association between Ficus septica and its pollinating wasps throughout the Philippines and Taiwan. Ceratosolen wasps pollinating F. septica are structured into a set of three vicariant black coloured species, and a fourth yellow coloured species whose distribution overlaps with those of the black species. However, two black pollinator species were found to co-occur on Lanyu island. Microsatellite data on F. septica indicates the presence of three gene pools that broadly mirrors the distribution of the three black clades. Moreover, receptive fig odours, the specific message used by pollinating wasps to locate their host tree, varied among locations. F. septica and its black pollinator clades exhibited similar geographic structuring. This could be due originally to geographic barriers leading to isolation, local adaptation, and finally co-structuring. Nevertheless, the co-occurrence of two black pollinator species on Lanyu island suggests that the parapatric distribution of the black clades is now maintained by the inability of migrating individuals of black pollinators to establish populations outside their range. On the other hand, the distribution of the yellow clade strongly suggests an initial case of character displacement followed by subsequent range extension: in our study system, phenotypic or microevolutionary plasticity has allowed the yellow clade to colonise hosts presenting distinct odours. Hence, while variation in receptive fig odours allows specificity in the interaction, this variation does not necessarily lead to coevolutionary plant-insect diversification. Globally, our results evidence evolutionary plasticity in the fig-fig wasp mutualism. This is the first documentation of the presence of two distinct processes in pollinating fig wasp diversification on a host species: the formation of vicariant species and the co-occurrence of other species over large parts of their ranges probably made possible by character displacement.

Odour discrimination learning in the Indian greater short-nosed fruit bat (Cynopterus sphinx): differential expression of Egr-1, C-fos and PP-1 in the olfactory bulb, amygdala and hippocampus.

PubMed

Mukilan, Murugan; Bogdanowicz, Wieslaw; Marimuthu, Ganapathy; Rajan, Koilmani Emmanuvel

2018-06-15

Activity-dependent expression of immediate-early genes (IEGs) is induced by exposure to odour. The present study was designed to investigate whether there is differential expression of IEGs ( Egr-1 , C-fos ) in the brain region mediating olfactory memory in the Indian greater short-nosed fruit bat, Cynopterus sphinx We assumed that differential expression of IEGs in different brain regions may orchestrate a preference odour (PO) and aversive odour (AO) memory in C. sphinx We used preferred (0.8% w/w cinnamon powder) and aversive (0.4% w/v citral) odour substances, with freshly prepared chopped apple, to assess the behavioural response and induction of IEGs in the olfactory bulb, hippocampus and amygdala. After experiencing PO and AO, the bats initially responded to both, later only engaging in feeding bouts in response to the PO food. The expression pattern of EGR-1 and c-Fos in the olfactory bulb, hippocampus and amygdala was similar at different time points (15, 30 and 60 min) following the response to PO, but was different for AO. The response to AO elevated the level of c-Fos expression within 30 min and reduced it at 60 min in both the olfactory bulb and the hippocampus, as opposed to the continuous increase noted in the amygdala. In addition, we tested whether an epigenetic mechanism involving protein phosphatase-1 (PP-1) acts on IEG expression. The observed PP-1 expression and the level of unmethylated/methylated promoter revealed that C-fos expression is possibly controlled by odour-mediated regulation of PP-1. These results in turn imply that the differential expression of C-fos in the hippocampus and amygdala may contribute to olfactory learning and memory in C. sphinx . © 2018. Published by The Company of Biologists Ltd.

Men's preferences for women's body odours are not associated with human leucocyte antigen.

PubMed

Probst, Fabian; Fischbacher, Urs; Lobmaier, Janek S; Wirthmüller, Urs; Knoch, Daria

2017-10-11

Body odours reportedly portray information about an individual's genotype at the major histocompatibility complex (MHC, called human leucocyte antigen, HLA, in humans). While there is strong experimental support for MHC-associated mating behaviour in animals, the situation in humans is more complex. A lot of effort has been spent on testing HLA-associated odour preferences of women. To date, only very few studies have looked at HLA-linked olfactory preferences in men and these studies have revealed inconsistent results. Here, we investigate men's HLA-associated preferences for women's body odours. Importantly, and in contrast to previous studies, these odours were gathered at peak fertility (i.e. just before ovulation) when any HLA-associated odour preferences should be strongest. We scrutinized whether men's preference for women's body odours is influenced by (i) the number of shared HLA alleles between men and women, (ii) HLA heterozygosity, and (iii) the frequency of rare HLA alleles. We found that men could readily differentiate between odours they found attractive and odours they found less attractive, but that these preferences were not associated with HLA. Specifically, men did not prefer odours from women who are HLA dissimilar, HLA heterozygous, or who have rare HLA alleles. Together, these findings suggest that HLA has no effect on men's odour preferences. © 2017 The Author(s).

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

PubMed Central

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

2013-01-01

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

The relationship between odour annoyance scores and modelled ambient air pollution in Sarnia, "Chemical Valley", Ontario.

PubMed

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

2009-10-01

This study aimed at establishing the relationship between annoyance scores and modelled air pollution in "Chemical Valley", Sarnia, Ontario (Canada). Annoyance scores were taken from a community health survey (N = 774); and respondents' exposure to nitrogen dioxide (NO(2)) and sulphur dioxide (SO(2)) were estimated using land use regression (LUR) models. The associations were examined by univariate analysis while multivariate logistic regression was used to examine the determinants of odour annoyance. The results showed that odour annoyance was significantly correlated to modelled pollutants at the individual (NO(2), r = 0.15; SO(2), r = 0.13) and census tract (NO(2), r = 0.56; SO(2), r = 0.67) levels. The exposure-response relationships show that residents of Sarnia react to very low pollution concentrations levels even if they are within the Ontario ambient air quality criteria. The study found that exposure to high NO(2) and SO(2) concentrations, gender, and perception of health effects were significant determinants of individual odour annoyance reporting. The observed association between odour annoyance and modelled ambient pollution suggest that individual and census tract level annoyance scores may serve as proxies for air quality in exposed communities because they capture the within area spatial variability of pollution. However, questionnaire-based odour annoyance scores need to be validated longitudinally and across different scales if they are to be adopted for use at the national level.

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

PubMed

Stevenson, Richard J; Mahmut, Mehmet K

2013-01-01

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

Prospects for developing odour baits to control Glossina fuscipes spp., the major vector of human African trypanosomiasis.

PubMed

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

2009-01-01

We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed on a black target (1x1 m). In addition responses to monitor lizard (Varanus niloticus) were assessed in Kenya. The effects of all four odours on the proportion of tsetse that entered a biconical trap were also determined. Sources of natural host odour were produced by placing live hosts in a tent or metal hut (volumes approximately 16 m(3)) from which the air was exhausted at approximately 2000 L/min. Odours from cattle, pigs and humans had no significant effect on attraction of G. f. fuscipes but lizard odour doubled the catch (P<0.05). Similarly, mammalian odours had no significant effect on landing or trap entry whereas lizard odour increased these responses significantly: landing responses increased significantly by 22% for males and 10% for females; the increase in trap efficiency was relatively slight (5-10%) and not always significant. For G. f. quanzensis, only pig odour had a consistent effect, doubling the catch of females attracted to the source and increasing the landing response for females by approximately 15%. Dispensing CO(2) at doses equivalent to natural hosts suggested that the response of G. f. fuscipes to lizard odour was not due to CO(2). For G. f. quanzensis, pig odour and CO(2) attracted similar numbers of tsetse, but CO(2) had no material effect on the landing response. The results suggest that identifying kairomones present in lizard odour for G. f. fuscipes and pig odour for G. f. quanzensis may improve the performance of targets for controlling these species.

Expression of CYP2A6, KIF12, and SULT1C1 in liver of sheep with divergent sheepmeat flavour and odour

NASA Astrophysics Data System (ADS)

Listyarini, K.; Jakaria; Furqon, A.; Sumantri, C.; Uddin, M. J.; Gunawan, A.

2018-05-01

The aim of this study was to investigate the expression of some of the key enzymes involved in liver sample of sheep with high and low sheepmeat flavour and odour. The study was conducted with Indonesian Javanese fat tailed sheep. Sheep having a fat branched chain fatty acids 4-methylnonanoic (MNA) greater and less than 215 μg g-1 and 229 will be defined as low and sheep meat odour, respectively. For the flavour, sheep having a fat skatole level less than 0.25 μg g-1 and greater than 0.25 μg g-1 will be defined as low and high flavour samples, respectively. The enzymes investigated were cytochrome P450 2A13 (CYP2A6), kinesin-like protein KIF12 (KIF12), and sulfotransferase 1C1 (SULT1C1). Expression of CYP2A6 in liver had differ between animals with high and low sheep meat flavour. Expression of CYP2A6, which catalyses the first stage of oxidation degradation, was increased in high sheep meat flavour and odour (P > 0.05). Similar pattern, the expression of SULT1C1, which catalyse the second stage of conjugation steroid catabolism, was increase in high sheep meat flavour and odour (P > 0.05). In contrast, the expression of KIF12 was decreased in high sheep meat flavour and odour animals. It is suggested that accumulation sheep meat flavour and odour in liver tissue of Indonesian Javanese fat tailed might be related to a high rate of oxidation in metabolic stage I and conjugation degradation in metabolic stage II.

Comparative evaluation of four mosquitoes sampling methods in rice irrigation schemes of lower Moshi, northern Tanzania.

PubMed

Kweka, Eliningaya J; Mahande, Aneth M

2009-07-06

Adult malaria vector sampling is the most important parameter for setting up an intervention and understanding disease dynamics in malaria endemic areas. The intervention will ideally be species-specific according to sampling output. It was the objective of this study to evaluate four sampling techniques, namely human landing catch, pit shelter, indoor resting collection and odour-baited entry trap. These four sampling methods were evaluated simultaneously for thirty days during October 2008, a season of low mosquitoes density and malaria transmission. These trapping methods were performed in one village for maximizing homogeneity in mosquito density. The cattle and man used in odour-baited entry trap were rotated between the chambers to avoid bias. A total of 3,074 mosquitoes were collected. Among these 1,780 (57.9%) were Anopheles arabiensis and 1,294 (42.1%) were Culex quinquefasciatus. Each trap sampled different number of mosquitoes, Indoor resting collection collected 335 (10.9%), Odour-baited entry trap-cow 1,404 (45.7%), Odour-baited entry trap-human 378 (12.3%), Pit shelter 562 (18.3%) and HLC 395 (12.8%). General linear model univariate analysis method was used, position of the trapping method had no effect on mosquito density catch (DF = 4, F = 35.596, P = 0.78). Days variation had no effect on the collected density too (DF = 29, F = 4.789, P = 0.09). The sampling techniques had significant impact on the caught mosquito densities (DF = 4, F = 34.636, P < 0.0001). The Wilcoxon pair-wise comparison between mosquitoes collected in human landing catch and pit shelter was significant (Z = -3.849, P < 0.0001), human landing catch versus Indoor resting collection was not significant (Z = -0.502, P = 0.615), human landing catch versus odour-baited entry trap-man was significant (Z = -2.687, P = 0.007), human landing catch versus odour-baited entry trap-cow was significant (Z = -3.127, P = 0.002). Odour-baited traps with different baits and pit shelter have shown high productivity in collecting higher densities of mosquitoes than human landing catch. These abilities are the possibilities of replacing the human landing catch practices for sampling malaria vectors in areas with An. arabiensis as malaria vectors. Further evaluations of these sampling methods need to be investigated is other areas with different species.

Effects of passive smoking on odour identification in children.

PubMed

Nageris, B; Braverman, I; Hadar, T; Hansen, M C; Frenkiel, S

2001-10-01

The effect of passive smoking on odour identification in children has rarely been reported. This study assessed the ability of such young subjects to identify a variety of odours. The study population consisted of 20 children, 10 who were exposed to passive smoke at home and 10 with nonsmoking parents. Ten odourants were tested: vinegar, ammonia, peppermint, roses, bleach, vanilla, cough drops, turpentine, licorice, and mothballs. Each child was presented with five test trays containing all 10 odourants in random order. Of the total of 500 odours presented, the control group correctly identified 396 (79%) and the study group identified 356 (71%) (p < .005). The study group tended to misidentify 4 of the 10 odourants tested, namely, vanilla, roses, mothballs, and cough drops-56 of 200 (28%), compared with 96 of 200 (48%) in the control group. This was a highly significant finding (p < .0005). This work demonstrated that children exposed to passive smoke have difficulty identifying odours in comparison with children raised in relatively smoke-free environments. The identification of four odourants, vanilla, roses, mothballs, and cough drops, was particularly diminished in this study group.

Olfactory language and abstraction across cultures

PubMed Central

Burenhult, Niclas; Stensmyr, Marcus; de Valk, Josje; Hansson, Bill S.

2018-01-01

Olfaction presents a particularly interesting arena to explore abstraction in language. Like other abstract domains, such as time, odours can be difficult to conceptualize. An odour cannot be seen or held, it can be difficult to locate in space, and for most people odours are difficult to verbalize. On the other hand, odours give rise to primary sensory experiences. Every time we inhale we are using olfaction to make sense of our environment. We present new experimental data from 30 Jahai hunter-gatherers from the Malay Peninsula and 30 matched Dutch participants from the Netherlands in an odour naming experiment. Participants smelled monomolecular odorants and named odours while reaction times, odour descriptors and facial expressions were measured. We show that while Dutch speakers relied on concrete descriptors, i.e. they referred to odour sources (e.g. smells like lemon), the Jahai used abstract vocabulary to name the same odours (e.g. musty). Despite this differential linguistic categorization, analysis of facial expressions showed that the two groups, nevertheless, had the same initial emotional reactions to odours. Critically, these cross-cultural data present a challenge for how to think about abstraction in language. This article is part of the theme issue ‘Varieties of abstract concepts: development, use and representation in the brain’. PMID:29915007

Activation, orientation and landing of female Culex quinquefasciatus in response to carbon dioxide and odour from human feet: 3-D flight analysis in a wind tunnel.

PubMed

Lacey, E S; Cardé, R T

2011-03-01

This study investigated the interaction between carbon dioxide (CO(2) ) and human foot odour on activation, upwind orientation and landing of host-seeking female Culex quinquefasciatus (Say) (Diptera: Culicidae) in a wind tunnel. More mosquitoes landed on warmed glass beads coated with foot odour than on clean beads; adding a plume of 4% CO(2) did not influence the proportion of mosquitoes landing. A second experiment used 3-dimensional video tracking to assess flight performance. Activation was more rapid with CO(2) and with CO(2) + foot odour than with clean air or with foot odour alone. Upwind flights were fastest with CO(2) and with clean air, and slowest with foot odour; the CO(2) + foot odour treatment overlapped the previous three treatments in significance. Flight headings tended more towards due upwind with CO(2) and with clean air than with CO(2) + foot odour or with foot odour alone. In both experiments, many mosquitoes flew upwind in clean air. There was little evidence of females changing course upon entering or exiting the CO(2) plume or reacting to foot odour during flight. © 2010 The Authors. Medical and Veterinary Entomology © 2010 The Royal Entomological Society.

Odour in composting processes at pilot scale: monitoring and biofiltration.

PubMed

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

2014-08-01

Although odour emissions associated with the composting process, especially during the hydrolytic stage, are widely known, their impact on surrounding areas is not easily quantifiable, For this reason, odour emissions during the first stage ofcomposting were evaluated by dynamic olfactometry at pilot scale in order to obtain results which can be extrapolated to industrial facilities. The composting was carried out in a commercial dynamic respirometer equipped with two biofilters at pilot scale filled with prunings (Populus) and mature compost obtained from the organic fraction of municipal solid waste. Given that the highest odour emissions occur in the first stage of the composting process, this stage was carried out in a closed system to better control the odour emissions, whose maximum value was estimated to be 2.78 ouF S-1 during the experiments. Odour concentration, the dynamic respiration index and temperature showed the same evolution during composting, thus indicating that odour could be a key variable in the monitoring process. Other variables such as total organic carbon (CTOC) and pH were also found to be significant in this study due to their influence over odour emissions. The efficiency of the biofilters (empty bed residence time of 86 s) was determined by quantifying the odour emissions at the inlet and outlet of both biofilters. The moisture content in the biofilters was found to be an important variable for improving odour removal efficiency, while the minimum moisture percentage to obtain successful results was found to be 55% (odour removal efficiency of 95%).

Calculation of odour emissions from aircraft engines at Copenhagen Airport.

PubMed

Winther, Morten; Kousgaard, Uffe; Oxbøl, Arne

2006-07-31

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

Associative learning for danger avoidance nullifies innate positive chemotaxis to host olfactory stimuli in a parasitic wasp

NASA Astrophysics Data System (ADS)

Benelli, Giovanni; Stefanini, Cesare; Giunti, Giulia; Geri, Serena; Messing, Russell H.; Canale, Angelo

2014-09-01

Animals rely on associative learning for a wide range of purposes, including danger avoidance. This has been demonstrated for several insects, including cockroaches, mosquitoes, drosophilid flies, paper wasps, stingless bees, bumblebees and honeybees, but less is known for parasitic wasps. We tested the ability of Psyttalia concolor (Hymenoptera: Braconidae) females to associate different dosages of two innately attractive host-induced plant volatiles (HIPVs), ethyl octanoate and decanal, with danger (electric shocks). We conducted an associative treatment involving odours and shocks and two non-associative controls involving shocks but not odours and odours but not shocks. In shock-only and odour-only trained wasps, females preferred on HIPV-treated than on blank discs. In associative-trained wasps, however, P. concolor's innate positive chemotaxis for HIPVs was nullified (lowest HIPV dosage tested) or reversed (highest HIPV dosage tested). This is the first report of associative learning of olfactory cues for danger avoidance in parasitic wasps, showing that the effects of learning can override innate positive chemotaxes.

Do terrestrial hermit crabs sniff? Air flow and odorant capture by flicking antennules

PubMed Central

Koehl, M. A. R.

2016-01-01

Capture of odorant molecules by olfactory organs from the surrounding fluid is the first step of smelling. Sniffing intermittently moves fluid across sensory surfaces, increasing delivery rates of molecules to chemosensory receptors and providing discrete odour samples. Aquatic malacostracan crustaceans sniff by flicking olfactory antennules bearing arrays of chemosensory hairs (aesthetascs), capturing water in the arrays during downstroke and holding the sample during return stroke. Terrestrial malacostracans also flick antennules, but how their flicking affects odour capture from air is not understood. The terrestrial hermit crab, Coenobita rugosus, uses antennules bearing shingle-shaped aesthetascs to capture odours. We used particle image velocimetry to measure fine-scale fluid flow relative to a dynamically scaled physical model of a flicking antennule, and computational simulations to calculate diffusion to aesthetascs by odorant molecules carried in that flow. Air does not flow into the aesthetasc array during flick downstrokes or recovery strokes. Odorants are captured from air flowing around the outside of the array during flick downstrokes, when aesthetascs face upstream and molecule capture rates are 21% higher than for stationary antennules. Bursts of flicking followed by pauses deliver discrete odour samples to olfactory sensors, causing intermittency in odour capture by a different mechanism than aquatic crustaceans use. PMID:26763332

Field background odour should be taken into account when formulating a pest attractant based on plant volatiles

PubMed Central

Cai, Xiaoming; Bian, Lei; Xu, Xiuxiu; Luo, Zongxiu; Li, Zhaoqun; Chen, Zongmao

2017-01-01

Attractants for pest monitoring and controlling can be developed based on plant volatiles. Previously, we showed that tea leafhopper (Empoasca onukii) preferred grapevine, peach plant, and tea plant odours to clean air. In this research, we formulated three blends with similar attractiveness to leafhoppers as peach, grapevine, and tea plant volatiles; these blends were composed of (Z)-3-hexenyl acetate, (E)-ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene, benzaldehyde, and ethyl benzoate. Based on these five compounds, we developed two attractants, formula-P and formula-G. The specific component relative to tea plant volatiles in formula-P was benzaldehyde, and that in formula-G was ethyl benzoate. These two compounds played a role in attracting leafhoppers. In laboratory assays, the two attractants were more attractive than tea plant volatiles to the leafhoppers, and had a similar level of attractiveness. However, the leafhoppers were not attracted to formula-P in the field. A high concentration of benzaldehyde was detected in the background odour of the tea plantations. In laboratory tests, benzaldehyde at the field concentration was attractive to leafhoppers. Our results indicate that the field background odour can interfere with a point-releasing attractant when their components overlap, and that a successful attractant must differ from the field background odour. PMID:28150728

Do terrestrial hermit crabs sniff? Air flow and odorant capture by flicking antennules.

PubMed

Waldrop, Lindsay D; Koehl, M A R

2016-01-01

Capture of odorant molecules by olfactory organs from the surrounding fluid is the first step of smelling. Sniffing intermittently moves fluid across sensory surfaces, increasing delivery rates of molecules to chemosensory receptors and providing discrete odour samples. Aquatic malacostracan crustaceans sniff by flicking olfactory antennules bearing arrays of chemosensory hairs (aesthetascs), capturing water in the arrays during downstroke and holding the sample during return stroke. Terrestrial malacostracans also flick antennules, but how their flicking affects odour capture from air is not understood. The terrestrial hermit crab, Coenobita rugosus, uses antennules bearing shingle-shaped aesthetascs to capture odours. We used particle image velocimetry to measure fine-scale fluid flow relative to a dynamically scaled physical model of a flicking antennule, and computational simulations to calculate diffusion to aesthetascs by odorant molecules carried in that flow. Air does not flow into the aesthetasc array during flick downstrokes or recovery strokes. Odorants are captured from air flowing around the outside of the array during flick downstrokes, when aesthetascs face upstream and molecule capture rates are 21% higher than for stationary antennules. Bursts of flicking followed by pauses deliver discrete odour samples to olfactory sensors, causing intermittency in odour capture by a different mechanism than aquatic crustaceans use. © 2016 The Author(s).

The Contribution of Malodour in Quality of Life of Patients With Hidradenitis Suppurativa.

PubMed

Alavi, Afsaneh; Farzanfar, Delaram; Lee, Rosa Kyuwon; Almutairi, Dalal

Malodourous discharge in patients with hidradenitis suppurativa (HS) has a strong psychosocial impact and is often reported as a source of embarrassment, low self-esteem, social stigma, and barriers to interpersonal relationships. Malodour is a maker of bacterial colonization, and its role in HS is understudied. The aim of this study is to assess the relationship between severity of malodourous discharge and quality-of-life impairment in patients with HS. This is a cross-sectional study of 51 patients recruited from the Women's College Hospital and the York Dermatology Centre. Quality of life was assessed using both the Dermatology Life Quality Index (DLQI) and the Skindex-29 instruments. Severity of odour significantly predicts the total Skindex score after controlling for disease severity as measured by the Hurley stage and Sartorius score ( R 2 = 0.39, F = 8.11, P < .0001). However, odour severity is not a predictor of DLQI ( R 2 = 0.17, F = 2.63, P = .064). There was no difference in mean DLQI scores for the low- vs high-odour groups, but patients with high odour had a greater quality of life impairment as measured by the Skindex tool ( t = -4.19, df = 43, P < .0001, mean difference = -18.87). Malodour is a common symptom that significantly impairs quality of life in patients with HS. The fact that this effect is captured in Skindex and not the DLQI may be attributed to the nonspecificity of the DLQI in terms of unique disease characteristics. It is important to address odour in the management of patients with HS.

Preliminary investigations on a new method of retaining the colour of shucked cockles ( Anadara Granosa), and the extension of shelflife by gamma irradiation and vacuum packing

NASA Astrophysics Data System (ADS)

Ng, Cher Siang; Low, Lai Kim; Chia, Lawrence H. L.

Live cockles were incubated in atmospheres containing different concentrations of carbon monoxide. Since CO combines more readily with myoglobin and haemoglobin than oxygen, the formation of in vivo deoxygenated haemoglobins and post mortem formation of methaemoglobin were retarded by the more stable carboxyhaemoglobin (HbCO). The bright red colour of the stable HbCO is retained during storage, giving the desired colour to the cockles. The colour of normal, chilled cockle meat deteriorated after 3 days ice storage while those treated with 50 and 100% CO retained the bright deep orange colour up to 10 days storage. Irradiation caused faster colour deterioration in both CO and non-CO treated samples. Vacuum packing influenced the colour of the cockles with irradiation and with CO treatments. In non-CO treated, irradiated samples, the effect of vacuum packing was not obvious. In CO treated, irradiated samples, vacuum packing retarded the deterioration of colour. Odour developments were influenced by irradiation, vacuum packing and storage temperature, and were not influenced by CO treatments. Irradiation suppressed the development of odour for the first 11 days storage (0°C) while vacuum packing depressed the odour by lowering its intensity instead. Odour development was slowed down by lowering the storage temperature. The odour of shucked cockles was rejected within one day at room temperature (26-28°C) while at 0°C the odour of the shucked cockles was still acceptable after 10 days. Suitable chemical indices for quality are K value and TVBN. Treatment with CO did not influence the K value development. Vacuum packing produced the highest K values after 19 days storage (0°C), while irradiated samples had higher K values than non-irradiated samples. The TVBN increased with storage and is an indicator of the odour development. The use of CO treatment extended the shelflife of the cockles based on appearance. A combination of CO treatment, vacuum packing, ice storage and irradiation extended the shelflife to beyond 18 days, based on odour, colour, and overall appearance.

Acquisition of species-specific perfume blends: influence of habitat-dependent compound availability on odour choices of male orchid bees (Euglossa spp.).

PubMed

Pokorny, T; Hannibal, M; Quezada-Euan, J J G; Hedenström, E; Sjöberg, N; Bång, J; Eltz, T

2013-06-01

Male orchid bees (Euglossini, Apidae, Hymenoptera) expose species-specific blends of volatile chemicals (perfume bouquets) during their courtship display. The perfumes are acquired by collecting fragrant substances from environmental sources, which are then accumulated in specialised hind leg pouches. To balance the perfume composition, the males need to find and collect the required substances in specific relative amounts while facing seasonal, local or habitat-dependent differences in compound availability. Experience-dependent choice of odours, i.e. 'learned avoidance' of recently collected components, has been proposed as the mechanism that mediates the accumulation of the stereotypical compound ratios. In the present study, we used the presence of certain compounds in male hind leg pouches as proxy for the respective local compound availability, and investigated whether differences in content are correlated with differences in chemical choice assays. Our results suggest that volatile availability differs between localities (n = 16) as well as habitats (n = 2; coastal vs. inland) across the Yucatán peninsula, Mexico, for both studied species. Male Euglossa dilemma showed a pronounced preference for benzyl benzoate and eugenol at locations where those compounds were rare in hind leg extracts, as predicted by the learned avoidance model. No equivalent correlations were found for Euglossa viridissima. This is the first study to combine chemical analyses of perfumes with bioassays of odour choice. It strengthens the view that negative feedback from collected odours modifies future chemical choice and helps males to acquire specific perfume blends.

Social relations and breath odour.

PubMed

McKeown, L

2003-11-01

In this retrospective qualitative study, the researcher reviewed 55 client records of The Breath Odour Clinic. The purpose was to determine if individuals attended a clinic specialised in treating oral malodour for medical or social reasons. The study focused on the psychosocial and breath odour history. Clients had agreed to the use of information for research purposes. Society uses odour as a means to define and interact with the world. The olfactory, smelling experience is intimate, emotionally charged and connects us with the world. It follows that the smell from mouth breath odour can connect or disconnect a person from their social environment and intimate relationships. How one experiences one's own body is very personal and private but also very public. Breath odour is public as it occurs within a social and cultural context and personal as it affects one's body image and self-confidence. Body image, self-image and social relations mesh, interact and impact upon each other. Breath odour is a dynamic and interactive aspect of the self-image. In addition, breath odour may be value-coded as 'bad'. In 75% of the cases reviewed, decreased self-confidence and insecurity in social and intimate relations led clients to seek treatment at the specialised breath odour clinic. Their doctor, dental hygienist or dentist had treated medical and oral conditions but not resolved their breath odour problem. When a person perceives a constant bad breath problem, she/he uses defence techniques, and may avoid social situations and social relations. This affects a person's well-being.

Smelling themselves: Dogs investigate their own odours longer when modified in an "olfactory mirror" test.

PubMed

Horowitz, Alexandra

2017-10-01

While domestic dogs, Canis familiaris, have been found to be skillful at social cognitive tasks and even some meta-cognitive tasks, they have not passed the test of mirror self-recognition (MSR). Acknowledging the motivational and sensory challenges that might hinder performance, even before the question of self-recognition is broached, this study creates and enacts a novel design extrapolated from the species' natural behaviour. Given dogs' use of olfactory signals in communication, this experiment presents dogs with various canisters for approach and investigation. Each holds an odorous stimulus: in the critical test, either an "olfactory mirror" of the subject - the dog's own urine - or one in which the odour stimulus is modified. By looking at subjects' investigation times of each canister, it is shown that dogs distinguish between the olfactory "image" of themselves when modified: investigating their own odour for longer when it had an additional odour accompanying it than when it did not. Such behaviour implies a recognition of the odour as being of or from "themselves." The ecological validity of this odour presentation is examined by presenting to the subjects odours of other known or unknown dogs: dogs spend longer investigating the odour of other dogs than their own odour. Finally, in a second experiment, subjects spent longer with the modified stimulus than with the modified odour by itself, indicating that novelty alone does not explain the dogs' behavior. This study translates the MSR study for a species whose primary sensory modality is olfaction, and finds both that natural sniffing behaviour can be replicated in the lab and that dogs show more investigative interest in their own odours when modified. Copyright © 2017 Elsevier B.V. All rights reserved.

Cat odour-induced anxiety--a study of the involvement of the endocannabinoid system.

PubMed

Sütt, Silva; Raud, Sirli; Areda, Tarmo; Reimets, Ain; Kõks, Sulev; Vasar, Eero

2008-07-01

Recent evidence suggests the involvement of the endocannabinoid (EC) system in the regulation of anxiety. The aim of present work was to study the role of the EC system in cat odour-induced anxiety in rats. Materials and methods Male Wistar rats were exposed to cat odour in home and motility cages. Exposure of rats to elevated zero-maze was used to determine changes in anxiety. Effect of rimonabant (0.3-3 mg/kg), antagonist of CB1 receptors, was studied on cat odour-induced alterations in exploratory behaviour. Real-time PCR was used to determine gene expression levels of EC-related genes in the brain. Anxiogenic-like action of cat odour was evident in the elevated zero-maze. Cat odour increased the expression of FAAH, the enzyme responsible for the degradation of anandamide, in the mesolimbic area. By contrast, in the amygdala and periaqueductal grey (PAG) levels of NAPE-PLD, the enzyme related to the synthesis of anandamide, and FAAH were remarkably decreased. Cat odour also decreased the expression of enzymes related to metabolism of 2-archidonoyl-glycerol in the amygdala and PAG. Pre-treatment of rats with rimonabant (0.3-3 mg/kg) reduced the exploratory behaviour of rats, but did not affect cat odour-induced changes. Exposure to cat odour induces anxiogenic-like effect on the behaviour in rats. Cat odour also causes moderate increase in expression of EC-related genes in the mesolimbic area, whereas significant down-regulation is established in the amygdala and PAG. Relation of predator odour-induced anxiety to the inhibition of the EC system in the amygdala and PAG is supported by behavioural studies where blockade of CB1 receptors by rimonabant induces anxiogenic-like action.

Continuous monitoring of odours from a composting plant using electronic noses.

PubMed

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

2007-01-01

The odour impact of a composting plant situated in an urbanized area was evaluated by continuously monitoring the ambient air close to the plant during a period of about 4 days using two electronic noses. One electronic nose was installed in a nearby house, and the other one inside the perimeter of the composting plant in order to compare the response of both instruments. The results of the monitoring are represented by tables that report the olfactory class and the odour concentration value attributed to the analyzed air for each of the 370 measurements carried out during the monitoring period. The electronic nose installed at the house detected the presence of odours coming from the composting plant for about 7.8% of the monitoring total duration. Of the odour detections, 86% (25 of 29 measurements) were classified as belonging to the olfactory class corresponding to the open air storage of the waste screening overflows heaps, which was therefore identified to be the major odour source of the monitored composting plant. In correspondence of the measurements during which the electronic nose inside the house detected the presence of odours from the composting plant, the olfactory classes recognized by both instruments coincide. Moreover, the electronic nose at the house detected the presence of odours from the composting plant at issue in correspondence of each odour perception of the house occupants. The results of the study show the possibility of using an electronic nose for environmental odours monitoring, which enables the classification of the quality of the air and to quantify the olfactory nuisance from an industrial source in terms of duration and odour concentration.

Key volatile aroma compounds of three black velvet tamarind (Dialium) fruit species.

PubMed

Lasekan, Ola; See, Ng Siew

2015-02-01

Nineteen odour-active compounds were quantified in three black velvet tamarind fruit species. Calculation of the odour activity values (OAVs) of the odorants showed that differences in odour profiles of the tamarinds were mainly caused by linalool, limonene, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, nonanal, and (Z)-3-hexenal. On the basis of their high OAVs, cis-linalool oxide (furanoid), geranyl acetone, and cinnamyl acetate were identified as other potent odorants in the three tamarinds. Sensory studies revealed very distinct aroma profiles, which are characteristic of these types of fruits. While the Dialiumguineense elicited floral, flowery, caramel-like notes, the other two species were dominated by leaf-like, caramel, and green notes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sensory perception of meat from entire male pigs processed by different heating methods.

PubMed

Peñaranda, Irene; Garrido, Ma Dolores; Egea, Macarena; Díaz, Pedro; Álvarez, Daniel; Oliver, Ma Angeles; Linares, Ma Belén

2017-12-01

The aim of this study was to evaluate the perception of androstenone in pork from entire male pigs with different androstenone levels (High≥2mgkg -1 ; Medium 0.5-0.7mgkg -1 ) applying four different heating methods (vacuum, grill, oven and frying). Androstenone (AND) perception was analysed during and after cooking by a trained panel. During cooking, the highest score for AND odour (greatest perception) was obtained with the grill and vacuum, while frying was the best option for reducing its perception, which was judged to be imperceptible for androstenone medium level (P<0.05). In cooked samples, there were level, heating method and its interaction effects for AND odour and flavour, meat flavour, juiciness and hardness (P<0.05). The samples treated by vacuum and frying had a proper texture profile. However the frying method provided the lowest score in AND perception, making it the best option for reducing both AND odour and flavour. In short, the use of different heating methods strongly affected AND perception. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of a novel wind tunnel for the measurement of the kinetics of odour emissions from piggery effluent.

PubMed

Sohn, J H; Smith, R; Yoong, E; Hudson, N; Kim, T I

2004-01-01

A novel laboratory wind tunnel, with the capability to control factors such as air flow-rate, was developed to measure the kinetics of odour emissions from liquid effluent. The tunnel allows the emission of odours and other volatiles under an atmospheric transport system similar to ambient conditions. Sensors for wind speed, temperature and humidity were installed and calibrated. To calibrate the wind tunnel, trials were performed to determine the gas recovery efficiency under different air flow-rates (ranging from 0.001 to 0.028m3/s) and gas supply rates (ranging from 2.5 to 10.0 L/min) using a standard CO gas mixture. The results have shown gas recovery efficiencies ranging from 61.7 to 106.8%, while the average result from the trials was 81.14%. From statistical analysis, it was observed that the highest, most reliable gas recovery efficiency of the tunnel was 88.9%. The values of air flow-rate and gas supply rate corresponding to the highest gas recovery efficiency were 0.028 m3/s and 10.0 L/min respectively. This study suggested that the wind tunnel would provide precise estimates of odour emission rate. However, the wind tunnel needs to be calibrated to compensate for errors caused by different air flow-rates.

Context-dependent responses to neighbours and strangers in wild European rabbits (Oryctolagus cuniculus).

PubMed

Monclús, Raquel; Saavedra, Irene; de Miguel, Javier

2014-07-01

Territorial animals defend their territories against intruders. The level of aggression directed to intruders depends on the familiarity and/or the relative threat they pose, and it could be modified by the context of the interaction. We explored in a wild social mammal, the European rabbit (Oryctolagus cuniculus), whether residents responded more aggressively to strangers or to neighbours (dear enemy or nasty neighbour effects, respectively). We simulated the intrusion of neighbours or strangers in different parts of the territory of wild European rabbits in a suburban area in central Spain. For that, we placed faecal pellets of neighbouring or stranger rabbits in the territory of 5 rabbit colonies. Resident rabbits counter-marked preferably the odour stations with stranger odour, compared to the ones with neighbour odour, and they did not make a difference between neighbour and a non-odour control stimuli. The results suggest that rabbits show a dear enemy effect. However, repeated intrusions escalated the responses of rabbits towards neighbours. The location within the territory or the sex of the stranger did not affect the level of response. We conclude that in rabbits the relative threat posed by the intruder triggers the intensity of the interaction. Copyright © 2014 Elsevier B.V. All rights reserved.

Reducing variation in decomposition odour profiling using comprehensive two-dimensional gas chromatography.

PubMed

Perrault, Katelynn A; Stefanuto, Pierre-Hugues; Stuart, Barbara H; Rai, Tapan; Focant, Jean-François; Forbes, Shari L

2015-01-01

Challenges in decomposition odour profiling have led to variation in the documented odour profile by different research groups worldwide. Background subtraction and use of controls are important considerations given the variation introduced by decomposition studies conducted in different geographical environments. The collection of volatile organic compounds (VOCs) from soil beneath decomposing remains is challenging due to the high levels of inherent soil VOCs, further confounded by the use of highly sensitive instrumentation. This study presents a method that provides suitable chromatographic resolution for profiling decomposition odour in soil by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry using appropriate controls and field blanks. Logarithmic transformation and t-testing of compounds permitted the generation of a compound list of decomposition VOCs in soil. Principal component analysis demonstrated the improved discrimination between experimental and control soil, verifying the value of the data handling method. Data handling procedures have not been well documented in this field and standardisation would thereby reduce misidentification of VOCs present in the surrounding environment as decomposition byproducts. Uniformity of data handling and instrumental procedures will reduce analytical variation, increasing confidence in the future when investigating the effect of taphonomic variables on the decomposition VOC profile. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Odour recognition memory and odour identification in patients with mild and severe major depressive disorders.

PubMed

Zucco, Gesualdo M; Bollini, Fabiola

2011-12-30

Olfactory deficits, in detection, recognition and identification of odorants have been documented in ageing and in several neurodegenerative and psychiatric conditions. However, olfactory abilities in Major Depressive Disorder (MDD) have been less investigated, and available studies have provided inconsistent results. The present study assessed odour recognition memory and odour identification in two groups of 12 mild MDD patients (M age 41.3, range 25-57) and 12 severe MDD patients (M age, 41.9, range 23-58) diagnosed according to DSM-IV criteria and matched for age and gender to 12 healthy normal controls. The suitability of olfactory identification and recognition memory tasks as predictors of the progression of MDD was also addressed. Data analyses revealed that Severe MDD patients performed significantly worse than Mild MDD patients and Normal controls on both tasks, with these last groups not differing significantly from one another. The present outcomes are consistent with previous studies in other domains which have shown reliable, although not conclusive, impairments in cognitive function, including memory, in patients with MDD, and highlight the role of olfactory identification and recognition tasks as an important additional tool to discriminate between patients characterised by different levels of severity of MDD. Copyright © 2011 Elsevier Ltd. All rights reserved.

Coral reef fish predator maintains olfactory acuity in degraded coral habitats.

PubMed

Natt, Michael; Lönnstedt, Oona M; McCormick, Mark I

2017-01-01

Coral reefs around the world are rapidly degrading due to a range of environmental stressors. Habitat degradation modifies the sensory landscape within which predator-prey interactions occur, with implications for olfactory-mediated behaviours. Predator naïve settlement-stage damselfish rely on conspecific damage-released odours (i.e., alarm odours) to inform risk assessments. Yet, species such as the Ambon damselfish, Pomacentrus amboinensis, become unable to respond appropriately to these cues when living in dead-degraded coral habitats, leading to increased mortality through loss of vigilance. Reef fish predators also rely on odours from damaged prey to locate, assess prey quality and engage in prey-stealing, but it is unknown whether their responses are also modified by the change to dead-degraded coral habitats. Implications for prey clearly depend on how their predatory counterparts are affected, therefore the present study tested whether olfactory-mediated foraging responses in the dusky dottyback, Pseudochromis fuscus, a common predator of P. amboinensis, were similarly affected by coral degradation. A y-maze was used to measure the ability of Ps. fuscus to detect and move towards odours, against different background water sources. Ps. fuscus were exposed to damage-released odours from juvenile P. amboinensis, or a control cue of seawater, against a background of seawater treated with either healthy or dead-degraded hard coral. Predators exhibited an increased time allocation to the chambers of y-mazes injected with damage-released odours, with comparable levels of response in both healthy and dead-degraded coral treated waters. In control treatments, where damage-released odours were replaced with a control seawater cue, fish showed no increased preference for either chamber of the y-maze. Our results suggest that olfactory-mediated foraging behaviours may persist in Ps. fuscus within dead-degraded coral habitats. Ps. fuscus may consequently gain a sensory advantage over P. amboinensis, potentially altering the outcome of predator-prey interactions.

Sensory and quality analysis of different melon cultivars after prolonged storage.

PubMed

Hoberg, Edelgard; Ulrich, Detlef; Schulz, Hartwig; Tuvia-Alkali, Sharon; Fallik, Elazar

2003-10-01

The purpose of this work was to evaluate the sensory and general quality of four different melon cultivars (Cucumis melo L.) immediately after harvest and at the end of storage and marketing simulation. After 16 days of storage at 5 degrees C and additional 3 days at 20 degrees C, only cultivar 'C-8' had a poor general appearance due to significant low firmness and relatively high decay incidence compared to the cultivars '5080', 'Ideal' and '7302'. The cultivar '7302' was found to have the higher overall quality. The human-sensory and organoleptic analyses revealed that the cultivars can be differentiated on the basis of retronasal odour. The texture of the melons seems to be dependent on the genotype. All the complex perceptions analysed in this work contribute to the acceptability, which is in the fresh fruits of '7302' the best and in 'Ideal' the worst. After storage and marketing simulation 'Ideal' and 'C-8' are no longer favoured, but '5080' and '7302', despite different characters, were found to be similarly accepted. It can be concluded that with the aid of the human-sensory method developed to characterize the melon varieties it is possible to distinguish the different genotypes.

Carbon dioxide instantly sensitizes female yellow fever mosquitoes to human skin odours.

PubMed

Dekker, Teun; Geier, Martin; Cardé, Ring T

2005-08-01

Female mosquitoes are noted for their ability to use odours to locate a host for a blood meal. Two sensory organs contribute to their sense of smell: the maxillary palps, which measure the level of CO2, and the antennae, which detect other host-released odours. To establish the relative importance and interactions of CO2 and other body emissions in freely flying mosquitoes, we presented female yellow fever mosquitoes Aedes aegypti L. with broad plumes of human skin odour and CO2 at natural concentrations and dilutions thereof in a wind tunnel. 3-D video-recorded flight tracks were reconstructed. Activation, flight velocity, upwind turning and source finding waned quickly as skin odours were diluted, whereas in the presence of CO2 these parameters remained unchanged over more than a 100-fold dilution from exhaled concentrations. Although mosquitoes were behaviourally less sensitive to skin odours than to CO2, their sensitivity to skin odours increased transiently by at least fivefold immediately following a brief encounter with a filament of CO2. This sensitization was reflected in flight velocity, track angle, turning rate upon entering and exiting the broad odour plume and, ultimately, in the source-finding rate. In Ae. aegypti, CO2 thus functions as a ;releaser' for a higher sensitivity and responsiveness to skin odours. The initially low responsiveness of mosquitoes to skin odours, their high sensitivity to CO2, and the sensitization of the olfactory circuitry by CO2 are ecologically relevant, because rapidly fluctuating CO2 levels reliably signal a potential host. Possible mechanisms of the instantaneous sensitization are considered.

Olfactory eavesdropping by a competitively foraging stingless bee, Trigona spinipes.

PubMed Central

Nieh, James C.; Barreto, Lillian S.; Contrera, Felipe A. L.; Imperatriz-Fonseca, Vera L.

2004-01-01

Signals that are perceived over long distances or leave extended spatial traces are subject to eavesdropping. Eavesdropping has therefore acted as a selective pressure in the evolution of diverse animal communication systems, perhaps even in the evolution of functionally referential communication. Early work suggested that some species of stingless bees (Hymenoptera, Apidae, Meliponini) may use interceptive olfactory eavesdropping to discover food sources being exploited by competitors, but it is not clear if any stingless bee can be attracted to the odour marks deposited by an interspecific competitor. We show that foragers of the aggressive meliponine bee, Trigona spinipes, can detect and orient towards odour marks deposited by a competitor, Melipona rufiventris, and then rapidly take over the food source, driving away or killing their competitors. When searching for food sources at new locations that they are not already exploiting, T. spinipes foragers strongly prefer M. rufiventris odour marks to odour marks deposited by their own nest-mates, whereas they prefer nest-mate odour marks over M. rufiventris odour marks at a location already occupied by T. spinipes nest-mates. Melipona rufiventris foragers flee from T. spinipes odour marks. This olfactory eavesdropping may have played a role in the evolution of potentially cryptic communication mechanisms such as shortened odour trails, point-source only odour marking and functionally referential communication concealed at the nest. PMID:15306311

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qamaruz-Zaman, N., E-mail: cenastaein@usm.my; Kun, Y.; Rosli, R.-N.

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

Intracellular regulation of the insect chemoreceptor complex impacts odour localization in flying insects.

PubMed

Getahun, Merid N; Thoma, Michael; Lavista-Llanos, Sofia; Keesey, Ian; Fandino, Richard A; Knaden, Markus; Wicher, Dieter; Olsson, Shannon B; Hansson, Bill S

2016-11-01

Flying insects are well known for airborne odour tracking and have evolved diverse chemoreceptors. While ionotropic receptors (IRs) are found across protostomes, insect odorant receptors (ORs) have only been identified in winged insects. We therefore hypothesized that the unique signal transduction of ORs offers an advantage for odour localization in flight. Using Drosophila, we found expression and increased activity of the intracellular signalling protein PKC in antennal sensilla following odour stimulation. Odour stimulation also enhanced phosphorylation of the OR co-receptor Orco in vitro, while site-directed mutation of Orco or mutations in PKC subtypes reduced the sensitivity and dynamic range of OR-expressing neurons in vivo, but not IR-expressing neurons. We ultimately show that these mutations reduce competence for odour localization of flies in flight. We conclude that intracellular regulation of OR sensitivity is necessary for efficient odour localization, which suggests a mechanistic advantage for the evolution of the OR complex in flying insects. © 2016. Published by The Company of Biologists Ltd.

Non-redundant coding of aversive odours in the main olfactory pathway.

PubMed

Dewan, Adam; Pacifico, Rodrigo; Zhan, Ross; Rinberg, Dmitry; Bozza, Thomas

2013-05-23

Many species are critically dependent on olfaction for survival. In the main olfactory system of mammals, odours are detected by sensory neurons that express a large repertoire of canonical odorant receptors and a much smaller repertoire of trace amine-associated receptors (TAARs). Odours are encoded in a combinatorial fashion across glomeruli in the main olfactory bulb, with each glomerulus corresponding to a specific receptor. The degree to which individual receptor genes contribute to odour perception is unclear. Here we show that genetic deletion of the olfactory Taar gene family, or even a single Taar gene (Taar4), eliminates the aversion that mice display to low concentrations of volatile amines and to the odour of predator urine. Our findings identify a role for the TAARs in olfaction, namely, in the high-sensitivity detection of innately aversive odours. In addition, our data reveal that aversive amines are represented in a non-redundant fashion, and that individual main olfactory receptor genes can contribute substantially to odour perception.

Fatty acid composition of intramuscular fat and odour-active compounds of lamb commercialized in northern Spain.

PubMed

Bravo-Lamas, Leire; Barron, Luis J R; Farmer, Linda; Aldai, Noelia

2018-05-01

Muscle fatty acid composition and odour-active compounds released during cooking were characterized in lamb chops (Longissimus thoracis et lumborum, n = 48) collected at retail level in northern Spain. Lamb samples were classified in two groups according to their 10 t/11 t-18:1 ratio: ≤1 (10 t-non-shifted, n = 21) and >1 (10 t-shifted, n = 27). Higher n-3 polyunsaturated fatty acid, vaccenic (11 t-18:1) and rumenic acid (9c,11 t-18:2), and iso-branched chain fatty acid contents were found in non-shifted lamb samples while n-6 polyunsaturated fatty acid, internal methyl-branched chain fatty acid, and 10 t-18:1 contents were greater in shifted samples. Regardless the fatty acid profile differences between lamb sample groups, odour-active compound profile was very similar and mostly affected by the cooking conditions. Overall, the main odour-active compounds of cooked lamb were described as "green", "meaty", "roasted", and "fatty" being methyl pyrazine, methional, dimethyl pyrazine, and dimethyl trisulphide the main odour-active compounds. Aldehydes and alcohols were the most abundant volatiles in all samples, and they were mostly originated from the oxidation of unsaturated fatty acids during cooking. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantification of volatile fatty acids from cattle manure via non-catalytic esterification for odour indication.

PubMed

Lee, Sang-Ryong; Lee, Jechan; Cho, Seong-Heon; Kim, Jieun; Oh, Jeong-Ik; Tsang, Daniel C W; Jeong, Kwang-Hwa; Kwon, Eilhann E

2018-01-01

This report proposes a new approach to evaluate the odour nuisance of cattle manure samples from three different cattle breeds (i.e., native cattle, beef cattle, and milk cow) by means of quantification and speciation of volatile fatty acids (VFAs). To this end, non-catalytic esterification thermally induced in the presence of a porous material (silica) was undertaken, and the optimal operational parameters such as the derivatizing temperature (330°C) for the maximum yield (≥99±0.4%) of volatile fatty acid methyl esters (VFAMEs) were established. Among the VFA species in cattle manure based on quantification of VFAs, the major species were acetic, butyric and valeric acid. Considering the odour threshold of each VFA, our experimental results suggested that the major contributors to odour nuisance were C 4-5 VFA species (i.e., butyric and valeric acid). Hydrothermal treatment was performed at 150°C for 0-40min to correlate the formation of VFAs with different types of cattle feed formulations. Our experimental data demonstrated that the formation of total VFAs is linearly proportional to the hydrothermal treatment duration and the total content of VFAs in native cattle, beef cattle, and milk cow manure samples reached up to ~1000, ~3200, and ~2800ppm, respectively. Thus, this study demonstrated that the degree of VFA formation is highly dependent on cattle feed formulations, which rely significantly on the protein content. Furthermore, the hydrothermal treatment provides a favourable condition for generating more VFAs. In this context, producing cattle manure into refused derived fuel (RDF) via a hydrothermal treatment is not a viable option to control odour. Copyright © 2017 Elsevier B.V. All rights reserved.

A cortical pathway to olfactory naming: evidence from primary progressive aphasia

PubMed Central

Rogalski, Emily; Harrison, Theresa; Mesulam, M.-Marsel; Gottfried, Jay A.

2013-01-01

It is notoriously difficult to name odours. Without the benefit of non-olfactory information, even common household smells elude our ability to name them. The neuroscientific basis for this olfactory language ‘deficit’ is poorly understood, and even basic models to explain how odour inputs gain access to transmodal representations required for naming have not been put forward. This study used patients with primary progressive aphasia, a clinical dementia syndrome characterized by primary deficits in language, to investigate the interactions between olfactory inputs and lexical access by assessing behavioural performance of olfactory knowledge and its relationship to brain atrophy. We specifically hypothesized that the temporal pole would play a key role in linking odour object representations to transmodal networks, given its anatomical proximity to olfactory and visual object processing areas. Behaviourally, patients with primary progressive aphasia with non-semantic subtypes were severely impaired on an odour naming task, in comparison with an age-matched control group. However, with the availability of picture cues or word cues, odour matching performance approached control levels, demonstrating an inability to retrieve but not to recognize the name and nature of the odorant. The magnitude of cortical thinning in the temporal pole was found to correlate with reductions in odour familiarity and odour matching to visual cues, whereas the inferior frontal gyrus correlated with both odour naming and matching. Volumetric changes in the mediodorsal thalamus correlated with the proportion of categorical mismatch errors, indicating a possible role of this region in error-signal monitoring to optimize recognition of associations linked to the odour. A complementary analysis of patients with the semantic subtype of primary progressive aphasia, which is associated with marked temporopolar atrophy, revealed much more pronounced impairments of odour naming and matching. In identifying the critical role of the temporal pole and inferior frontal gyrus in transmodal linking and verbalization of olfactory objects, our findings provide a new neurobiological foundation for understanding why even common odours are hard to name. PMID:23471695

Sensory analysis of characterising flavours: evaluating tobacco product odours using an expert panel.

PubMed

Krüsemann, Erna J Z; Lasschuijt, Marlou P; de Graaf, C; de Wijk, René A; Punter, Pieter H; van Tiel, Loes; Cremers, Johannes W J M; van de Nobelen, Suzanne; Boesveldt, Sanne; Talhout, Reinskje

2018-05-23

Tobacco flavours are an important regulatory concept in several jurisdictions, for example in the USA, Canada and Europe. The European Tobacco Products Directive 2014/40/EU prohibits cigarettes and roll-your-own tobacco having a characterising flavour. This directive defines characterising flavour as 'a clearly noticeable smell or taste other than one of tobacco […]'. To distinguish between products with and without a characterising flavour, we trained an expert panel to identify characterising flavours by smelling. An expert panel (n=18) evaluated the smell of 20 tobacco products using self-defined odour attributes, following Quantitative Descriptive Analysis. The panel was trained during 14 attribute training, consensus training and performance monitoring sessions. Products were assessed during six test sessions. Principal component analysis, hierarchical clustering (four and six clusters) and Hotelling's T-tests (95% and 99% CIs) were used to determine differences and similarities between tobacco products based on odour attributes. The final attribute list contained 13 odour descriptors. Panel performance was sufficient after 14 training sessions. Products marketed as unflavoured that formed a cluster were considered reference products. A four-cluster method distinguished cherry-flavoured, vanilla-flavoured and menthol-flavoured products from reference products. Six clusters subdivided reference products into tobacco leaves, roll-your-own and commercial products. An expert panel was successfully trained to assess characterising odours in cigarettes and roll-your-own tobacco. This method could be applied to other product types such as e-cigarettes. Regulatory decisions on the choice of reference products and significance level are needed which directly influences the products being assessed as having a characterising odour. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Odour emission characteristics of 22 recreational rivers in Nanjing.

PubMed

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

2014-10-01

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

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

PubMed

Shiue, Ivy

2015-09-01

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

Calcium imaging in the ant Camponotus fellah reveals a conserved odour-similarity space in insects and mammals

PubMed Central

2010-01-01

Background Olfactory systems create representations of the chemical world in the animal brain. Recordings of odour-evoked activity in the primary olfactory centres of vertebrates and insects have suggested similar rules for odour processing, in particular through spatial organization of chemical information in their functional units, the glomeruli. Similarity between odour representations can be extracted from across-glomerulus patterns in a wide range of species, from insects to vertebrates, but comparison of odour similarity in such diverse taxa has not been addressed. In the present study, we asked how 11 aliphatic odorants previously tested in honeybees and rats are represented in the antennal lobe of the ant Camponotus fellah, a social insect that relies on olfaction for food search and social communication. Results Using calcium imaging of specifically-stained second-order neurons, we show that these odours induce specific activity patterns in the ant antennal lobe. Using multidimensional analysis, we show that clustering of odours is similar in ants, bees and rats. Moreover, odour similarity is highly correlated in all three species. Conclusion This suggests the existence of similar coding rules in the neural olfactory spaces of species among which evolutionary divergence happened hundreds of million years ago. PMID:20187931

Lyme disease bacterium does not affect attraction to rodent odour in the tick vector.

PubMed

Berret, Jérémy; Voordouw, Maarten Jeroen

2015-04-28

Vector-borne pathogens experience a conflict of interest when the arthropod vector chooses a vertebrate host that is incompetent for pathogen transmission. The qualitative manipulation hypothesis suggests that vector-borne pathogens can resolve this conflict in their favour by manipulating the host choice behaviour of the arthropod vector. European Lyme disease is a model system for studying this conflict because Ixodes ricinus is a generalist tick species that vectors Borrelia pathogens that are specialized on different classes of vertebrate hosts. Avian specialists like B. garinii cannot survive in rodent reservoir hosts and vice versa for rodent specialists like B. afzelii. The present study tested whether Borrelia genospecies influenced the attraction of field-collected I. ricinus nymphs to rodent odours. Nymphs were significantly attracted to questing perches that had been scented with mouse odours. However, there was no difference in questing behaviour between nymphs infected with rodent- versus bird-specialized Borrelia genospecies. Our study suggests that the tick, and not the pathogen, controls the early stages of host choice behaviour.

Survey of the effect of odour impact on communities.

PubMed

Hayes, J E; Stevenson, R J; Stuetz, R M

2017-12-15

In the context of environmental malodour, surveys are valuable as they allow for the relatively detailed analysis of multiple factors pertaining to odour perception and subsequent reaction. However, the causes for an individual to experience odour impact while a neighbour will not are still not understood. The goal of this current survey design was to consolidate varying research paths for surveys within the environmental odour research space. This survey investigated the area of effect for wastewater treatment plants by using stratified random sampling techniques that radiated from the industrial areas. Additionally, this survey provided a "non-alerted" response to environmental malodour that represents a step forward for ecological validity. We found a small number of items relating to odour annoyance and home ownership that can be used in order to predict odour impact for individual community members. However, we also did not find any relationship with odour impact and perceived control. This survey design and analysis reconciles the varied approaches towards community surveys administered in prior literature, as well as providing information to improve future community engagement policies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cross-Fostering of Male Mice Subtly Affects Female Olfactory Preferences

PubMed Central

Liu, Ying-Juan; Zhang, Yao-Hua; Li, Lai-Fu; Du, Rui-Qing; Zhang, Jin-Hua; Zhang, Jian-Xu

2016-01-01

The maternal environment has been shown to influence female olfactory preferences through early chemosensory experience. However, little is known about the influence of the maternal environment on chemosignals. In this study, we used two inbred mouse strains, C57BL/6 (C57) and BALB/c (BALB), and explored whether adoption could alter male chemosignals and thus influence female olfactory preferences. In Experiment 1, C57 pups were placed with BALB dams. Adult BALB females then served as the subjects in binary choice tests between paired male urine odours (BALB vs. C57, BALB vs. adopted C57 and C57 vs. adopted C57). In Experiment 2, BALB pups were placed with C57 dams, and C57 females served as the subjects in binary choice tests between paired male urine odours (C57 vs. BALB, C57 vs. adopted BALB, and BALB vs. adopted BALB). In both experiments, we found that females preferred the urine of males from different genetic backgrounds, suggesting that female olfactory preferences may be driven by genetic compatibility. Cross-fostering had subtle effects on female olfactory preferences. Although the females showed no preference between the urine odours of adopted and non-adopted males of the other strain, the BALB females preferred the urine odour of BALB males to that of adopted C57 males, whereas the C57 females showed no preference between the urine odour of C57 and adopted BALB males. Using gas chromatography-mass spectrometry (GC-MS) and stepwise discriminant analysis, we found that the ratios of volatile chemicals from urine and preputial gland secretions were altered in the fostered male mice; these changes may have resulted in the behavioural changes observed in the females. Overall, the results suggest that female mice prefer urine odours from males with different genetic backgrounds; this preference may be driven by genetic compatibility. The early maternal environment influences the chemosignals of males and thus may influence the olfactory preferences of females. Our study provides additional evidence in support of genotype-dependent maternal influences on phenotypic variability in adulthood. PMID:26756471

Continuous Odour Measurement with Chemosensor Systems

NASA Astrophysics Data System (ADS)

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

2009-05-01

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

The scent of mixtures: rules of odour processing in ants

PubMed Central

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

2015-01-01

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

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

PubMed

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

2015-03-01

Emission of odours during the thermal drying in sludge handling processes is one of the main sources of odour problems in wastewater treatment plants. The objective of this work was to assess the use of the response surface methodology as a technique to optimize the chemical conditioning process of undigested sewage sludges, in order to improve the dewaterability, and to reduce the odour emissions during the thermal drying of the sludge. Synergistic effects between inorganic conditioners (iron chloride and calcium oxide) were observed in terms of sulphur emissions and odour reduction. The developed quadratic models indicated that optimizing the conditioners dosage is possible to increase a 70% the dewaterability, reducing a 50% and 54% the emission of odour and volatile sulphur compounds respectively. The optimization of the conditioning process was validated experimentally. Copyright © 2014 Elsevier Ltd. All rights reserved.

Responses to colour and host odour cues in three cereal pest species, in the context of ecology and control.

PubMed

Arnold, S E J; Stevenson, P C; Belmain, S R

2015-08-01

Many insects show a greater attraction to multimodal cues, e.g. odour and colour combined, than to either cue alone. Despite the potential to apply the knowledge to improve control strategies, studies of multiple stimuli have not been undertaken for stored product pest insects. We tested orientation towards a food odour (crushed white maize) in combination with a colour cue (coloured paper with different surface spectral reflectance properties) in three storage pest beetle species, using motion tracking to monitor their behaviour. While the maize weevil, Sitophilus zeamais (Motsch.), showed attraction to both odour and colour stimuli, particularly to both cues in combination, this was not observed in the bostrichid pests Rhyzopertha dominica (F.) (lesser grain borer) or Prostephanus truncatus (Horn) (larger grain borer). The yellow stimulus was particularly attractive to S. zeamais, and control experiments showed that this was neither a result of the insects moving towards darker-coloured areas of the arena, nor their being repelled by optical brighteners in white paper. Visual stimuli may play a role in location of host material by S. zeamais, and can be used to inform trap design for the control or monitoring of maize weevils. The lack of visual responses by the two grain borers is likely to relate to their different host-seeking behaviours and ecological background, which should be taken into account when devising control methods.

Aerodynamic performance of a low-speed wind tunnel.

PubMed

Frechen, F-B; Frey, M; Wett, M; Löser, C

2004-01-01

The determination of the odour mass flow emitted from a source is a very important step and forms the basis for all subsequent considerations and calculations. Wastewater treatment plants, as well as waste treatment facilities, consist of different kinds of odour sources. Unfortunately, most of the sources are passive sources, where no outward air flow-rate can be measured, but where odorants are obviously emitted. Thus, a type of sampling is required that allows to measure the emitted odour flow-rate (OFR). To achieve this, different methods are in use worldwide. Besides indirect methods, such as micrometeorological atmospheric dispersion models, which have not been used in Germany (in other countries due to different problems, direct methods are also used). Direct measurements include hood methods, commonly divided into static flux chambers, dynamic flux chambers and wind tunnels. The wind tunnel that we have been operating in principle since 1983 is different from all subsequent presented wind tunnels, in that we operate it at a considerably lower wind speed than the others. To describe the behaviour of this wind tunnel, measurement of the flow pattern in this low-speed tunnel are under way, and some initial results are presented here.

Fitness and community consequences of avoiding multiple predators.

PubMed

Peckarsky, Barbara L; McIntosh, Angus R

1998-02-01

We investigated the fitness and community consequences of behavioural interactions with multiple predators in a four-trophic-level system. We conducted an experiment in oval flow-through artificial-stream tanks to examine the single and interactive sublethal effects of brook trout and stoneflies on the size at emergence of Baetis bicaudatus (Ephemeroptera: Baetidae), and the cascading trophic effects on algal biomass, the food resource of the mayflies. No predation was allowed in the experiment, so that all effects were mediated through predator modifications of prey behaviour. We reared trout stream Baetis larvae from just before egg development until emergence in tanks with four treatments: (1) water from a holding tank with two brook trout (trout odour), (2) no trout odour + eight stoneflies with glued mouthparts, (3) trout odour + stoneflies and (4) no trout odour or stoneflies. We ended the experiment after 3 weeks when ten male and ten female subimagos had emerged from each tank, measured the size of ten male and ten female mature nymphs (with black wing pads), and collected algal samples from rocks at six locations in each tank. To determine the mechanism responsible for sublethal and cascading effects on lower trophic levels we made day and night observations of mayfly behaviour for the first 6 days by counting mayflies drifting in the water column and visible on natural substrata in the artificial streams. Trout odour and stoneflies similarly reduced the size of male and female Baetis emerging from artificial streams, with non-additive effects of both predators. While smaller females are less fecund, a fitness cost of small male size has not been determined. The mechanism causing sublethal effects on Baetis differed between predators. While trout stream Baetis retained their nocturnal periodicity in all treatments, stoneflies increased drift dispersal of mayflies at night, and trout suppressed night-time feeding and drift of mayflies. Stoneflies had less effect on Baetis behaviour when fish odour was present. Thus, we attribute the non-additivity of effects of fish and stoneflies on mayfly growth to an interaction modification whereby trout odour reduced the impact of stoneflies on Baetis behaviour. Since stonefly activity was also reduced in the presence of fish odour, this modification may be attributed to the effect of fish odour on stonefly behaviour. Only stoneflies delayed Baetis emergence, suggesting that stoneflies had a greater sublethal effect on Baetis fitness than did trout. Delayed emergence may reduce Baetis fitness by increasing risks of predation and parasitism on larvae, and increasing competition for mates or oviposition sites among adults. Finally, algal biomass was higher in tanks with both predators than in the other three treatments. These data implicate a behavioural trophic cascade because predators were not allowed to consume prey. Therefore, differences in algal biomass were attributed to predator-induced changes in mayfly behaviour. Our study demonstrates the importance of considering multiple predators when measuring direct sublethal effects of predators on prey fitness and indirect effects on lower trophic levels. Identification of an interaction modification illustrates the value of obtaining detailed information on behavioural mechanisms as an aid to understanding the complex interactions occurring among components of ecological communities.

Assessment of olfactory function after traumatic brain injury: comparison of single odour tool with detailed assessment tool.

PubMed

Humphries, Thomas; Singh, Rajiv

2018-01-01

Olfactory disturbance (OD) is common after traumatic brain injury (TBI). Screening for OD can be performed by several different methods. While odour identification tools are considered more accurate, they are time consuming. The predominant method in clinical practice remains the use of a single odour. This study aimed to compare a brief single-odour identification tool (BSOIT) with a more detailed 12-odour assessment tool. One hundred seventy consecutive patients with TBI had their olfaction assessed using BSOIT and a 12-item tool at a single time point. The sensitivity and specificity of the BSOIT were calculated. The sensitivity and specificity of the BSOIT as compared to the Burghart tool were 57.5% and 100%, respectively, for all ODs (anosmia and hyposmia). The sensitivity and specificity for anosmia only were 93.5% and 96.7%, respectively. For the two tools, the Cohen's kappa coefficient showed moderate agreement when both anosmia and hyposmia were considered (k = 0.619, p < 0.001) but a very strong agreement when only anosmia was considered (k = 0.844, p < 0.001). For both the tools, anosmia had a significant association with TBI severity (p < 0.001). However, hyposmia showed no such association. The BSOIT is very effective at identifying anosmia but not hyposmia, producing comparable results to a more detailed test. It can be effective in clinical practice and takes considerably less time.

Fatal Attraction Phenomenon in Humans – Cat Odour Attractiveness Increased for Toxoplasma-Infected Men While Decreased for Infected Women

PubMed Central

Flegr, Jaroslav; Lenochová, Pavlína; Hodný, Zdeněk; Vondrová, Marta

2011-01-01

Background Latent toxoplasmosis, a lifelong infection with the protozoan Toxoplasma gondii, has cumulative effects on the behaviour of hosts, including humans. The most impressive effect of toxoplasmosis is the “fatal attraction phenomenon,” the conversion of innate fear of cat odour into attraction to cat odour in infected rodents. While most behavioural effects of toxoplasmosis were confirmed also in humans, neither the fatal attraction phenomenon nor any toxoplasmosis-associated changes in olfactory functions have been searched for in them. Principal Findings Thirty-four Toxoplasma-infected and 134 noninfected students rated the odour of urine samples from cat, horse, tiger, brown hyena and dog for intensity and pleasantness. The raters were blind to their infection status and identity of the samples. No signs of changed sensitivity of olfaction were observed. However, we found a strong, gender dependent effect of toxoplasmosis on the pleasantness attributed to cat urine odour (p = 0.0025). Infected men rated this odour as more pleasant than did the noninfected men, while infected women rated the same odour as less pleasant than did noninfected women. Toxoplasmosis did not affect how subjects rated the pleasantness of any other animal species' urine odour; however, a non-significant trend in the same directions was observed for hyena urine. Conclusions The absence of the effects of toxoplasmosis on the odour pleasantness score attributed to large cats would suggest that the amino acid felinine could be responsible for the fatal attraction phenomenon. Our results also raise the possibility that the odour-specific threshold deficits observed in schizophrenia patients could be caused by increased prevalence of Toxoplasma-infected subjects in this population rather than by schizophrenia itself. The trend observed with the hyena urine sample suggests that this carnivore, and other representatives of the Feliformia suborder, should be studied for their possible role as definitive hosts in the life cycle of Toxoplasma. PMID:22087345

Odour Detection Methods: Olfactometry and Chemical Sensors

PubMed Central

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

2011-01-01

The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective “analytical instrument” for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out through both the techniques is finally reviewed in order to show the complementary responses of human and instrumental sensing. PMID:22163901

Odour detection methods: olfactometry and chemical sensors.

PubMed

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

2011-01-01

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

Loss-of-function mutations in sodium channel Nav1.7 cause anosmia

PubMed Central

Weiss, Jan; Pyrski, Martina; Jacobi, Eric; Bufe, Bernd; Willnecker, Vivienne; Schick, Bernhard; Zizzari, Philippe; Gossage, Samuel J.; Greer, Charles A.; Leinders-Zufall, Trese; Woods, C. Geoffrey; Wood, John N.; Zufall, Frank

2013-01-01

Loss of function of the gene SCN9A, encoding the voltage-gated sodium channel Nav1.7, causes a congenital inability to experience pain in humans. Here we show that Nav1.7 is not only necessary for pain sensation but is also an essential requirement for odour perception in both mice and humans. We examined human patients with loss-of-function mutations in SCN9A and show that they are unable to sense odours. To establish the essential role of Nav1.7 in odour perception, we generated conditional null mice in which Nav1.7 was removed from all olfactory sensory neurons. In the absence of Nav1.7, these neurons still produce odour-evoked action potentials but fail to initiate synaptic signalling from their axon terminals at the first synapse in the olfactory system. The mutant mice no longer display vital, odour-guided behaviours such as innate odour recognition and avoidance, short-term odour learning, and maternal pup retrieval. Our study creates a mouse model of congenital general anosmia and provides new strategies to explore the genetic basis of the human sense of smell. PMID:21441906

Loss-of-function mutations in sodium channel Nav1.7 cause anosmia.

PubMed

Weiss, Jan; Pyrski, Martina; Jacobi, Eric; Bufe, Bernd; Willnecker, Vivienne; Schick, Bernhard; Zizzari, Philippe; Gossage, Samuel J; Greer, Charles A; Leinders-Zufall, Trese; Woods, C Geoffrey; Wood, John N; Zufall, Frank

2011-04-14

Loss of function of the gene SCN9A, encoding the voltage-gated sodium channel Na(v)1.7, causes a congenital inability to experience pain in humans. Here we show that Na(v)1.7 is not only necessary for pain sensation but is also an essential requirement for odour perception in both mice and humans. We examined human patients with loss-of-function mutations in SCN9A and show that they are unable to sense odours. To establish the essential role of Na(v)1.7 in odour perception, we generated conditional null mice in which Na(v)1.7 was removed from all olfactory sensory neurons. In the absence of Na(v)1.7, these neurons still produce odour-evoked action potentials but fail to initiate synaptic signalling from their axon terminals at the first synapse in the olfactory system. The mutant mice no longer display vital, odour-guided behaviours such as innate odour recognition and avoidance, short-term odour learning, and maternal pup retrieval. Our study creates a mouse model of congenital general anosmia and provides new strategies to explore the genetic basis of the human sense of smell.

Floral to green: mating switches moth olfactory coding and preference.

PubMed

Saveer, Ahmed M; Kromann, Sophie H; Birgersson, Göran; Bengtsson, Marie; Lindblom, Tobias; Balkenius, Anna; Hansson, Bill S; Witzgall, Peter; Becher, Paul G; Ignell, Rickard

2012-06-22

Mating induces profound physiological changes in a wide range of insects, leading to behavioural adjustments to match the internal state of the animal. Here, we show for the first time, to our knowledge, that a noctuid moth switches its olfactory response from food to egg-laying cues following mating. Unmated females of the cotton leafworm (Spodoptera littoralis) are strongly attracted to lilac flowers (Syringa vulgaris). After mating, attraction to floral odour is abolished and the females fly instead to green-leaf odour of the larval host plant cotton, Gossypium hirsutum. This behavioural switch is owing to a marked change in the olfactory representation of floral and green odours in the primary olfactory centre, the antennal lobe (AL). Calcium imaging, using authentic and synthetic odours, shows that the ensemble of AL glomeruli dedicated to either lilac or cotton odour is selectively up- and downregulated in response to mating. A clear-cut behavioural modulation as a function of mating is a useful substrate for studies of the neural mechanisms underlying behavioural decisions. Modulation of odour-driven behaviour through concerted regulation of odour maps contributes to our understanding of state-dependent choice and host shifts in insect herbivores.

Individual and gender fingerprints in human body odour.

PubMed

Penn, Dustin J; Oberzaucher, Elisabeth; Grammer, Karl; Fischer, Gottfried; Soini, Helena A; Wiesler, Donald; Novotny, Milos V; Dixon, Sarah J; Xu, Yun; Brereton, Richard G

2007-04-22

Individuals are thought to have their own distinctive scent, analogous to a signature or fingerprint. To test this idea, we collected axillary sweat, urine and saliva from 197 adults from a village in the Austrian Alps, taking five sweat samples per subject over 10 weeks using a novel skin sampling device. We analysed samples using stir bar sorptive extraction in connection with thermal desorption gas chromatograph-mass spectrometry (GC-MS), and then we statistically analysed the chromatographic profiles using pattern recognition techniques. We found more volatile compounds in axillary sweat than in urine or saliva, and among these we found 373 peaks that were consistent over time (detected in four out of five samples per individual). Among these candidate compounds, we found individually distinct and reproducible GC-MS fingerprints, a reproducible difference between the sexes, and we identified the chemical structures of 44 individual and 12 gender-specific volatile compounds. These individual compounds provide candidates for major histocompatibility complex and other genetically determined odours. This is the first study on human axillary odour to sample a large number of subjects, and our findings are relevant to understanding the chemical nature of human odour, and efforts to design electronic sensors (e-nose) for biometric fingerprinting and disease diagnoses.

Odour discrimination and identification are improved in early blindness.

PubMed

Cuevas, Isabel; Plaza, Paula; Rombaux, Philippe; De Volder, Anne G; Renier, Laurent

2009-12-01

Previous studies showed that early blind humans develop superior abilities in the use of their remaining senses, hypothetically due to a functional reorganization of the deprived visual brain areas. While auditory and tactile functions have been investigated for long, little is known about the effects of early visual deprivation on olfactory processing. However, blind humans make an extensive use of olfactory information in their daily life. Here we investigated olfactory discrimination and identification abilities in early blind subjects and age-matched sighted controls. Three levels of cuing were used in the identification task, i.e., free-identification (no cue), categorization (semantic cues) and multiple choice (semantic and phonological cues). Early blind subjects significantly outperformed the controls in odour discrimination, free-identification and categorization. In addition, the larger group difference was observed in the free-identification as compared to the categorization and the multiple choice conditions. This indicated that a better access to the semantic information from odour perception accounted for part of the improved olfactory performances in odour identification in the blind. We concluded that early blind subjects have both improved perceptual abilities and a better access to the information stored in semantic memory than sighted subjects.

State-dependent and odour-mediated anemotactic responses of the predatory mite Phytoseiulus persimilis in a wind tunnel.

PubMed

Van Tilborg, Merijn; Sabelis, Maurice W; Roessingh, Peter

2004-01-01

Anemotaxis in the predatory mite Phytoseiulus persimilis (both well-fed and starved), has previously been studied on a wire grid under slight turbulent airflow conditions yielding weak, yet distinct, gradients in wind speed and odour concentration (Sabelis and Van der Weel 1993). Such conditions might have critically influenced the outcome of the study. We repeated these experiments, under laminar airflow conditions on a flat surface in a wind tunnel, thereby avoiding variation in wind speed and odour concentration. Treatments for starved and well-fed mites were (1) still-air without herbivore-induced plant volatiles (HIPV) (well-fed mites only), (2) an HIPV-free air stream, and (3) an air stream with HIPV (originating from Lima bean plants infested by two-spotted spider mites, Tetranychus urticae). Well-fed mites oriented in random directions in still-air without HIPV. In an air stream, starved mites always oriented upwind, whether plant odours were present or not. Well-fed mites oriented downwind in an HIPV-free air stream, but in random directions in an air stream with HIPV. Only under the last treatment our results differed from those of Sabelis and Van der Weel (1993).

Wind tunnel behavioural response and field trapping of the blowfly Calliphora vicina.

PubMed

Aak, A; Knudsen, G K; Soleng, A

2010-09-01

The attraction of the blowfly Calliphora vicina Robineau-Desvoidy, 1830 (Diptera: Calliphoridae) to single synthetic compounds, blends and authentic odours was investigated in a wind tunnel. A total of 1850 C. vicina (1750 females and 100 males) were tested. A comparison of male and female responses showed significant differences in attraction between the sexes. Females were more attracted than males to liver odour. The attraction of females lay in the ranges of 0-22% for single compounds, 26-64% for synthetic blends and 58-88% for authentic odours. Dimethyl trisulphide was the most attractive single compound. Significant improvement in attraction was achieved with blends and a three-component lure, consisting of dimethyl trisulphide, mercaptoethanol and o-cresol, was found to be the best solution for field trapping of C. vicina. Authentic odours from dead fish and mice were significantly more attractive than liver and the three-component blend, and the blend and liver were similarly effective as attractants. Field tests support the results of the wind tunnel study and a high number of C. vicina were caught in funnel traps. Overall, 99.1% of the specimens caught were females.

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Feo, Giovanni, E-mail: g.defeo@unisa.it; De Gisi, Sabino; Williams, Ian D.

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

Recent odour regulation developments in Flanders: ambient odour quality standards based on dose-response relationships.

PubMed

Van Broeck, G; Van Langenhove, H; Nieuwejaers, B

2001-01-01

Until now there has been little uniformity in the approach of odour nuisance problems in Flanders. A switch to a standardised and scientifically underpinned approach is essential and is currently in full development. This paper mainly discusses the results of five year research on odour concentration standard developments in Flanders, executed in the period 1996-2000. The research was focused on five pilot sectors: pig farms, slaughterhouses, paint spray installations, sewage treatment plants and textile plants. The general approach of the method to determine the dose-response relation was found to be sufficient. The methodology used is fully described in the paper presented by Van Broeck and Van Langenhove at the CIWEM and IAWO Joint International Conference on Control and Prevention of Odours in the Water Industry in September 1999. For each location (16 locations in total) an unambiguous dose-response relation could be derived (rising nuisance for rising concentrations). In most cases, a "no effect" level could be determined. The background percentage nuisance fluctuated between 0 and 15%. For the sectors of the slaughterhouses, paint spray installations and sewage treatment plants a no effect level was 0.5, 2.0 and 0.5 sniffing units m(-3) as 98th percentile (sniffing units are odour concentrations measured by means of sniffing measurements on the field) was determined. For the sectors of the textile plants and pig farms, no unambiguous no effect level was found. Currently research is undertaken to translate the no effect levels to odour standards. Other initiatives, taken to underpin the Flemish odour regulations, such as the development of an odour source inventory and a complaint handling system, are also briefly discussed.

Odour Identification in Frontotemporal Lobar Degeneration

PubMed Central

Rami, Lorena; Loy, Clement T.; Hailstone, Julia; Warren, Jason D.

2008-01-01

Little information is available concerning olfactory processing in frontotemporal lobar degeneration (FTLD). We undertook a case-control study of olfactory processing in three male patients fulfilling clinical criteria for FTLD. Odour identification (semantic analysis) and odour discrimination (perceptual analysis) were investigated using tests adapted from the University of Pennsylvania Smell Identification Test. General neuropsychometry and structural volumetric brain magnetic resonance imaging (MRI) were also performed. The three patients with FTLD exhibited a disorder of olfactory processing with the characteristics of a predominantly semantic (odour identification) deficit. This olfactory deficit was more prominent in patients with greater involvement of the temporal lobes on MRI. Central deficits of odour identification may be more common in FTLD than previously recognised, and these deficits may assist in clinical characterisation. PMID:17380245

Toxoplasma gondii strain-dependent effects on mouse behaviour.

PubMed

Kannan, Geetha; Moldovan, Krisztina; Xiao, Jian-Chun; Yolken, Robert H; Jones-Brando, Lorraine; Pletnikov, Mikhail V

2010-06-01

Toxoplasma gondii reportedly manipulates rodent behaviour to increase transmission to its definitive feline host. We compared the effects of mouse infection by two Type II strains of T. gondii, Prugniaud (PRU) and ME49, on attraction to cat odour, locomotor activity, anxiety, sensorimotor gating, and spatial working and recognition memory 2 months post-infection (mpi). Attraction to cat odour was reassessed 7 mpi. At 2 mpi, mice infected with either strain exhibited significantly more attraction to cat odour than uninfected animals did, but only PRU-infected mice exhibited this behaviour 7 mpi. PRU-infected mice had significantly greater body weights and hyperactivity, while ME49-infected mice exhibited impaired spatial working memory. No differences in parasite antibody titres were seen between PRU- and ME49-infected mice. The present data suggest the effect of T. gondii infection on mouse behaviour is parasite strain-dependent.

Feeding and resting behaviour of malaria vector, Anopheles arabiensis with reference to zooprophylaxis.

PubMed

Mahande, Aneth; Mosha, Franklin; Mahande, Johnson; Kweka, Eliningaya

2007-07-30

The most important factor for effective zooprophylaxis in reducing malaria transmission is a predominant population of a strongly zoophilic mosquito, Anopheles arabiensis. The feeding preference behaviour of Anopheline mosquitoes was evaluated in odour-baited entry trap (OBET). Mosquitoes were captured daily using odour-baited entry traps, light traps and hand catch both indoor and in pit traps. Experimental huts were used for release and recapture experiment. The mosquitoes collected were compared in species abundances. Anopheles arabiensis was found to account for over 99% of Anopheles species collected in the study area in Lower Moshi, Northern Tanzania. In experimental release/capture trials conducted at the Mabogini verandah huts, An. arabiensis was found to have higher exophilic tendency (80.7%) compared to Anopheles gambiae (59.7%) and Culex spp. (60.8%). OBET experiments conducted at Mabogini collected a total of 506 An. arabiensis in four different trials involving human, cattle, sheep, goat and pig. Odours from the cattle attracted 90.3% (243) compared to odours from human, which attracted 9.7% (26) with a significant difference at P = 0.005. Odours from sheep, goat and pig attracted 9.7%, 7.2% and 7.3%, respectively. Estimation of HBI in An. arabiensis collected from houses in three lower Moshi villages indicated lower ratios for mosquitoes collected from houses with cattle compared to those without cattles. HBI was also lower in mosquitoes collected outdoors (0.1-0.3) compared to indoor (0.4-0.9). In discussing the results, reference has been made to observation of exophilic, zoophilic and feeding tendencies of An. arabiensis, which are conducive for zooprophylaxis. It is recommended that in areas with a predominant An. arabiensis population, cattle should be placed close to dwelling houses in order to maximize the effects of zooprophylaxis. Protective effects of human from malaria can further be enhanced by keeping cattle in surroundings of residences.

Feeding and resting behaviour of malaria vector, Anopheles arabiensis with reference to zooprophylaxis

PubMed Central

Mahande, Aneth; Mosha, Franklin; Mahande, Johnson; Kweka, Eliningaya

2007-01-01

Background The most important factor for effective zooprophylaxis in reducing malaria transmission is a predominant population of a strongly zoophilic mosquito, Anopheles arabiensis. The feeding preference behaviour of Anopheline mosquitoes was evaluated in odour-baited entry trap (OBET). Methods Mosquitoes were captured daily using odour-baited entry traps, light traps and hand catch both indoor and in pit traps. Experimental huts were used for release and recapture experiment. The mosquitoes collected were compared in species abundances. Results Anopheles arabiensis was found to account for over 99% of Anopheles species collected in the study area in Lower Moshi, Northern Tanzania. In experimental release/capture trials conducted at the Mabogini verandah huts, An. arabiensis was found to have higher exophilic tendency (80.7%) compared to Anopheles gambiae (59.7%) and Culex spp. (60.8%). OBET experiments conducted at Mabogini collected a total of 506 An. arabiensis in four different trials involving human, cattle, sheep, goat and pig. Odours from the cattle attracted 90.3% (243) compared to odours from human, which attracted 9.7% (26) with a significant difference at P = 0.005. Odours from sheep, goat and pig attracted 9.7%, 7.2% and 7.3%, respectively. Estimation of HBI in An. arabiensis collected from houses in three lower Moshi villages indicated lower ratios for mosquitoes collected from houses with cattle compared to those without cattles. HBI was also lower in mosquitoes collected outdoors (0.1–0.3) compared to indoor (0.4–0.9). Conclusion In discussing the results, reference has been made to observation of exophilic, zoophilic and feeding tendencies of An. arabiensis, which are conducive for zooprophylaxis. It is recommended that in areas with a predominant An. arabiensis population, cattle should be placed close to dwelling houses in order to maximize the effects of zooprophylaxis. Protective effects of human from malaria can further be enhanced by keeping cattle in surroundings of residences. PMID:17663787

Prospects for the development of odour baits to control the tsetse flies Glossina tachinoides and G. palpalis s.l.

PubMed

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

2010-03-16

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

Maternal odours induce Fos in the main but not the accessory olfactory bulbs of neonatal male and female ferrets.

PubMed

Chang, Y M; Kelliher, K R; Baum, M J

2001-06-01

Previous research demonstrated that exposing gonadectomized adult ferrets to odours in oestrous female bedding induced nuclear Fos-immunoreactivity (Fos-IR; a marker of neuronal activity) in the main as opposed to the accessory olfactory system in a sexually dimorphic fashion, which was further augmented in both sexes by treatment with testosterone propionate. Ferrets are born in an altricial state and presumably use maternal odour cues to locate the nipples until the eyes open after postnatal (P) day 23. We investigated whether maternal odours augment neuronal Fos preferentially in the main versus accessory olfactory system of neonatal male and female ferret kits. Circulating testosterone levels peak in male ferrets on postnatal day P15, and mothers provide maximal anogenital stimulation (AGS) to males at this same age. Therefore, we assessed the ability of maternal odours to augment Fos-IR in the accessory olfactory bulb (AOB), the main olfactory bulb (MOB) and other forebrain regions of male and female ferret kits on P15 and investigated whether artificial AGS (provided with a paintbrush) would further enhance any effects of maternal odours. After separation from their mothers for 4 h, groups of male and female kits that were placed for 1.5 h with their anaesthetized mother had significantly more Fos-IR cells in the MOB granule cell layer and in the anterior-cortical amygdala, but not in the AOB cell layer, compared to control kits that were left on the heating pad. Artificial AGS failed to amplify these effects of maternal odours. Maternal odours (with or without concurrent AGS) failed to augment neuronal Fos-IR in medial amygdaloid and hypothalamic regions that are activated in adult ferrets by social odours. In neonatal ferrets of both sexes, as in adults, socially relevant odours are detected by the main olfactory epithelium and initially processed by the MOB and the anterior-cortical amygdala. In neonates, unlike adults, medial amygdaloid and hypothalamic neurones either do not respond to these inputs or respond in a manner that fails to induce Fos expression.

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

PubMed

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

2015-03-15

In this study, the evolution of odour concentration (ouE/m(3)STP) emitted during the pile composting of the organic fraction of municipal solid waste (OFMSW) was monitored by dynamic olfactometry. Physical-chemical variables as well as the respirometric variables were also analysed. The aim of this work was twofold. The first was to determine the relationship between odour and traditional variables to determine if dynamic olfactometry is a feasible and adequate technique for monitoring an aerobic stabilisation process (composting). Second, the composting process odour impact on surrounding areas was simulated by a dispersion model. The results showed that the decrease of odour concentration, total organic carbon and respirometric variables was similar (around 96, 96 y 98% respectively). The highest odour emission (5224 ouE/m(3)) was reached in parallel with the highest microbiological activity (SOUR and OD20 values of 25 mgO2/gVS · h and 70 mgO2/gVS, respectively). The validity of monitoring odour emissions during composting in combination with traditional and respirometric variables was demonstrated by the adequate correlation obtained between the variables. Moreover, the quantification of odour emissions by dynamic olfactometry and the subsequent application of the dispersion model permitted making an initial prediction of the impact of odorous emissions on the population. Finally, the determination of CO2 and CH4 emissions allowed the influence of composting process on carbon reservoirs and global warming to be evaluated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of lime and struvite on microbial community succession and odour emission during food waste composting.

PubMed

Wang, Xuan; Selvam, Ammaiyappan; Lau, Sam S S; Wong, Jonathan W C

2018-01-01

Lime addition as well as formation of struvite through the addition of magnesium and phosphorus salts provide good pH buffering and may reduce odour emission. This study investigated the odour emission during food waste composting under the influence of lime addition, and struvite formation. Composting was performed in 20-L reactors for 56days using artificial food waste mixed with sawdust at 1.2:1 (w/w dry basis). VFA was one of the most important odours during food waste composting. However, during thermophilic phase, ammonia is responsible for max odour index in the exhaust gas. Trapping ammonia through struvite formation significantly reduced the maximum odour unit of ammonia from 3.0×10 4 to 1.8×10 4 . The generation and accumulation of acetic acid and butyric acid led to the acidic conditions. The addition of phosphate salts in treatment with struvite formation improved the variation of total bacteria, which in turn increased the organic decomposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular basis of human body odour formation: insights deduced from corynebacterial genome sequences.

PubMed

Barzantny, H; Brune, I; Tauch, A

2012-02-01

During the past few decades, there has been an increased interest in the essential role of commensal skin bacteria in human body odour formation. It is now generally accepted that skin bacteria cause body odour by biotransformation of sweat components secreted in the human axillae. Especially, aerobic corynebacteria have been shown to contribute strongly to axillary malodour, whereas other human skin residents seem to have little influence. Analysis of odoriferous sweat components has shown that the major odour-causing substances in human sweat include steroid derivatives, short volatile branched-chain fatty acids and sulphanylalkanols. In this mini-review, we describe the molecular basis of the four most extensively studied routes of human body odour formation, while focusing on the underlying enzymatic processes. Considering the previously reported role of β-oxidation in odour formation, we analysed the genetic repertoire of eight Corynebacterium species concerning fatty acid metabolism. We particularly focused on the metabolic abilities of the lipophilic axillary isolate Corynebacterium jeikeium K411. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

After infection with Leishmania infantum, Golden Hamsters (Mesocricetus auratus) become more attractive to female sand flies (Lutzomyia longipalpis).

PubMed

Nevatte, T M; Ward, R D; Sedda, L; Hamilton, J G C

2017-07-21

In Brazil, human and canine visceral leishmaniasis is caused by infection with Leishmania infantum, a Protist parasite transmitted by blood-feeding female Lutzomyia longipalpis sand flies. The objective of this study was to determine if the odour of hamsters, infected with Le. infantum, was more attractive than the odour of the same hamsters, before they were infected. The attractiveness of odour collected from individual hamsters (n = 13), before they were infected, was compared in a longitudinal study, with the attractiveness of the odour of the same hamster in a Y-tube olfactometer bioassay, at a late stage of infection. The odour of six of the golden hamsters was significantly more attractive to 50% of the female sand flies at the end of infection compared to before infection and the odour of four of the golden hamsters was significantly more attractive to 75% of the female sand flies at the end of infection. These results strongly indicate that hamsters infected with Le. infantum become significantly more attractive to a greater proportion of female sand flies as the infection progresses.

Control of odour nuisance in urban areas: the efficiency and social acceptance of the application of masking agents.

PubMed

Lazarova, Valentina; Abed, Brahim; Markovska, Gabriela; Dezenclos, Thierry; Amara, Aït

2013-01-01

This paper presents and discusses the results of the project named 'Jasmin' implemented in Algiers to control the strong odours of the river named Oued El Harrach, one of the largest rivers in the centre of the city. Pending the achievement of curative solutions, a temporary option for mitigation of nuisance odour by masking agents was implemented in the vicinity of the main bridges. The efficiency of this technology has been followed by means of an odour panel with the participation of representatives of all stakeholders. A sociological study by means of 1,000 questionnaires and face-to-face interviews of the local population demonstrated the benefits and the positive outcomes of the attenuation of odour nuisance: 70% of the surveyed population is satisfied or very satisfied with the application of masking agents and 96% of respondents support the continuation of the project. In terms of size and public access, the project Jasmin is a world-first demonstration of odour control in urban areas in developing countries.

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

NASA Astrophysics Data System (ADS)

Trincavelli, Marco; Coradeschi, Silvia; Loutfi, Amy

2009-05-01

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

Odorant cues linked to social immunity induce lateralized antenna stimulation in honey bees (Apis mellifera L.).

PubMed

McAfee, Alison; Collins, Troy F; Madilao, Lufiani L; Foster, Leonard J

2017-04-07

Hygienic behaviour (HB) is a social immunity trait in honey bees (Apis mellifera L.) whereby workers detect, uncap and remove unhealthy brood, improving disease resistance in the colony. This is clearly economically valuable; however, the molecular mechanism behind it is not well understood. The freeze-killed brood (FKB) assay is the conventional method of HB selection, so we compared odour profiles of FKB and live brood to find candidate HB-inducing odours. Surprisingly, we found that significantly more brood pheromone (β-ocimene) was released from FKB. β-ocimene abundance also positively correlated with HB, suggesting there could be a brood effect contributing to overall hygiene. Furthermore, we found that β-ocimene stimulated worker antennae in a dose-dependent manner, with the left antennae responding significantly stronger than right antennae in hygienic bees, but not in non-hygienic bees. Five other unidentifiable compounds were differentially emitted from FKB which could also be important for HB. We also compared odour profiles of Varroa-infested brood to healthy brood and found an overall interactive effect between developmental stage and infestation, but specific odours did not drive these differences. Overall, the data we present here is an important foundation on which to build our understanding the molecular mechanism behind this complex behaviour.

Wake up and smell the conflict: odour signals in female competition

PubMed Central

Stockley, Paula; Bottell, Lisa; Hurst, Jane L.

2013-01-01

Odour signals used in competitive and aggressive interactions between males are well studied in the context of sexual selection. By contrast, relatively little is known about comparable signals used by females, despite current interest in the evolution of female ornaments and weaponry. Available evidence suggests that odour signals are important in competitive interactions between female mammals, with reductions or reversals of male-biased sexual dimorphism in signalling where female competition is intense. Scent marking is often associated with conflict between females over access to resources or reproductive opportunities. Female scent marks may therefore provide reliable signals of competitive ability that could be used both by competitors and potential mates. Consistent with this hypothesis, we report that aggressive behaviour of female house mice is correlated with the amount of major urinary protein (MUP) excreted in their urine, a polymorphic set of proteins that are used in scent mark signalling. Under semi-natural conditions, females with high MUP output are more likely to produce offspring sired by males that have high reproductive success, and less likely to produce offspring by multiple different sires, suggesting that females with strong MUP signals are monopolized by males of particularly high quality. We conclude that odour signals are worthy of more detailed investigation as mediators of female competition. PMID:24167312

Major histocompatibility complex class II compatibility, but not class I, predicts mate choice in a bird with highly developed olfaction.

PubMed

Strandh, Maria; Westerdahl, Helena; Pontarp, Mikael; Canbäck, Björn; Dubois, Marie-Pierre; Miquel, Christian; Taberlet, Pierre; Bonadonna, Francesco

2012-11-07

Mate choice for major histocompatibility complex (MHC) compatibility has been found in several taxa, although rarely in birds. MHC is a crucial component in adaptive immunity and by choosing an MHC-dissimilar partner, heterozygosity and potentially broad pathogen resistance is maximized in the offspring. The MHC genotype influences odour cues and preferences in mammals and fish and hence olfactory-based mate choice can occur. We tested whether blue petrels, Halobaena caerulea, choose partners based on MHC compatibility. This bird is long-lived, monogamous and can discriminate between individual odours using olfaction, which makes it exceptionally well suited for this analysis. We screened MHC class I and II B alleles in blue petrels using 454-pyrosequencing and quantified the phylogenetic, functional and allele-sharing similarity between individuals. Partners were functionally more dissimilar at the MHC class II B loci than expected from random mating (p = 0.033), whereas there was no such difference at the MHC class I loci. Phylogenetic and non-sequence-based MHC allele-sharing measures detected no MHC dissimilarity between partners for either MHC class I or II B. Our study provides evidence of mate choice for MHC compatibility in a bird with a high dependency on odour cues, suggesting that MHC odour-mediated mate choice occurs in birds.

A study of the suppression of body odour in elderly subjects by anti-fungal agents.

PubMed

Ozeki, C; Moro, O

2016-06-01

The suppression of body odour following the use of shampoos or soaps containing the anti-fungal agent miconazole nitrate (MCZ) has been recognized anecdotally. To determine whether MCZ could play a role in the suppression of body odour through inhibiting squalene oxidation. A prospective study recruited 54 elderly subjects residing in a nursing facility who needed bathing assistance. Subjects bathed with three types of body soap over a 6-week study period (regular soap, sample soap (soap containing MCZ), control soap; 2 weeks per type of soap). Body odour was evaluated based on olfactory assessment of the subjects and their clothing. The subjects and the examiners were blinded to the type of soap (sample or control) being used during the study. An analysis using GC/MS was also carried out to identify the volatile compounds associated with body odour. Suppression of unpleasant body odour of the neck and axilla was reported in subjects who used the sample soap. Three common volatile compounds were detected from the T-shirts worn by the subjects: 2-ethylbutanal, 6-methyl-5-hepten-2-one, and geranylacetone. The occurrence of these compounds was reduced using the sample soap. Our findings suggest that MCZ could play a role in the suppression of body odour. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Asthma symptoms in relation to building dampness and odour in older multifamily houses in Stockholm.

PubMed

Engvall, K; Norrby, C; Norbäck, D

2001-05-01

Respiratory symptoms and hay fever in adults in relation to the indoor environment. To study relationships between reports on respiratory symptoms and hay fever and building dampness and odours in older multifamily dwellings. A questionnaire study in a random sample of 231 multifamily buildings built before 1961, which included 4224 apartments. The response rate was 77% (n = 3241). Information on building characteristics was gathered from building owners and the central building register in Stockholm. Multiple logistic regression analysis was applied, adjusting for age, sex, current smoking, population density, type of ventilation and ownership. In total, 22% reported at least one sign of dampness, and 32% reported odour in the dwelling. All types of odours were more common in damp buildings. Reports on dampness and odours were related to asthma symptoms and current cough, even when adjusting for potential confounders. A combination of odour and signs of high air humidity was related to an increase in asthma symptoms (OR = 2.82; 95%CI 2.70-2.95) and current cough (OR = 5.29; 95%CI 4.99-5.62). Similar findings were observed for a combination of odour and history of water leakage in the last 5 years, with an increase in asthma symptoms (OR = 3.59; 95%CI 3.37-3.82) and current cough (OR = 2.86; 95%CI 2.61-3.14). There was a dose-response relationship between respiratory symptoms and the number of signs of dampness. An association was also observed between dampness and a history of pollen allergy. Signs of high indoor air humidity, water leakage and odours were common, and related to respiratory symptoms. Exposure to odorous compounds from building dampness may be significant with respect to respiratory symptoms and possibly atopic sensitisation.

Discrimination of smokeless powders by headspace SPME-GC-MS and SPME-GC-ECD, and the potential implications upon training canine detection of explosives

NASA Astrophysics Data System (ADS)

Harper, Ross J.; Almirall, Jose R.; Furton, Kenneth G.

2005-05-01

This presentation will provide an odour analysis of a variety of smokeless powders & communicate the rapid SPME-GC-ECD method utilized. This paper will also discuss the implications of the headspace analysis of Smokeless Powders upon the choice of training aids for Explosives Detection Canines. Canine detection of explosives relies upon the dogs" ability to equate finding a given explosive odour with a reward, usually in the form of praise or play. The selection of explosives upon which the dogs are trained thus determines which explosives the canines can and potentially cannot find. Commonly, the training is focussed towards high explosives such as TNT and Composition 4, and the low explosives such as Black and Smokeless Powders are added often only for completeness. Powder explosives constitute a major component of explosive incidents throughout the US, and canines trained to detect explosives must be trained across the entire range of powder products. Given the variability in the manufacture and product make-up many smokeless powders do not share common odour chemicals, giving rise to concerns over the extensiveness of canine training. Headspace analysis of a selection of Smokeless Powders by Solid Phase Microextraction Gas Chromatography using Mass Spectrometry (SPME-GC-MS) and Electron Capture Detectors (SPME-GC-ECD) has highlighted significant differences in the chemical composition of the odour available from different brands. This suggests that greater attention should be paid towards the choice of Powder Explosives when assigning canine training aids.

Laboratory investigation of supported permeable organic covers for the management of odour emissions from anaerobic piggery waste ponds.

PubMed

Hudson, N; Casey, K; Melvin, S; Nicholas, P

2001-01-01

Australian research has linked much of the odour arising from intensive livestock operations to pond treatment systems. A reduction in emissions from treatment ponds would therefore generally reduce odour emissions from intensive livestock operations. Published data indicates that the application of straw and other biological materials to effluent pond surfaces as a continuous cover reduces odour emissions. The effectiveness of these covers has not, however, been researched under controlled conditions. Using locally available materials, the efficacy of supported covers has been investigated using a series of laboratory anaerobic digesters treating typical piggery effluent. Research to date has focused on: identifying effective cover and cover support materials; quantifying odour reduction; identifying the impact use these covers may have on greenhouse gas emissions; devising practical and effective methods for constructing these covers. Results have confirmed that a variety of cover materials are effective in reducing pond odour emissions. Supporting the pond cover appears to extend the cover life expectancy. While greenhouse gas emissions appear to vary according to cover type, the overall significance of these emissions is not yet clear. The impact of permeable pond covers on overall pond performance requires additional research.

Odour as a determinant of persistent symptoms after a chemical explosion, a longitudinal study

PubMed Central

TJALVIN, Gro; MAGERØY, Nils; BRÅTVEIT, Magne; LYGRE, Stein Håkon Låstad; HOLLUND, Bjørg Eli; MOEN, Bente Elisabeth

2016-01-01

Foul-smelling environmental pollution was a major concern following a chemical workplace explosion. Malodorous pollution has previously been associated with aggravated physical and psychological health, and in persons affected by a trauma, an incidence-related odour can act as a traumatic reminder. Olfaction may even be of significance in the development and persistence of post-traumatic stress symptoms (PTSS). The present longitudinal study assessed whether perceived smell related to malodorous environmental pollution in the aftermath of the explosion was a determinant of subjective health complaints (SHC) and PTSS among gainfully employed adults, when the malodorous pollution was present, and after pollution clean-up. Questionnaire data from validated instruments were analysed using mixed effects models. Individual odour scores were computed, and the participants (n=486) were divided into high and low odour score groups, respectively. Participants in the high odour score group (n=233) reported more SHC and PTSS than those in the low odour score group (n=253), before and even after the pollution was eliminated. These associations lasted for at least three years after the pollution was removed, and might indicate that prompt clean-up is important to avoid persistent health effects after malodorous chemical spills. PMID:27916759

Odour as a determinant of persistent symptoms after a chemical explosion, a longitudinal study.

PubMed

Tjalvin, Gro; Magerøy, Nils; Bråtveit, Magne; Lygre, Stein Håkon Låstad; Hollund, Bjørg Eli; Moen, Bente Elisabeth

2017-04-07

Foul-smelling environmental pollution was a major concern following a chemical workplace explosion. Malodorous pollution has previously been associated with aggravated physical and psychological health, and in persons affected by a trauma, an incidence-related odour can act as a traumatic reminder. Olfaction may even be of significance in the development and persistence of post-traumatic stress symptoms (PTSS). The present longitudinal study assessed whether perceived smell related to malodorous environmental pollution in the aftermath of the explosion was a determinant of subjective health complaints (SHC) and PTSS among gainfully employed adults, when the malodorous pollution was present, and after pollution clean-up. Questionnaire data from validated instruments were analysed using mixed effects models. Individual odour scores were computed, and the participants (n=486) were divided into high and low odour score groups, respectively. Participants in the high odour score group (n=233) reported more SHC and PTSS than those in the low odour score group (n=253), before and even after the pollution was eliminated. These associations lasted for at least three years after the pollution was removed, and might indicate that prompt clean-up is important to avoid persistent health effects after malodorous chemical spills.

Odour-based discrimination of similarity at the major histocompatibility complex in birds

PubMed Central

Strandh, Maria; Mardon, Jérôme; Westerdahl, Helena; Bonadonna, Francesco

2017-01-01

Many animals are known to preferentially mate with partners that are dissimilar at the major histocompatibility complex (MHC) in order to maximize the antigen binding repertoire (or disease resistance) in their offspring. Although several mammals, fish or lizards use odour cues to assess MHC similarity with potential partners, the ability of birds to assess MHC similarity using olfactory cues has not yet been explored. Here we used a behavioural binary choice test and high-throughput-sequencing of MHC class IIB to determine whether blue petrels can discriminate MHC similarity based on odour cues alone. Blue petrels are seabirds with particularly good sense of smell, they have a reciprocal mate choice and are known to preferentially mate with MHC-dissimilar partners. Incubating males preferentially approached the odour of the more MHC-dissimilar female, whereas incubating females showed opposite preferences. Given their mating pattern, females were, however, expected to show preference for the odour of the more MHC-dissimilar male. Further studies are needed to determine whether, as in women and female mice, the preference varies with the reproductive cycle in blue petrel females. Our results provide the first evidence that birds can use odour cues only to assess MHC dissimilarity. PMID:28077776

What Makes Us Smell: The Biochemistry of Body Odour and the Design of New Deodorant Ingredients.

PubMed

Natsch, Andreas

2015-08-19

Today, axilla odours are socially stigmatized and are targeted with deodorants and antiperspirants representing a multi-billion market. Axilla odours aren't simple byproducts of our metabolism but specifically formed by an intricate interplay between i) specific glands, ii) secreted amino acid conjugates of highly specific odorants and iii) selective enzymes present in microorganisms colonizing our skin, providing a natural 'controlled-release' mechanism. Within a multidisciplinary research project, we were able to elucidate the structure of key body odorants, isolate and characterize secreted amino acid conjugates and identify the enzymes responsible for odour release. These enzymes then served as targets for the development of specific active compounds in an almost medicinal chemistry approach, an approach rarely used in the cosmetic field so far. Here we review the key new insights into the biochemistry of human body odour formation, with some remarks on the experimental steps undertaken and hurdles encountered. The development of deodorant actives and the difficult path to market for such specifically acting cosmetic actives is discussed. The basic insights into the biochemistry also opened the way to address some questions in population genetics: Why have large proportions of Asians lost the 'ability' to form body odours? Do twins smell the same? Are our typical body odours indeed influenced by the immune system as often claimed? After addressing these questions, I'll conclude with the key remaining challenges in this field on an ecological niche that is 'anatomically very close to our heart'.

What Makes Us Smell: The Biochemistry of Body Odour and the Design of New Deodorant Ingredients.

PubMed

Natsch, Andreas

2015-01-01

Today, axilla odours are socially stigmatized and are targeted with deodorants and antiperspirants representing a multi-billion market. Axilla odours aren't simple byproducts of our metabolism but specifically formed by an intricate interplay between i) specific glands, ii) secreted amino acid conjugates of highly specific odorants and iii) selective enzymes present in microorganisms colonizing our skin, providing a natural 'controlled-release' mechanism. Within a multidisciplinary research project, we were able to elucidate the structure of key body odorants, isolate and characterize secreted amino acid conjugates and identify the enzymes responsible for odour release. These enzymes then served as targets for the development of specific active compounds in an almost medicinal chemistry approach, an approach rarely used in the cosmetic field so far. Here we review the key new insights into the biochemistry of human body odour formation, with some remarks on the experimental steps undertaken and hurdles encountered. The development of deodorant actives and the difficult path to market for such specifically acting cosmetic actives is discussed. The basic insights into the biochemistry also opened the way to address some questions in population genetics: Why have large proportions of Asians lost the 'ability' to form body odours? Do twins smell the same? Are our typical body odours indeed influenced by the immune system as often claimed? After addressing these questions, I'll conclude with the key remaining challenges in this field on an ecological niche that is 'anatomically very close to our heart'.

Visual stimuli induced by self-motion and object-motion modify odour-guided flight of male moths (Manduca sexta L.).

PubMed

Verspui, Remko; Gray, John R

2009-10-01

Animals rely on multimodal sensory integration for proper orientation within their environment. For example, odour-guided behaviours often require appropriate integration of concurrent visual cues. To gain a further understanding of mechanisms underlying sensory integration in odour-guided behaviour, our study examined the effects of visual stimuli induced by self-motion and object-motion on odour-guided flight in male M. sexta. By placing stationary objects (pillars) on either side of a female pheromone plume, moths produced self-induced visual motion during odour-guided flight. These flights showed a reduction in both ground and flight speeds and inter-turn interval when compared with flight tracks without stationary objects. Presentation of an approaching 20 cm disc, to simulate object-motion, resulted in interrupted odour-guided flight and changes in flight direction away from the pheromone source. Modifications of odour-guided flight behaviour in the presence of stationary objects suggest that visual information, in conjunction with olfactory cues, can be used to control the rate of counter-turning. We suggest that the behavioural responses to visual stimuli induced by object-motion indicate the presence of a neural circuit that relays visual information to initiate escape responses. These behavioural responses also suggest the presence of a sensory conflict requiring a trade-off between olfactory and visually driven behaviours. The mechanisms underlying olfactory and visual integration are discussed in the context of these behavioural responses.

Unravelling important odorants in horseradish (Armoracia rusticana).

PubMed

Kroener, Eva-Maria; Buettner, Andrea

2017-10-01

Horseradish (Armoracia rusticana) is a plant well known for its roots' spicy aroma. The present study investigates the main aroma constituents of horseradish roots in general by analysing the aroma profiles of six different horseradish varieties, with one variety grown in two different soils. Odorants were characterised by means of gas chromatography-olfactometry and identified via their mass spectra, retention indices on two columns with different polarity, and their characteristic odour. A series of new aroma compounds from different substance groups were identified that have hitherto not been described in horseradish. Moreover, several of these constituents were successfully shown to exhibit high odour potency, alongside a high potential to influence the overall aroma of horseradish roots, like (3S,3aS,7aR)-wine lactone and 3-isopropyl-2-methoxypyrazine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pulsed mass recruitment by a stingless bee, Trigona hyalinata.

PubMed

Nieh, James C; Contrera, Felipe A L; Nogueira-Neto, Paulo

2003-10-22

Research on bee communication has focused on the ability of the highly social bees, stingless bees (Hymenoptera, Apidae, Meliponini) and honeybees (Apidae, Apini), to communicate food location to nest-mates. Honeybees can communicate food location through the famous waggle dance. Stingless bees are closely related to honeybees and communicate food location through a variety of different mechanisms, many of which are poorly understood. We show that a stingless bee, Trigona hyalinata, uses a pulsed mass-recruitment system that is highly focused in time and space. Foragers produced an ephemeral, polarized, odour trail consisting of mandibular gland secretions. Surprisingly, the odour trail extended only a short distance away from the food source, instead of providing a complete trail between the nest and the food source (as has been described for other stingless bees). This abbreviated trail may represent an intermediate strategy between full-trail marking, found in some stingless bees, and odour marking of the food alone, found in stingless bees and honeybees.

Pulsed mass recruitment by a stingless bee, Trigona hyalinata.

PubMed Central

Nieh, James C; Contrera, Felipe A L; Nogueira-Neto, Paulo

2003-01-01

Research on bee communication has focused on the ability of the highly social bees, stingless bees (Hymenoptera, Apidae, Meliponini) and honeybees (Apidae, Apini), to communicate food location to nest-mates. Honeybees can communicate food location through the famous waggle dance. Stingless bees are closely related to honeybees and communicate food location through a variety of different mechanisms, many of which are poorly understood. We show that a stingless bee, Trigona hyalinata, uses a pulsed mass-recruitment system that is highly focused in time and space. Foragers produced an ephemeral, polarized, odour trail consisting of mandibular gland secretions. Surprisingly, the odour trail extended only a short distance away from the food source, instead of providing a complete trail between the nest and the food source (as has been described for other stingless bees). This abbreviated trail may represent an intermediate strategy between full-trail marking, found in some stingless bees, and odour marking of the food alone, found in stingless bees and honeybees. PMID:14561284

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

NASA Astrophysics Data System (ADS)

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

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

Major histocompatibility complex class II compatibility, but not class I, predicts mate choice in a bird with highly developed olfaction

PubMed Central

Strandh, Maria; Westerdahl, Helena; Pontarp, Mikael; Canbäck, Björn; Dubois, Marie-Pierre; Miquel, Christian; Taberlet, Pierre; Bonadonna, Francesco

2012-01-01

Mate choice for major histocompatibility complex (MHC) compatibility has been found in several taxa, although rarely in birds. MHC is a crucial component in adaptive immunity and by choosing an MHC-dissimilar partner, heterozygosity and potentially broad pathogen resistance is maximized in the offspring. The MHC genotype influences odour cues and preferences in mammals and fish and hence olfactory-based mate choice can occur. We tested whether blue petrels, Halobaena caerulea, choose partners based on MHC compatibility. This bird is long-lived, monogamous and can discriminate between individual odours using olfaction, which makes it exceptionally well suited for this analysis. We screened MHC class I and II B alleles in blue petrels using 454-pyrosequencing and quantified the phylogenetic, functional and allele-sharing similarity between individuals. Partners were functionally more dissimilar at the MHC class II B loci than expected from random mating (p = 0.033), whereas there was no such difference at the MHC class I loci. Phylogenetic and non-sequence-based MHC allele-sharing measures detected no MHC dissimilarity between partners for either MHC class I or II B. Our study provides evidence of mate choice for MHC compatibility in a bird with a high dependency on odour cues, suggesting that MHC odour-mediated mate choice occurs in birds. PMID:22951737

PHARMACOGNOSTIC EVALUATION OF THE LEAF OF Rhus succedanea VAR. HIMALAICA. J. D HOOKER.

PubMed Central

Khan, Shafqat Ali; Ibrar, Muhammad; Barkatullah

2016-01-01

Background: Rhus succedanea is generally traded, distributed and sold in the markets in its crude and raw form. This may have been mixed with adulterants, mismanaged by malpractices and substituted with other closely related drugs having different effect. This study is therefore carried out to authenticate the plant through pharmacogonostic evaluations. Material & Methods: The organoleptic studies were carried through sensory organs i.e size, shape, texrure, odour, etc. Histological studies were conducted by preparing hand slides, mounting the specimen in potato tuber; fluorescence characters were determined through UV and phytochemical screening was investigated using various standard and common methods from relevant literature. Results: Morphologically, the Rhus is a perennial small sized deciduous tree, 5–9 m tall with opposite imparipinnately compound leaves and small grayish yellow flowers born on paniculate inflorescence; locally, called as Rakhkal in Pashto and Kakarsingi in Urdu. The organoleptic evaluation showed leaf had pleasant, aromatic odour and astringent taste. Transverse section of leaf through midrib region was worked out. The anatomy of the midrib has shown to be surrounded by both upper and lower epidermis with multicellular non-glandular trichomes. The leaf was hypostomatic showing anomocytic stomata with average stomatal number 27.1 ± 7.2 and stomatal index 14 ± 3.63. The average vein islet, vein termination and palisade ratios were 13.6 ± 3.04, 10.21 ± 1.92 and 6 ± 2.01 respectively. Leaf powder showed the existance of anomocytic stomata, spirally thickened xylem vessels, non-glandular multicellular and stellate trichomes. Fluorescence study and percent extractive values was also carried out. The phytochemical screening showed the presence of carbohydrates, protein, alkaloids, phenols, flavonoids, terpenoids and anthraquenones, while tannins and fixed oil was not detected. Quantitatively highest amount of alkaloids 16% and flavonoids 19% in leaf was detected. Conclusion: The results of the of the anatomical, organoleptic and physiochemical studies of the powder of leaf will be helpful in standardization of R. succedanea the crude drug. PMID:28480367

Preferences of newborn mice for odours indicating closer genetic relatedness: is experience necessary?

PubMed

Todrank, Josephine; Busquet, Nicolas; Baudoin, Claude; Heth, Giora

2005-10-07

Evidence from studies with adult rodents indicates that individual recognition enables distinctions between familiar individuals irrespective of relatedness (but including close kin) and a separate mechanism enables discriminations based on genetic relatedness without prior familiarity. For example, adult mice could assess the extent of their genetic relatedness to unfamiliar individuals using perceptual similarities between their individual odours. The ontogeny of this genetic relatedness assessment mechanism, however, had not been investigated. Here, in two-choice tests, newborn mice differentially preferred odours of more genetically similar lactating females (paternal aunts to unrelated conspecific and conspecific to heterospecific) even without prior direct exposure to adults with the tested genotypes. The results provide a direct demonstration of genetic relatedness assessment abilities in newborns and show that experience with parental odours is not necessary for genetic relatedness distinctions. Future studies will be necessary to determine whether exposure to odours of other foetuses in the womb or littermates shortly after birth affects this genetic relatedness assessment process.

Preferences of newborn mice for odours indicating closer genetic relatedness: is experience necessary?

PubMed Central

Todrank, Josephine; Busquet, Nicolas; Baudoin, Claude; Heth, Giora

2005-01-01

Evidence from studies with adult rodents indicates that individual recognition enables distinctions between familiar individuals irrespective of relatedness (but including close kin) and a separate mechanism enables discriminations based on genetic relatedness without prior familiarity. For example, adult mice could assess the extent of their genetic relatedness to unfamiliar individuals using perceptual similarities between their individual odours. The ontogeny of this genetic relatedness assessment mechanism, however, had not been investigated. Here, in two-choice tests, newborn mice differentially preferred odours of more genetically similar lactating females (paternal aunts to unrelated conspecific and conspecific to heterospecific) even without prior direct exposure to adults with the tested genotypes. The results provide a direct demonstration of genetic relatedness assessment abilities in newborns and show that experience with parental odours is not necessary for genetic relatedness distinctions. Future studies will be necessary to determine whether exposure to odours of other foetuses in the womb or littermates shortly after birth affects this genetic relatedness assessment process. PMID:16191620

The participation of cortical amygdala in innate, odour-driven behaviour.

PubMed

Root, Cory M; Denny, Christine A; Hen, René; Axel, Richard

2014-11-13

Innate behaviours are observed in naive animals without prior learning or experience, suggesting that the neural circuits that mediate these behaviours are genetically determined and stereotyped. The neural circuits that convey olfactory information from the sense organ to the cortical and subcortical olfactory centres have been anatomically defined, but the specific pathways responsible for innate responses to volatile odours have not been identified. Here we devise genetic strategies that demonstrate that a stereotyped neural circuit that transmits information from the olfactory bulb to cortical amygdala is necessary for innate aversive and appetitive behaviours. Moreover, we use the promoter of the activity-dependent gene arc to express the photosensitive ion channel, channelrhodopsin, in neurons of the cortical amygdala activated by odours that elicit innate behaviours. Optical activation of these neurons leads to appropriate behaviours that recapitulate the responses to innate odours. These data indicate that the cortical amygdala plays a critical role in generating innate odour-driven behaviours but do not preclude its participation in learned olfactory behaviours.

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

PubMed

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

2015-01-01

Food wastes with high moisture and organic matter content are likely to emit odours as a result of the decomposition process. The management of odour from decomposing wastes is needed to sustain the interest of residents and local councils in the source separation of kitchen wastes. This study investigated the potential of baking soda (at 50 g, 75 g and 100g per kg food waste) to control odour from seven days stored food waste. It was found that 50 g of baking soda, spread at the bottom of 8l food wastes bin, can reduce the odour by about 70%. A higher amount (above 100g) is not advised as a pH higher than 9.0 may be induced leading to the volatilization of odorous ammonia. This research finding is expected to benefit the waste management sector, food processing industries as well as the local authorities where malodour from waste storage is a pressing issue. Copyright © 2014 Elsevier Ltd. All rights reserved.

Odour-based discrimination of similarity at the major histocompatibility complex in birds.

PubMed

Leclaire, Sarah; Strandh, Maria; Mardon, Jérôme; Westerdahl, Helena; Bonadonna, Francesco

2017-01-11

Many animals are known to preferentially mate with partners that are dissimilar at the major histocompatibility complex (MHC) in order to maximize the antigen binding repertoire (or disease resistance) in their offspring. Although several mammals, fish or lizards use odour cues to assess MHC similarity with potential partners, the ability of birds to assess MHC similarity using olfactory cues has not yet been explored. Here we used a behavioural binary choice test and high-throughput-sequencing of MHC class IIB to determine whether blue petrels can discriminate MHC similarity based on odour cues alone. Blue petrels are seabirds with particularly good sense of smell, they have a reciprocal mate choice and are known to preferentially mate with MHC-dissimilar partners. Incubating males preferentially approached the odour of the more MHC-dissimilar female, whereas incubating females showed opposite preferences. Given their mating pattern, females were, however, expected to show preference for the odour of the more MHC-dissimilar male. Further studies are needed to determine whether, as in women and female mice, the preference varies with the reproductive cycle in blue petrel females. Our results provide the first evidence that birds can use odour cues only to assess MHC dissimilarity. © 2017 The Author(s).

Odour removal with a trickling filter at a small WWTP strongly influenced by the tourism season.

PubMed

Patria, L; Cathelain, M; Laurens, P; Barbere, J P

2001-01-01

Etaples-Le Touquet's wastewater treatment plant (WWTP) is based on a coastal area of the Artois-Picardie region. The pollution load can vary from 20,000 p.e. to 60,000 p.e. over a weekend or in summer. The Collectivity and the Water Agency decided to cover and ventilate the main odour source points of the plant. The foul air was directed to a 2,500 m3/h inorganic bed biofilter (Alizair) for odour control. An odour monitoring took place during the first year of operation taking into account cold and warm seasons, high and low tourism seasons. The Alizair biofilter appeared an appropriate odour control process for small sized wastewater treatment plants, easy to operate and efficient even in areas where tourism seasons have a great impact on the pollution load arriving at the plant. The neighbourhood did not complain about odours any more and the operator was very confident with such a simple and effective system. The local Authorities and the Water Agency agreed to recommend Alizair biofilters with an autotrophic biomass adapted in the case of an old WWTP that cannot be up graded any more or for large pumping stations and wastewater storage prior treatment.

Community reappraisal of the perceived health effects of a petroleum refinery.

PubMed

Luginaah, Isaac N; Taylor, S Martin; Elliott, Susan J; Eyles, John D

2002-07-01

This paper presents results from a study of the community health impacts of a petroleum refinery in Oakville, Ontario in Canada. The research is informed by the environmental stress and coping literatures and the focus is on community reappraisal of the refinery's impacts before and after the implementation of a substantive odour reduction initiative on the part of the refinery operators. Community health surveys were conducted in 1992 (n = 391) and 1997 (n = 427) to examine changes in odour perception and annoyance and self-reported health status attributable to the odour reduction plan. The findings reported here suggest an on-going process of cognitive reappraisal, whereby negative perceptions and concerns decreased between 1992 and 1997. Irrespective of this positive reappraisal of the refinery efforts, those living close to the refinery continue to report negative health impacts. A strong mediating effect of odours on the refinery exposure-symptom reporting relationship was confirmed by our results. While the relationship between odour perception and symptom reporting indicates the importance of odour perception and annoyance as the principal mechanism mediating ill-health reporting, the plausibility of other causal pathways is recognized. Residents' sensitivity to the negative effects of the refinery on their health and the health of their children suggests a psychosocial reaction to the environmental stress associated with perceived and actual refinery emissions.

Assessment of the Indoor Odour Impact in a Naturally Ventilated Room

PubMed Central

Eusebio, Lidia; Derudi, Marco; Capelli, Laura; Nano, Giuseppe; Sironi, Selena

2017-01-01

Indoor air quality influences people’s lives, potentially affecting their health and comfort. Nowadays, ventilation is the only technique commonly used for regulating indoor air quality. CO2 is the reference species considered in order to calculate the air exchange rates of indoor environments. Indeed, regarding air quality, the presence of pleasant or unpleasant odours can strongly influence the environmental comfort. In this paper, a case study of indoor air quality monitoring is reported. The indoor field tests were conducted measuring both CO2 concentration, using a photoacoustic multi-gas analyzer, and odour trends, using an electronic nose, in order to analyze and compare the information acquired. The indoor air monitoring campaign was run for a period of 20 working days into a university room. The work was focused on the determination of both CO2 and odour emission factors (OEF) emitted by the human activity and on the evaluation of the odour impact in a naturally ventilated room. The results highlighted that an air monitoring and recycling system based only on CO2 concentration and temperature measurements might be insufficient to ensure a good indoor air quality, whereas its performances could be improved by integrating the existing systems with an electronic nose for odour detection. PMID:28379190

Persistent anosmia in a traumatic brain injury patient: role of orbitofrontal cortex.

PubMed

Caminiti, Fabrizia; Ciurleo, Rosella; Bramanti, Placido; Marino, Silvia

2013-01-01

The olfactory loss due to traumatic brain injury is a common clinical condition. The understanding of the cortical areas involved in ability to detect, discriminate and identify the odours is still limited. However, it has been shown that the orbitofrontal cortex (OFC) is involved in the discrimination and recognition of odours and in particular the right OFC has a dominant role in the central processing of smell. This study used the Sniffin' Sticks Test to evaluate olfactory function of a 40-year-old female with persistent post-traumatic anosmia and to have a objective measure method for the follow-up. A marked decrease in the ability to identify and discriminate odours was found. On the other hand the ability to perceive the odours was little compromised. A cerebral Magnetic Resonance Imaging, performed 10 months after the trauma, showed the presence of a post-traumatic scarring in the right frontal lobe involving the OFC. In this case of post-traumatic anosmia, the ability to perceive and recognize odours does not seem to be compromised in the same measure. It is postulated that the post-traumatic outcomes, involving areas of multisensory integration such as the OFC, have an important pathogenetic role in the loss of ability to recognize and discriminate odours.

Elimination of seaweed odour and its effect on antioxidant activity

NASA Astrophysics Data System (ADS)

Keyimu, Xiren Guli; Abdullah, Aminah

2014-09-01

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

Short-term memory in olfactory network dynamics

NASA Astrophysics Data System (ADS)

Stopfer, Mark; Laurent, Gilles

1999-12-01

Neural assemblies in a number of animal species display self-organized, synchronized oscillations in response to sensory stimuli in a variety of brain areas.. In the olfactory system of insects, odour-evoked oscillatory synchronization of antennal lobe projection neurons (PNs) is superimposed on slower and stimulus-specific temporal activity patterns. Hence, each odour activates a specific and dynamic projection neuron assembly whose evolution during a stimulus is locked to the oscillation clock. Here we examine, using locusts, the changes in population dynamics of projection-neuron assemblies over repeated odour stimulations, as would occur when an animal first encounters and then repeatedly samples an odour for identification or localization. We find that the responses of these assemblies rapidly decrease in intensity, while they show a marked increase in spike time precision and inter-neuronal oscillatory coherence. Once established, this enhanced precision in the representation endures for several minutes. This change is stimulus-specific, and depends on events within the antennal lobe circuits, independent of olfactory receptor adaptation: it may thus constitute a form of sensory memory. Our results suggest that this progressive change in olfactory network dynamics serves to converge, over repeated odour samplings, on a more precise and readily classifiable odour representation, using relational information contained across neural assemblies.

Humidification and perceived indoor air quality in the office environment.

PubMed Central

Reinikainen, L M; Aunela-Tapola, L; Jaakkola, J J

1997-01-01

OBJECTIVE: To evaluate the effect of humidification on the odour, acceptability, and stuffiness of indoor air. METHODS: In a six period cross over trial at the Pasila Office Center, Helsinki, the air of two wings of the building in turn were ventilated with air of 30%-40% humidity. A third wing served as a non-humidified control area. The quality of indoor air was assessed weekly by a panel containing 18 to 23 members. The intraindividual differences in the ratings for odour, stuffiness, and acceptability between humidified and non-humidified wings were used to assess the effect of humidification. The roles of sex, current smoking, and age as potential effect modifiers were assessed by comparing the mean intraindividual differences in ratings between the groups. RESULTS: Humidified air was found to be more odorous and stuffy (paired t test P = 0.0001) and less acceptable than the non-humidified air (McNemar's test P < 0.001). The differences in odour and stuffiness between humidified and non-humidified air were greater for women and for non-smokers, and greatest differences were in the youngest age group, and least in the oldest age group. The differences were not significant. CONCLUSIONS: An untrained panel of 20 members is able to differentiate a slight malodour and stuffiness in indoor air. The results suggest that steam air humidification decreases the perceived air quality. This effect is strongest in women and young subjects. PMID:9196454

Using a new odour-baited device to explore options for luring and killing outdoor-biting malaria vectors: a report on design and field evaluation of the Mosquito Landing Box

PubMed Central

2013-01-01

Background Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the ‘Mosquito Landing Box’ (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challenges relevant to luring and killing outdoor-biting malaria vectors in endemic settings. Methods Field experiments were conducted in Tanzania to assess if wild host-seeking mosquitoes 1) visited the MLBs, 2) stayed long or left shortly after arrival at the device, 3) visited the devices at times when humans were also outdoors, and 4) could be killed by contaminants applied on the devices. Odours suctioned from volunteer-occupied tents were also evaluated as a potential low-cost bait, by comparing baited and unbaited MLBs. Results There were significantly more Anopheles arabiensis, An. funestus, Culex and Mansonia mosquitoes visiting baited MLB than unbaited controls (P≤0.028). Increasing sampling frequency from every 120 min to 60 and 30 min led to an increase in vector catches of up to 3.6 fold (P≤0.002), indicating that many mosquitoes visited the device but left shortly afterwards. Outdoor host-seeking activity of malaria vectors peaked between 7:30 and 10:30pm, and between 4:30 and 6:00am, matching durations when locals were also outdoors. Maximum mortality of mosquitoes visiting MLBs sprayed or painted with formulations of candidate mosquitocidal agent (pirimiphos-methyl) was 51%. Odours from volunteer occupied tents attracted significantly more mosquitoes to MLBs than controls (P<0.001). Conclusion While odour-baited devices such as the MLBs clearly have potential against outdoor-biting mosquitoes in communities where LLINs are used, candidate contaminants must be those that are effective at ultra-low doses even after short contact periods, since important vector species such as An. arabiensis make only brief visits to such devices. Natural human odours suctioned from occupied dwellings could constitute affordable sources of attractants to supplement odour baits for the devices. The killing agents used should be environmentally safe, long lasting, and have different modes of action (other than pyrethroids as used on LLINs), to curb the risk of physiological insecticide resistance. PMID:23642306

Effect of female odour on male hamsters mediated by the vomeronasal organ.

PubMed

Steel, E; Keverne, E B

1985-08-01

A comparison was made of the response to female vaginal odour, between males that were intact (I), had an ablated vomeronasal epithelium (VNOX) or had the main olfactory epithelium destroyed by zinc sulphate lavage (ZN). I males, after exposure to vaginal odour, can subsequently discriminate between the donor of the odour and other, mismatching females. VNOX males are unable to discriminate. Peripherally anosmic males (ZN) could still discriminate mismatching females. Neither treatment affected the amount of sniffing directed at novel females. This confirms a previous study in which it was found that the non-volatile fraction of the female vaginal discharge is necessary for match/mismatch discrimination and that this is most likely to be sampled via the vomeronasal organ.

Population and behavioural responses of native prey to alien predation.

PubMed

Kovacs, Eszter Krasznai; Crowther, Mathew S; Webb, Jonathan K; Dickman, Christopher R

2012-04-01

The introduction of invasive alien predators often has catastrophic effects on populations of naïve native prey, but in situations where prey survive the initial impact a predator may act as a strong selective agent for prey that can discriminate and avoid it. Using two common species of Australian small mammals that have persisted in the presence of an alien predator, the European red fox Vulpes vulpes, for over a century, we hypothesised that populations of both would perform better where the activity of the predator was low than where it was high and that prey individuals would avoid signs of the predator's presence. We found no difference in prey abundance in sites with high and low fox activity, but survival of one species-the bush rat Rattus fuscipes-was almost twofold higher where fox activity was low. Juvenile, but not adult rats, avoided fox odour on traps, as did individuals of the second prey species, the brown antechinus, Antechinus stuartii. Both species also showed reduced activity at foraging trays bearing fox odour in giving-up density (GUD) experiments, although GUDs and avoidance of fox odour declined over time. Young rats avoided fox odour more strongly where fox activity was high than where it was low, but neither adult R. fuscipes nor A. stuartii responded differently to different levels of fox activity. Conservation managers often attempt to eliminate alien predators or to protect predator-naïve prey in protected reserves. Our results suggest that, if predator pressure can be reduced, otherwise susceptible prey may survive the initial impact of an alien predator, and experience selection to discriminate cues to its presence and avoid it over the longer term. Although predator reduction is often feasible, identifying the level of reduction that will conserve prey and allow selection for avoidance remains an important challenge.

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

PubMed

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

2013-01-01

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

Influence of salt content and processing time on sensory characteristics of cooked "lacón".

PubMed

Purriños, Laura; Bermúdez, Roberto; Temperán, Sara; Franco, Daniel; Carballo, Javier; Lorenzo, José M

2011-04-01

The influence of salt content and processing time on the sensory properties of cooked "lacón" were determined. "Lacón" is a traditional dry-cured and ripened meat product made in the north-west of Spain from the fore leg of the pig, following a similar process to that of dry-cured ham. Six batches of "lacón" were salted with different amounts of salt (LS (3 days of salting), MS (4 days of salting) and HS (5 days of salting)) and ripened during two times (56 and 84 days of dry-ripening). Cured odour in all batches studied, red colour and rancid odour in MS and HS batches, flavour intensity in MS batch and fat yellowness, rancid flavour and hardness in the HS batch were significantly different with respect to the time of processing. Appearance, odour, flavour and texture were not significantly affected by the salt content (P>0.05). However, the saltiness score showed significant differences with respect to the salt levels in all studied batches (56 and 84 days of process). The principal component analysis showed that physicochemical traits were the most important ones concerning the quality of dry-cured "lacón" and offered a good separation of the mean samples according to the dry ripening days and salt level. © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2012-01-01

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

Genic rather than genome-wide differences between sexually deceptive Ophrys orchids with different pollinators.

PubMed

Sedeek, Khalid E M; Scopece, Giovanni; Staedler, Yannick M; Schönenberger, Jürg; Cozzolino, Salvatore; Schiestl, Florian P; Schlüter, Philipp M

2014-12-01

High pollinator specificity and the potential for simple genetic changes to affect pollinator attraction make sexually deceptive orchids an ideal system for the study of ecological speciation, in which change of flower odour is likely important. This study surveys reproductive barriers and differences in floral phenotypes in a group of four closely related, coflowering sympatric Ophrys species and uses a genotyping-by-sequencing (GBS) approach to obtain information on the proportion of the genome that is differentiated between species. Ophrys species were found to effectively lack postpollination barriers, but are strongly isolated by their different pollinators (floral isolation) and, to a smaller extent, by shifts in flowering time (temporal isolation). Although flower morphology and perhaps labellum coloration may contribute to floral isolation, reproductive barriers may largely be due to differences in flower odour chemistry. GBS revealed shared polymorphism throughout the Ophrys genome, with very little population structure between species. Genome scans for FST outliers identified few markers that are highly differentiated between species and repeatable in several populations. These genome scans also revealed highly differentiated polymorphisms in genes with putative involvement in floral odour production, including a previously identified candidate gene thought to be involved in the biosynthesis of pseudo-pheromones by the orchid flowers. Taken together, these data suggest that ecological speciation associated with different pollinators in sexually deceptive orchids has a genic rather than a genomic basis, placing these species at an early phase of genomic divergence within the 'speciation continuum'. © 2014 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.

Odour-impact assessment around a landfill site from weather-type classification, complaint inventory and numerical simulation.

PubMed

Chemel, C; Riesenmey, C; Batton-Hubert, M; Vaillant, H

2012-01-01

Gases released from landfill sites into the atmosphere have the potential to cause olfactory nuisances within the surrounding communities. Landfill sites are often located over complex topography for convenience mainly related to waste disposal and environmental masking. Dispersion of odours is strongly conditioned by local atmospheric dynamics. Assessment of odour impacts needs to take into account the variability of local atmospheric dynamics. In this study, we discuss a method to assess odour impacts around a landfill site located over complex terrain in order to provide information to be used subsequently to identify management strategies to reduce olfactory nuisances in the residential neighbourhoods. A weather-type classification is defined in order to identify meteorological conditions under which olfactory nuisances are to be expected. A non-steady state Gaussian model and a full-physics meteorological model are used to predict olfactory nuisances, for both the winter and summer scenarios that lead to the majority of complaints in neighbourhoods surrounding the landfill site. Simulating representative scenarios rather than full years make a high resolution simulation of local atmospheric dynamics in space and time possible. Results underline the key role of local atmospheric dynamics in driving the dispersion of odours. The odour concentration simulated by the full-physics meteorological model is combined with the density of the population in order to calculate an average population exposure for the two scenarios. Results of this study are expected to provide helpful information to develop technical solutions for an effective management of landfill operations, which would reduce odour impacts within the surrounding communities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Trade-offs between predator avoidance and electric shock avoidance in hermit crabs demonstrate a non-reflexive response to noxious stimuli consistent with prediction of pain.

PubMed

Magee, Barry; Elwood, Robert W

2016-09-01

Arthropods have long been thought to respond to noxious stimuli by reflex reaction. One way of testing if this is true is to provide the animal with a way to avoid the stimulus but to vary the potential cost of avoidance. If avoidance varies with potential cost then a decision making process is evident and the behaviour is not a mere reflex. Here we examine the responses of hermit crabs to electric shock within their shell when also exposed to predator or non-predator odours or to no odour. The electric shocks start with low voltage but increase in voltage with each repetition to determine how odour affects the voltage at which the shell is abandoned. There was no treatment effect on the voltage at which hermit crabs left their shells, however, those exposed to predator odours were less likely to evacuate their shells compared with no odour or low concentrations of non-predator odour. However, highly concentrated non-predator also inhibited evacuation. The data show that these crabs trade-off avoidance of electric shock with predator avoidance. They are thus not responding purely by reflex and the data are thus consistent with predictions of pain but do not prove pain. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of chemicals, possibly originating from misuse of refillable PET bottles, responsible for consumer complaints about off-odours in water and soft drinks.

PubMed

Widén, H; Leufvén, A; Nielsen, T

2005-07-01

Mineral water and soft drinks with a perceptible off-odour were analysed to identify contaminants originating from previous misuse of the refillable polyethylene terephthalate (PET) bottle. Consumers detected the off-odour after opening the bottle and duly returned it with the remaining content to the producers. The contaminants in question had thus been undetected by the in-line detection devices (so-called 'sniffers') that are supposed to reject misused bottles. GC-MS analysis was carried out on the headspace of 31 returned products and their corresponding reference products, and chromatograms were compared to find the possible off-odour compounds. Substances believed to be responsible for the organoleptic change were 2-methoxynaphthalene (10 bottles), dimethyl disulfide (4), anethole (3), petroleum products (4), ethanol with isoamyl alcohol (1) and a series of ethers (1). The mouldy/musty odour (5 bottles) was caused by trichloroanisole in one instance. In some cases, the origins of the off-odours are believed to be previous consumer misuse of food products (liquorice-flavoured alcohol, home-made alcohol containing fusel oil) or non-food products (cleaning products, petroleum products, oral moist snuff and others). The results also apply to 1.5-litre recyclable PET bottles, since the nature and extent of consumer misuse can be expected to be similar for the two bottle types.

Occupational tellurium exposure and garlic odour.

PubMed

Berriault, C J; Lightfoot, N E

2011-03-01

Few studies have considered garlic odour as a socially important outcome of occupational tellurium (Te) exposure or concurrent exposures, and most known guidelines focus on other signs and symptoms (e.g. weight loss and somnolence). This study considers workers exposed to tellurium and selenium (Se) at an Ontario, Canada silver refinery. To establish the relation of urinary tellurium concentrations to reporting garlic odour, while considering other work-related factors such as concurrent urinary selenium concentrations. Historical surveillance records of urinary analyses for tellurium and selenium concentrations (μmol Te or Se/mol creatinine in urine) and symptom self-reports were used. Records were available from December 1986 to June 2002. Logistic regression models were fitted using age at sampling, tellurium and selenium urine concentration and duration of employment. Individual main effects were age adjusted and the final model was fitted for tellurium and selenium urine concentration and duration of employment. Urinary tellurium concentration was significantly associated with garlic odour reporting (odds ratio = 1.74, 95% confidence interval 1.01-2.97, P < 0.05). Furthermore, the likelihood of reporting garlic odour rose as workers reached urinary tellurium concentrations >1 μmol/mol creatinine. Tellurium urinary concentrations of <1 μmol/mol creatinine appear to limit, but not eliminate, the likelihood of reporting garlic odour. Future studies should consider the effect of concurrent selenium exposure as well as other workplace factors and hygiene.

Main compounds responsible for off-odour of strawberries infected by Phytophthora cactorum.

PubMed

Jeleń, H H; Krawczyk, J; Larsen, T O; Jarosz, A; Gołebniak, B

2005-01-01

Volatile compounds present in strawberries infected with Phytophthora cactorum, especially those responsible for the characteristic off-odour of such fruits were the subject of this study. Six strawberry varieties (Redgauntlet, Selva, Korona, Tenira, Real, Pegasus) inoculated with P. cactorum strain (PC-5), isolated from naturally infected fruit and one variety inoculated with 15 strains of P. cactorum in the laboratory were analysed. All the samples had a distinct, to a various degree, off-odour reminiscent of watercolour paint with phenolic notes. Volatile compounds were isolated by solid phase microextraction and simultaneous distillation extraction methods. To detect compounds responsible for the characteristic off-odour, gas chromatography-olfactometry was used. Two compounds were found to be responsible for the characteristic off-odour of strawberries infected by P. cactorum: 4-ethyl phenol and 4-ethyl-2-metoxy phenol (4-ethyl guaiacol). The content of these compounds in infected varieties ranged from 1.12 to 22.56 mg kg(-1) and 0.14-1.05 mg kg(-1) respectively. Other volatile compounds, not detected in noninoculated sound strawberries, were also identified: camphene, 1-octene-3-ol, 3-octanone, o-cymene, phenyl methanol, cis-linaloloxide, nonanal, phenyl ethyl alcohol, 2-undecanone and alpha-muurolene. Volatile compounds responsible for the characteristic off-odour of strawberries infected with P. cactorum were identified. Also compounds produced as a result of P. cactorum growth on strawberry fruit were characterized.

Identification of the odour and chemical composition of alumina refinery air emissions.

PubMed

Coffey, P S; Ioppolo-Armanios, M

2004-01-01

Alcoa World Alumina Australia has undertaken comprehensive air emissions monitoring aimed at characterising and quantifying the complete range of emissions to the atmosphere from Bayer refining of alumina at its Western Australian refineries. To the best of our knowledge, this project represents the most complete air emissions inventory of a Bayer refinery conducted in the worldwide alumina industry. It adds considerably to knowledge of air emission factors available for use in emissions estimation required under national pollutant release and transfer registers (NPRTs), such as the Toxic Releases Inventory, USA, and the National Pollutant Inventory, Australia. It also allows the preliminary identification of the key chemical components responsible for characteristic alumina refinery odours and the contribution of these components to the quality, or hedonic tone, of the odours. The strength and acceptability of refinery odours to employees and neighbours appears to be dependent upon where and in what proportion the odorous gases have been emitted from the refineries. This paper presents the results of the programme and develops a basis for classifying the odour properties of the key emission sources in the alumina-refining process.

Odour maps in the brain of butterflies with divergent host-plant preferences.

PubMed

Carlsson, Mikael A; Bisch-Knaden, Sonja; Schäpers, Alexander; Mozuraitis, Raimondas; Hansson, Bill S; Janz, Niklas

2011-01-01

Butterflies are believed to use mainly visual cues when searching for food and oviposition sites despite that their olfactory system is morphologically similar to their nocturnal relatives, the moths. The olfactory ability in butterflies has, however, not been thoroughly investigated. Therefore, we performed the first study of odour representation in the primary olfactory centre, the antennal lobes, of butterflies. Host plant range is highly variable within the butterfly family Nymphalidae, with extreme specialists and wide generalists found even among closely related species. Here we measured odour evoked Ca(2+) activity in the antennal lobes of two nymphalid species with diverging host plant preferences, the specialist Aglais urticae and the generalist Polygonia c-album. The butterflies responded with stimulus-specific combinations of activated glomeruli to single plant-related compounds and to extracts of host and non-host plants. In general, responses were similar between the species. However, the specialist A. urticae responded more specifically to its preferred host plant, stinging nettle, than P. c-album. In addition, we found a species-specific difference both in correlation between responses to two common green leaf volatiles and the sensitivity to these compounds. Our results indicate that these butterflies have the ability to detect and to discriminate between different plant-related odorants.

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

PubMed Central

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

2011-01-01

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

Transition from sea to land: olfactory function and constraints in the terrestrial hermit crab Coenobita clypeatus

PubMed Central

Krång, Anna-Sara; Knaden, Markus; Steck, Kathrin; Hansson, Bill S.

2012-01-01

The ability to identify chemical cues in the environment is essential to most animals. Apart from marine larval stages, anomuran land hermit crabs (Coenobita) have evolved different degrees of terrestriality, and thus represent an excellent opportunity to investigate adaptations of the olfactory system needed for a successful transition from aquatic to terrestrial life. Although superb processing capacities of the central olfactory system have been indicated in Coenobita and their olfactory system evidently is functional on land, virtually nothing was known about what type of odourants are detected. Here, we used electroantennogram (EAG) recordings in Coenobita clypeatus and established the olfactory response spectrum. Interestingly, different chemical groups elicited EAG responses of opposite polarity, which also appeared for Coenobita compressus and the closely related marine hermit crab Pagurus bernhardus. Furthermore, in a two-choice bioassay with C. clypeatus, we found that water vapour was critical for natural and synthetic odourants to induce attraction or repulsion. Strikingly, also the physiological response was found much greater at higher humidity in C. clypeatus, whereas no such effect appeared in the terrestrial vinegar fly Drosophila melanogaster. In conclusion, our results reveal that the Coenobita olfactory system is restricted to a limited number of water-soluble odourants, and that high humidity is most critical for its function. PMID:22673356

Individual human scent as a forensic identifier using mantrailing.

PubMed

Woidtke, Leif; Dreßler, Jan; Babian, Carsten

2018-01-01

Specially trained dogs have long been used by law enforcement agencies to help in criminal investigations and in searching for missing persons. Still, it is unclear which components of human scent released into the environment contribute to successful searches of individuals. In this study, saliva and axillary sweat samples were taken from a total of 190 people. Additionally, DNA was extracted from whole blood of seven different people and used as an odour sample as well. Overall 675 tests (trails) were performed during a period of 18 months. The ability to track individuals with the odour samples mentioned above was examined with seven dogs, four of which were specially-trained dogs (mantrailer) from the Saxony Police. Results indicated that specially-trained police dogs can track a person with an average success rate of 82% and correctly identify the absence of an odour track with an average success rate of 97% under various conditions. Private rescue dogs were less successful with an average success rate of 65% and 75% respectively. These data suggest that the potential error rate of a well-trained handler team is low and can be a useful tool for law enforcement personnel. Saliva, as a reference odour source, was found to be particularly suitable for the search. The results of the study suggest that the components contained in axillary sweat, saliva and DNA extracted from whole blood are sufficient, serving as a key stimulus for individualized searches. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2014-01-01

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

Infection with an acanthocephalan manipulates an amphipod's reaction to a fish predator's odours.

PubMed

Baldauf, Sebastian A; Thünken, Timo; Frommen, Joachim G; Bakker, Theo C M; Heupel, Oliver; Kullmann, Harald

2007-01-01

Many parasites with complex life cycles increase the chances of reaching a final host by adapting strategies to manipulate their intermediate host's appearance, condition or behaviour. The acanthocephalan parasite Pomphorhynchus laevis uses freshwater amphipods as intermediate hosts before reaching sexual maturity in predatory fish. We performed a series of choice experiments with infected and uninfected Gammarus pulex in order to distinguish between the effects of visual and olfactory predator cues on parasite-induced changes in host behaviour. When both visual and olfactory cues, as well as only olfactory cues were offered, infected and uninfected G. pulex showed significantly different preferences for the predator or the non-predator side. Uninfected individuals significantly avoided predator odours while infected individuals significantly preferred the side with predator odours. When only visual contact with a predator was allowed, infected and uninfected gammarids behaved similarly and had no significant preference. Thus, we believe we show for the first time that P. laevis increases its chance to reach a final host by olfactory-triggered manipulation of the anti-predator behaviour of its intermediate host.

Niépce-Bell or Turing: how to test odour reproduction.

PubMed

Harel, David

2016-12-01

Decades before the existence of anything resembling an artificial intelligence system, Alan Turing raised the question of how to test whether machines can think, or, in modern terminology, whether a computer claimed to exhibit intelligence indeed does so. This paper raises the analogous issue for olfaction: how to test the validity of a system claimed to reproduce arbitrary odours artificially, in a way recognizable to humans. Although odour reproduction systems are still far from being viable, the question of how to test candidates thereof is claimed to be interesting and non-trivial, and a novel method is proposed. Despite the similarity between the two questions and their surfacing long before the tested systems exist, the present question cannot be answered adequately by a Turing-like method. Instead, our test is very different: it is conditional, requiring from the artificial no more than is required from the original, and it employs a novel method of immersion that takes advantage of the availability of easily recognizable reproduction methods for sight and sound, a la Nicéphore Niépce and Alexander Graham Bell. © 2016 The Authors.

Niépce–Bell or Turing: how to test odour reproduction

PubMed Central

2016-01-01

Decades before the existence of anything resembling an artificial intelligence system, Alan Turing raised the question of how to test whether machines can think, or, in modern terminology, whether a computer claimed to exhibit intelligence indeed does so. This paper raises the analogous issue for olfaction: how to test the validity of a system claimed to reproduce arbitrary odours artificially, in a way recognizable to humans. Although odour reproduction systems are still far from being viable, the question of how to test candidates thereof is claimed to be interesting and non-trivial, and a novel method is proposed. Despite the similarity between the two questions and their surfacing long before the tested systems exist, the present question cannot be answered adequately by a Turing-like method. Instead, our test is very different: it is conditional, requiring from the artificial no more than is required from the original, and it employs a novel method of immersion that takes advantage of the availability of easily recognizable reproduction methods for sight and sound, a la Nicéphore Niépce and Alexander Graham Bell. PMID:28003527

Identification of compounds inhibiting the C-S lyase activity of a cell extract from a Staphylococcus sp. isolated from human skin.

PubMed

Egert, M; Höhne, H-M; Weber, T; Simmering, R; Banowski, B; Breves, R

2013-12-01

The C-S lyase activity of bacteria in the human armpit releases highly malodorous, volatile sulfur compounds from nonvolatile precursor molecules. Such compounds significantly contribute to human body odour. Hence, C-S lyase represents an attractive target for anti-body-odour cosmetic products. Here, aiming at a final use in an ethanol-based deodorant formulation, 267 compounds and compound mixtures were screened for their ability to inhibit the C-S lyase activity of a Stapyhlococcus sp. crude extract. Staphylococcus sp. Isolate 128, closely related to Staphylococcus hominis, was chosen as the test bacterium, as it showed a reproducibly high specific C-S lyase activity on three different culturing media. Using a photometric assay and benzylcysteine as substrate, six rather complex, plant-derived compound mixtures and five well defined chemical compounds or compound mixtures were identified as inhibitors, leading to an inhibition of ≥70% at concentrations of ≤0·5% in the assay. The inhibition data have demonstrated that compounds with two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue are characteristic for the inhibition. The substances identified as C-S lyase inhibitors have the potential to improve the performance of anti-body-odour cosmetic products, for example, ethanol-based deodorants. Bacterial C-S lyase represents one of the key enzymes involved in human body odour formation. The aim of this study was to identify compounds inhibiting the C-S lyase activity of a Staphylococcus sp. isolate from the human skin. The compounds identified as the best inhibitors are characterized by the following features: two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue. They might be used to improve the performance of cosmetic products aiming to prevent the formation of microbially caused human body odour, for example, ethanol-based deodorants. © 2013 The Society for Applied Microbiology.

Structure-activity relationships of sandalwood odorants: synthesis and odour of methyl-beta-santalol.

PubMed

Buchbauer, G; Zechmeister-Machhart, F; Weiss-Greiler, P; Wolschann, P

1997-04-01

The synthesis and odour properties of the new santalol analogue, methyl-beta-santalol, are described. The additional methyl group adjacent to the hydroxyl function of the standard molecule, beta-santalol, deprives the new compound of the sandalwood note. The synthesis and the odour evaluation of this compound supports the proposed model for sandalwood fragrance as it shows that the methyl group located at the osmophoric center prevents association of the molecule with the hypothetical receptor.

Instrumental measurement of odour nuisance in city agglomeration using electronic nose

NASA Astrophysics Data System (ADS)

Szulczyński, Bartosz; Dymerski, Tomasz; Gębicki, Jacek; Namieśnik, Jacek

2018-01-01

The paper describes an operation principle of odour nuisance monitoring network in a city agglomeration. Moreover, it presents the results of investigation on ambient air quality with respect to odour obtained during six-month period. The investigation was carried out using a network comprised of six prototypes of electronic nose and Nasal Ranger field olfactometers employed as a reference method. The monitoring network consisted of two measurement stations localized in a vicinity of crude oil processing plant and four stations localized near the main emitters of volatile odorous compounds such as sewage treatment plant, municipal landfill, phosphatic fertilizer production plant. The electronic nose prototype was equipped with a set of six semiconductor sensors by FIGARO Co. and one PID-type sensor. The field olfactometers were utilized for determination of mean concentration of odorants and for calibration of the electronic nose prototypes in order to provide their proper operation. Mean monthly values of odour concentration depended on the site of measurement and on meteorological parameters. They were within 0 - 6.0 ou/m3 range. Performed investigations revealed the possibility of electronic nose instrument application as a tool for monitoring of odour nuisance.

Body malodours and their topical treatment agents.

PubMed

Kanlayavattanakul, M; Lourith, N

2011-08-01

Body malodour, including foot odour, suppresses social interaction by diminishing self-confidence and accelerating damage to the wearer's clothes and shoes. Most treatment agents, including aluminium anti-perspirant salts, inhibit the growth of malodourous bacteria. These metallic salts also reduce sweat by blocking the excretory ducts of sweat glands, minimizing the water source that supports bacterial growth. However, there are some drawback effects that limit the use of aluminium anti-perspirant salts. In addition, over-the-counter anti-perspirant and deodourant products may not be sufficiently effective for heavy sweaters, and strong malodour producers. Body odour treatment agents are rarely mentioned in the literature compared with other cosmetic ingredients. This review briefly summarizes the relationship among sweat, skin bacteria, and body odour; describes how odourous acids, thiols, and steroids are formed; and discusses the active ingredients, including metallic salts and herbs, that are used to treat body odour. A new class of ingredients that function by regulating the release of malodourants will also be described. These ingredients do not alter the balance of the skin flora. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Design and validation of a wind tunnel system for odour sampling on liquid area sources.

PubMed

Capelli, L; Sironi, S; Del Rosso, R; Céntola, P

2009-01-01

The aim of this study is to describe the methods adopted for the design and the experimental validation of a wind tunnel, a sampling system suitable for the collection of gaseous samples on passive area sources, which allows to simulate wind action on the surface to be monitored. The first step of the work was the study of the air velocity profiles. The second step of the work consisted in the validation of the sampling system. For this purpose, the odour concentration of some air samples collected by means of the wind tunnel was measured by dynamic olfactometry. The results of the air velocity measurements show that the wind tunnel design features enabled the achievement of a uniform and homogeneous air flow through the hood. Moreover, the laboratory tests showed a very good correspondence between the odour concentration values measured at the wind tunnel outlet and the odour concentration values predicted by the application of a specific volatilization model, based on the Prandtl boundary layer theory. The agreement between experimental and theoretical trends demonstrate that the studied wind tunnel represents a suitable sampling system for the simulation of specific odour emission rates from liquid area sources without outward flow.

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

PubMed

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

2007-01-01

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

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

PubMed

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

2009-01-01

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

Evaluation of textile substrates for dispensing synthetic attractants for malaria mosquitoes.

PubMed

Mweresa, Collins K; Mukabana, Wolfgang R; Omusula, Philemon; Otieno, Bruno; Gheysens, Tom; Takken, Willem; van Loon, Joop J A

2014-08-16

The full-scale impact of odour-baited technology on the surveillance, sampling and control of vectors of infectious diseases is partly limited by the lack of methods for the efficient and sustainable dispensing of attractants. In this study we investigated whether locally-available and commonly used textiles are efficient substrates for the release of synthetic odorant blends attracting malaria mosquitoes. The relative efficacy of (a) polyester, (b) cotton, (c) cellulose + polyacrylate, and (d) nylon textiles as substrates for dispensing a synthetic odour blend (Ifakara blend 1(IB1)) that attracts malaria mosquitoes was evaluated in western Kenya. The study was conducted through completely randomized Latin square experimental designs under semi-field and field conditions. Traps charged with IB1-impregnated polyester, cotton and cellulose + polyacrylate materials caught significantly more female Anopheles gambiae sensu stricto (semi-field conditions) and An. gambiae sensu lato (field conditions) mosquitoes than IB1-treated nylon (P = 0.001). The IB1-impregnated cellulose + polyacrylate material was the most attractive to female An. funestus mosquitoes compared to all other dispensing textile substrates (P < 0.001). The responses of female An. funestus mosquitoes to IB1-treated cotton and polyester were equal (P = 0.45). Significantly more female Culex mosquitoes were attracted to IB1-treated cotton than to the other treatments (P < 0.001). Whereas IB1-impregnated cotton and cellulose + polyacrylate material attracted equal numbers of female Mansonia mosquitoes (P = 0.44), the catches due to these two substrates were significantly higher than those associated with the other substrates (P < 0.001). The number and species of mosquitoes attracted to a synthetic odour blend is influenced by the type of odour-dispensing material used. Thus, surveillance and intervention programmes for malaria and other mosquito vectors using attractive odour baits should select an odour-release material that optimizes the odour blend.

Halitosis: a new definition and classification.

PubMed

Aydin, M; Harvey-Woodworth, C N

2014-07-11

There is no universally accepted, precise definition, nor standardisation in terminology and classification of halitosis. To propose a new definition, free from subjective descriptions (faecal, fish odour, etc), one-time sulphide detector readings and organoleptic estimation of odour levels, and excludes temporary exogenous odours (for example, from dietary sources). Some terms previously used in the literature are revised. A new aetiologic classification is proposed, dividing pathologic halitosis into Type 1 (oral), Type 2 (airway), Type 3 (gastroesophageal), Type 4 (blood-borne) and Type 5 (subjective). In reality, any halitosis complaint is potentially the sum of these types in any combination, superimposed on the Type 0 (physiologic odour) present in health. This system allows for multiple diagnoses in the same patient, reflecting the multifactorial nature of the complaint. It represents the most accurate model to understand halitosis and forms an efficient and logical basis for clinical management of the complaint.

Volatile and key odourant compounds of Turkish Berberis crataegina fruit using GC-MS-Olfactometry.

PubMed

Sonmezdag, Ahmet Salih; Kelebek, Hasim; Selli, Serkan

2018-04-01

This research was conducted to identify the aroma and aroma-active compounds of Berberis crataegina for the first time. Volatile profile of B. crataegina was obtained using the purge and trap extraction method with dichloromethane. Gas chromatography was coupled to mass spectrometry (GC-MS) allowed the quantitative and qualitative detection of 22 compounds in the sample. Aldehydes were the main chemical group in the sample and followed by aromatic alcohols and lactone. Aroma extract dilution analysis was implemented for the specification of key odourants of B. crataegina. In total, eight key odourants were detected in the extract of the sample, using GC-MS-Olfactometry and aldehydes were the leading chemical group. The key odourants, found to be contributing to the overall aroma in B. crataegina, were nonanal (FD = 1024; green, flowery), hexanal (FD = 512; green) and linalool (FD = 256; flowery, rose) because of high FD factors.

Towards a bacterial treatment for armpit malodour.

PubMed

Callewaert, Chris; Lambert, Jo; Van de Wiele, Tom

2017-05-01

Axillary malodour is a frustrating condition for many people. It can lead to significant discomforts and various psychological effects. The underarm microbiome plays a major role in axillary malodour formation. Not only the bacteria on the epidermis, but also and especially those living in the sweat glands, sweat pores and hair follicles play a pivotal role in malodour development. To treat underarm malodour, this viewpoint article envisions a bacterial treatment. Replacing the autochthonous malodour-causing microbiome with a non-odour-causing microbiome, through an armpit bacterial transplantation or direct application of probiotics/non-odour-causing bacteria, could resolve the condition. Selective steering of the microbiome with prebiotics, biochemicals or plant extracts can likewise greatly help in improving the underarm odour. Elimination/inhibition of the "bad bugs" and application/stimulation of the "good bugs" will be part of the future treatment for axillary body odour. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

PubMed

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

2015-11-01

The paper presents a novel encoding scheme for neuronal code generation for odour recognition using an electronic nose (EN). This scheme is based on channel encoding using multiple Gaussian receptive fields superimposed over the temporal EN responses. The encoded data is further applied to a spiking neural network (SNN) for pattern classification. Two forms of SNN, a back-propagation based SpikeProp and a dynamic evolving SNN are used to learn the encoded responses. The effects of information encoding on the performance of SNNs have been investigated. Statistical tests have been performed to determine the contribution of the SNN and the encoding scheme to overall odour discrimination. The approach has been implemented in odour classification of orthodox black tea (Kangra-Himachal Pradesh Region) thereby demonstrating a biomimetic approach for EN data analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Body odour of monozygotic human twins: a common pattern of odorant carboxylic acids released by a bacterial aminoacylase from axilla secretions contributing to an inherited body odour type.

PubMed

Kuhn, Fabian; Natsch, Andreas

2009-04-06

It is currently not fully established whether human individuals have a genetically determined, individual-specific body odour. Volatile carboxylic acids are a key class of known human body odorants. They are released from glutamine conjugates secreted in axillary skin by a specific Nalpha-acyl-glutamine-aminoacylase present in skin bacteria. Here, we report a quantitative investigation of these odorant acids in 12 pairs of monozygotic twins. Axilla secretions were sampled twice and treated with the Nalpha-acyl-glutamine-aminoacylase. The released acids were analysed as their methyl esters with comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry detection. The pattern of the analytes was compared with distance analysis. The distance was lowest between samples of the right and the left axilla taken on the same day from the same individual. It was clearly greater if the same subject was sampled on different days, but this intra-individual distance between samples was only slightly lower than the distance between samples taken from two monozygotic twins. A much greater distance was observed when comparing unrelated individuals. By applying cluster and principal component analyses, a clear clustering of samples taken from one pair of monozygotic twins was also confirmed. In conclusion, the specific pattern of precursors for volatile carboxylic acids is subject to a day-to-day variation, but there is a strong genetic contribution. Therefore, humans have a genetically determined body odour type that is at least partly composed of these odorant acids.

Honeybees Learn Odour Mixtures via a Selection of Key Odorants

PubMed Central

Reinhard, Judith; Sinclair, Michael; Srinivasan, Mandyam V.; Claudianos, Charles

2010-01-01

Background The honeybee has to detect, process and learn numerous complex odours from her natural environment on a daily basis. Most of these odours are floral scents, which are mixtures of dozens of different odorants. To date, it is still unclear how the bee brain unravels the complex information contained in scent mixtures. Methodology/Principal Findings This study investigates learning of complex odour mixtures in honeybees using a simple olfactory conditioning procedure, the Proboscis-Extension-Reflex (PER) paradigm. Restrained honeybees were trained to three scent mixtures composed of 14 floral odorants each, and then tested with the individual odorants of each mixture. Bees did not respond to all odorants of a mixture equally: They responded well to a selection of key odorants, which were unique for each of the three scent mixtures. Bees showed less or very little response to the other odorants of the mixtures. The bees' response to mixtures composed of only the key odorants was as good as to the original mixtures of 14 odorants. A mixture composed of the other, non-key-odorants elicited a significantly lower response. Neither an odorant's volatility or molecular structure, nor learning efficiencies for individual odorants affected whether an odorant became a key odorant for a particular mixture. Odorant concentration had a positive effect, with odorants at high concentration likely to become key odorants. Conclusions/Significance Our study suggests that the brain processes complex scent mixtures by predominantly learning information from selected key odorants. Our observations on key odorant learning lend significant support to previous work on olfactory learning and mixture processing in honeybees. PMID:20161714

Hyper-homeostatic learning of anticipatory hunger in rats.

PubMed

Jarvandi, Soghra; Booth, David A; Thibault, Louise

2007-11-23

Anticipatory hunger is a learnt increase in intake of food having a flavour or texture that predicts a long fast. This learning was studied in rats trained on a single food or a choice between protein-rich and carbohydrate-rich foods, presented for 1.5 h after 3 h without maintenance food at the start of the dark phase. Eight training cycles provided a pseudo-random sequence of 3 h and 10 h post-prandial fasts with a day on maintenance food between each training fast. The measure of anticipatory hunger is the difference over one 4-day cycle between the intake of test food having an odour predictive of the longer fast (TL) and intake of food with an odour cuing to the shorter fast (TS). Previous experiments showed that conditioning of preference for the odour before the shorter fast competes with learning to avoid hunger during the longer fast (anticipatory hunger), generating a cubic or quartic contrast. TL minus TS showed a strong cubic trend over 8 training cycles with both single and choice meals. There was a switch from preference for the short-fast odour at cycle 2 (TL-TS=-0.86 g) to a peak of anticipatory hunger at cycle 6 (TL-TS=1.57 g). We conclude that anticipatory hunger is learnt when a choice is given between protein-rich and carbohydrate-rich foods as well as on a single food. In addition, since anticipatory hunger extinguishes itself, such learning improves on negative-feedback homeostasis with a feed-forward "hyper-homeostatic" mechanism.

The impact of malodour on communities: a review of assessment techniques.

PubMed

Hayes, J E; Stevenson, R J; Stuetz, R M

2014-12-01

Malodours remain the biggest source of complaints regarding environmental issues. This factor is likely to increase, as the urban development steadily encroaches into areas that have malodourous emitting industries (such as wastewater and waste management operations and intensive livestock practices), and has the potential to be both time and fiscally expensive. Despite the enormous amount of research involved in odour detection and abatement, as well as the creation of several distinct methodologies, there has yet been no definitive procedure to evaluate odour impact on communities, as well as community response. This paper is a review of the current methods that explore this problem, as well as a précis of this research field's goals and challenges. The first aim of this review is to illustrate the dichotomy between regulatory-established procedures, such as panellist testing, and methods that are centred around producing a more comprehensive explanation of factors that influence an odour's impact on a community or individual. In that regard, we have addressed several predominant paradigms of inquiry for this field: analytical methods, panellist testing, qualitative research, and survey methods, with associated variants. Secondly, the challenges of measuring and monitoring community impact are discussed. While the quantification of odorants is crucial to appreciating impact, individual-based modifiers of perception have an enormous scope for which to shape the effect of those odours. Perceptual differences are also likely the most dominant variables that influence the elicited behaviour of individuals who have experienced malodour exposure. Copyright © 2014 Elsevier B.V. All rights reserved.

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

PubMed

Bindra, Navin; Dubey, Brajesh; Dutta, Animesh

2015-09-15

As more municipalities and communities across developed world look towards implementing organic waste management programmes or upgrading existing ones, composting facilities are emerging as a popular choice. However, odour from these facilities continues to be one of the most important concerns in terms of cost & effective mitigation. This paper provides a technological and life cycle assessment of some of the different odour control technologies and treatment methods that can be implemented in organics processing facilities. The technological assessment compared biofilters, packed tower wet scrubbers, fine mist wet scrubbers, activated carbon adsorption, thermal oxidization, oxidization chemicals and masking agents. The technologies/treatment methods were evaluated and compared based on a variety of operational, usage and cost parameters. Based on the technological assessment it was found that, biofilters and packed bed wet scrubbers are the most applicable odour control technologies for use in organics processing faculties. A life cycle assessment was then done to compare the environmental impacts of the packed-bed wet scrubber system, organic (wood-chip media) bio-filter and inorganic (synthetic media) bio-filter systems. Twelve impact categories were assessed; cumulative energy demand (CED), climate change, human toxicity, photochemical oxidant formation, metal depletion, fossil depletion, terrestrial acidification, freshwater eutrophication, marine eutrophication, terrestrial eco-toxicity, freshwater eco-toxicity and marine eco-toxicity. The results showed that for all impact categories the synthetic media biofilter had the highest environmental impact, followed by the wood chip media bio-filter system. The packed-bed system had the lowest environmental impact for all categories. Copyright © 2015 Elsevier B.V. All rights reserved.

A simple behaviour provides accuracy and flexibility in odour plume tracking--the robotic control of sensory-motor coupling in silkmoths.

PubMed

Ando, Noriyasu; Kanzaki, Ryohei

2015-12-01

Odour plume tracking is an essential behaviour for animal survival. A fundamental strategy for this is to move upstream and then across-stream. Male silkmoths, Bombyx mori, display this strategy as a pre-programmed sequential behaviour. They walk forward (surge) in response to the female sex pheromone and perform a zigzagging 'mating dance'. Though pre-programmed, the surge direction is modulated by bilateral olfactory input and optic flow. However, the nature of the interaction between these two sensory modalities and contribution of the resultant motor command to localizing an odour source are still unknown. We evaluated the ability of the silkmoth to localize an odour source under conditions of disturbed sensory-motor coupling, using a silkmoth-driven mobile robot. The significance of the bilateral olfaction of the moth was confirmed by inverting the olfactory input to the antennae, or its motor output. Inversion of the motor output induced consecutive circling, which was inhibited by covering the visual field of the moth. This suggests that the corollary discharge from the motor command and the reafference of self-generated optic flow generate compensatory signals to guide the surge accurately. Additionally, after inverting the olfactory input, the robot successfully tracked the odour plume by using a combination of behaviours. These results indicate that accurate guidance of the reflexive surge by integrating bilateral olfactory and visual information with innate pre-programmed behaviours increases the flexibility to track an odour plume even under disturbed circumstances. © 2015. Published by The Company of Biologists Ltd.

Real time monitoring to the odour of excrement for health of infants and elderly completely bedridden

NASA Astrophysics Data System (ADS)

Ye, Jiancheng; Huang, Guoliang

2017-01-01

In the domain of biomedical signals measurements, monitoring human physiological parameters is an important issue. With the rapid development of wireless body area network, it makes monitor, transmit and record physiological parameters faster and more convenient. Infants and the elderly completely bedridden are two special groups of the society who need more medical care. According to researches investigating current frontier domains and the market products, the detection of physiological parameters from the excrement is rare. However, urine and faeces contain a large number of physiological information, which are high relative to health. The mainly distributed odour from urine is NH4 and the distributed odour from feces is mainly H2S, which are both could be detected by the sensors. In this paper, we introduce the design and implementation of a portable wireless device based on body area network for real time monitoring to the odour of excrement for health of infants and the elderly completely bedridden. The device not only could monitor in real time the emitted odour of faeces and urine for health analysis, but also measures the body temperature and environment humidity, and send data to the mobile phone of paramedics to alarm or the server for storage and process, which has prospect to monitoring infants and the paralysis elderly.

Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blazy, V., E-mail: vincent.blazy@irstea.fr; Guardia, A. de, E-mail: amaury.de-guardia@irstea.fr; Benoist, J.C

Highlights: • The gaseous emissions produced by various composting process conditions were characterized and quantified. • Nine compounds were potentially odorous: TMA, NH{sub 3}, 2-pentanone, 1-propanol-2-methyl, acetophenone and sulphur forms. • The tested composting process conditions reduced odour emissions by a factor of 5–10. • A reduction of 10{sup 5} to 10{sup 6} is required to reach an odour threshold limit at peak event emissions. • Both aeration rate and bulking agent had the most impact on reducing odour emissions. - Abstract: Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, compostingmore » odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aeration in 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10 < 20 and 20 < 30 mm. Out-going gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC–MS). Fifty-nine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and bulking agent to waste ratio: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone and 1-propanol-2-methyl. However, dropping the aeration rate and increasing the bulking agent to waste ratio reduced gaseous odour emissions by a factor of 5–10, when the required threshold dilution factor ranged from 10{sup 5} to 10{sup 6}, to avoid nuisance at peak emission rates. Process influence on emissions of dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide were poorly correlated with both aeration rate and bulking agent to waste ratio as a reaction with hydrogen sulphide was suspected. Acetophenone emissions originated from the wood chips. Olfactory measurements need to be correlated to gaseous emissions for a more accurate odour emission evaluation.« less

Behavioural responses of stable flies to cattle manure slurry associated odourants

USDA-ARS?s Scientific Manuscript database

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

Profiling the decomposition odour at the grave surface before and after probing.

PubMed

Forbes, S L; Troobnikoff, A N; Ueland, M; Nizio, K D; Perrault, K A

2016-02-01

Human remains detection (HRD) dogs are recognised as a valuable and non-invasive search method for remains concealed in many different environments, including clandestine graves. However, the search for buried remains can be a challenging task as minimal odour may be available at the grave surface for detection by the dogs. Handlers often use a soil probe during these searches in an attempt to increase the amount of odour available for detection, but soil probing is considered an invasive search technique. The aim of this study was to determine whether the soil probe assists with increasing the abundance of volatile organic compounds (VOCs) available at the grave surface. A proof-of-concept method was developed using porcine remains to collect VOCs within the grave without disturbing the burial environment, and to compare their abundance at the grave surface before and after probing. Detection and identification of the VOC profiles required the use of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) due to its superior sensitivity and selectivity for decomposition odour profiling. The abundance of decomposition VOCs was consistently higher within the grave environment compared to the grave surface, except when the grave surface had been disturbed, confirming the reduced availability of odour at the grave surface. Although probing appeared to increase the abundance of VOCs at the grave surface on many of the sampling days, there were no clear trends identified across the study and no direct relationships with the environmental variables measured. Typically, the decomposition VOCs that were most prevalent in the grave soil were the same VOCs detected at the grave surface, whereas the trace VOCs detected in these environments varied throughout the post-burial period. This study highlighted that probing the soil can assist with releasing decomposition VOCs but is likely correlated to environmental and burial variables which require further study. The use of a soil probe to assist HRD dogs should not be disregarded but should only follow the use of non-invasive methods if deemed appropriate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Odours from marine plastic debris induce food search behaviours in a forage fish.

PubMed

Savoca, Matthew S; Tyson, Chris W; McGill, Michael; Slager, Christina J

2017-08-16

Plastic pollution is an anthropogenic stressor in marine ecosystems globally. Many species of marine fish (more than 50) ingest plastic debris. Ingested plastic has a variety of lethal and sublethal impacts and can be a route for bioaccumulation of toxic compounds throughout the food web. Despite its pervasiveness and severity, our mechanistic understanding of this maladaptive foraging behaviour is incomplete. Recent evidence suggests that the chemical signature of plastic debris may explain why certain species are predisposed to mistaking plastic for food. Anchovy ( Engraulis sp.) are abundant forage fish in coastal upwelling systems and a critical prey resource for top predators. Anchovy ingest plastic in natural conditions, though the mechanism they use to misidentify plastic as prey is unknown. Here, we presented wild-caught schools of northern anchovy ( Engraulis mordax ) with odour solutions made of plastic debris and clean plastic to compare school-wide aggregation and rheotactic responses relative to food and food odour presentations. Anchovy schools responded to plastic debris odour with increased aggregation and reduced rheotaxis. These results were similar to the effects food and food odour presentations had on schools. Conversely, these behavioural responses were absent in clean plastic and control treatments. To our knowledge, this is the first experimental evidence that adult anchovy use odours to forage. We conclude that the chemical signature plastic debris acquires in the photic zone can induce foraging behaviours in anchovy schools. These findings provide further support for a chemosensory mechanism underlying plastic consumption by marine wildlife. Given the trophic position of forage fish, these findings have considerable implications for aquatic food webs and possibly human health. © 2017 The Author(s).

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

NASA Technical Reports Server (NTRS)

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

1996-01-01

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

Improvement of a wind-tunnel sampling system for odour and VOCs.

PubMed

Wang, X; Jiang, J; Kaye, R

2001-01-01

Wind-tunnel systems are widely used for collecting odour emission samples from surface area sources. Consequently, a portable wind-tunnel system was developed at the University of New South Wales that was easy to handle and suitable for sampling from liquid surfaces. Development work was undertaken to ensure even air-flows above the emitting surface and to optimise air velocities to simulate real situations. However, recovery efficiencies for emissions have not previously been studied for wind-tunnel systems. A series of experiments was carried out for determining and improving the recovery rate of the wind-tunnel sampling system by using carbon monoxide as a tracer gas. It was observed by mass balance that carbon monoxide recovery rates were initially only 37% to 48% from a simulated surface area emission source. It was therefore apparent that further development work was required to improve recovery efficiencies. By analysing the aerodynamic character of air movement and CO transportation inside the wind-tunnel, it was determined that the apparent poor recoveries resulted from uneven mixing at the sample collection point. A number of modifications were made for the mixing chamber of the wind-tunnel system. A special sampling chamber extension and a sampling manifold with optimally distributed sampling orifices were developed for the wind-tunnel sampling system. The simulation experiments were repeated with the new sampling system. Over a series of experiments, the recovery efficiency of sampling was improved to 83-100% with an average of 90%, where the CO tracer gas was introduced at a single point and 92-102% with an average of 97%, where the CO tracer gas was introduced along a line transverse to the sweep air. The stability and accuracy of the new system were determined statistically and are reported.

Pregnancy is detected via odour in a wild cooperative breeder.

PubMed

Mitchell, J; Cant, M A; Nichols, H J

2017-11-01

Among mammals, scent has long been known to encode oestrus; however, in many species, detecting pregnancy may also be important in terms of both competition and mate-choice. Here, we show, through odour presentation experiments, that pregnancy is discernible via scent by both sexes in the cooperatively breeding banded mongoose, Mungos mungo Males spent more time investigating and were more likely to scent mark the odours of non-pregnant females, compared to pregnant females. Females showed increased levels of scent marking when odours were of the same reproductive state as themselves. These results present the first direct demonstration that pregnancy is detectable via scent in wild cooperative breeders. Detecting pregnancy may be particularly important in cooperative breeders as, in addition to the competition between males for receptive mates, there is also intense competition between females for access to alloparental care. Consequently, dominant females benefit from targeting reproductive suppression towards subordinates that represent direct threats, such as pregnant females. © 2017 The Author(s).

Round robin test for odour testing of migration waters.

PubMed

Rapp, Thomas; Günther, Herbert

2015-04-15

For a round robin test for EN 1420-1 (Odour assessment for organic materials in contact with drinking water) with 14 contributing laboratories from 10 European countries segments of a plastic pipe were sent to the laboratories which performed a migration test and an odour analysis of the migration waters (water that had contact with the organic material) according to the procedure described in the standard from 1999. In addition reference substances (Methyl tert-butyl ether, 1-butanol and hexanal) were investigated for their suitability to qualify the panels and the individual panellists. Methyl tert-butyl ether (MtBE) and 1-butanol proved to be suitable for this purpose, whereas hexanal showed a wide distribution of the individual odour threshold concentrations. Both possible testing options (unforced and forced choice) were performed and gave similar results. However, with respect to the qualification of the panellists and the data analysis the unforced choice procedure showed advantages. As human olfactory perception is used for the analysis, the reproducibility and the comparability between laboratories is of particular concern. For the pipe material the TON results of the different laboratories were in a range of ±1.5 dilutions based on a dilution factor of 2. This might be improved by taking the individual sensitivities of the panellists into account more strongly. Appropriate measures for the improvement of the test method appear to be the use of the proposed reference substances for the training of the panellists as well as the auditing and the selection of the panellists. The results of this round robin test are used in the revision process of the standard. Copyright © 2015 Elsevier Ltd. All rights reserved.

Context-dependent memory: colour versus odour.

PubMed

Pointer, S C; Bond, N W

1998-06-01

An olfactory stimulus and a visual stimulus were employed in a context-dependent memory study using a prose passage as the to-be-remembered item. Ninety-five university students (aged 17-35 years) learned the passage of prose in the presence of one of the stimuli and were then asked to recall the passage with the original context either reinstated or not reinstated. The results revealed a significant context-dependent memory effect for the olfactory cue but not for the visual cue. They demonstrate support for the effectiveness of odours as context cues and it is suggested that context-dependent memory processes may underlie the formation and retrieval of odour-evoked autobiographical memories.

Identification and quantification of odours from oxobiodegradable polyethylene oxidised under a free radical flow by headspace solid-phase microextraction followed by gas chromatography-olfactometry-mass spectrometry.

PubMed

Wrona, Magdalena; Vera, Paula; Pezo, Davinson; Nerín, Cristina

2017-09-01

Recently oxobiodegradable polyethylene gained popularity as food packaging material due to its potential to reduce polymer waste. However, this type of material can release after its oxidation off-odour compounds that affect the organoleptic properties of packaged food. Odour compounds released from both polyethylene and oxobiodegradable polyethylene before and after oxidation under a free radicals flow were investigated after 1 day, 2 days and 3 days of oxidation. The samples were analysed using headspace solid phase microextraction followed by gas chromatography-mass spectrometry and headspace solid phase microextraction coupled to gas chromatography-olfactometry-mass spectrometry. Sixty-two different odorous compounds were identified. 4-methylthio-2-butanone (fruit), nonanal (fat) and 3,6-nonadienal (fat) were present in different materials before oxidation. Multiple headspace-solid phase microextraction has been used to quantify all analytes. The most abundant compound was (Z)-3-hexenyl hexanoate with a concentration range between 1.5791±0.1387µg/g and 4.8181±0.3123µg/g. Compounds such as 2-dodecenal, 2-octenal, 2-pentanol, 3-nonenal, 3,6-nonadienal, ethyl 3-methylbutanoate, ethyl octenoate, hexanone, isopropyl hexanoate, octanal were below their LOD evaluated using MS detector; however, they were detected by gas chromatography-olfactometry. The minimum LOD and LOQ were 0.011µg/g and 0.036µg/g, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2015-01-01

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

Social learning of floral odours inside the honeybee hive.

PubMed

Farina, Walter M; Grüter, Christoph; Díaz, Paula C

2005-09-22

A honeybee hive serves as an information centre in which communication among bees allows the colony to exploit the most profitable resources in a continuously changing environment. The best-studied communication behaviour in this context is the waggle dance performed by returning foragers, which encodes information about the distance and direction to the food source. It has been suggested that another information cue, floral scents transferred within the hive, is also important for recruitment to food sources, as bee recruits are more strongly attracted to odours previously brought back by foragers in both honeybees and bumble-bees. These observations suggested that honeybees learn the odour from successful foragers before leaving the hive. However, this has never been shown directly and the mechanisms and properties of the learning process remain obscure. We tested the learning and memory of recruited bees in the laboratory using the proboscis extension response (PER) paradigm, and show that recruits indeed learn the nectar odours brought back by foragers by associative learning and retrieve this memory in the PER paradigm. The associative nature of this learning reveals that information was gained during mouth-to-mouth contacts among bees (trophallaxis). Results further suggest that the information is transferred to long-term memory. Associative learning of food odours in a social context may help recruits to find a particular food source faster.

Characterization of the spoilage potential of pure and mixed cultures of bacterial species isolated from tropical yellowfin tuna (Thunnus albacares).

PubMed

Silbande, A; Cornet, J; Cardinal, M; Chevalier, F; Rochefort, K; Smith-Ravin, J; Adenet, S; Leroi, F

2018-02-01

The spoilage potential of 28 bacterial strains isolated from spoiled raw yellowfin tuna was evaluated. Bacterial species were inoculated in irradiated tuna matrix. Chemical changes, bacterial growth and sensory quality were monitored during aerobic storage at 8°C. Pseudomonas spp., Enterobacter spp. and Escherichia hermanii had no spoiling effect. Brochothrix thermosphacta and Carnobacterium divergens/maltaromaticum developed moderate unpleasant odours. Hafnia paralvei and Serratia spp. released strong off-odours (pyrrolidine, sulphur/cabbage). No bacterial group (except H. paralvei) combined with Pseudomonas spp. deteriorated the sensory quality of tuna. When C. divergens/maltaromaticum was associated with H. paralvei or B. thermosphacta, the odour is close to the naturally contaminated tuna stored on the same conditions. The pH, total volatile basic nitrogen (TVBN) and trimethylamine (TMA) were not correlated with the spoilage. The bacterial species had a different impact on the sensory quality of the fish. The bacterial interactions lead to an enhancement or an inhibition of the spoilage potential and the bacterial growth. The specific spoilage organism (SSO) appears to be an association of lactic acid bacteria (LAB) with Enterobacteriaceae or B. thermosphacta. Pseudomonas, often dominant at the sensory rejection time, is not a good quality indicator. © 2017 The Society for Applied Microbiology.

Informational conflicts created by the waggle dance

PubMed Central

Grüter, Christoph; Balbuena, M. Sol; Farina, Walter M

2008-01-01

The honeybee (Apis mellifera) waggle dance is one of the most intriguing animal communication signals. A dancing bee communicates the location of a profitable food source and its odour. Followers may often experience situations in which dancers indicate an unfamiliar location but carry the scent of a flower species the followers experienced previously at different locations. Food scents often reactivate bees to resume food collection at previously visited food patches. This double function of the dance creates a conflict between the social vector information and the private navigational information. We investigated which kind of information followers with field experience use in this situation and found that followers usually ignored the spatial information encoded by the waggle dance even if they followed a dance thoroughly (five waggle runs or more). They relied on private information about food source locations instead (in 93% of all cases). Furthermore, foragers preferred to follow dancers carrying food odours they knew from previous field trips, independently of the spatial information encoded in the dance. Surprisingly, neither odour identity nor the location indicated by the dancer was an important factor for the reactivation success of a dance. Our results contrast with the assumption that (i) followers usually try to decode the vector information and (ii) dances indicating an unfamiliar location are of little interest to experienced foragers. PMID:18331980

Informational conflicts created by the waggle dance.

PubMed

Grüter, Christoph; Balbuena, M Sol; Farina, Walter M

2008-06-07

The honeybee (Apis mellifera) waggle dance is one of the most intriguing animal communication signals. A dancing bee communicates the location of a profitable food source and its odour. Followers may often experience situations in which dancers indicate an unfamiliar location but carry the scent of a flower species the followers experienced previously at different locations. Food scents often reactivate bees to resume food collection at previously visited food patches. This double function of the dance creates a conflict between the social vector information and the private navigational information. We investigated which kind of information followers with field experience use in this situation and found that followers usually ignored the spatial information encoded by the waggle dance even if they followed a dance thoroughly (five waggle runs or more). They relied on private information about food source locations instead (in 93% of all cases). Furthermore, foragers preferred to follow dancers carrying food odours they knew from previous field trips, independently of the spatial information encoded in the dance. Surprisingly, neither odour identity nor the location indicated by the dancer was an important factor for the reactivation success of a dance. Our results contrast with the assumption that (i) followers usually try to decode the vector information and (ii) dances indicating an unfamiliar location are of little interest to experienced foragers.

Sensory aspects of drinking water in contact with epoxy lined copper pipe.

PubMed

Heim, T H; Dietrich, A M

2007-01-01

Pipe relining via in situ epoxy lining is used to remediate corroded plumbing or distribution systems. This investigation examined the effects on odour, TOC, THM formation and disinfectant demand in water exposed to epoxy-lined copper pipes used for home plumbing. The study was conducted in accordance with the Utility Quick Test, a migration/leaching method for utilities to conduct sensory analysis of materials in contact with drinking water. The test was performed using water with no disinfectant and levels of chlorine and monochloramines representative of those found in the distribution system. Panelists repeatedly and consistently described a "plastic/adhesive/putty" odour in the water from the pipes. The odour intensity remained relatively constant for each of two subsequent flushes. Water samples stored in the epoxy-lined pipes showed a significant increase in the leaching of organic compounds (as TOC), and this TOC was demonstrated to react with free chlorine to form trichloromethane. Water stored in the pipes also showed a marked increase in disinfectant demand relative to the water stored in glass control flasks. A study conducted at a full scale installation at an apartment demonstrated that after installation and regular use, the epoxy lining did not yield detectable differences in water quality.

Performance study of biofilter developed to treat H2S from wastewater odour

PubMed Central

Omri, Ilhem; Aouidi, Fethia; Bouallagui, Hassib; Godon, Jean-Jacques; Hamdi, Moktar

2013-01-01

Biofiltration is an efficient biotechnological process used for waste gas abatement in various industrial processes. It offers low operating and capital costs and produces minimal secondary waste streams. The objective of this study was to evaluate the performance of a pilot scale biofilter in terms of pollutants’ removal efficiencies and the bacterial dynamics under different inlet concentrations of H2S. The treatment of odourous pollutants by biofiltration was investigated at a municipal wastewater treatment plant (WWTP) (Charguia, Tunis, Tunisia). Sampling and analyses were conducted for 150 days. Inlet H2S concentration recorded was between 200 and 1300 mg H2S.m−3. Removal efficiencies reached 99% for the majority of the running time at an empty bed retention time (EBRT) of 60 s. Heterotrophic bacteria were found to be the dominant microorganisms in the biofilter. The bacteria were identified as the members of the genus Bacillus, Pseudomonas and xanthomonadacea bacterium. The polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) method showed that bacterial community profiles changed with the H2S inlet concentration. Our results indicated that the biofilter system, containing peat as the packing material, was proved able to remove H2S from the WWTP odourous pollutants. PMID:23961233

Infection and body odours: evolutionary and medical perspectives.

PubMed

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

2009-09-01

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

[Blockade of the pheromonal effects in rat by central deafferentation of the accessory olfactory system].

PubMed

Sánchez-Criado, J E

1979-06-01

Female rats reared without sex odours from male rats have a five day stral cycle. With exposure to male odour the estral cycle is shortened from five to four days. This pheromonal effect is blocked on deafferenting the vomeronasal system by electrolytically damaging both accessory olfactory bulbs.

Origins of brain asymmetry: lateralization of odour memory recall in primitive Australian stingless bees.

PubMed

Frasnelli, Elisa; Vallortigara, Giorgio; Rogers, Lesley J

2011-10-10

Left-right antennal asymmetry has been reported in honeybees. We studied primitive social bees to investigate the evolutionary origins of the asymmetry. Three species of Australian native, stingless bees (Trigona carbonaria, Trigona hockingsi and Austroplebeia australis) were trained to discriminate two odours, lemon (+)/vanilla (-), using the Proboscis Extension Reflex (PER). Recall of the olfactory memory at 1h after training was better when the odour was presented on the right than on the left side of the bee. In contrast, recall at 5h after training was better when the odour was presented on the left than on the right side of the bee. An additional experiment with T. hockingsi bees, fed with sugar 1h before recall and tested at 5h, produced similar results, showing that the shift in lateralized recall was due to the lapse of time per se and not to changes in motivation to feed. Stingless bees show the same laterality as honeybees, suggesting that asymmetry evolved prior to the evolutionary divergence of these species. Copyright © 2011 Elsevier B.V. All rights reserved.

Round goby Neogobius melanostomus attraction to conspecific and heterospecific egg odours.

PubMed

Yavno, S; Corkum, L D

2011-06-01

In this study, cannibalistic and predatory responses of juvenile Neogobius melanostomus (either fed or deprived of food and caught during the reproductive summer or non-reproductive winter season) to water washings of fertilized eggs from conspecifics (N. melanostomus), heterospecifics (rainbow trout Oncorhynchus mykiss) and control lake water were tested. Fed juveniles (summer season) spent significantly more time on the side of the flume containing stimuli from conspecific eggs over control water, while significantly preferring control water to heterospecific stimuli. In addition, fish showed a significant preference towards stimuli from conspecific eggs over heterospecific stimuli by associating near conspecific egg odours 1·5 times longer [Correction added after online publication 28 April 2011, text changed]. Fish that were deprived of food, regardless of whether caught during the summer or winter season, did not show any preference towards either conspecific or heterospecific stimuli. These findings show that conspecific egg odours attract fed juveniles and that there is a potential to lure fish to odour traps as a means of control. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Effect of light Sphagnum peat on odour formation in the early stages of biowaste composting.

PubMed

Kurola, Jukka M; Arnold, Mona; Kontro, Merja H; Talves, Matti; Romantschuk, Martin

2010-05-01

In the present study, we investigated the effects of two bulking materials, Sphagnum peat and pine wood chips, on the early stages of biowaste composting in two pilot-scale processes. Emphasis was placed on studying the formation conditions of malodorous compost gases in the initial phases of the processes. The results showed that gas emission leaving an open windrow and a closed drum composting system contained elevated concentrations of fermentative microbial metabolites when acid Sphagnum peat (pH 3.2) was used as a bulking material. Moreover, the gas emission of the peat amended drum composter contained a high concentration of odour (up to 450,000oum(-3) of air). The highest odour values in the outlet gas of peat amended composts coincided with the elevated concentrations of volatile organic compounds such as acetoin and buthanedion. We conclude that the acidifying qualities of composting substrates or bulking material may intensify odour emission from biowaste composts and prolong the early stages of the composting process. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Comparison of field olfactometers in a controlled chamber using hydrogen sulfide as the test odorant.

PubMed

McGinley, M A; McGinley, C M

2004-01-01

A standard method for measuring and quantifying odour in the ambient air utilizes a portable odour detecting and measuring device known as a field olfactometer (US Public Health Service Project Grant A-58-541). The field olfactometer dynamically dilutes the ambient air with carbon-filtered air in distinct ratios known as "Dilutions-to-Threshold" dilution factors (D/Ts), i.e. 2, 4, 7, 15, etc. Thirteen US states and several cities in North America currently utilize field olfactometry as a key component of determining compliance to odour regulations and ordinances. A controlled environmental chamber was utilized, with hydrogen sulfide as the known test odorant. A hydrogen sulfide environment was created in this controlled chamber using an Advanced Calibration Designs, Inc. Cal2000 Hydrogen Sulfide Generator. The hydrogen sulfide concentration inside the chamber was monitored using an Arizona Instruments, Inc. Jerome Model 631 H2S Analyzer. When the environmental chamber reached a desired test concentration, test operators entered the chamber. The dilution-to-threshold odour concentration was measured using a Nasal Ranger Field Olfactometer (St Croix Sensory, Inc.) and a Barnebey Sutcliffe Corp. Scentometer. The actual hydrogen sulfide concentration was also measured at the location in the room where the operators were standing while using the two types of field olfactometers. This paper presents a correlation between dilution-to-threshold values (D/T) and hydrogen sulfide ambient concentration. For example, a D/T of 7 corresponds to ambient H2S concentrations of 5.7-15.6 microg/m3 (4-11 ppbv). During this study, no significant difference was found between results obtained using the Scentometer or the Nasal Ranger (r = 0.82). Also, no significant difference was found between results of multiple Nasal Ranger users (p = 0.309). The field olfactometers yielded hydrogen sulfide thresholds of 0.7-3.0 microg/m3 (0.5-2.0 ppbv). Laboratory olfactometry yielded comparable thresholds of 0.64-1.3 microg/m3 (0.45-0.9 ppbv). These thresholds are consistent with published values.

Differential Attraction of Malaria Mosquitoes to Volatile Blends Produced by Human Skin Bacteria

PubMed Central

Verhulst, Niels O.; Andriessen, Rob; Groenhagen, Ulrike; Bukovinszkiné Kiss, Gabriella; Schulz, Stefan; Takken, Willem; van Loon, Joop J. A.; Schraa, Gosse; Smallegange, Renate C.

2010-01-01

The malaria mosquito Anopheles gambiae sensu stricto is mainly guided by human odour components to find its blood host. Skin bacteria play an important role in the production of human body odour and when grown in vitro, skin bacteria produce volatiles that are attractive to A. gambiae. The role of single skin bacterial species in the production of volatiles that mediate the host-seeking behaviour of mosquitoes has remained largely unknown and is the subject of the present study. Headspace samples were taken to identify volatiles that mediate this behaviour. These volatiles could be used as mosquito attractants or repellents. Five commonly occurring species of skin bacteria were tested in an olfactometer for the production of volatiles that attract A. gambiae. Odour blends produced by some bacterial species were more attractive than blends produced by other species. In contrast to odours from the other bacterial species tested, odours produced by Pseudomonas aeruginosa were not attractive to A. gambiae. Headspace analysis of bacterial volatiles in combination with behavioural assays led to the identification of six compounds that elicited a behavioural effect in A. gambiae. Our results provide, to our knowledge, the first evidence for a role of selected bacterial species, common on the human skin, in determining the attractiveness of humans to malaria mosquitoes. This information will be used in the further development of a blend of semiochemicals for the manipulation of mosquito behaviour. PMID:21209854

Searching for anatomical correlates of olfactory lateralization in the honeybee antennal lobes: A morphological and behavioural study

PubMed Central

Frasnelli, Elisa; Vinegoni, Claudio; Antolini, Renzo; Anfora, Gianfranco; Vallortigara, Giorgio; Haase, Albrecht

2011-01-01

The honeybee, Apis mellifera L. (Hymenoptera: Apidae), has recently become a model for studying brain asymmetry among invertebrates. A strong lateralization favouring the right antenna was discovered in odour learning and short-term memory recall experiments, and a lateral shift favouring the left antenna for long-term memory recall. Corresponding morphological asymmetries have been found in the distribution of olfactory sensilla between the antennae and confirmed by electrophysiological odour response measurements in isolated right and left antennae. The aim of this study was to investigate whether a morphological asymmetry can be observed in the volume of the primary olfactory centres of the central nervous system, the antennal lobes (ALs). Precise volume measurements of a subset of their functional units, the glomeruli, were performed in both sides of the brain, exploiting the advantages of two-photon microscopy. This novel method allowed minimal invasive acquisition of volume images of the ALs, avoiding artefacts from brain extraction and dehydration. The study was completed by a series of behavioural experiments in which response asymmetry in odour recall following proboscis extension reflex conditioning was assessed for odours, chosen to stimulate strong activity in the same glomeruli as in the morphological study. The volumetric measurements found no evidence of lateralization in the investigated glomeruli within the experimental limits. Instead, in the behavioural experiments, a striking odour dependence of the lateralization was observed. The results are discussed on the basis of recent neurophysiological and ethological experiments in A. mellifera. PMID:21402106

Body odour preferences in men and women: do they aim for specific MHC combinations or simply heterozygosity?

PubMed Central

Wedekind, C; Füri, S

1997-01-01

The major histocompatibility complex (MHC) is an immunologically important group of genes that appears to be under natural as well as sexual selection. Several hypotheses suggest that certain MHC-allele combinations (usually heterozygous ones) are superior under selective pressure by pathogens. This could influence mate choice in a way that preferences function to create MHC-heterozygous offspring, or that they function to create specific allele combinations that are beneficial under the current environmental conditions through their complementary or epistatic effects. To test these hypotheses, we asked 121 men and women to score the odours of six T-shirts, worn by two women and four men. Their scorings of pleasantness correlated negatively with the degree of MHC similarity between smeller and T-shirt-wearer in men and women who were not using the contraceptive pill (but not in Pill-users). Depending on the T-shirt-wearer, the amount of variance in the scorings of odour pleasantness that was explained by the degree of MHC similarity (r2) varied between nearly 0 and 23%. There was no apparent effect of gender in this correlation: the highest r2 was actually reached with one of the male odours sniffed by male smellers. Men and women who were reminded of their own mate/ex-mate when sniffing a T-shirt had significantly fewer MHC-alleles in common with this T-shirt-wearer than expected by chance. This suggests that the MHC or linked genes influence human mate choice. We found no significant effect when we tested for an influence of the MHC on odour preferences after the degree of similarity between T-shirt-wearer and smeller was statistically controlled for. This suggests that in our study populations the MHC influences body odour preferences mainly, if not exclusively, by the degree of similarity or dissimilarity. The observed preferences would increase heterozygosity in the progeny. They do not seem to aim for more specific MHC combinations. PMID:9364787

Odour Samples Degradation During Detention in Tedlar® Bags.

PubMed

Szyłak-Szydłowski, Mirosław

In indirect olfactometry analysis, to avoid condensation or adsorption processes during or storage of the sample, containers made of suitable materials should be used. Also, reaction between the chemicals during transport from the source of the odour to the research laboratory is an important process which can influence on examinations' results. Study included determination of the odour and compound concentrations of six gas mixtures. Gas samples were collected by silicone hoses into Tedlar ® bags and tested by Nasal Ranger, SM-100 olfactometers and Photovac Voyager gas chromatograph. Time of keeping gas in bags was 78 h, and concentration of compounds was measured every hour, eight times per day. For benzene, acetone, 1,1-dichloroethylene, c-1,2-dichloroethylene, t-1,2-dichloroethylene, methyl ethyl ketone and vinyl chloride, 100 % decrease of concentration has been noticed within 78 h of holding in the bag. Average rate of loss of most compounds concentration was from 0.01 to 2.50 % for the first 30 h and from 0.35 to 18.50 % during the last 48 h of examination. Decreasing of odour concentration measured by Nasal Ranger (NR) in all series was between 0.00 and 4.98 % till 30 h, between 1.91 and 100 % in the last 48 h of test and between 1.61 and 100 % in 78 h. In case of odour concentration measured by SM, those values were, respectively, 1.26-4.93 %, 1.39-4.93 % and 2.40-3.18 %. Values of average rate of intensity decreasing were, respectively, 0.77-1.75 %, 2.36-4.67 % and 1.18-2.07 %. Statistically significant correlation coefficients for compound concentrations and intensity, odour concentration obtained by SM-100 as well as NR were, respectively, 0.55-0.97, 0.47-0.99 and 0.37-0.98.

Key considerations for the experimental training and evaluation of cancer odour detection dogs: lessons learnt from a double-blind, controlled trial of prostate cancer detection

PubMed Central

2014-01-01

Background Cancer detection using sniffer dogs is a potential technology for clinical use and research. Our study sought to determine whether dogs could be trained to discriminate the odour of urine from men with prostate cancer from controls, using rigorous testing procedures and well-defined samples from a major research hospital. Methods We attempted to train ten dogs by initially rewarding them for finding and indicating individual prostate cancer urine samples (Stage 1). If dogs were successful in Stage 1, we then attempted to train them to discriminate prostate cancer samples from controls (Stage 2). The number of samples used to train each dog varied depending on their individual progress. Overall, 50 unique prostate cancer and 67 controls were collected and used during training. Dogs that passed Stage 2 were tested for their ability to discriminate 15 (Test 1) or 16 (Tests 2 and 3) unfamiliar prostate cancer samples from 45 (Test 1) or 48 (Tests 2 and 3) unfamiliar controls under double-blind conditions. Results Three dogs reached training Stage 2 and two of these learnt to discriminate potentially familiar prostate cancer samples from controls. However, during double-blind tests using new samples the two dogs did not indicate prostate cancer samples more frequently than expected by chance (Dog A sensitivity 0.13, specificity 0.71, Dog B sensitivity 0.25, specificity 0.75). The other dogs did not progress past Stage 1 as they did not have optimal temperaments for the sensitive odour discrimination training. Conclusions Although two dogs appeared to have learnt to select prostate cancer samples during training, they did not generalise on a prostate cancer odour during robust double-blind tests involving new samples. Our study illustrates that these rigorous tests are vital to avoid drawing misleading conclusions about the abilities of dogs to indicate certain odours. Dogs may memorise the individual odours of large numbers of training samples rather than generalise on a common odour. The results do not exclude the possibility that dogs could be trained to detect prostate cancer. We recommend that canine olfactory memory is carefully considered in all future studies and rigorous double-blind methods used to avoid confounding effects. PMID:24575737

Improvement of organoleptic quality of retted cassava products by alkali pretreatment of roots and addition of sodium nitrate during retting.

PubMed

Ogbo, Frank C

2003-12-15

Alkali pretreatment of cassava roots before retting and addition of sodium nitrate during retting were used to manipulate the metabolism of microorganisms involved in cassava (Manihot esculenta Crantz) retting, as a method for removing the characteristic offensive odour of retted cassava products. Odour was assessed by organoleptic methods. The characteristics of fermentation of cassava by the traditional method (control) were as follows; aerobic mesophilic count (APC) on nutrient agar (NA) at 30 degrees C/48 h, attained a maximum of 2.3 x 10(7)/ml retting juice while counts on de Man Rogosa and Sharpe agar (MRS) at 30 degrees C/48 h were 1.6 x 10(8)/ml. Maximum titrable acidity was 0.062% lactic acid by weight of retting juice. Cassava was retted in 3 days and the product exhibited characteristic offensive odour. Addition of NaNO3 into retting water effectively removed odour at a concentration of 0.3 g/l. Maximum APC on NA/30 degrees C/48 h was 6.8 x 10(6)/ml. Counts on MRS/30 degrees C/48 h exceeded 2.4 x 10(9)/ml. Retting was complete in 3 days with a final titrable acidity of 0.068% of retting juice. Removal of odour likely resulted from selection of homo-fermentative lactic acid bacteria, thus producing mostly odourless lactic acid. Alkali pretreatment of roots before retting was efficacious in removing odour at a concentration of 10 g/l for 30 min. This fermentation was characterized by APC on NA/30 degrees C/48 h of 5.4 x 10(6)/ml; MRS/30 degrees C/48 h reached a maximum of only 10 x 10(4)/ml and correspondingly low titrable acidity of 0.003%. Low counts of lactic acid bacteria correlate well with the absence of odour in this sample. Both treatments did not adversely affect the detoxification process, yielding "foo-foo" with HCN levels lower than 10 mg/kg. Residual nitrates and nitrites of 30 mg/kg in the sodium nitrate-treated sample were also within the safe limits of 156 mg/kg allowed in many countries. Organoleptically improved samples were acceptable to the public.

Physicochemical and sensory (aroma and colour) characterisation of a non-centrifugal cane sugar ("panela") beverage.

PubMed

García, Juliana María; Narváez, Paulo César; Heredia, Francisco José; Orjuela, Álvaro; Osorio, Coralia

2017-08-01

Non-centrifugal cane sugar (NCS), also called "panela", is a high carbohydrate-content food obtained by boil evaporation of the sugar cane juice. This study was undertaken to assess physicochemical properties and sensory characteristics of panela beverage at two different concentrations. Evaluation of pH, °Brix, and colour (tristimulus colorimetry) was carried out in all panela drink samples. In order to characterise the odour-active volatiles of the beverage, a simultaneous steam distillation-solvent extraction method was applied using a mixture of diethyl ether-pentane (1:1,w/w) as solvent. The Aroma Extract Dilution Analysis revealed the presence of six odour-active compounds, being 2-methyl pyrazine the key aroma compound of this beverage. PCA (Principal Component Analysis) showed that there were no differences in the aroma and physicochemical properties (pH and °Brix) with respect to the geographical origin of analysed samples; however colour depends on heating during processing of NCS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sensory quality of beef from different finishing diets.

PubMed

Resconi, V C; Campo, M M; Font i Furnols, M; Montossi, F; Sañudo, C

2010-11-01

Beef production under different local husbandry systems might have meat sensory quality implications for the marketing of these products abroad. In order to assess the effect of finishing diet systems on beef quality, a trained sensory taste panel assessed meat aged for 20 days from 80 Uruguayan Hereford steers that were finished on one of the following diets: T1=Pasture [4% of animal live weight (LW)], T2=Pasture [3% LW plus concentrate (0.6% LW)], T3=Pasture [3% LW plus concentrate (1.2% LW)], or T4=Concentrate plus hay ad libitum. Beef odour and flavour intensities decreased with an increase in the energy content of the diet. The meat from T2 had the lowest acid flavour and strange odours intensities. In general, steers fed only concentrate plus hay (T4) produced meat that had an inferior sensory quality because they had more pronounced off-flavours and was tougher. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Comparison of four kinds of extraction techniques and kinetics of microwave-assisted extraction of vanillin from Vanilla planifolia Andrews.

PubMed

Dong, Zhizhe; Gu, Fenglin; Xu, Fei; Wang, Qinghuang

2014-04-15

Vanillin yield, microscopic structure, antioxidant activity and overall odour of vanilla extracts obtained by different treatments were investigated. MAE showed the strongest extraction power, shortest time and highest antioxidant activity. Maceration gave higher vanillin yields than UAE and PAE, similar antioxidant activity with UAE, but longer times than UAE and PAE. Overall odour intensity of different vanilla extracts obtained by UAE, PAE and MAE were similar, while higher than maceration extracts. Then, powered vanilla bean with a sample/solvent ratio of 4 g/100 mL was selected as the optimum condition for MAE. Next, compared with other three equations, two-site kinetic equation with lowest RMSD and highest R²(adj) was shown to be more suitable in describing the kinetics of vanillin extraction. By fitting the parameters C(eq), k₁, k₂, and f, a kinetics model was constructed to describe vanillin extraction in terms of irradiation power, ethanol concentration, and extraction time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Consumers' sensitivity to androstenone and the evaluation of different cooking methods to mask boar taint.

PubMed

Borrisser-Pairó, F; Panella-Riera, N; Gil, M; Kallas, Z; Linares, M B; Egea, M; Garrido, M D; Oliver, M A

2017-01-01

Boar taint is an unpleasant odour and flavour present in some entire male pigs that is due to the presence of androstenone and skatole. The aim of the study was to assess the sensitivity of 150 consumers to androstenone and to compare the acceptability and liking of meat from castrated and entire pigs, cooked with different cooking methods. Meat samples consisted of loins from castrated (CM) and entire male pigs (EM) with high levels of androstenone cooked by two cooking methods: sous-vide and fried/breaded with garlic and parsley. Consumers evaluated smell and flavour acceptability, and overall liking of CM and EM for each cooking method. The results of the study showed that dislike of androstenone odour increased significantly with sensitivity. The results of acceptability and overall liking were similar in CM and EM for both cooking methods. Therefore, the two cooking methods used in the study may be useful to mask boar taint. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of an active packaging with citrus extract on lipid oxidation and sensory quality of cooked turkey meat.

PubMed

Contini, Claudia; Álvarez, Rocío; O'Sullivan, Michael; Dowling, Denis P; Gargan, Sean Óg; Monahan, Frank J

2014-03-01

An antioxidant active packaging was prepared by coating a citrus extract, consisting of a mixture of carboxylic acids and flavanones, on polyethylene terephthalate trays. The effect of the packaging in reducing lipid oxidation in cooked turkey meat and on meat pH, colour characteristics and sensorial parameters was investigated. An untrained sensory panel evaluated the odour, taste, tenderness, juiciness and overall acceptability of the meat, using triangle, paired preference and quantitative response scale tests. A comparison between the antioxidant effects of the different components of the extract was also carried out. The packaging led to a significant reduction in lipid oxidation. After 2 days of refrigerated storage the sensory panel detected differences in odour and, after 4 days, rated the meat stored in the active packaging higher for tenderness and overall acceptability. Citric acid appeared to be the most important component of the extract with regard to its antioxidant potency. Copyright © 2013 Elsevier Ltd. All rights reserved.

Intra-oral adsorption and release of aroma compounds following in-mouth wine exposure.

PubMed

Esteban-Fernández, Adelaida; Rocha-Alcubilla, Nuria; Muñoz-González, Carolina; Moreno-Arribas, María Victoria; Pozo-Bayón, María Ángeles

2016-08-15

Wine "after-odour" defined as the long lasting aroma perception that remains after wine swallowing is an outstanding characteristic in terms of wine quality but a relatively unstudied phenomenon. Among the different parameters that might affect wine after-odour, the adsorption of odorants by the oral mucosa could be important but has been little explored. In this work, the impact of the chemical characteristics of aroma compounds on intra-oral adsorption was assessed by an in vivo approach that determined the amounts of odorants remaining in expectorated wine samples. In addition, the subsequent aroma release after in-mouth wine exposure was studied by means of intra-oral SPME/GC-MS using three different panellists. Oral adsorption of the aroma compounds added to the wines ranged from 6% to 43%, depending on their physicochemical characteristics. A progressive intra-oral aroma decrease at different decay rates depending on compound type and panellist was also found. The strength of the aroma-oral mucosa interactions seems to explain these results more than the amount of compound adsorbed by the oral mucosa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantification of brown dog tick repellents, 2-hexanone and benzaldehyde, and release from tick-resistant beagles, Canis lupus familiaris

USDA-ARS?s Scientific Manuscript database

We have recently shown that repellency of the tick Rhipicephalus sanguineus sensu lato by the tick resistant dog breed Beagle is mediated by volatile organic compounds 2-hexanone and benzaldehyde present in Beagle dog odour. Ectoparasite location on animal hosts is affected by variation in odour com...

OTM Machine Acceptance: In the Arab Culture

NASA Astrophysics Data System (ADS)

Rashed, Abdullah; Santos, Henrique

Basically, neglecting the human factor is one of the main reasons for system failures or for technology rejection, even when important technologies are considered. Biometrics mostly have the characteristics needed for effortless acceptance, such as easiness and usefulness, that are essential pillars of acceptance models such as TAM (technology acceptance model). However, it should be investigated. Many studies have been carried out to research the issues of technology acceptance in different cultures, especially the western culture. Arabic culture lacks these types of studies with few publications in this field. This paper introduces a new biometric interface for ATM machines. This interface depends on a promising biometrics which is odour. To discover the acceptance of this biometrics, we distributed a questionnaire via a web site and called for participation in the Arab Area and found that most respondents would accept to use odour.

'Nosing Around' the human skin: what information is concealed in skin odour?

PubMed

Kippenberger, Stefan; Havlíček, Jan; Bernd, August; Thaçi, Diamant; Kaufmann, Roland; Meissner, Markus

2012-09-01

In today's world, natural body odour is mostly considered as being unpleasant and combated by intensive cleansing, deodorants and perfumes. However, there is evidence that volatile body compounds provide the recipient with important information. Here, we present the chemical identity of odorous compounds derived from odourless precursors within sweat and sebum. Moreover, distinct volatile markers may be relevant for the clinical diagnosis of disease. Interestingly, ageing seems to correlate with the appearance of specific compounds that convey the so-called old man smell. Finally, it is discussed if human skin odour has the quality to act as pheromone transmitting information between individuals in terms of major histocompatibility complex type or reproductive status. © 2012 John Wiley & Sons A/S.

Study of Odours and taste for Space Food

NASA Astrophysics Data System (ADS)

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

2012-07-01

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

Differential ultrasonic indices of separation distress in the presence and absence of maternal cues in infant rats bred for high and low positive social affect.

PubMed

Iacobucci, Paolo; Colonnello, Valentina; Fuchs, Thomas; D'Antuono, Laura; Panksepp, Jaak

2013-10-01

Preclinical models of human mood disorders commonly focus on the study of negative affectivity, without comparably stressing the role of positive affects and their ability to promote resilient coping styles. We evaluated the role of background constitutional affect of rats by studying the separation and reunion responses of infants from low and high positive affect genetic lines (i.e., differentially selected for High and Low 50 kHz ultrasonic vocalisations (USVs). Infants from Low and High 50 kHz USV breeding lines were isolated from mothers and exposed to either social (familiar or unfamiliar bedding) or neutral (clean bedding) odour cues between two short isolation periods, and tested in homeothermic and hypothermic ambient temperatures. Negative affect was estimated by monitoring separation distress calls (35-45 kHz USVs). Low Line pups called at higher rates than High Line, and their rates were stable regardless of odour cue. In contrast, High Line pups increased vocalisations during the second compared with the first isolation periods and during exposure to both familiar and unfamiliar odour cues, but not to neutral odour. Furthermore, the greatest increase in USV emission was seen in the second isolation period following exposure to the unfamiliar odour. However, both lines showed comparable elevated distress USVs to the thermal stressor. High Line animals, selected for a positive affective phenotype (50 kHz USVs), exhibited reduced separation anxiety responses in infancy, making this a promising animal model for the role of constitutional affective states in emotional responsivity and potential resilience against emotional disorders.

Long-term study of migration of volatile organic compounds from cross-linked polyethylene (PEX) pipes and effects on drinking water quality.

PubMed

Lund, Vidar; Anderson-Glenna, Mary; Skjevrak, Ingun; Steffensen, Inger-Lise

2011-09-01

The objectives of this study were to investigate migration of volatile organic compounds (VOCs) from cross-linked polyethylene (PEX) pipes used for drinking water produced by different production methods, and to evaluate their potential risk for human health and/or influence on aesthetic drinking water quality. The migration tests were carried out in accordance with EN-1420-1, and VOCs were analysed by gas chromatography-mass spectrometry. The levels of VOC migrating from new PEX pipes were generally low, and decreasing with time of pipe use. No association was found between production method of PEX pipes and concentration of migration products. 2,4-di-tert-butyl phenol and methyl tert-butyl ether (MTBE) were two of the major individual components detected. In three new PEX pipes, MTBE was detected in concentrations above the recommended US EPA taste and odour value for drinking water, but decreased below this value after 5 months in service. However, the threshold odour number (TON) values for two pipes were similar to new pipes even after 1 year in use. For seven chemicals for which conclusions on potential health risk could be drawn, this was considered of no or very low concern. However, odour from some of these pipes could negatively affect drinking water for up to 1 year.

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

ERIC Educational Resources Information Center

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

2009-01-01

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

Foraging activity of commensal Mus musculus in semi-captivity conditions. Effect of predator odours, previous experience and moonlight.

PubMed

Busch, María; Burroni, Nora E

2015-12-01

Mus musculus is a pest in urban and rural habitats where it consumes and contaminates food and may transmit diseases to human and domestic animals. Its control by anticoagulants is partially effective because of aversive behaviours and resistance. In this context, we wanted to assess the potential of the use of predator odours as repellents in experimental feeding trials using urine and faeces of domestic cats and faeces of geoffroyi cat, a wild small felid that is one of the main rodent predators in the study area. We also assessed the effect of previous experience and moonlight on foraging activity. We did not find an aversive response to cat odours in Mus musculus individuals. There was a trend to consume food in the same feeding stations over time, and the visit rate was lower in periods with high moonlight than in periods with low moonlight. Predator odours did not seem to be useful as rodent repellents, but maintaining illumination may lower rodent foraging activity. As rodents maintain their feeding sites over time, toxic baits may be more efficiently placed at sites previously known to be used by rodents. © 2014 Society of Chemical Industry.

Effect of matured compost as an inoculating agent on odour removal and maturation of vegetable and fruit waste compost.

PubMed

Chen, Chih-Yu; Kuo, Jong-Tar; Chung, Ying-Chien

2013-01-01

The use of matured compost as an inoculation agent to improve the composting of vegetable and fruit wastes in a laboratory-scale composter was evaluated, and the commercial feasibility of this approach in a pilot-scale (1.8 x 10(4) L) composter was subsequently confirmed. The effect of aeration rate on the physico-chemical and biological properties of compost was also studied. Aeration rate affected the fermentation temperature, moisture content, pH, O2 consumption rate, CO2 production rate and the formation of odour. The optimal aeration rate was 2.5 L air/kg dry solid/min. The CO2 production rate approached the theoretical value during composting and was linearly dependent on temperature, indicating that the compost system had good operating characteristics. The inoculation of cellulolytic bacteria and deodorizing bacteria to compost in the pilot-scale composter led to an 18.2% volatile solids loss and a 64.3% volume reduction ratio in 52 h; only 1.5 ppm(v) odour was detected. This is the first study to focus on both operating performance and odour removal in a pilot-scale composter.

Olfactory impairment in first-episode schizophrenia: a case-control study, and sex dimorphism in the relationship between olfactory impairment and psychotic symptoms.

PubMed

Chen, Xiacan; Xu, Jiajun; Li, Bin; Guo, Wanjun; Zhang, Jun; Hu, Junmei

2018-06-18

A body of studies has focused on the olfactory impairment among people with schizophrenia. The effect of sex on this relationship has attracted the attention of researchers. These issues have not been studied much in Chinese schizophrenia patients. We conducted a case-control study of 110 first-episode antipsychotic medicine naïve schizophrenia patients aged 18-35 years and 110 controls, matched by age and sex. Odour threshold, discrimination and identification were assessed by the "Sniffin' Sticks" test. Psychotic symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). The odour threshold, discrimination and identification scores of patients with schizophrenia were significantly lower than those of the healthy control group. The difference in identification score had statistical significance between male and female patients with schizophrenia (t = - 2.45, P < 0.05). Controlling for confounding factor, in male schizophrenia participants, the negative subscale score was significantly and inversely correlated with the discrimination (γ = - 0.37, p < 0.008), identification (γ = - 0.45, p < 0.008) and TDI (γ = - 0.50, p < 0.008) scores; the general psychopathology subscale score was inversely and significantly correlated with the identification (γ = - 0.47, p < 0.008) and TDI (γ = - 0.41, p < 0.008) scores. For female schizophrenia patients, positive and general psychopathology subscale scores had a significant inverse correlation with the identification score (positive: γ = - 0.47, p < 0.008; general psychopathology: γ = - 0.42, p < 0.008). Controlling for confounder, negative symptoms were related to impaired odour discrimination and identification in male schizophrenia patients, while positive symptoms were correlated with impaired odour identification in female schizophrenia patients. This sex dimorphism could provide useful information for future studies aiming to finding biomarkers of schizophrenia.

Patterns of odour emission, thermogenesis and pollinator activity in cones of an African cycad: what mechanisms apply?

PubMed

Suinyuy, Terence N; Donaldson, John S; Johnson, Steven D

2013-09-01

Ontogenetic patterns of odour emissions and heating associated with plant reproductive structures may have profound effects on insect behaviour, and consequently on pollination. In some cycads, notably Macrozamia, temporal changes in emission of specific odour compounds and temperature have been interpreted as a 'push-pull' interaction in which pollinators are either attracted or repelled according to the concentration of the emitted volatiles. To establish which mechanisms occur in the large Encephalartos cycad clade, the temporal patterns of volatile emissions, heating and pollinator activity of cones of Encephalartos villosus in the Eastern Cape (EC) and KwaZulu Natal (KZN) of South Africa were investigated. Gas chromatography-mass spectrometry (GC-MS) analyses of Encephalartos villosus cone volatiles showed that emissions, dominated by eucalyptol and 2-isopropyl-3-methoxypyrazine in EC populations and (3E)-1,3-octadiene and (3E,5Z)-1,3,5-octatriene in the KZN populations, varied across developmental stages but did not vary significantly on a daily cycle. Heating in male cones was higher at dehiscence than during pre- and post-dehiscence, and reached a maximum at about 1830 h when temperatures were between 7·0 and 12·0 °C above ambient. Daily heating of female cones was less pronounced and reached a maximum at about 1345 h when it was on average between 0·9 and 3·0 °C above ambient. Insect abundance on male cones was higher at dehiscence than at the other stages and significantly higher in the afternoon than in the morning and evening. There are pronounced developmental changes in volatile emissions and heating in E. villosus cones, as well as strong daily changes in thermogenesis. Daily patterns of volatile emissions and pollinator abundance in E. villosus are different from those observed in some Macrozamia cycads and not consistent with the push-pull pattern as periods of peak odour emission do not coincide with mass exodus of insects from male cones.

Emissions of volatile sulfur compounds (VSCs) throughout wastewater biosolids processing.

PubMed

Fisher, R M; Le-Minh, N; Alvarez-Gaitan, J P; Moore, S J; Stuetz, R M

2018-03-01

Volatile sulfur compounds (VSCs) are important contributors to nuisance odours from the processing of wastewater sludge and biosolids. However, emission characteristics are difficult to predict as they vary between sites and are likely to be affected by biosolids processing configuration and operation. VSC emissions from biosolids throughout 6 wastewater treatment plants (WWTPs) in Sydney, Australia were examined in this study. H 2 S was the VSC found at the highest concentrations throughout the WWTPs, with concentrations ranging from 7 to 39,000μg/m 3 . Based on odour activity values (OAVs), H 2 S was typically also the most dominant odorant. However, methyl mercaptan (MeSH) was also found to be sensorially important in the biosolids storage areas given its low odour detection threshold (ODT). High concentrations of VOSCs such as MeSH in the storage areas were shown to potentially interfere with H 2 S measurements using the Jerome 631-X H 2 S sensor and these interferences should be investigated in more detail. The VSC composition of emissions varied throughout biosolids processing as well as between the different WWTPs. The primary sludge and biosolids after dewatering and during storage, were key stages producing nuisance odours as judged by the determination of OAVs. Cluster analysis was used to group sampling locations according to VSC emissions. These groups were typically the dewatered and stored biosolids, primary and thickened primary sludge, and waste activated sludge (WAS), thickened WAS, digested sludge and centrate. Effects of biosolids composition and process operation on VSC emissions were evaluated using best subset regression. Emissions from the primary sludge were dominated by H 2 S and appeared to be affected by the presence of organic matter, pH and Fe content. While volatile organic sulfur compounds (VOSCs) emitted from the produced biosolids were shown to be correlated with upstream factors such as Fe and Al salt dosing, anaerobic digestion and dewatering parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed

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

2007-07-01

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

Impact of olfactory and auditory priming on the attraction to foods with high energy density.

PubMed

Chambaron, S; Chisin, Q; Chabanet, C; Issanchou, S; Brand, G

2015-12-01

\\]\\Recent research suggests that non-attentively perceived stimuli may significantly influence consumers' food choices. The main objective of the present study was to determine whether an olfactory prime (a sweet-fatty odour) and a semantic auditory prime (a nutritional prevention message), both presented incidentally, either alone or in combination can influence subsequent food choices. The experiment included 147 participants who were assigned to four different conditions: a control condition, a scented condition, an auditory condition or an auditory-scented condition. All participants remained in the waiting room during15 min while they performed a 'lure' task. For the scented condition, the participants were unobtrusively exposed to a 'pain au chocolat' odour. Those in the auditory condition were exposed to an audiotape including radio podcasts and a nutritional message. A third group of participants was exposed to both olfactory and auditory stimuli simultaneously. In the control condition, no stimulation was given. Following this waiting period, all participants moved into a non-odorised test room where they were asked to choose, from dishes served buffet-style, the starter, main course and dessert that they would actually eat for lunch. The results showed that the participants primed with the odour of 'pain au chocolat' tended to choose more desserts with high energy density (i.e., a waffle) than the participants in the control condition (p = 0.06). Unexpectedly, the participants primed with the nutritional auditory message chose to consume more desserts with high energy density than the participants in the control condition (p = 0.03). In the last condition (odour and nutritional message), they chose to consume more desserts with high energy density than the participants in the control condition (p = 0.01), and the data reveal an additive effect of the two primes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fish odor syndrome.

PubMed

Rehman, H U

1999-08-01

Fish odour syndrome (trimethylaminuria) is a metabolic syndrome caused by abnormal excretion of trimethylamine in the breath, urine, sweat, saliva and vaginal secretions. Trimethylamine is derived from the intestinal bacterial degradation of foods rich in choline and carnitine and is normally oxidised by the liver to odorless trimethylamine N-oxide which is then excreted in the urine. Impaired oxidation of trimethylamine is thought to be the cause of the fish odour syndrome and is responsible for the smell of rotting fish. Certain foods rich in choline exacerbate the condition and the patients have a variety of psychological problems. Recognition of the condition is important as dietary adjustments reduce the excretion of trimethylamine and may reduce the odour. Occasionally, a short course of metronidazole, neomycin and lactulose may suppress production of trimethylamine by reducing the activity of gut microflora.

Different molecular types of Pseudomonas fragi have the same overall behaviour as meat spoilers.

PubMed

Ercolini, Danilo; Casaburi, Annalisa; Nasi, Antonella; Ferrocino, Ilario; Di Monaco, Rossella; Ferranti, Pasquale; Mauriello, Gianluigi; Villani, Francesco

2010-08-15

The functional diversity of a population of sixty-five different strains of P. fragi isolated from fresh and spoiled meat was studied in order to evaluate the population heterogeneity related to meat spoilage potential. The strains were characterized for the proteolytic activity at 4 degrees C on beef sarcoplasmic proteins and only 9 strains were found to be proteolytic. An iron-dependent growth behaviour was shown when each strain was grown in citrate medium containing either myoglobin, haemoglobin or iron chloride as iron sources. Increase of maximum population and mu(max) in presence of different iron sources was registered. The release of volatile organic compounds (VOC) by each strain in beef during aerobic storage at 4 degrees C was evaluated by GC-MS. A considerable variability of occurrence of each molecule in the GC-MS profiles obtained by the different strains was observed ranging from 3% to 79% although the strains showed a high degree of similarity. In particular, ethylhexanoate, ethyloctanoate, ethylnonenoate, ethyldecanoate, 1-octen-3-ol, 3-octanone, 4-methylthiophenol, and 2-pentylfurane were produced by more than 50% of the strains. Representative strains were used to spoil meat in the same conditions used for the VOC analysis and the samples were evaluated by a sensory panel. The results of the sensory analysis indicated that the different strains could significantly affect the odour of meat and strains characterized by production of esters gave fruity odours to the spoiled meat. However, the similarity of strains based on the sensory profiles does not necessarily match the similarity shown in VOC profiles. P. fragi has a significant role in the microbial ecology of meat and the influence of meat-related sources of iron on the growth behaviour of many different strains suggests that meat can be an ecological niche for P. fragi. Regardless of the proteolytic and lipolytic capacities shown in vitro, different molecular types of P. fragi can release odour active volatile molecules and play a similar overall role as spoilage agents of meat. Copyright 2010 Elsevier B.V. All rights reserved.

Detection and quantification of ochratoxin A and deoxynivalenol in barley grains by GC-MS and electronic nose.

PubMed

Olsson, J; Börjesson, T; Lundstedt, T; Schnürer, J

2002-02-05

Mycotoxin contamination of cereal grains can be detected and quantified using complex extraction procedures and analytical techniques. Normally, the grain odour, i.e. the presence of non-grain volatile metabolites, is used for quality classification of grain. We have investigated the possibility of using fungal volatile metabolites as indicators of mycotoxins in grain. Ten barley samples with normal odour, and 30 with some kind of off-odour were selected from Swedish granaries. The samples were evaluated with regard to moisture content, fungal contamination, ergosterol content, and levels of ochratoxin A (OA) and deoxynivalenol (DON). Volatile compounds were also analysed using both an electronic nose and gas chromatography combined with mass spectrometry (GC-MS). Samples with normal odour had no detectable ochratoxin A and average DON contents of 16 microg kg(-1) (range 0-80), while samples with off-odour had average OA contents of 76 microg kg(-1) (range 0-934) and DON contents of 69 microg kg(-1) (range 0-857). Data were evaluated by multivariate data analysis using projection methods such as principal component analysis (PCA) and partial least squares (PLS). The results show that it was possible to classify the OA level as below or above the maximum limit of 5 microg kg(-1) cereal grain established by the Swedish National Food Administration, and that the DON level could be estimated using PLS. Samples with OA levels below 5 microg kg(-1) had higher concentration of aldehydes (nonanal, 2-hexenal) and alcohols (1-penten-3-ol, 1-octanol). Samples with OA levels above 5 microg kg(-1) had higher concentrations of ketones (2-hexanone, 3-octanone). The GC-MS system predicted OA concentrations with a higher accuracy than the electronic nose, since the GC-MS misclassified only 3 of 37 samples and the electronic nose 7 of 37 samples. No correlation was found between odour and OA level, as samples with pronounced or strong off-odours had OA levels both below and above 5 microg kg(-1). We were able to predict DON levels in the naturally contaminated barley samples using the volatile compounds detected and quantified by either GC-MS or the electronic nose. Pentane, methylpyrazine, 3-pentanone, 3-octene-2-ol and isooctylacetate showed a positive correlation with DON, while ethylhexanol, pentadecane, toluene, 1-octanol, 1-nonanol, and 1-heptanol showed a negative correlation with DON. The root mean square error of estimation values for prediction of DON based on GC-MS and electronic nose data were 16 and 25 microg kg(-1), respectively.

Flavour-enhanced cortisol release during gum chewing

PubMed Central

Hasegawa, Yoko; Tachibana, Yoshihisa; Ono, Takahiro; Kishimoto, Hiromitsu

2017-01-01

There is some evidence to suggest that chewing gum reduces chronic stress. However, it remains controversial how the taste and odour properties of chewing gum influence stress. The present study was designed to investigate this issue in human subjects. Using an enzyme-linked immunosorbent assay, we tested salivary cortisol concentration, which is thought to be a stress marker, in 96 adults who chewed gum with different combinations of taste and odour. Subjects could discriminate between the types of gum without prior information. Salivary cortisol concentrations were highest and lowest for the subjects who chewed the most flavourful gum and the least flavourful gum, respectively. These findings suggest that the salivary cortisol level during gum chewing is not a marker of negative emotions (i.e., stressful conditions) as traditionally considered but, rather, an index of positive emotions that can facilitate biological responses to overcome stressful conditions. PMID:28379983

Flavour-enhanced cortisol release during gum chewing.

PubMed

Hasegawa, Yoko; Tachibana, Yoshihisa; Ono, Takahiro; Kishimoto, Hiromitsu

2017-01-01

There is some evidence to suggest that chewing gum reduces chronic stress. However, it remains controversial how the taste and odour properties of chewing gum influence stress. The present study was designed to investigate this issue in human subjects. Using an enzyme-linked immunosorbent assay, we tested salivary cortisol concentration, which is thought to be a stress marker, in 96 adults who chewed gum with different combinations of taste and odour. Subjects could discriminate between the types of gum without prior information. Salivary cortisol concentrations were highest and lowest for the subjects who chewed the most flavourful gum and the least flavourful gum, respectively. These findings suggest that the salivary cortisol level during gum chewing is not a marker of negative emotions (i.e., stressful conditions) as traditionally considered but, rather, an index of positive emotions that can facilitate biological responses to overcome stressful conditions.

Lateral presynaptic inhibition mediates gain control in an olfactory circuit.

PubMed

Olsen, Shawn R; Wilson, Rachel I

2008-04-24

Olfactory signals are transduced by a large family of odorant receptor proteins, each of which corresponds to a unique glomerulus in the first olfactory relay of the brain. Crosstalk between glomeruli has been proposed to be important in olfactory processing, but it is not clear how these interactions shape the odour responses of second-order neurons. In the Drosophila antennal lobe (a region analogous to the vertebrate olfactory bulb), we selectively removed most interglomerular input to genetically identified second-order olfactory neurons. Here we show that this broadens the odour tuning of these neurons, implying that interglomerular inhibition dominates over interglomerular excitation. The strength of this inhibitory signal scales with total feedforward input to the entire antennal lobe, and has similar tuning in different glomeruli. A substantial portion of this interglomerular inhibition acts at a presynaptic locus, and our results imply that this is mediated by both ionotropic and metabotropic receptors on the same nerve terminal.

NaturCare from AlphaMed: the non-scented ostomy deodorant.

PubMed

Rudoni, C; Sica, J

NaturCare is an ostomy deodorant manufactured and distributed by AlphaMed. Currently, it is the only non-scented deodorant available on prescription. Odour can be extremely stressful to both the person with a stoma (ostomist) and those involved in their care. Since NaturCare has no artificial scents added to its formula, it can be extremely helpful to those who find the odour embarrassing.

Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge.

PubMed

Blazy, V; de Guardia, A; Benoist, J C; Daumoin, M; Lemasle, M; Wolbert, D; Barrington, S

2014-07-01

Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, composting odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aerationin 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10<20 and 20<30 mm. Out-going gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC-MS). Fifty-nine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and bulking agent to waste ratio: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone and 1-propanol-2-methyl. However, dropping the aeration rate and increasing the bulking agent to waste ratio reduced gaseous odour emissions by a factor of 5-10, when the required threshold dilution factor ranged from 10(5) to 10(6), to avoid nuisance at peak emission rates. Process influence on emissions of dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide were poorly correlated with both aeration rate and bulking agent to waste ratio as a reaction with hydrogen sulphide was suspected. Acetophenone emissions originated from the wood chips. Olfactory measurements need to be correlated to gaseous emissions for a more accurate odour emission evaluation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Removal of geosmin and 2-methylisoborneol by biological filtration.

PubMed

Elhadi, S L N; Huck, P M; Slawson, R M

2004-01-01

The quality of drinking water is sometimes diminished by the presence of certain compounds that can impart particular tastes or odours. One of the most common and problematic types of taste and odour is the earthy/musty odour produced by geosmin (trans-1, 10-dimethyl-trans-9-decalol) and MIB (2-methylisoborneol). Taste and odour treatment processes including powdered activated carbon, and oxidation using chlorine, chloramines, potassium permanganate, and sometimes even ozone are largely ineffective for reducing these compounds to below their odour threshold concentration levels. Ozonation followed by biological filtration, however, has the potential to provide effective treatment. Ozone provides partial removal of geosmin and MIB but also creates other compounds more amenable to biodegradation and potentially undesirable biological instability. Subsequent biofiltration can remove residual geosmin and MIB in addition to removing these other biodegradable compounds. Bench scale experiments were conducted using two parallel filter columns containing fresh and exhausted granular activated carbon (GAC) media and sand. Source water consisted of dechlorinated tap water to which geosmin and MIB were added, as well as, a cocktail of easily biodegradable organic matter (i.e. typical ozonation by-products) in order to simulate water that had been subjected to ozonation prior to filtration. Using fresh GAC, total removals of geosmin ranged from 76 to 100% and total MIB removals ranged from 47% to 100%. The exhausted GAC initially removed less geosmin and MIB but removals increased over time. Overall the results of these experiments are encouraging for the use of biofiltration following ozonation as a means of geosmin and MIB removal. These results provide important information with respect to the role biofilters play during their startup phase in the reduction of these particular compounds. In addition, the results demonstrate the potential biofilters have in responding to transient geosmin and MIB episodes.

Identifying environmental reservoirs of Clostridium difficile with a scent detection dog: preliminary evaluation.

PubMed

Bryce, E; Zurberg, T; Zurberg, M; Shajari, S; Roscoe, D

2017-10-01

Prompted by an article describing a dog trained to detect Clostridium difficile in patients, our institution evaluated a dog's ability to detect C. difficile scent from equipment and surfaces to assist in strategic deployment of adjunctive cleaning measures. An expert in drug and explosives scent dog handling trained a canine to identify odours from pure cultures and/or faecal specimens positive for C. difficile. Methods used to assess explosive and drug detection dogs were adapted and included evaluation of (i) odour recognition, using containers positive and negative for the scent of C. difficile, and of (ii) search capability, on a simulation ward with hidden scents. After demonstration that the canine could accurately and reliably detect the scent of C. difficile, formal assessments of all clinical areas began. Odour recognition (N = 75 containers) had a sensitivity of 100% and specificity of 97%. Search capability was 80% sensitive and 92.9% specific after removal of results from one room where dog and trainer fatigue influenced performance. Both odour recognition and search capability had an overall sensitivity of 92.3% and specificity of 95.4%. The clinical unit sweeps over a period of five months revealed a sensitivity of 100% in alerting on positive quality control hides. These clinical unit sweeps also resulted in 83 alerts during 49 sweep days. A dog can be trained to accurately and reliably detect C. difficile odour from environmental sources to guide the best deployment of adjunctive cleaning measures and can be successfully integrated into a quality infection control programme. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

orco mutant mosquitoes lose strong preference for humans and are not repelled by volatile DEET.

PubMed

DeGennaro, Matthew; McBride, Carolyn S; Seeholzer, Laura; Nakagawa, Takao; Dennis, Emily J; Goldman, Chloe; Jasinskiene, Nijole; James, Anthony A; Vosshall, Leslie B

2013-06-27

Female mosquitoes of some species are generalists and will blood-feed on a variety of vertebrate hosts, whereas others display marked host preference. Anopheles gambiae and Aedes aegypti have evolved a strong preference for humans, making them dangerously efficient vectors of malaria and Dengue haemorrhagic fever. Specific host odours probably drive this strong preference because other attractive cues, including body heat and exhaled carbon dioxide (CO2), are common to all warm-blooded hosts. Insects sense odours via several chemosensory receptor families, including the odorant receptors (ORs), membrane proteins that form heteromeric odour-gated ion channels comprising a variable ligand-selective subunit and an obligate co-receptor called Orco (ref. 6). Here we use zinc-finger nucleases to generate targeted mutations in the orco gene of A. aegypti to examine the contribution of Orco and the odorant receptor pathway to mosquito host selection and sensitivity to the insect repellent DEET (N,N-diethyl-meta-toluamide). orco mutant olfactory sensory neurons have greatly reduced spontaneous activity and lack odour-evoked responses. Behaviourally, orco mutant mosquitoes have severely reduced attraction to honey, an odour cue related to floral nectar, and do not respond to human scent in the absence of CO2. However, in the presence of CO2, female orco mutant mosquitoes retain strong attraction to both human and animal hosts, but no longer strongly prefer humans. orco mutant females are attracted to human hosts even in the presence of DEET, but are repelled upon contact, indicating that olfactory- and contact-mediated effects of DEET are mechanistically distinct. We conclude that the odorant receptor pathway is crucial for an anthropophilic vector mosquito to discriminate human from non-human hosts and to be effectively repelled by volatile DEET.

Interference with olfactory memory by visual and verbal tasks.

PubMed

Annett, J M; Cook, N M; Leslie, J C

1995-06-01

It has been claimed that olfactory memory is distinct from memory in other modalities. This study investigated the effectiveness of visual and verbal tasks in interfering with olfactory memory and included methodological changes from other recent studies. Subjects were allocated to one of four experimental conditions involving interference tasks [no interference task; visual task; verbal task; visual-plus-verbal task] and presented 15 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Recognition and recall performance both showed effects of interference of visual and verbal tasks but there was no effect for time of testing. While the results may be accommodated within a dual coding framework, further work is indicated to resolve theoretical issues relating to task complexity.

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

PubMed

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

2016-04-07

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

Kin discrimination via odour in the cooperatively breeding banded mongoose.

PubMed

Mitchell, J; Kyabulima, S; Businge, R; Cant, M A; Nichols, H J

2018-03-01

Kin discrimination is often beneficial for group-living animals as it aids in inbreeding avoidance and providing nepotistic help. In mammals, the use of olfactory cues in kin discrimination is widespread and may occur through learning the scents of individuals that are likely to be relatives, or by assessing genetic relatedness directly through assessing odour similarity (phenotype matching). We use scent presentations to investigate these possibilities in a wild population of the banded mongoose Mungos mungo , a cooperative breeder in which inbreeding risk is high and females breed communally, disrupting behavioural cues to kinship. We find that adults show heightened behavioural responses to unfamiliar (extra-group) scents than to familiar (within-group) scents. Interestingly, we found that responses to familiar odours, but not unfamiliar odours, varied with relatedness. This suggests that banded mongooses are either able to use an effective behavioural rule to identify likely relatives from within their group, or that phenotype matching is used in the context of within-group kin recognition but not extra-group kin recognition. In other cooperative breeders, familiarity is used within the group and phenotype matching may be used to identify unfamiliar kin. However, for the banded mongoose this pattern may be reversed, most likely due to their unusual breeding system which disrupts within-group behavioural cues to kinship.

Resolving the smell of wood - identification of odour-active compounds in Scots pine (Pinus sylvestris L.).

PubMed

Schreiner, Linda; Bauer, Patrick; Buettner, Andrea

2018-05-29

Being one of the most common trees in forests, Pinus sylvestris L. is a frequently used raw material for wood products. Its specific odour is, however, mostly unresolved to date. Accordingly, we investigated Scots pine wood samples grown in Germany for their main odorant composition. We employed dedicated odorant analysis techniques such as gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA) and successfully detected 44 odour-active compounds; of these, 39 substances were successfully identified by gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and two-dimensional gas chromatography-mass spectrometry/olfactometry (2D-GC-MS/O). Among the main odorants found were (E,E)-nona-2,4-dienal, vanillin, phenylacetic acid, 3-phenylpropanoic acid, δ-octalactone and α-pinene, all of them having been detected with high flavour dilution factors during GC-O analyses. The majority of the identified odorants were fatty acid degradation products, plus some terpenoic substances and odorous substances resulting from the degradation of lignin. Although some of the detected substances have previously been reported as constituents of wood, 11 substances are reported here for the first time as odour-active compounds in wood, amongst them heptanoic acid, γ-octalactone, δ-nonalactone and (E,Z,Z)-trideca-2,4,7-trienal.

Annoyance and Worry in a Petrochemical Industrial Area—Prevalence, Time Trends and Risk Indicators

PubMed Central

Axelsson, Gösta; Stockfelt, Leo; Andersson, Eva; Gidlof-Gunnarsson, Anita; Sallsten, Gerd; Barregard, Lars

2013-01-01

In 1992, 1998, and 2006, questionnaires were sent to stratified samples of residents aged 18–75 years living near petrochemical industries (n = 600–800 people on each occasion) and in a control area (n = 200–1,000). The aims were to estimate the long-term prevalence and change over time of annoyance caused by industrial odour, industrial noise, and worries about possible health effects, and to identify risk indicators. In 2006, 20% were annoyed by industrial odour, 27% by industrial noise (1–4% in the control area), and 40–50% were worried about health effects or industrial accidents (10–20% in the control area). Multiple logistic regression analyses revealed significantly lower prevalence of odour annoyance in 1998 and 2006 than in 1992, while industrial noise annoyance increased significantly over time. The prevalence of worry remained constant. Risk of odour annoyance increased with female sex, worry of health effects, annoyance by motor vehicle exhausts and industrial noise. Industrial noise annoyance was associated with traffic noise annoyance and worry of health effects of traffic. Health-risk worry due to industrial air pollution was associated with female sex, having children, annoyance due to dust/soot in the air, and worry of traffic air pollution. PMID:23552810

Bacterial pathogen indicators regrowth and reduced sulphur compounds' emissions during storage of electro-dewatered biosolids.

PubMed

Navab-Daneshmand, Tala; Enayet, Samia; Gehr, Ronald; Frigon, Dominic

2014-10-01

Electro-dewatering (ED) increases biosolids dryness from 10-15 to 30-50%, which helps wastewater treatment facilities control disposal costs. Previous work showed that high temperatures due to Joule heating during ED inactivate total coliforms to meet USEPA Class A biosolids requirements. This allows biosolids land application if the requirements are still met after the storage period between production and application. In this study, we examined bacterial regrowth and odour emissions during the storage of ED biosolids. No regrowth of total coliforms was observed in ED biosolids over 7d under aerobic or anaerobic incubations. To mimic on-site contamination during storage or transport, ED samples were seeded with untreated sludge. Total coliform counts decreased to detection limits after 4d in inoculated samples. Olfactometric analysis of ED biosolids odours showed that odour concentrations were lower compared to the untreated and heat-treated control biosolids. Furthermore, under anaerobic conditions, odorous reduced sulphur compounds (methanethiol, dimethyl sulphide and dimethyl disulphide) were produced by untreated and heat-treated biosolids, but were not detected in the headspaces above ED samples. The data demonstrate that ED provides advantages not only as a dewatering technique, but also for producing biosolids with lower microbial counts and odour levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison between conventional biofilters and biotrickling filters applied to waste bio-drying in terms of atmospheric dispersion and air quality.

PubMed

Schiavon, Marco; Ragazzi, Marco; Torretta, Vincenzo; Rada, Elena Cristina

2016-01-01

Biofiltration has been widely applied to remove odours and volatile organic compounds (VOCs) from industrial off-gas and mechanical-biological waste treatments. However, conventional open biofilters cannot guarantee an efficient dispersion of air pollutants emitted into the atmosphere. The aim of this paper is to compare conventional open biofilters with biotrickling filters (BTFs) in terms of VOC dispersion in the atmosphere and air quality in the vicinity of a hypothetical municipal solid waste bio-drying plant. Simulations of dispersion were carried out regarding two VOCs of interest due to their impact in terms of odours and cancer risk: dimethyl disulphide and benzene, respectively. The use of BTFs, instead of conventional biofilters, led to significant improvements in the odour impact and the cancer risk: when adopting BTFs instead of an open biofilter, the area with an odour concentration > 1 OU m(-3) and a cancer risk > 10(-6) was reduced by 91.6% and 95.2%, respectively. When replacing the biofilter with BTFs, the annual mean concentrations of odorants and benzene decreased by more than 90% in the vicinity of the plant. These improvements are achieved above all because of the higher release height of BTFs and the higher velocity of the outgoing air flow.

A microbial spoilage profile of half shell Pacific oysters (Crassostrea gigas) and Sydney rock oysters (Saccostrea glomerata).

PubMed

Madigan, Thomas L; Bott, Nathan J; Torok, Valeria A; Percy, Nigel J; Carragher, John F; de Barros Lopes, Miguel A; Kiermeier, Andreas

2014-04-01

This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters. Copyright © 2013 Elsevier Ltd. All rights reserved.

Distinct Olfactory Cross-Modal Effects on the Human Motor System

PubMed Central

Rossi, Simone; De Capua, Alberto; Pasqualetti, Patrizio; Ulivelli, Monica; Falzarano, Vincenzo; Bartalini, Sabina; Passero, Stefano; Nuti, Daniele

2008-01-01

Background Converging evidence indicates that action observation and action-related sounds activate cross-modally the human motor system. Since olfaction, the most ancestral sense, may have behavioural consequences on human activities, we causally investigated by transcranial magnetic stimulation (TMS) whether food odour could additionally facilitate the human motor system during the observation of grasping objects with alimentary valence, and the degree of specificity of these effects. Methodology/Principal Findings In a repeated-measure block design, carried out on 24 healthy individuals participating to three different experiments, we show that sniffing alimentary odorants immediately increases the motor potentials evoked in hand muscles by TMS of the motor cortex. This effect was odorant-specific and was absent when subjects were presented with odorants including a potentially noxious trigeminal component. The smell-induced corticospinal facilitation of hand muscles during observation of grasping was an additive effect which superimposed to that induced by the mere observation of grasping actions for food or non-food objects. The odour-induced motor facilitation took place only in case of congruence between the sniffed odour and the observed grasped food, and specifically involved the muscle acting as prime mover for hand/fingers shaping in the observed action. Conclusions/Significance Complex olfactory cross-modal effects on the human corticospinal system are physiologically demonstrable. They are odorant-specific and, depending on the experimental context, muscle- and action-specific as well. This finding implies potential new diagnostic and rehabilitative applications. PMID:18301777

Odour-based kin discrimination in the cooperatively breeding meerkat.

PubMed

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

2013-02-23

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

What determines human body odour?

PubMed

Hamada, Kaoru; Haruyama, Sanehito; Yamaguchi, Takashi; Yamamoto, Kayo; Hiromasa, Kana; Yoshioka, Manabu; Nishio, Daisuke; Nakamura, Motonobu

2014-05-01

Human body odour and earwax type are genetically dependent on a single-nucleotide polymorphism (SNP) located in the ABCC11 gene. So far, it still remains to be clear how SNP in the ABCC11 gene is associated with human malodour. In a recent issue of Experimental Dermatology, Baumann et al. propose one of the underlying molecular pathways. Although one of the amino acid conjugated of the odorants, Cys-Gly-3-methyl-3-sulfanylhexanol (3M3SH), was not taken up by the transporter ABCC11, glutathione conjugate of 3MSH (SG-3MSH) was transported by ABCC11. Moreover, SG-3MSH was processed to 3M3SH by γ-glutamyl-transferase 1 (GGT1), which was abundantly expressed in apocrine sweat glands. These findings may pave a way for the pharmacogenetics of human body odour and the development of innovative deodorant products. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of nitrite on the odourant volatile fraction of cooked ham.

PubMed

Thomas, Caroline; Mercier, Frédéric; Tournayre, Pascal; Martin, Jean-Luc; Berdagué, Jean-Louis

2013-08-15

The aim of this work was to reliably identify the key odour compounds in cooked ham and acquire new knowledge on the role of sodium nitrite on the formation of its aroma. Gas chromatography coupled with mass spectrometry and (or) olfactometry was used. In all, 24 odourants were identified in the volatile fraction of cooked ham. Their main origins are discussed. Orthonasal sniffing of the hams was used to study how these substances contributed to the overall aroma of the product. The aroma of cooked ham is a balance between that of certain sulfur compounds produced during cooking and that of oxidation compounds commonly found in cooked meats. In the absence of nitrite, this balance is disturbed by extensive formation of oxidation compounds that mask the meaty notes induced by the sulfur compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Are biopolymers potential deodourising agents in wound management?

PubMed

Lee, G; Anand, S C; Rajendran, S

2009-07-01

To investigate the odour-adsorbing properties of biopolymers, with a view to using the findings to develop a novel dressing with odour-adsorbing properties. The odour-adsorbing properties of a selection of biopolymers (aloe vera, tea tree oil, neem oil and manuka honey) and three commercially available dressings containing activated charcoal cloth (ACC) were quantitatively assessed using laboratory test equipment. An aloe vera-containing composite dressing, designed and developed by the authors, was also compared with the ACC dressings. Aloe vera was the most adsorbent of the biopolymers and a 40% dilution had comparable values to those of the ACC dressings. Furthermore, values for the novel composite dressing were similar to those of the ACC dressings. The novel composite dressing may be a potential alternative to ACC dressings, and has the added advantages of having antimicrobial properties as well as the ability to promote a moist wound environment. However, more research is needed.

Evolution of mosquito preference for humans linked to an odorant receptor

PubMed Central

McBride, Carolyn S.; Baier, Felix; Omondi, Aman B.; Spitzer, Sarabeth A.; Lutomiah, Joel; Sang, Rosemary; Ignell, Rickard; Vosshall, Leslie B.

2014-01-01

Female mosquitoes are major vectors of human disease and the most dangerous are those that preferentially bite humans. A ‘domestic’ form of the mosquito Aedes aegypti has evolved to specialize in biting humans and is the major worldwide vector of dengue, yellow fever, and Chikungunya viruses. The domestic form coexists with an ancestral, animal-biting ‘forest’ form along the coast of Kenya. We collected the two forms, established laboratory colonies, and document striking divergence in preference for human versus animal odour. We further show that the evolution of preference for human odour in domestic mosquitoes is tightly linked to increases in the expression and ligand-sensitivity of the odorant receptor AaegOr4, which we found recognises a compound present at high levels in human odour. Our results provide a rare example of a gene contributing to behavioural evolution and provide insight into how disease-vectoring mosquitoes came to specialise on humans. PMID:25391959

Olfactory abnormalities in Huntington's disease: decreased plasticity in the primary olfactory cortex of R6/1 transgenic mice and reduced olfactory discrimination in patients.

PubMed

Lazic, Stanley E; Goodman, Anna O G; Grote, Helen E; Blakemore, Colin; Morton, A Jennifer; Hannan, Anthony J; van Dellen, Anton; Barker, Roger A

2007-06-02

Reduced neuronal plasticity in the striatum, hippocampus, and neocortex is a common feature of transgenic mouse models of Huntington's disease (HD). Doublecortin (DCX) and polysialylated neural cell adhesion molecule (PSA-NCAM) are associated with structural plasticity in the adult mammalian brain, are markers of newly formed neurons in the dentate gyrus of the adult hippocampus, and are highly expressed in primary olfactory (piriform) cortex. Animal studies have demonstrated that a reduction in plasticity in the piriform cortex is associated with a selective impairment in odour discrimination. Therefore, the number of DCX and PSA-NCAM immunoreactive cells in the piriform cortex were quantified as measures of plasticity in early stage (fifteen week old) R6/1 transgenic HD mice. The transgenic mice had a large reduction in the number of DCX and PSA-NCAM immunoreactive cells in the piriform cortex, similar to that previously reported in the R6/2 mice. We also tested whether odour discrimination, as well as identification and detection, were impaired in HD patients and found that patients (at a similar disease stage as the mice) had an impairment in odour discrimination and identification, but not odour detection. These results suggest that olfactory impairments observed in HD patients may be the result of reduced plasticity in the primary olfactory cortex.

Microbiological and biochemical origins of human axillary odour.

PubMed

James, A Gordon; Austin, Corrine J; Cox, Diana S; Taylor, David; Calvert, Ralph

2013-03-01

The generation of malodour on various sites of the human body is caused by the microbial biotransformation of odourless natural secretions into volatile odorous molecules. On the skin surface, distinctive odours emanate, in particular, from the underarm (axilla), where a large and permanent population of microorganisms thrives on secretions from the eccrine, apocrine and sebaceous glands. Traditional culture-based microbiological studies inform us that this resident microbiota consists mainly of Gram-positive bacteria of the genera Staphylococcus, Micrococcus, Corynebacterium and Propionibacterium. Among the molecular classes that have been implicated in axillary malodour are short- and medium-chain volatile fatty acids, 16-androstene steroids and, most recently, thioalcohols. Most of the available evidence suggests that members of the Corynebacterium genus are the primary causal agents of axillary odour, with the key malodour substrates believed to originate from the apocrine gland. In this article, we examine, in detail, the microbiology and biochemistry of malodour formation on axillary skin, focussing on precursor-product relationships, odour-forming enzymes and metabolic pathways and causal organisms. As well as reviewing the literature, some relevant new data are presented and considered alongside that already available in the public domain to reach an informed view on the current state-of-the-art, as well as future perspectives. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Relationship between sensory attributes and volatile compounds of polish dry-cured loin

PubMed Central

Górska, Ewa; Nowicka, Katarzyna; Jaworska, Danuta; Przybylski, Wiesław; Tambor, Krzysztof

2017-01-01

Objective The aim of this work was to determine the relationship between objective sensory descriptors and volatile flavour compound composition of Polish traditional dry-cured loin. Methods The volatile compounds were investigated by using solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). For sensory assessment, the quantitative descriptive analysis (QDA) method was used. Results A total of 50 volatile compounds were found and assigned to 17 chemical families. Most of the detected volatile compounds derived from smoking, lipid oxidative reactions and seasoning (46.8%, 21.7%, and 18.9%, respectively). The dominant compounds were: aromatic hydrocarbon (toluene); alkanes (hexane, heptane, and 2,2,4-trimethylpentane); aldehyde (hexanal); alcohol (2-furanmethanol); ketone (3-hydroxy-2-butanone); phenol (guaiacol); and terpenes (eucalyptol, cymene, γ-terpinen, and limonene). Correlation analysis showed that some compounds derived from smoking were positively correlated with the intensity of cured meat odour and flavour and negatively with the intensity of dried meat odour and flavour, while terpenes were strongly correlated with odour and flavour of added spices. Conclusion The analysed dry-cured loins were characterized by specific and unique sensory profile. Odour and flavour of studied loins was mainly determined by volatile compounds originating from smoking, seasoning and lipid oxidation. Obtained results suggest that smoking process is a crucial stage during Polish traditional dry-cured loins production. PMID:27456422

Monitoring aroma changes during human milk storage at +4 °C by sensory and quantification experiments.

PubMed

Spitzer, Johanna; Klos, Katharina; Buettner, Andrea

2013-12-01

The effect of human milk storage in the refrigerator has been investigated with regard to sensory changes and modifications to the molecular composition of the milk odour-active volatiles. In the present study, characteristic odorants from fat oxidation, known from previous studies, as well as free fatty acids were quantified as representative marker substances by means of stable isotope dilution assays of fresh milk samples and milk samples stored at +4 °C for one and three days, respectively. Sensory evaluation showed that rancid and sweaty odour attributes were generated during storage, resulting in an unpleasant aroma profile for adults; however, odour changes were not as pronounced as those observed in our previous study for freeze storage. Fatty and buttery odour notes and a cooked milk-like smell were also generated. In total eight odorants from fat oxidation were determined and some potent odorants showed slight concentration increases. Moreover, five free fatty acids were determined and these all showed drastic concentration increases, even after storage for just one day. These investigations support our previous findings that storage recommendations for breast milk might need to be slightly reconsidered in view of potential sensory changes; on the other hand, no negative physiological effects are to be expected from these changes. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Patterns of odour emission, thermogenesis and pollinator activity in cones of an African cycad: what mechanisms apply?

PubMed Central

Suinyuy, Terence N.; Donaldson, John S.; Johnson, Steven D.

2013-01-01

Background and Aims Ontogenetic patterns of odour emissions and heating associated with plant reproductive structures may have profound effects on insect behaviour, and consequently on pollination. In some cycads, notably Macrozamia, temporal changes in emission of specific odour compounds and temperature have been interpreted as a ‘push–pull’ interaction in which pollinators are either attracted or repelled according to the concentration of the emitted volatiles. To establish which mechanisms occur in the large Encephalartos cycad clade, the temporal patterns of volatile emissions, heating and pollinator activity of cones of Encephalartos villosus in the Eastern Cape (EC) and KwaZulu Natal (KZN) of South Africa were investigated. Methods and Key Results Gas chromatography–mass spectrometry (GC-MS) analyses of Encephalartos villosus cone volatiles showed that emissions, dominated by eucalyptol and 2-isopropyl-3-methoxypyrazine in EC populations and (3E)-1,3-octadiene and (3E,5Z)-1,3,5-octatriene in the KZN populations, varied across developmental stages but did not vary significantly on a daily cycle. Heating in male cones was higher at dehiscence than during pre- and post-dehiscence, and reached a maximum at about 1830 h when temperatures were between 7·0 and 12·0 °C above ambient. Daily heating of female cones was less pronounced and reached a maximum at about 1345 h when it was on average between 0·9 and 3·0 °C above ambient. Insect abundance on male cones was higher at dehiscence than at the other stages and significantly higher in the afternoon than in the morning and evening. Conclusions There are pronounced developmental changes in volatile emissions and heating in E. villosus cones, as well as strong daily changes in thermogenesis. Daily patterns of volatile emissions and pollinator abundance in E. villosus are different from those observed in some Macrozamia cycads and not consistent with the push–pull pattern as periods of peak odour emission do not coincide with mass exodus of insects from male cones. PMID:23887092

Characterisation of odorants in roasted stem tea using gas chromatography-mass spectrometry and gas chromatography-olfactometry analysis.

PubMed

Sasaki, Tetsuya; Koshi, Erina; Take, Harumi; Michihata, Toshihide; Maruya, Masachika; Enomoto, Toshiki

2017-04-01

Roasted stem tea has a characteristic flavour, which is obtained by roasting tea stems, by-product of green tea production. This research aims to understand the characteristic odorants in roasted stem tea by comparing it to roasted leaf tea. We revealed potent odorants in commercial roasted stem tea using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry with aroma extract dilution analysis (AEDA). The difference between roasted stem and leaf tea derived from the same tea plants were investigated using GC-MS. Pyrazine compounds exhibited a roasted odour and high flavour dilution (FD) factors, as determined via AEDA. Roasted stem tea was richer in these pyrazines than roasted leaf tea. Geraniol and linalool exhibited high FD factors and a floral odour, and roasted stem tea was richer in these compounds than roasted leaf tea. These results may have a positive impact on the development of tea products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of volatile compounds responsible for the aroma in naturally fermented sausages by gas chromatography-olfactometry.

PubMed

Olivares, Alicia; Navarro, José Luis; Flores, Mónica

2015-03-01

The objective of this study was to characterize naturally fermented dry sausages produced without the use of microbial starters and to determine which odour-active compounds are responsible for their aroma. The traditional manufacture was responsible for different chemical characteristics and consumer's acceptance. The volatile compounds detected in the headspace comprised a complex mixture of volatile compounds derived from bacterial metabolism (mainly esterase activity of Staphyloccoci), spices and lipid auto-oxidation. The odour-active volatile compounds were identified using gas chromatography coupled to olfactometry (GC-O) using the detection frequency method. The aroma profile was characterized by the presence of several compounds such as acetic acid, ethyl butanoate, hexanal, methional, 1-octen-3-ol, benzeneacetaldehyde and 4-methyl-phenol. However, naturally fermented sausages were also characterized by numerous esters, both ethyl and methyl esters, which impart a wide variety of fruity notes. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Heritability of Attractiveness to Mosquitoes

PubMed Central

Fernández-Grandon, G. Mandela; Gezan, Salvador A.; Armour, John A. L.; Pickett, John A.; Logan, James G.

2015-01-01

Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. Body odour can be controlled genetically but the existence of a genetic basis for differential attraction to insects has never been formally demonstrated. This study investigated heritability of attractiveness to mosquitoes by evaluating the response of Aedes aegypti (=Stegomyia aegypti) mosquitoes to odours from the hands of identical and non-identical twins in a dual-choice assay. Volatiles from individuals in an identical twin pair showed a high correlation in attractiveness to mosquitoes, while non-identical twin pairs showed a significantly lower correlation. Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124) for relative attraction and 0.67 (0.354) for flight activity based on the average of ten measurements. The results demonstrate an underlying genetic component detectable by mosquitoes through olfaction. Understanding the genetic basis for attractiveness could create a more informed approach to repellent development. PMID:25901606

Extraction of essential oil from Cupressus sempervirens: comparison of global yields, chemical composition and antioxidant activity obtained by hydrodistillation and supercritical extraction.

PubMed

Nejia, Herzi; Séverine, Camy; Jalloul, Bouajila; Mehrez, Romdhane; Stéphane, Condoret Jean

2013-01-01

In this study, supercritical fluid extraction (SFE) with CO2 and hydrodistillation (HD) were compared as methods to isolate the essential oil from Cupressus sempervirens. The odour of the oil obtained by SFE at 90 bar and 40°C was very close to the odour of the leaves of C. sempervirens before the extraction. Compounds extracted by both SFE and HD were identified by GC-FID and GC-MS. Moreover, the difference in the chemical composition obtained by SFE and HD was quite noticeable qualitatively and quantitatively. Phenolic composition and antioxidant activity were also determined. Compared to HD, the SFE method presents some advantages: the extraction was completed after 1 h in SFE, although 4 h is necessary for HD, and the yield was improved by 34%. Finally, it has also been shown that SFE is very selective towards some specific components such as manoyl oxide, trans-totarol and α-acoradiene.

Combining Synthetic Human Odours and Low-Cost Electrocuting Grids to Attract and Kill Outdoor-Biting Mosquitoes: Field and Semi-Field Evaluation of an Improved Mosquito Landing Box

PubMed Central

Matowo, Nancy S.; Koekemoer, Lizette L.; Moore, Sarah J.; Mmbando, Arnold S.; Mapua, Salum A.; Coetzee, Maureen; Okumu, Fredros O.

2016-01-01

Background On-going malaria transmission is increasingly mediated by outdoor-biting vectors, especially where indoor insecticidal interventions such as long-lasting insecticide treated nets (LLINs) are widespread. Often, the vectors are also physiologically resistant to insecticides, presenting major obstacles for elimination. We tested a combination of electrocuting grids with synthetic odours as an alternative killing mechanism against outdoor-biting mosquitoes. Methods An odour-baited device, the Mosquito Landing Box (MLB), was improved by fitting it with low-cost electrocuting grids to instantly kill mosquitoes attracted to the odour lure, and automated photo switch to activate attractant-dispensing and mosquito-killing systems between dusk and dawn. MLBs fitted with one, two or three electrocuting grids were compared outdoors in a malaria endemic village in Tanzania, where vectors had lost susceptibility to pyrethroids. MLBs with three grids were also tested in a large semi-field cage (9.6×9.6×4.5m), to assess effects on biting-densities of laboratory-reared Anopheles arabiensis on volunteers sitting near MLBs. Results Significantly more mosquitoes were killed when MLBs had two or three grids, than one grid in wet and dry seasons (P<0.05). The MLBs were highly efficient against Mansonia species and malaria vector, An. arabiensis. Of all mosquitoes, 99% were non-blood fed, suggesting host-seeking status. In the semi-field, the MLBs reduced mean number of malaria mosquitoes attempting to bite humans fourfold. Conclusion The improved odour-baited MLBs effectively kill outdoor-biting malaria vector mosquitoes that are behaviourally and physiologically resistant to insecticidal interventions e.g. LLINs. The MLBs reduce human-biting vector densities even when used close to humans, and are insecticide-free, hence potentially antiresistance. The devices could either be used as surveillance tools or complementary mosquito control interventions to accelerate malaria elimination where outdoor transmission is significant. PMID:26789733

Correlation between preconception maternal non-occupational exposure to interior decoration or oil paint odour and average birth weight of neonates: findings from a nationwide cohort study in China’s rural areas

PubMed Central

Liu, Huiting; Chen, Shi; Zhu, Huijuan; Yang, Hongbo; Gong, Fengying; Wang, Linjie; Jiang, Yu; Lian, Bill Q; Yan, Chengsheng; Li, Jianqang; Wang, Qing; Zhang, Shikun; Pan, Hui

2017-01-01

Background Birth weight is a critical indicator of neonatal health and foretells people’s health in adolescence and even adulthood. Some researchers have warned against the adverse effects on babies’ birth weight of exposure to pollutants in interior decoration or oil paint by odour intake. This study evaluated the effects of maternal exposure to such factors before conception on the birth weights of neonates. Methods Data on 213 461 cases in this study were from the database of the free National Pre-pregnancy Checkups Project. Defined as ‘exposed’ were those women exposed to oil paint odour or interior decoration at home or in the workplace within 6 months before their pregnancy. The study focused on revealing the correlation between such exposure and the birth weight of the neonates of these women, especially the incidence of macrosomia and low birth weight (LBW). Statistical analysis was conducted using the Kruskal–Wallis H test, the Mann–Whitney U test and logistic regression. Results The birth weight of babies from mothers non-occupationally exposed to such settings averaged 3465 g (range 3150–3650 g), whereas the birth weight of those from mothers free of such exposure averaged 3300 g (range 3000–3600g). Maternal exposure preconception to interior decoration or oil paint odour reduced the incidence of LBW in their babies (p=0.003, OR 0.749, 95% CI 0.617 to 0.909). Such exposure may also augment the probability of macrosomia (p<0.001, OR 1.297, 95% CI 1.133 to 1.484). Conclusion Maternal exposure to interior decoration or oil paint odour preconception may increase the average birth weight of neonates, as well as the incidence of macrosomia. PMID:28827230

Social learning in a high-risk environment: incomplete disregard for the 'minnow that cried pike' results in culturally transmitted neophobia.

PubMed

Crane, Adam L; Mathiron, Anthony G E; Ferrari, Maud C O

2015-08-07

Many prey species rely on conspecifics to gather information about unknown predation threats, but little is known about the role of varying environmental conditions on the efficacy of social learning. We examined predator-naive minnows that had the opportunity to learn about predators from experienced models that were raised in either a low- or high-risk environment. There were striking differences in behaviour among models; high-risk models showed a weaker response to the predator cue and became neophobic in response to the control cue (a novel odour, NO). Observers that were previously paired with low-risk models acquired a strong antipredator response only to the predator cue. However, observers that interacted with high-risk models, displayed a much weaker response to the predator odour and a weak neophobic response to the NO. This is the first study reporting such different outcomes of social learning under different environmental conditions, and suggests high-risk environments promote the cultural transmission of neophobia more so than social learning. If such a transfer can be considered similar to secondary traumatization in humans, culturally transmitted neophobia in minnows may provide a good model system for understanding more about the social ecology of fear disorders. © 2015 The Author(s).

Olfactory Disorder Pattern In Patients With Neurological Diseases Excluding Psychiatric And Traumatic Aetiologies.

PubMed

de Haro-Licer, Josep; González-Fernández, Adela; Planas-Comes, Albert; González-Ares, Josep Antón

2018-03-23

The most common cause of olfactory ENT disorders are colds and flu, chronic sinusitis, allergies and traumatic brain injury. Rarer aetiologies include certain neurological, psychiatric and metabolic injuries. The aim of this paper was to check the sort of olfactory disorders found in people who have suffered a brain injury, excluding: cranial traumas, psychiatric diseases, epilepsy, Parkinson's and Alzheimer's disease, and synaesthesia. A descriptive study based on 61 patients with diagnoses of various neurological injuries, which were tested by BAST-24 olfactometer. The results were compared with those of a control group (n= 120). The results show major impairment in these patients' olfactory sense. The neurological injury patients were able to detect from 60-77% of the odours, while the control group were able to detect between 98-100%. The neurological patients were able, at best, to identify, 11-32% of the odours correctly, while the control group were able to correctly detect between 59 -75%. The differences between odour detection and correct identification were statistically significant (p<.05). We concluded: a) Neurological injury, not caused by traumatic brain injury, psychiatric disorders or ENT diseases, ranged from 68-89% of the olfactory failures. b) We must bear in mind that these sorts of injuries can cause olfactory disorders. c) ENT and Neurologists should collaborate in the treatment of these disorders. Copyright © 2018 Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. Publicado por Elsevier España, S.L.U. All rights reserved.

Flavour preferences in youth versus adults: a review

PubMed Central

Hoffman, Allison C; Salgado, Raydel Valdes; Dresler, Carolyn; Faller, Rachel Williams; Bartlett, Christopher

2016-01-01

Objective To understand the available evidence of how children and adults differ in their preferences for flavours that may be used in tobacco products. Data sources A total of 474 articles published between 1931 and August 2015 were retrieved through searches conducted in PubMed, EMBASE, Web of Science and PsycINFO. Study selection and extraction A 2-phase relevancy review process resulted in the identification of 59 articles and information was extracted by 2 independent reviewers. Data synthesis Findings were grouped by taste and smell preferences, which are important components of overall flavour. For taste, evidence is summarised in the following categories: sweet, salty, sour, bitter, umami and fat; within each of them, findings are organised by age categories. For smell, evidence is summarised as follows: fruit/herbal/spices, tobacco and coffee and other odours. Major findings from this search indicated that sweet preference in children and adolescents was higher than in adults. Examples of preferred food-related tastes and odours for young people included cherry, candy, strawberry, orange, apple and cinnamon. Currently, all these are used to flavour cigars, cartridges for electronic cigarettes, hookah (waterpipe) and smokeless tobacco products. Conclusions Infants and children exhibited elevated sweet and salty preference relative to adults. Age-related changes in bitter, sour, umami and fat taste were not clear and more research would be useful. ‘Sweet’ food odours were highly preferred by children. Tobacco products in flavours preferred by young people may impact tobacco use and initiation, while flavours preferred by adults may impact product switching or dual use. PMID:27633764

Effects of 20 mg oral Δ9-tetrahydrocannabinol on the olfactory function of healthy volunteers*

PubMed Central

Walter, Carmen; Oertel, Bruno G; Ludyga, Dagmar; Ultsch, Alfred; Hummel, Thomas; Lötsch, Jörn

2014-01-01

Aims Olfactory loss impairs the patient's quality of life. In individualized therapies, olfactory drug effects gain clinical importance. Molecular evidence suggests that among drugs with potential olfactory effects is Δ9-tetrahydrocannabinol (THC), which is approved for several indications, including neuropathic pain or analgesia in cancer patients. The present study aimed at assessing the olfactory effects of THC to be expected during analgesic treatment. Methods The effects of 20 mg oral THC on olfaction were assessed in a placebo-controlled, randomized cross-over study in healthy volunteers. Using an established olfactory test (Sniffin' Sticks), olfactory thresholds, odour discrimination and odour identification were assessed in 15 subjects at baseline and 2 h after THC administration. Results Δ9-Tetrahydrocannabinol impaired the performance of subjects (n = 15) in the olfactory test. Specifically, olfactory thresholds were increased and odour discrimination performance was reduced. This resulted in a significant drop in composite threshold, discrimination, identification (TDI) olfactory score by 5.5 points (from 37.7 ± 4.2 to 32.2 ± 5.6, 95% confidence interval for differences THC vs. placebo, −7.8 to −2.0, P = 0.003), which is known to be a subjectively perceptible impairment of olfactory function. Conclusions Considering the resurgence of THC in medical use for several pathological conditions, the present results indicate that THC-based analgesics may be accompanied by subjectively noticeable reductions in olfactory acuity. In particular, for patients relying on their sense of smell, this might be relevant information for personalized therapy strategies. PMID:24802974

Effects of 20 mg oral Δ(9) -tetrahydrocannabinol on the olfactory function of healthy volunteers.

PubMed

Walter, Carmen; Oertel, Bruno G; Ludyga, Dagmar; Ultsch, Alfred; Hummel, Thomas; Lötsch, Jörn

2014-11-01

Olfactory loss impairs the patient's quality of life. In individualized therapies, olfactory drug effects gain clinical importance. Molecular evidence suggests that among drugs with potential olfactory effects is Δ(9) -tetrahydrocannabinol (THC), which is approved for several indications, including neuropathic pain or analgesia in cancer patients. The present study aimed at assessing the olfactory effects of THC to be expected during analgesic treatment. The effects of 20 mg oral THC on olfaction were assessed in a placebo-controlled, randomized cross-over study in healthy volunteers. Using an established olfactory test (Sniffin' Sticks), olfactory thresholds, odour discrimination and odour identification were assessed in 15 subjects at baseline and 2 h after THC administration. Δ(9) -Tetrahydrocannabinol impaired the performance of subjects (n = 15) in the olfactory test. Specifically, olfactory thresholds were increased and odour discrimination performance was reduced. This resulted in a significant drop in composite threshold, discrimination, identification (TDI) olfactory score by 5.5 points (from 37.7 ± 4.2 to 32.2 ± 5.6, 95% confidence interval for differences THC vs. placebo, -7.8 to -2.0, P = 0.003), which is known to be a subjectively perceptible impairment of olfactory function. Considering the resurgence of THC in medical use for several pathological conditions, the present results indicate that THC-based analgesics may be accompanied by subjectively noticeable reductions in olfactory acuity. In particular, for patients relying on their sense of smell, this might be relevant information for personalized therapy strategies. © 2014 The British Pharmacological Society.

A model explaining and predicting lamb flavour from the aroma-active chemical compounds released upon grilling light lamb loins.

PubMed

Bueno, Mónica; Campo, M Mar; Cacho, Juan; Ferreira, Vicente; Escudero, Ana

2014-12-01

The objective of the work is to understand the role of the different aroma compounds in the perception of the local "lamb flavour" concept. For this, a set of 70 loins (Longissimus dorsi) from approximately seventy day-old Rasa Aragonesa male lambs were grilled and the aroma-active chemicals released during the grilling process were trapped and analyzed. Carbonyl compounds were derivatizated and determined by GC-NCI-MS, whereas other aromatic compounds were directly analyzed by GC-GC-MS. Odour activity values (OAVs) were calculated using their odour threshold values in air. Lamb flavour could be satisfactory explained by a partial least-squares model (74% explained variance in cross-validation) built by the OAVs of 32 aroma-active chemical compounds. The model demonstrates that the lamb flavour concept is the result of a complex balance. Its intensity critically and positively depends to the levels of volatile fatty acids and several dimethylpyrazines while is negatively influenced by the different alkenals and alkadienals. (E,E)-2,4-decadienal and (E)-2-nonenal showed top OAVs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Objective assessment of olfactory function using functional magnetic resonance imaging.

PubMed

Toledano, Adolfo; Borromeo, Susana; Luna, Guillermo; Molina, Elena; Solana, Ana Beatriz; García-Polo, Pablo; Hernández, Juan Antonio; Álvarez-linera, Juan

2012-01-01

To show the results of a device that generates automated olfactory stimuli suitable for functional magnetic resonance imaging (fMRI) experiments. Ten normal volunteers, 5 women and 5 men, were studied. The system allows the programming of several sequences, providing the capability to synchronise the onset of odour presentation with acquisition by a trigger signal of the MRI scanner. The olfactometer is a device that allows selection of the odour, the event paradigm, the time of stimuli and the odour concentration. The paradigm used during fMRI scanning consisted of 15-s blocks. The odorant event took 2s with butanol, mint and coffee. We observed olfactory activity in the olfactory bulb, entorhinal cortex (4%), amygdala (2.5%) and temporo-parietal cortex, especially in the areas related to emotional integration. The device has demonstrated its effectiveness in stimulating olfactory areas and its capacity to adapt to fMRI equipment. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Chemical ecology of interactions between human skin microbiota and mosquitoes.

PubMed

Verhulst, Niels O; Takken, Willem; Dicke, Marcel; Schraa, Gosse; Smallegange, Renate C

2010-10-01

Microbiota on the human skin plays a major role in body odour production. The human microbial and chemical signature displays a qualitative and quantitative correlation. Genes may influence the chemical signature by shaping the composition of the microbiota. Recent studies on human skin microbiota, using 16S rRNA gene sequencing, found a high inter- and intrapersonal variation in bacterial species on the human skin, which is relatively stable over time. Human body odours mediate the attraction of mosquitoes to their blood hosts. Odours produced by skin microbiota are attractive to mosquitoes as shown by in vitro studies, and variation in bacterial species on the human skin may explain the variation in mosquito attraction between humans. Detailed knowledge of the ecology and genetics of human skin microbiota is needed in order to unravel the evolutionary mechanisms that underlie the interactions between mosquitoes and their hosts. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Effect of cooking on aroma profile of red kidney beans (Phaseolus vulgaris) and correlation with sensory quality.

PubMed

Mishra, Prashant K; Tripathi, Jyoti; Gupta, Sumit; Variyar, Prasad S

2017-01-15

Volatile aroma compounds of three varieties of red kidney beans (Phaseolus vulgaris) namely Kashmiri red, Sharmili and Chitra were extracted in raw state using solid-phase microextraction (SPME) and cooked state using simultaneous distillation extraction (SDE). During cooking a significant (p<0.05) reduction in the content of several aldehydes, alcohols and terpene hydrocarbons while an increase in content of various sulfurous compounds, terpene alcohols, ketones and pyrazines was noted. Descriptive sensory analysis showed that the maximum intensity of 'kidney bean', 'earthy' and 'smoky' odour was observed in Kashmiri red while Sharmili variety was characterised by 'sulfurous' odour. Correlation of volatile profile data with descriptive sensory analysis and odour activity values clearly established the role of compounds, such as methanethiol, diethyl sulfide, dimethyl disulfide, methional and dimethyl trisulfide, in contributing to 'cooked kidney bean' aroma, while dimethyl sulfoxide, dimethyl sulfone and ethyl methyl sulfone were responsible for 'sulfurous' aroma. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nrp2 is sufficient to instruct circuit formation of mitral-cells to mediate odour-induced attractive social responses.

PubMed

Inokuchi, Kasumi; Imamura, Fumiaki; Takeuchi, Haruki; Kim, Ryang; Okuno, Hiroyuki; Nishizumi, Hirofumi; Bito, Haruhiko; Kikusui, Takefumi; Sakano, Hitoshi

2017-07-21

Odour information induces various innate responses that are critical to the survival of the individual and for the species. An axon guidance molecule, Neuropilin 2 (Nrp2), is known to mediate targeting of olfactory sensory neurons (primary neurons), to the posteroventral main olfactory bulb (PV MOB) in mice. Here we report that Nrp2-positive (Nrp2 + ) mitral cells (MCs, second-order neurons) play crucial roles in transmitting attractive social signals from the PV MOB to the anterior part of medial amygdala (MeA). Semaphorin 3F, a repulsive ligand to Nrp2, regulates both migration of Nrp2 + MCs to the PV MOB and their axonal projection to the anterior MeA. In the MC-specific Nrp2 knockout mice, circuit formation of Nrp2 + MCs and odour-induced attractive social responses are impaired. In utero, electroporation demonstrates that activation of the Nrp2 gene in MCs is sufficient to instruct their circuit formation from the PV MOB to the anterior MeA.

Effect of Thiobacillus thioparus 1904 and sulphur addition on odour emission during aerobic composting.

PubMed

Gu, Wenjie; Sun, Wen; Lu, Yusheng; Li, Xia; Xu, Peizhi; Xie, Kaizhi; Sun, Lili; Wu, Hangtao

2018-02-01

The effects of sulphur and Thiobacillus thioparus 1904 on odour emissions during composting were studied. Results indicated that the sulphur addition reduced the pH and decreased cumulative emission of ammonia and the nitrogen loss by 47.80% and 44.23%, respectively, but the amount of volatile sulphur compounds (VSCs) and the sulphur loss increased. The addition of T. thioparus 1904 effectively reduced the cumulative emissions of H 2 S, methyl sulphide, methanethiol, dimethyl disulphide and the sulphur loss by 33.24%, 81.24%, 32.70%, 54.22% and 54.24%, respectively. T. thioparus 1904 also limited the nitrogen loss. The combined application of sulphur and T. thioparus 1904 resulted in the greatest amount of nitrogen retention. The accumulation of ammonia emissions was reduced by 63.33%, and the nitrogen loss was reduced by 71.93%. The combined treatment did not increase the emission of VSCs. The application of sulphur and T. thioparus 1904 may help to control the odour of compost. Copyright © 2017. Published by Elsevier Ltd.

Semiochemical compounds of preen secretion reflect genetic make-up in a seabird species

USGS Publications Warehouse

Leclaire, S.; Merkling, T.; Raynaud, C.; Mulard, Hervé; Bessiere, J.-M.; Lhuillier, E.M.; Hatch, Shyla A.; Danchin, E.

2012-01-01

Several vertebrates choose their mate according to genetic heterozygosity and relatedness, and use odour cues to assess their conspecifics' genetic make-up. In birds, although several species (including the blacklegged kittiwake) exhibit non-random mating according to genetic traits, the cues used to assess genetic characteristics remain unknown. The importance of olfaction in birds' social behaviour is gaining attention among researchers, and it has been suggested that, as in other vertebrates, bird body scent may convey information about genetic traits. Here, we combined gas chromatography data and genetic analyses at microsatellite loci to test whether semiochemical messages in preen secretion of kittiwakes carried information about genetic heterozygosity and relatedness. Semiochemical profile was correlated with heterozygosity in males and females, while semiochemical distance was correlated with genetic distance only in male-male dyads. Our study is the first to demonstrate a link between odour and genetics in birds, which sets the stage for the existence of sophisticated odour-based mechanisms of mate choice also in birds. ?? 2011 The Royal Society.

Volatile constituents of commercial imported and domestic black-ripe table olives (Olea europaea).

PubMed

Sansone-Land, Angelina; Takeoka, Gary R; Shoemaker, Charles F

2014-04-15

Volatile constituents of commercial black-ripe table olives (Olea europaea) from the United States, Spain, Egypt and Morocco were analysed by gas chromatography and gas chromatography-mass spectrometry (GC-MS). Dynamic headspace sampling was used to isolate a variety of aldehydes, alcohols, esters, ketones, phenols, terpenes, norisoprenoids, and pyridines. Odour unit values, calculated from concentration and odour threshold data, indicate that the following compounds are major contributors to black-ripe table olive aroma: β-damascenone, nonanal, (E)-dec-2-enal, 3-methylbutanal, ethyl benzoate, octanal, 2-methoxyphenol, 2-methylbutanal and 2-methoxy-4-methylphenol. Imported olives contained a variety of fermentation derived volatiles that were not detected in domestic olives. Constituents such as ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, oct-1-en-3-one, ethyl hexanoate, (Z)-hex-3-enyl acetate, hexyl acetate, ethyl cyclohexanecarboxylate, benzyl acetate and 4-ethylphenol contributed to the odour of imported olives but were not detected in domestic olives. Published by Elsevier Ltd.

Pharmacognostical and Phytochemical Studies of Helleborus niger L Root.

PubMed

Kumar, V Kishor; Lalitha, K G

2017-01-01

Helleborus niger L (Ranunculaceae) is used Ayurvedic and Unani systems and other herbal medicine systems. The roots of H. niger have a good medicinal value. To conduct a pharmacognostical and phytochemical study of H. niger . The pharmacognostical studies on roots including parameters such as taxonomical, macroscopic, microscopic characters, physico-chemical, ultra-violet analysis and phytochemical studies are established. Macroscopically, the roots are brownish-black in colour, cylindrical in shape, feeble odour, slightly acrid taste with irregularly branched. Microscopically the root showed the presence of epidermis, air-chambers, fissure periderm, periderm, inner cortex, pith, phloem, xylem, vessels and xylem vessels. Microscopic examination of the powder showed the presence of parenchyma cells, parenchyma mass, periderm, cell inclusion, laticifer, lateral wall pith, perforation, xylem bundle and xylem elements. Ultra-violet and ordinary light analyses with different reagents were conducted to identify the drug in powder form. Physico-chemical evaluation established, Ash values - Total, acid insoluble, water soluble and sulphated ash values were 7.3%, 4.1%, 3.7% and 5.2%, respectively. Extractive values - Alcohol soluble, water soluble and ether soluble extractive values were 22.8%, 7.4% and 5.6%, respectively. Loss on drying was 3.3%. Preliminary phytochemical screening showed the presence of carbohydrate, glycoside, saponins, flavonoid, phytosterols, tannins and phenolic compounds. The results of the study can serve as a valuable resource of pharmacognostic and phytochemical information. This will serve as appropriate, standards for discovery of this plant material in future investigations and applications and also contribute towards establishing pharmacopoeial standards.

Assessment of tobacco heating product THP1.0. Part 4: Characterisation of indoor air quality and odour.

PubMed

Forster, Mark; McAughey, John; Prasad, Krishna; Mavropoulou, Eleni; Proctor, Christopher

2018-03-01

The tobacco heating product THP1.0, which heats but does not burn tobacco, was tested as part of a modified-risk tobacco product assessment framework for its impacts on indoor air quality and residual tobacco smoke odour. THP1.0 heats the tobacco to less than 240 °C ± 5 °C during puffs. An environmentally controlled room was used to simulate ventilation conditions corresponding to residential, office and hospitality environments. An analysis of known tobacco smoke constituents, included CO, CO 2 , NO, NO 2 , nicotine, glycerol, 3-ethenyl pyridine, sixteen polycyclic aromatic hydrocarbons, eight volatile organic compounds, four carbonyls, four tobacco-specific nitrosamines and total aerosol particulate matter. Significant emissions reductions in comparison to conventional cigarettes were measured for THP1.0. Levels of nicotine, acetaldehyde, formaldehyde and particulate matter emitted from THP1.0 exceeded ambient air measurements, but were more than 90% reduced relative to cigarette smoke emissions within the laboratory conditions defined Residual tobacco smoke odour was assessed by trained sensory panels after exposure of cloth, hair and skin to both mainstream and environmental emissions from the test products. Residual tobacco smoke odour was significantly lower from THP1.0 than from a conventional cigarette. These data show that using THP1.0 has the potential to result in considerably reduced environmental emissions that affect indoor air quality relative to conventional cigarettes. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Effect of irradiation on stored vacuum packaged Wiltshire bacon

NASA Astrophysics Data System (ADS)

Dempster, JF; Halls, NA

Wiltshire cured 'middle-cut' bacon (NaCl, 4.87%; 40 mg/kg NO 2; 53 mg/kg NO 3) was boned, sliced and vacuum packaged. It was irradiated (25 kGy: 10 kGy) and stored aerobically (5 0 : 15 0). At weekly intervals the bacon was evaluated bacteriologically and organoleptically (appearance, odour, colour of lean and fat) against unirradiated (control) samples). Results indicated that irradiation (10 kGy) did not permanently inhibit bacterial growth. After initial reductions in count of 0.99 g -1-1(15 0C) and log 3.61 g -1 (5 0C), maximum numbers were reached in 28 days at 15 0C (log 10.32 g -1) and in 35 days at 5 0C (log 8.05 g -1). However viability was significantly affected by 25 kGy irradiation: final numbers reached being log 2.22 g -1 (15 0C) at 35 days and log 3.38 g -1 (5 0C) at 42 days. Appearance and colour (fat and lean) were not significantly impaired by irradiation. However the interaction of storage temperature (5 0 : 15 0C), irradiation (10 kGy: 25 kGy): duration of storage (42 days) and initial count (log 7.24 g -1) had pronounced adverse effects on odour judgements. Evaluation of odour changes in bacon due to irradiation require further investigation. This is especially so since it is often possible to detect odour changes in raw meat after doses as low as 0.5 kGy (Coleby 1959).

Effects of analgesics on olfactory function and the perception of intranasal trigeminal stimuli.

PubMed

Mizera, L; Gossrau, G; Hummel, T; Haehner, A

2017-01-01

There is some evidence suggesting that analgesics have an impact on human chemosensory function, especially opioids and cannabinoids are known to interfere with olfactory function. However, largely unknown is the effect of a long-term use of analgesics on the intranasal trigeminal system so far. Here, we investigated olfactory function and the perception of intranasal trigeminal stimuli in pain patients with long-term use of analgesics compared to age-matched healthy controls. For this purpose, a psychophysical approach was chosen to measure these sensory functions in 100 chronic pain patients and 95 controls. Olfactory testing was performed using the 'Sniffin' Sticks' test kit, which involves tests for odour threshold, odour discrimination and odour identification. Further, participants were asked to rate the intensity of trigeminal stimuli by using a visual analogue scale. We observed that the chronic use of pain medication was associated with significantly reduced perception of intranasal trigeminal stimuli and olfactory function compared to age-matched controls without intake of analgesics. Results indicate that non-opioid and opioid drugs, or a combination of both did not differ in their effects on chemosensory function. Further, after eliminating the effect of a co-existing depression and the use of co-analgesics, the negative influence of analgesics on olfactory function and trigeminal perception was still evident. The observed effect might be mediated due to interaction with opioid receptors in trigeminal ganglia and nuclei or due to trigeminal/olfactory interaction. As a practical consequence, patients should be made aware of a possible impairment of their olfactory and trigeminal function under long-term analgesic treatment. WHAT DOES THIS STUDY ADD?: We observed that the chronic use of pain medication was associated with significantly reduced olfactory function and perception of intranasal trigeminal stimuli compared to age-matched controls without intake of analgesics. Non-opioid and opioid drugs did not differ in their effects on chemosensory function. © 2016 European Pain Federation - EFIC®.

Transcriptome and proteome data reveal candidate genes for pollinator attraction in sexually deceptive orchids.

PubMed

Sedeek, Khalid E M; Qi, Weihong; Schauer, Monica A; Gupta, Alok K; Poveda, Lucy; Xu, Shuqing; Liu, Zhong-Jian; Grossniklaus, Ueli; Schiestl, Florian P; Schlüter, Philipp M

2013-01-01

Sexually deceptive orchids of the genus Ophrys mimic the mating signals of their pollinator females to attract males as pollinators. This mode of pollination is highly specific and leads to strong reproductive isolation between species. This study aims to identify candidate genes responsible for pollinator attraction and reproductive isolation between three closely related species, O. exaltata, O. sphegodes and O. garganica. Floral traits such as odour, colour and morphology are necessary for successful pollinator attraction. In particular, different odour hydrocarbon profiles have been linked to differences in specific pollinator attraction among these species. Therefore, the identification of genes involved in these traits is important for understanding the molecular basis of pollinator attraction by sexually deceptive orchids. We have created floral reference transcriptomes and proteomes for these three Ophrys species using a combination of next-generation sequencing (454 and Solexa), Sanger sequencing, and shotgun proteomics (tandem mass spectrometry). In total, 121 917 unique transcripts and 3531 proteins were identified. This represents the first orchid proteome and transcriptome from the orchid subfamily Orchidoideae. Proteome data revealed proteins corresponding to 2644 transcripts and 887 proteins not observed in the transcriptome. Candidate genes for hydrocarbon and anthocyanin biosynthesis were represented by 156 and 61 unique transcripts in 20 and 7 genes classes, respectively. Moreover, transcription factors putatively involved in the regulation of flower odour, colour and morphology were annotated, including Myb, MADS and TCP factors. Our comprehensive data set generated by combining transcriptome and proteome technologies allowed identification of candidate genes for pollinator attraction and reproductive isolation among sexually deceptive orchids. This includes genes for hydrocarbon and anthocyanin biosynthesis and regulation, and the development of floral morphology. These data will serve as an invaluable resource for research in orchid floral biology, enabling studies into the molecular mechanisms of pollinator attraction and speciation.

Transcriptome and Proteome Data Reveal Candidate Genes for Pollinator Attraction in Sexually Deceptive Orchids

PubMed Central

Sedeek, Khalid E. M.; Qi, Weihong; Schauer, Monica A.; Gupta, Alok K.; Poveda, Lucy; Xu, Shuqing; Liu, Zhong-Jian; Grossniklaus, Ueli; Schiestl, Florian P.; Schlüter, Philipp M.

2013-01-01

Background Sexually deceptive orchids of the genus Ophrys mimic the mating signals of their pollinator females to attract males as pollinators. This mode of pollination is highly specific and leads to strong reproductive isolation between species. This study aims to identify candidate genes responsible for pollinator attraction and reproductive isolation between three closely related species, O. exaltata, O. sphegodes and O. garganica. Floral traits such as odour, colour and morphology are necessary for successful pollinator attraction. In particular, different odour hydrocarbon profiles have been linked to differences in specific pollinator attraction among these species. Therefore, the identification of genes involved in these traits is important for understanding the molecular basis of pollinator attraction by sexually deceptive orchids. Results We have created floral reference transcriptomes and proteomes for these three Ophrys species using a combination of next-generation sequencing (454 and Solexa), Sanger sequencing, and shotgun proteomics (tandem mass spectrometry). In total, 121 917 unique transcripts and 3531 proteins were identified. This represents the first orchid proteome and transcriptome from the orchid subfamily Orchidoideae. Proteome data revealed proteins corresponding to 2644 transcripts and 887 proteins not observed in the transcriptome. Candidate genes for hydrocarbon and anthocyanin biosynthesis were represented by 156 and 61 unique transcripts in 20 and 7 genes classes, respectively. Moreover, transcription factors putatively involved in the regulation of flower odour, colour and morphology were annotated, including Myb, MADS and TCP factors. Conclusion Our comprehensive data set generated by combining transcriptome and proteome technologies allowed identification of candidate genes for pollinator attraction and reproductive isolation among sexually deceptive orchids. This includes genes for hydrocarbon and anthocyanin biosynthesis and regulation, and the development of floral morphology. These data will serve as an invaluable resource for research in orchid floral biology, enabling studies into the molecular mechanisms of pollinator attraction and speciation. PMID:23734209

Olfactory learning without the mushroom bodies: Spiking neural network models of the honeybee lateral antennal lobe tract reveal its capacities in odour memory tasks of varied complexities

PubMed Central

2017-01-01

The honeybee olfactory system is a well-established model for understanding functional mechanisms of learning and memory. Olfactory stimuli are first processed in the antennal lobe, and then transferred to the mushroom body and lateral horn through dual pathways termed medial and lateral antennal lobe tracts (m-ALT and l-ALT). Recent studies reported that honeybees can perform elemental learning by associating an odour with a reward signal even after lesions in m-ALT or blocking the mushroom bodies. To test the hypothesis that the lateral pathway (l-ALT) is sufficient for elemental learning, we modelled local computation within glomeruli in antennal lobes with axons of projection neurons connecting to a decision neuron (LHN) in the lateral horn. We show that inhibitory spike-timing dependent plasticity (modelling non-associative plasticity by exposure to different stimuli) in the synapses from local neurons to projection neurons decorrelates the projection neurons’ outputs. The strength of the decorrelations is regulated by global inhibitory feedback within antennal lobes to the projection neurons. By additionally modelling octopaminergic modification of synaptic plasticity among local neurons in the antennal lobes and projection neurons to LHN connections, the model can discriminate and generalize olfactory stimuli. Although positive patterning can be accounted for by the l-ALT model, negative patterning requires further processing and mushroom body circuits. Thus, our model explains several–but not all–types of associative olfactory learning and generalization by a few neural layers of odour processing in the l-ALT. As an outcome of the combination between non-associative and associative learning, the modelling approach allows us to link changes in structural organization of honeybees' antennal lobes with their behavioural performances over the course of their life. PMID:28640825

Modification of CO2 avoidance behaviour in Drosophila by inhibitory odorants.

PubMed

Turner, Stephanie Lynn; Ray, Anandasankar

2009-09-10

The fruitfly Drosophila melanogaster exhibits a robust and innate olfactory-based avoidance behaviour to CO(2), a component of odour emitted from stressed flies. Specialized neurons in the antenna and a dedicated neuronal circuit in the higher olfactory system mediate CO(2) detection and avoidance. However, fruitflies need to overcome this avoidance response in some environments that contain CO(2) such as ripening fruits and fermenting yeast, which are essential food sources. Very little is known about the molecular and neuronal basis of this unique, context-dependent modification of innate olfactory avoidance behaviour. Here we identify a new class of odorants present in food that directly inhibit CO(2)-sensitive neurons in the antenna. Using an in vivo expression system we establish that the odorants act on the Gr21a/Gr63a CO(2) receptor. The presence of these odorants significantly and specifically reduces CO(2)-mediated avoidance behaviour, as well as avoidance mediated by 'Drosophila stress odour'. We propose a model in which behavioural avoidance to CO(2) is directly influenced by inhibitory interactions of the novel odours with CO(2) receptors. Furthermore, we observe differences in the temporal dynamics of inhibition: the effect of one of these odorants lasts several minutes beyond the initial exposure. Notably, animals that have been briefly pre-exposed to this odorant do not respond to the CO(2) avoidance cue even after the odorant is no longer present. We also show that related odorants are effective inhibitors of the CO(2) response in Culex mosquitoes that transmit West Nile fever and filariasis. Our findings have broader implications in highlighting the important role of inhibitory odorants in olfactory coding, and in their potential to disrupt CO(2)-mediated host-seeking behaviour in disease-carrying insects like mosquitoes.

Olfactory learning without the mushroom bodies: Spiking neural network models of the honeybee lateral antennal lobe tract reveal its capacities in odour memory tasks of varied complexities.

PubMed

MaBouDi, HaDi; Shimazaki, Hideaki; Giurfa, Martin; Chittka, Lars

2017-06-01

The honeybee olfactory system is a well-established model for understanding functional mechanisms of learning and memory. Olfactory stimuli are first processed in the antennal lobe, and then transferred to the mushroom body and lateral horn through dual pathways termed medial and lateral antennal lobe tracts (m-ALT and l-ALT). Recent studies reported that honeybees can perform elemental learning by associating an odour with a reward signal even after lesions in m-ALT or blocking the mushroom bodies. To test the hypothesis that the lateral pathway (l-ALT) is sufficient for elemental learning, we modelled local computation within glomeruli in antennal lobes with axons of projection neurons connecting to a decision neuron (LHN) in the lateral horn. We show that inhibitory spike-timing dependent plasticity (modelling non-associative plasticity by exposure to different stimuli) in the synapses from local neurons to projection neurons decorrelates the projection neurons' outputs. The strength of the decorrelations is regulated by global inhibitory feedback within antennal lobes to the projection neurons. By additionally modelling octopaminergic modification of synaptic plasticity among local neurons in the antennal lobes and projection neurons to LHN connections, the model can discriminate and generalize olfactory stimuli. Although positive patterning can be accounted for by the l-ALT model, negative patterning requires further processing and mushroom body circuits. Thus, our model explains several-but not all-types of associative olfactory learning and generalization by a few neural layers of odour processing in the l-ALT. As an outcome of the combination between non-associative and associative learning, the modelling approach allows us to link changes in structural organization of honeybees' antennal lobes with their behavioural performances over the course of their life.

Evaluation of Effective Microorganisms on home scale organic waste composting.

PubMed

Fan, Yee Van; Lee, Chew Tin; Klemeš, Jiří Jaromír; Chua, Lee Suan; Sarmidi, Mohamad Roji; Leow, Chee Woh

2018-06-15

Home composting can be an effective way to reduce the volume of municipal solid waste. The aim of this study is to evaluate the effect of Effective Microorganism™ (EM) for the home scale co-composting of food waste, rice bran and dried leaves. A general consensus is lacking regarding the efficiency of inoculation composting. Home scale composting was carried out with and without EM (control) to identify the roles of EM. The composting parameters for both trials showed a similar trend of changes during the decomposition. As assayed by Fourier Transform Infrared Spectroscopy (FTIR), the functional group of humic acid was initially dominated by aliphatic structure but was dominated by the aromatic in the final compost. The EM compost has a sharper peak of aromatic CC bond presenting a better degree of humification. Compost with EM achieved a slightly higher temperature at the early stage, with foul odour suppressed, enhanced humification process and a greater fat reduction (73%). No significant difference was found for the final composts inoculated with and without EM. The properties included pH (∼7), electric conductivity (∼2), carbon-to-nitrogen ratio (C: N < 14), colour (dark brown), odour (earthy smell), germination index (>100%), humic acid content (4.5-4.8%) and pathogen content (no Salmonella, <1000 Most Probable Number/g E. coli). All samples were well matured within 2 months. The potassium and phosphate contents in both cases were similar however the EM compost has a higher nitrogen content (+1.5%). The overall results suggested the positive effect provided by EM notably in odour control and humification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Developing a carob-based milk beverage using different varieties of carob pods and two roasting treatments and assessing their effect on quality characteristics.

PubMed

Srour, Nadine; Daroub, Hamza; Toufeili, Imad; Olabi, Ammar

2016-07-01

This work aimed at formulating a carob-based milk beverage and assessing its chemical and sensory properties. Six varieties of carob pods, each processed into roasted and unroasted powders, were used to develop 12 prototypes of the beverage. Chemical and physico-chemical analyses (moisture, ash, fibre, protein, sugars, total-phenolics, total-antioxidants, water activity and colour) and sensory tests were conducted. The variety of carob pod had a significant effect on all chemical variables in carob powders (P < 0.01), except for sugars, and when incorporated in the beverage, on moisture, total phenolics, total antioxidant activity and colour parameters (L, a, b; P-values < 0.001). Roasting treatment significantly increased fibre, total phenolics, total antioxidant activity (P-values < 0.001), fructose, glucose (P-values < 0.05), and a-value levels (P < 0.01), significantly lowered moisture (P < 0.05), water activity, L- and b-values (P-values < 0.001) in carob powders; and significantly increased the beverage's total phenolics, a-value (P-values < 0.001) and total antioxidant activity (P < 0.01). Roasting treatment significantly increased the beverage's acceptability ratings. Beverages formulated with roasted carob powder had higher ratings for level of residue, colour, caramel odour, mocha odour and flavour, roasted coffee odour and flavour, viscosity mouthfeel and bitter aftertaste. Principal component analysis was conducted; PC1 and PC2 separated attributes according to roasting treatment and variety of carob pods, respectively. The use of Akkari roasted and Baladi Ikleem el Kharoob roasted to formulate a carob-based milk beverage is recommended. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Asthma, allergy and eczema among adults in multifamily houses in Stockholm (3-HE study)--associations with building characteristics, home environment and energy use for heating.

PubMed

Norbäck, Dan; Lampa, Erik; Engvall, Karin

2014-01-01

Risk factors for asthma, allergy and eczema were studied in a stratified random sample of adults in Stockholm. In 2005, 472 multifamily buildings (10,506 dwellings) were invited (one subject/dwelling) and 7,554 participated (73%). Associations were analyzed by multiple logistic regression, adjusting for gender, age, smoking, country of birth, income and years in the dwelling. In total, 11% had doctor's diagnosed asthma, 22% doctor's diagnosed allergy, 23% pollen allergy and 23% eczema. Doctor's diagnosed asthma was more common in dwellings with humid air (OR = 1.74) and mould odour (OR = 1.79). Doctor's diagnosed allergy was more common in buildings with supply exhaust air ventilation as compared to exhaust air only (OR = 1.45) and was associated with redecoration (OR = 1.48) and mould odour (OR = 2.35). Pollen allergy was less common in buildings using more energy for heating (OR = 0.75) and was associated with humid air (OR = 1.76) and mould odour (OR = 2.36). Eczema was more common in larger buildings (OR 1.07) and less common in buildings using more energy for heating (OR = 0.85) and was associated with water damage (OR = 1.47), humid air (OR = 1.73) and mould odour (OR = 2.01). Doctor's diagnosed allergy was less common in buildings with management accessibility both in the neighbourhood and in larger administrative divisions, as compared to management in the neighbourhood only (OR = 0.49; 95% CI 0.29-0.82). Pollen allergy was less common if the building maintenance was outsourced (OR = 0.67; 95% CI 0.51-0.88). Eczema was more common when management accessibility was only at the division level (OR = 1.49; 95% CI 1.06-2.11). In conclusions, asthma, allergy or eczema were more common in buildings using less energy for heating, in larger buildings and in dwellings with redecorations, mould odour, dampness and humid air. There is a need to reduce indoor chemical emissions and to control dampness. Energy saving may have consequences for allergy and eczema. More epidemiological studies are needed on building management organization.

Attraction of the cutaneous leishmaniasis vector Nyssomyia neivai (Diptera: Psychodidae) to host odour components in a wind tunnel

PubMed Central

2012-01-01

Background Laboratory studies of host-seeking olfactory behaviour in sandflies have largely been restricted to the American visceral leishmaniasis vector Lutzomyia longipalpis. In comparison, almost nothing is known about the chemical ecology of related species, which transmit American cutaneous leishmaniasis (ACL), due in part to difficulties in raising these insects in the laboratory. Understanding how ACL vectors locate their hosts will be essential to developing new vector control strategies to combat this debilitating disease. Methods This study examined host-odour seeking behaviour of the ACL vector Nyssomyia neivai (Pinto) (=Lutzomyia neivai) using a wind tunnel olfactometer. The primary aim was to determine whether field-collected female N. neivai would respond to host odours in the laboratory, thereby eliminating the need to maintain colonies of these insects for behavioural experiments. Responses to two key host odour components, 1-octen-3-ol and lactic acid, and a commercially-available mosquito lure (BG-Lure™) were assessed and compared relative to an air control. We also tested whether trials could be conducted outside of the normal evening activity period of N. neivai without impacting on fly behaviour, and whether the same flies could be used to assess baseline responses to air without affecting responses to octenol, thereby reducing the number of flies required for experiments. Results Octenol was found to both activate host-seeking behaviour and attract female N. neivai in the wind tunnel, while lactic acid elicited weaker responses of activation and attractiveness under identical conditions. The BG-Lure did not activate or attract N. neivai under test conditions. Further experiments showed that sandfly behaviour in the wind tunnel was not affected by time of day, such that experiments need not be restricted to nocturnal hours. Moreover, using the same flies to measure both baseline responses to air and attraction to test compounds did not affect odour-seeking behaviour. Conclusions The results of this study demonstrate that N. neivai taken from the field are suitable for use in laboratory olfactometer experiments. It is hoped this work will facilitate further research into chemical ecology of this species, and other ACL vectors. PMID:23009099

Attraction of the cutaneous leishmaniasis vector Nyssomyia neivai (Diptera: Psychodidae) to host odour components in a wind tunnel.

PubMed

Pinto, Mara C; Bray, Daniel P; Eiras, Alvaro E; Carvalheira, Henrique P; Puertas, Camila P

2012-09-25

Laboratory studies of host-seeking olfactory behaviour in sandflies have largely been restricted to the American visceral leishmaniasis vector Lutzomyia longipalpis. In comparison, almost nothing is known about the chemical ecology of related species, which transmit American cutaneous leishmaniasis (ACL), due in part to difficulties in raising these insects in the laboratory. Understanding how ACL vectors locate their hosts will be essential to developing new vector control strategies to combat this debilitating disease. This study examined host-odour seeking behaviour of the ACL vector Nyssomyia neivai (Pinto) (=Lutzomyia neivai) using a wind tunnel olfactometer. The primary aim was to determine whether field-collected female N. neivai would respond to host odours in the laboratory, thereby eliminating the need to maintain colonies of these insects for behavioural experiments. Responses to two key host odour components, 1-octen-3-ol and lactic acid, and a commercially-available mosquito lure (BG-Lure™) were assessed and compared relative to an air control. We also tested whether trials could be conducted outside of the normal evening activity period of N. neivai without impacting on fly behaviour, and whether the same flies could be used to assess baseline responses to air without affecting responses to octenol, thereby reducing the number of flies required for experiments. Octenol was found to both activate host-seeking behaviour and attract female N. neivai in the wind tunnel, while lactic acid elicited weaker responses of activation and attractiveness under identical conditions. The BG-Lure did not activate or attract N. neivai under test conditions. Further experiments showed that sandfly behaviour in the wind tunnel was not affected by time of day, such that experiments need not be restricted to nocturnal hours. Moreover, using the same flies to measure both baseline responses to air and attraction to test compounds did not affect odour-seeking behaviour. The results of this study demonstrate that N. neivai taken from the field are suitable for use in laboratory olfactometer experiments. It is hoped this work will facilitate further research into chemical ecology of this species, and other ACL vectors.

Male rats treated with subchronic PCP show intact olfaction and enhanced interest for a social odour in the olfactory habituation/dishabituation test.

PubMed

Tarland, Emilia; Brosda, Jan

2018-06-01

The olfactory system participates in many sensory processes, and olfactory endophenotypes appear in a variety of neurological disorders such as Alzheimer's and Parkinson's disease, depression and schizophrenia. Social withdrawal is a core negative symptom of schizophrenia and animal models have proven to be invaluable for studying the neurobiological mechanisms and cognitive processes behind the formation of social relationships. The subchronic phencyclidine (PCP) rat model is a validated model for negative symptoms of schizophrenia, such as impaired sociability. However, the complete range of social behaviour and deficits in the model are still not fully understood. Intact rodent olfaction is essential for a wide range of social behaviour and disrupted olfactory function could have severe effects on social communication and recognition. In order to examine the olfactory ability of male rats treated with subchronic PCP, we conducted an olfactory habituation/dishabituation test including both non-social and social odours. The subchronic PCP-treated rats successfully recognized and discriminated among the odours, indicative of intact olfaction. Interestingly, the subchronic PCP-treated rats showed greater interest for a novel social odour compared to the saline-treated rats and the rationale remains to be elucidated. Our data indicate that subchronic PCP treatment does not disrupt olfactory function in male rats. By ruling out impaired olfaction as cause for the poor social interaction performance in subchronic PCP-treated rats, our data supports the use of NMDA receptor antagonists to model the negative symptoms of schizophrenia. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Occupational hygiene in a Finnish drum composting plant.

PubMed

Tolvanen, Outi; Nykänen, Jenni; Nivukoski, Ulla; Himanen, Marina; Veijanen, Anja; Hänninen, Kari

2005-01-01

Bioaerosols (microbes, dust and endotoxins) and volatile organic compounds (VOCs) were determined in the working air of a drum composting plant treating source-separated catering waste. Different composting activities at the Oulu drum composting plant take place in their own units separated by modular design and constructions. Important implication of this is that the control room is a relatively clean working environment and the risk of exposure to harmful factors is low. However, the number of viable airborne microbes was high both in the biowaste receiving hall and in the drum composting hall. The concentration (geometric average) of total microbes was 21.8 million pcs/m3 in the biowaste receiving hall, 13.9 million pcs/m3 in the drum composting hall, and just 1.4 million pcs/m3 in the control room. Endotoxin concentrations were high in the biowaste receiving hall and in the drum composting hall. The average (arithmetic) endotoxin concentration was over the threshold value of 200 EU/m3 in both measurement locations. In all working areas, the average (arithmetic) dust concentrations were in a low range of 0.6-0.7 mg/m3, being below the Finnish threshold value of 5 mg/m3. In the receiving hall and drum composting hall, the concentrations of airborne microbes and endotoxins may rise to levels hazardous to health during prolonged exposure. It is advisable to use a respirator mask (class P3) in these areas. Detected volatile organic compounds were typical compounds of composting plants: carboxylic acids and their esters, alcohols, ketones, aldehydes, and terpenes. Concentrations of VOCs were much lower than the Finnish threshold limit values (Finnish TLVs), many of the quantified compounds exceeded their threshold odour concentrations (TOCs). Primary health effects due VOCs were not presumable at these concentrations but unpleasant odours may cause secondary symptoms such as nausea and hypersensitivity reactions. This situation is typical of composting plants where the workers are exposed to dozens of VOCs simultaneously. The odour units (OU/m3) were measured using olfactometer. The numbers were 23,000 OU/m3 at the output end of the composting drum and 6300 OU/m3 in the exhaust pipe. Inside the composting hall, the number of odour units was 500 and 560 OU/m3.

MHC odours are not required or sufficient for recognition of individual scent owners

PubMed Central

Hurst, Jane L; Thom, Michael D; Nevison, Charlotte M; Humphries, Richard E; Beynon, Robert J

2005-01-01

To provide information about specific depositors, scent marks need to encode a stable signal of individual ownership. The highly polymorphic major histocompatibility complex (MHC) influences scents and contributes to the recognition of close kin and avoidance of inbreeding when MHC haplotypes are shared. MHC diversity between individuals has also been proposed as a primary source of scents used in individual recognition. We tested this in the context of scent owner recognition among male mice, which scent mark their territories and countermark scents from other males. We examined responses towards urine scent according to the scent owner's genetic difference to the territory owner (MHC, genetic background, both and neither) or genetic match to a familiar neighbour. While urine of a different genetic background from the subject always stimulated greater scent marking than own, regardless of familiarity, MHC-associated odours were neither necessary nor sufficient for scent owner recognition and failed to stimulate countermarking. Urine of a different MHC type to the subject stimulated increased investigation only when this matched both the MHC and genetic background of a familiar neighbour. We propose an associative model of scent owner recognition in which volatile scent profiles, contributed by both fixed genetic and varying non-genetic factors, are learnt in association with a stable involatile ownership signal provided by other highly polymorphic urine components. PMID:15906464

King penguins can detect two odours associated with conspecifics.

PubMed

Cunningham, Gregory B; Bonadonna, Francesco

2015-11-01

Recent studies on olfaction in penguins have focused on their use of odours while foraging. It has been proposed for some seabirds that an olfactory landscape shaped by odours coming from feeding areas exists. Islands and colonies, however, may also contribute to the olfactory landscape and may act as an orienting map. To test sensitivities to a colony scent we studied whether King penguins (Aptenodytes patagonicus) could detect the smell of sand, feathers or feces by holding presentations beneath their beaks while they naturally slept on the beach. Penguins had a significantly greater response to the feathers and feces presentations than to sand. Although only a first step in exploring a broader role of olfaction in this species, our results raise the possibility of olfaction being used by King penguins in three potential ways: (1) locating the colony from the water or the shore, (2) finding the rendezvous zone within the colony where a chick or partner may be found, or (3) recognizing individuals by scent, as in Humboldt penguins (Spheniscus demersus). © 2015. Published by The Company of Biologists Ltd.

Pyrazine odour makes visually conspicuous prey aversive.

PubMed

Lindström, L; Rowe, C; Guilford, T

2001-01-22

Unpalatable insects frequently adopt multimodal signals to ward off predators, incorporating sounds and odours into their colourful displays. Pyrazine is an odour commonly used in insect warning displays, and has previously been shown to elicit unlearned biases against common warning colours, e.g. yellow and red in naive predators. We designed two experiments to test for similar effects of pyrazine on the conspicuousness of prey, perhaps the most ubiquitous aspect of aposematic coloration. In the first experiment, we offered predators (Gallus gallus domesticus) a choice between conspicuous crumbs and cryptic crumbs in the presence or absence of pyrazine. In the second experiment, we manipulated the birds' experience of conspicuous prey during an initial training phase. Only in the presence of pyrazine did birds show a bias against conspicuously coloured food, and this occurred whether or not they had previously experienced food that contrasted with the background. This emergent behaviour relied upon the visual and odorous signal components being presented together. These unlearned, yet hidden, responses against conspicuousness demonstrate that there are initial benefits to prey being conspicuous when the multimodal nature of warning signals is accounted for.

Floral scent emitted by white and coloured morphs in orchids.

PubMed

Dormont, L; Delle-Vedove, R; Bessière, J-M; Schatz, B

2014-04-01

Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined. Copyright © 2014 Elsevier Ltd. All rights reserved.

Factors Influencing the Flavour of Bovine Milk and Cheese from Grass Based versus Non-Grass Based Milk Production Systems

PubMed Central

Faulkner, Hope; Clarke, Holly J.; O’Sullivan, Maurice G.; Kerry, Joseph P.

2018-01-01

There has been a surge in interest in relation to differentiating dairy products derived from pasture versus confined systems. The impact of different forage types on the sensory properties of milk and cheese is complex due to the wide range of on farm and production factors that are potentially involved. The main effect of pasture diet on the sensory properties of bovine milk and cheese is increased yellow intensity correlated to β-carotene content, which is a possible biomarker for pasture derived dairy products. Pasture grazing also influences fat and fatty acid content which has been implicated with texture perception changes in milk and cheese and increased omega-3 fatty acids. Changes in polyunsaturated fatty acids in milk and cheese due to pasture diets has been suggested may increase susceptibility to lipid oxidation but does not seem to be an issue to due increased antioxidants and the reducing environment of cheese. It appears that pasture derived milk and cheese are easier to discern by trained panellists and consumers than milk derived from conserved or concentrate diets. However, milk pasteurization, inclusion of concentrate in pasture diets, cheese ripening time, have all been linked to reducing pasture dietary effects on sensory perception. Sensory evaluation studies of milk and cheese have, in general, found that untrained assessors who best represent consumers appear less able to discriminate sensory differences than trained assessors and that differences in visual and textural attributes are more likely to be realized than flavour attributes. This suggests that sensory differences due to diet are often subtle. Evidence supports the direct transfer of some volatiles via inhalation or ingestion but more so with indirect transfer post rumen metabolism dietary components. The impact of dietary volatiles on sensory perception of milk and dairy products obviously depends upon their concentration and odour activity, however very little quantitative studies have been carried out to date. Some studies have highlighted potential correlation of pasture with enhanced “barny” or “cowy” sensory attributes and subsequently linked these to accumulation of p-cresol from the metabolism of β-carotene and aromatic amino acids or possibly isoflavones in the rumen. p-Cresol has also been suggested as a potential biomarker for pasture derived dairy products. Other studies have linked terpenes to specific sensory properties in milk and cheese but this only appears to be relevant in milk and cheese derived from unseeded wild pasture where high concentrations accumulate, as their odour threshold is quite high. Toluene also a product of β-carotene metabolism has been identified as a potential biomarker for pasture derived dairy products but it has little impact on sensory perception due to its high odour threshold. Dimethyl sulfone has been linked to pasture diets and could influence sensory perception as its odour threshold is low. Other studies have linked the presence of maize and legumes (clover) in silage with adverse sensory impacts in milk and cheese. Considerably more research is required to define key dietary related impacts on the flavour of milk and cheese. PMID:29534042

A centrifugal pathway to the mouse accessory olfactory bulb from the medial amygdala conveys gender-specific volatile pheromonal signals

PubMed Central

Martel, Kristine L.; Baum, Michael J.

2009-01-01

We previously found that female mice exhibited Fos responses in the accessory olfactory bulb (AOB) after exposure to volatile opposite-, but not same-sex, urinary odours. This effect was eliminated by lesioning the main olfactory epithelium, raising the possibility that the AOB receives information about gender via centrifugal inputs originating in the main olfactory system instead of from the vomeronasal organ. We asked which main olfactory forebrain targets send axonal projections to the AOB, and whether these input neurons express Fos in response to opposite-sex urinary volatiles. Female mice received bilateral injections of the retrograde tracer, cholera toxin B (CTB), into the AOB, and were exposed to either same- or opposite-sex volatile urinary odours one week later. We found CTB- labeled cell bodies in several forebrain sites including the bed nucleus of the accessory olfactory tract, the rostral portion of the medial amygdala (MeA), and the posteromedial cortical nucleus of the amygdala. A significant increase in the percentage of CTB/Fos co-labeled cells was seen only in the MeA of female subjects exposed to male but not to female urinary volatiles. In Experiment 2, CTB-injected females were later exposed to volatile odours from male mouse urine, food, or cat urine. Again, a significant increase in the percentage of CTB/Fos co-labeled cells was seen in the MeA of females exposed to male mouse urinary volatiles but not to food or predator odours. Main olfactory - MeA -AOB signaling may motivate approach behaviour to opposite-sex pheromonal signals that ensure successful reproduction. PMID:19077123

A re-evaluation of the taste and odour of methyl tertiary butyl ether (MTBE) in drinking water.

PubMed

Suffet, I H

2007-01-01

Methyl tertiary butyl ether (MTBE) is a gasoline additive that has been found in groundwater when an underground gasoline storage tank leaks. Although dependent on the clean-up standards that are applied, clean-up costs have been estimated in the US alone to be in the billions of dollars. MTBE is considered primarily a taste and odour concern and not a toxicity issue at concentrations found in drinking water. Thus, the clean-up of MTBE problems is controlled by the MTBE odour threshold concentration (OTC). The level of clean-up and associated differential of millions of dollars is a matter of concern for water purveyors and well owners. A 1993 study of nine OTC studies showed the OTC of MTBE in water to be between 0.04 and 0.06 microg/L, a level over two orders of magnitude less than eight other studies. This 1993 study was repeated at the original laboratory in 2004 and is reported in this paper. The laboratory's quality control programme and ability to repeat one of the eight other studies indicated the laboratory was qualified to repeat its original OTC study. The flavour and odour detection threshold range in the 1993 study, however, could not be confirmed by trained assessors repeating the original study in 2004. The inconsistencies in the data and the high detection on water blanks indicate that the dilution series of the test solutions for the 1993 study were mainly at subthreshold levels. Therefore, the original study of 1993 is not a valid OTC study for MTBE and should not be used to develop drinking water and clean-up standards. The OTC of MTBE is over 15 microg/L for the eight valid studies.

Modulation of Higher-Order Olfaction Components on Executive Functions in Humans.

PubMed

Fagundo, Ana B; Jiménez-Murcia, Susana; Giner-Bartolomé, Cristina; Islam, Mohammed Anisul; de la Torre, Rafael; Pastor, Antoni; Casanueva, Felipe F; Crujeiras, Ana B; Granero, Roser; Baños, Rosa; Botella, Cristina; Fernández-Real, Jose M; Frühbeck, Gema; Gómez-Ambrosi, Javier; Menchón, José M; Tinahones, Francisco J; Fernández-Aranda, Fernando

2015-01-01

The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both executive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test-WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the ''Sniffin' Sticks'' test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All participants were female, aged between 18 and 60. Results showed that participants with hyposmia displayed worse performance in decision making (IGT; Cohen's-d = 0.91) and cognitive flexibility (WCST; Cohen's-d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants' age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive measures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders.

Short-term experiments in using digestate products as substitutes for mineral (N) fertilizer: Agronomic performance, odours, and ammonia emission impacts.

PubMed

Riva, C; Orzi, V; Carozzi, M; Acutis, M; Boccasile, G; Lonati, S; Tambone, F; D'Imporzano, G; Adani, F

2016-03-15

Anaerobic digestion produces a biologically stable and high-value fertilizer product, the digestate, which can be used as an alternative to mineral fertilizers on crops. However, misuse of digestate can lead to annoyance for the public (odours) and to environmental problems such as nitrate leaching and ammonia emissions into the air. Full field experimental data are needed to support the use of digestate in agriculture, promoting its correct management. In this work, short-term experiments were performed to substitute mineral N fertilizers (urea) with digestate and products derived from it to the crop silage maize. Digestate and the liquid fraction of digestate were applied to soil at pre-sowing and as topdressing fertilizers in comparison with urea, both by surface application and subsurface injection during the cropping seasons 2012 and 2013. After each fertilizer application, both odours and ammonia emissions were measured, giving data about digestate and derived products' impacts. The AD products could substitute for urea without reducing crop yields, apart from the surface application of AD-derived fertilizers. Digestate and derived products, because of high biological stability acquired during the AD, had greatly reduced olfactometry impact, above all when they were injected into soils (82-88% less odours than the untreated biomass, i.e. cattle slurry). Ammonia emission data indicated, as expected, that the correct use of digestate and derived products required their injection into the soil avoiding, ammonia volatilization into the air and preserving fertilizer value. Sub-surface injection allowed ammonia emissions to be reduced by 69% and 77% compared with surface application during the 2012 and 2013 campaigns. Copyright © 2015 Elsevier B.V. All rights reserved.

Visual capability to receive character information. Part I: How many characters can we recognize at a glance?

PubMed

Fukuda, T

1992-01-01

A study was made on the capability to receive character information and the factors restricting it. The study showed that the capability indicated by the memory span was limited by the average number of characters for words that are made up of individual characters, and calculated in terms of information quantity, there was no difference among the individual characters. The differences in memory span, depending on the size of the pattern presented, was negligible. The difference in the way characters were arranged produced the difference in memory span saturation. This phenomenon is explained by the nature of the lateral interference effect working among the adjacent characters.

How much does nasal cavity morphology matter? Patterns and rates of olfactory airflow in phyllostomid bats

PubMed Central

Eiting, Thomas P.; Perot, J. Blair; Dumont, Elizabeth R.

2015-01-01

The morphology of the nasal cavity in mammals with a good sense of smell includes features that are thought to improve olfactory airflow, such as a dorsal conduit that delivers odours quickly to the olfactory mucosa, an enlarged olfactory recess at the back of the airway, and a clear separation of the olfactory and respiratory regions of the nose. The link between these features and having a good sense of smell has been established by functional examinations of a handful of distantly related mammalian species. In this paper, we provide the first detailed examination of olfactory airflow in a group of closely related species that nevertheless vary in their sense of smell. We study six species of phyllostomid bats that have different airway morphologies and foraging ecologies, which have been linked to differences in olfactory ability or reliance. We hypothesize that differences in morphology correlate with differences in the patterns and rates of airflow, which in turn are consistent with dietary differences. To compare species, we make qualitative and quantitative comparisons of the patterns and rates of airflow through the olfactory region during both inhalation and exhalation across the six species. Contrary to our expectations, we find no clear differences among species in either the patterns of airflow through the airway or in rates of flow through the olfactory region. By and large, olfactory airflow seems to be conserved across species, suggesting that morphological differences appear to be driven by other mechanical demands on the snout, such as breathing and feeding. Olfactory ability may depend on other aspects of the system, such as the neurobiological processing of odours that work within the existing morphology imposed by other functional demands on the nasal cavity. PMID:25520358

The cultivation of the mushroom Agaricus bisporus (Champignon) and some environmental and health aspects.

PubMed

Zicari, Giuseppe; Rivetti, Daniela; Soardo, Vincenzo; Cerrato, Elena

2012-01-01

The cultivation of the mushroom Agaricus bisporus, also known as button mushroom, requires the use of substrates for its cultivation, such as chicken and/or horse manure and the application of manufacturing steps, such as storage and composting that produce odours. The odours may cause disturbance to people living near the plant and may be a problem for workers. This article examines some measures that can be taken to reduce the odorous emissions during the production of Agaricus bisporus. The possibility of recovery of some organic matter left from the cultivation is examined. Finally, some occupational hazards for workers are highlighted.

From antenna to antenna: lateral shift of olfactory memory recall by honeybees.

PubMed

Rogers, Lesley J; Vallortigara, Giorgio

2008-06-04

Honeybees, Apis mellifera, readily learn to associate odours with sugar rewards and we show here that recall of the olfactory memory, as demonstrated by the bee extending its proboscis when presented with the trained odour, involves first the right and then the left antenna. At 1-2 hour after training using both antennae, recall is possible mainly when the bee uses its right antenna but by 6 hours after training a lateral shift has occurred and the memory can now be recalled mainly when the left antenna is in use. Long-term memory one day after training is also accessed mainly via the left antenna. This time-dependent shift from right to left antenna is also seen as side biases in responding to odour presented to the bee's left or right side. Hence, not only are the cellular events of memory formation similar in bees and vertebrate species but also the lateralized networks involved may be similar. These findings therefore seem to call for remarkable parallel evolution and suggest that the proper functioning of memory formation in a bilateral animal, either vertebrate or invertebrate, requires lateralization of processing.

Body odour disgust sensitivity predicts authoritarian attitudes

PubMed Central

Lindholm, Torun; Hawley, Caitlin B.; Gustafsson Sendén, Marie; Ekström, Ingrid; Olsson, Mats J.; Olofsson, Jonas K.

2018-01-01

Authoritarianism has resurfaced as a research topic in political psychology, as it appears relevant to explain current political trends. Authoritarian attitudes have been consistently linked to feelings of disgust, an emotion that is thought to have evolved to protect the organism from contamination. We hypothesized that body odour disgust sensitivity (BODS) might be associated with authoritarianism, as chemo-signalling is a primitive system for regulating interpersonal contact and disease avoidance, which are key features also in authoritarianism. We used well-validated scales for measuring BODS, authoritarianism and related constructs. Across two studies, we found that BODS is positively related to authoritarianism. In a third study, we showed a positive association between BODS scores and support for Donald Trump, who, at the time of data collection, was a presidential candidate with an agenda described as resonating with authoritarian attitudes. Authoritarianism fully explained the positive association between BODS and support for Donald Trump. Our findings highlight body odour disgust as a new and promising domain in political psychology research. Authoritarianism and BODS might be part of the same disease avoidance framework, and our results contribute to the growing evidence that contemporary social attitudes might be rooted in basic sensory functions. PMID:29515834

Mechanosensory Interactions Drive Collective Behaviour in Drosophila

PubMed Central

Ramdya, Pavan; Lichocki, Pawel; Cruchet, Steeve; Frisch, Lukas; Tse, Winnie; Floreano, Dario; Benton, Richard

2014-01-01

Collective behaviour enhances environmental sensing and decision-making in groups of animals1,2. Experimental and theoretical investigations of schooling fish, flocking birds and human crowds have demonstrated that simple interactions between individuals can explain emergent group dynamics3,4. These findings imply the existence of neural circuits that support distributed behaviours, but the molecular and cellular identities of relevant sensory pathways are unknown. Here we show that Drosophila melanogaster exhibits collective responses to an aversive odour: individual flies weakly avoid the stimulus, but groups show enhanced escape reactions. Using high-resolution behavioural tracking, computational simulations, genetic perturbations, neural silencing and optogenetic activation we demonstrate that this collective odour avoidance arises from cascades of appendage touch interactions between pairs of flies. Inter-fly touch sensing and collective behaviour require the activity of distal leg mechanosensory sensilla neurons and the mechanosensory channel NOMPC5,6. Remarkably, through these inter-fly encounters, wild-type flies can elicit avoidance behaviour in mutant animals that cannot sense the odour – a basic form of communication. Our data highlight the unexpected importance of social context in the sensory responses of a solitary species and open the door to a neural circuit level understanding of collective behaviour in animal groups. PMID:25533959

Virgin queen attraction toward males in honey bees.

PubMed

Bastin, Florian; Cholé, Hanna; Lafon, Grégory; Sandoz, Jean-Christophe

2017-07-24

Although the honeybee is a crucial agricultural agent and a prominent scientific model organism, crucial aspects of its reproductive behaviour are still unknown. During the mating season, honeybee males, the drones, gather in congregations 10-40 m above ground. Converging evidence suggests that drones emit a pheromone that can attract other drones, thereby increasing the size of the congregation. Virgin queens join the vicinity of the congregation after it has formed, and mate with as many as 20 males in mid-air. It is still unclear which sensory cues help virgin queens find drone congregations in the first place. Beside visual cues for long-range orientation, queens may use olfactory cues. We thus tested virgin queens' olfactory orientation on a walking simulator in which they have full control over odour stimulation. We show that sexually-mature virgin queens are attracted to the odour bouquet from a group of living drones. They are not attracted to the bouquet from a group of workers. In addition, non-sexually receptive females (workers) of the same age are not attracted to the drone odour bouquet. Interpreted in the context of mating, these results may suggest that virgin queens use volatile olfactory cues from the drones to find the congregations.

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

PubMed

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

2015-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2009-02-01

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

Anopheles darlingi (Diptera: Culicidae) displays increased attractiveness to infected individuals with Plasmodium vivax gametocytes.

PubMed

Batista, Elis Pa; Costa, Elizangela Fm; Silva, Alexandre A

2014-05-29

Most hematophagous insects use host odours as chemical cues. The odour components, some physiological parameters and host attractiveness are affected by several conditions, including infection by parasites, e.g., plasmodia and, therefore, change the epidemiological scenario. This study evaluated the attractiveness of individuals with vivax malaria before, during (7 days) and after treatment (14 days) with specific antimalarial drugs. Mosquito attractiveness to vivax-infected patients was assessed using a vertical olfactometer using the foot as a source of body odour. The ratio of Anopheles darlingi mosquitoes in the lower chamber of the olfactometer was used to calculate the attractiveness, and patient temperature was measured using a digital thermometer. An increased attractiveness was found only in patients bearing vivax gametocytes during the first experiment (early infection) (P<0.001). Patients in the first experiment tended to have a higher body temperature, but grouping patients into fever and non-fever resulted in a higher attractiveness only in the fever group of gametocyte carriers, suggesting a synergistic effect of temperature and gametocytes in the host attractiveness to A. darlingi. Gametocyte presence and fever in vivax malaria patients increased short distance host attractiveness to An. darlingi.

Body odour disgust sensitivity predicts authoritarian attitudes.

PubMed

Liuzza, Marco Tullio; Lindholm, Torun; Hawley, Caitlin B; Gustafsson Sendén, Marie; Ekström, Ingrid; Olsson, Mats J; Olofsson, Jonas K

2018-02-01

Authoritarianism has resurfaced as a research topic in political psychology, as it appears relevant to explain current political trends. Authoritarian attitudes have been consistently linked to feelings of disgust, an emotion that is thought to have evolved to protect the organism from contamination. We hypothesized that body odour disgust sensitivity (BODS) might be associated with authoritarianism, as chemo-signalling is a primitive system for regulating interpersonal contact and disease avoidance, which are key features also in authoritarianism. We used well-validated scales for measuring BODS, authoritarianism and related constructs. Across two studies, we found that BODS is positively related to authoritarianism. In a third study, we showed a positive association between BODS scores and support for Donald Trump, who, at the time of data collection, was a presidential candidate with an agenda described as resonating with authoritarian attitudes. Authoritarianism fully explained the positive association between BODS and support for Donald Trump. Our findings highlight body odour disgust as a new and promising domain in political psychology research. Authoritarianism and BODS might be part of the same disease avoidance framework, and our results contribute to the growing evidence that contemporary social attitudes might be rooted in basic sensory functions.

Asthma, Allergy and Eczema among Adults in Multifamily Houses in Stockholm (3-HE Study) - Associations with Building Characteristics, Home Environment and Energy Use for Heating

PubMed Central

Norbäck, Dan; Lampa, Erik; Engvall, Karin

2014-01-01

Risk factors for asthma, allergy and eczema were studied in a stratified random sample of adults in Stockholm. In 2005, 472 multifamily buildings (10,506 dwellings) were invited (one subject/dwelling) and 7,554 participated (73%). Associations were analyzed by multiple logistic regression, adjusting for gender, age, smoking, country of birth, income and years in the dwelling. In total, 11% had doctor's diagnosed asthma, 22% doctor's diagnosed allergy, 23% pollen allergy and 23% eczema. Doctor's diagnosed asthma was more common in dwellings with humid air (OR = 1.74) and mould odour (OR = 1.79). Doctor's diagnosed allergy was more common in buildings with supply exhaust air ventilation as compared to exhaust air only (OR = 1.45) and was associated with redecoration (OR = 1.48) and mould odour (OR = 2.35). Pollen allergy was less common in buildings using more energy for heating (OR = 0.75) and was associated with humid air (OR = 1.76) and mould odour (OR = 2.36). Eczema was more common in larger buildings (OR 1.07) and less common in buildings using more energy for heating (OR = 0.85) and was associated with water damage (OR = 1.47), humid air (OR = 1.73) and mould odour (OR = 2.01). Doctor's diagnosed allergy was less common in buildings with management accessibility both in the neighbourhood and in larger administrative divisions, as compared to management in the neighbourhood only (OR = 0.49; 95% CI 0.29–0.82). Pollen allergy was less common if the building maintenance was outsourced (OR = 0.67; 95% CI 0.51–0.88). Eczema was more common when management accessibility was only at the division level (OR = 1.49; 95% CI 1.06–2.11). In conclusions, asthma, allergy or eczema were more common in buildings using less energy for heating, in larger buildings and in dwellings with redecorations, mould odour, dampness and humid air. There is a need to reduce indoor chemical emissions and to control dampness. Energy saving may have consequences for allergy and eczema. More epidemiological studies are needed on building management organization. PMID:25479551

Migration and sensory properties of plastics-based nets used as food-contacting materials under ambient and high temperature heating conditions.

PubMed

Kontominas, M G; Goulas, A E; Badeka, A V; Nerantzaki, A

2006-06-01

Overall migration from a wide range of commercial plastics-based netting materials destined to be used as either meat or vegetable packaging materials into the fatty food simulant isooctane or the aqueous simulant distilled water, respectively, was studied. In addition, sensory tests of representative netting materials were carried out in bottled water in order to investigate possible development of off-odour/taste and discoloration in this food simulant as a result of migration from the netting material. Sensory tests were supplemented by determination of the volatile compounds' profile in table water exposed to the netting materials using SPME-GC/MS. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to European Union Directives 90/128 (EEC, 1990) and 2002/72 (EEC, 2002). The results showed that for both PET and polyethylene-based netting materials, overall migration values into distilled water ranged between 11.5 and 48.5 mg l(-1), well below the upper limit (60 mg l(-1)) for overall migration values from plastics-packaging materials set by the European Union. The overall migration values from netting materials into isooctane ranged between 38.0 and 624.0 mg l(-1), both below and above the European Union upper limit for migration. Sensory tests involving contact of representative samples with table water under refluxing (100 degrees C/4 h) conditions showed a number of the netting materials produced both off-odour and/or taste as well as discoloration of the food simulant rendering such materials unfit for the packaging of foodstuffs in applications involving heating at elevated temperatures. GC/MS analysis showed the presence of numerous volatile compounds being produced after netting materials/water contact under refluxing conditions. Although it is extremely difficult to establish a clear correlation between sensory off-odour development and GC/MS volatile compounds' profile, it may be postulated that plastics oxidation products such as hexanal, heptanal, octanal and 2,6 di-tert-butylquinone may contribute to off-odour development using commercially bottled table water as a food simulant. Likewise, compounds such as carbon disulfide, [1,1'-biphenyl]-2-ol and propanoic acid, 2 methyl 1-(1,1-dimethyl)-2-methyl-1,3-propanediyl ester probably originating from cotton and rubber components of netting materials may also contribute to off-odour/taste development.

Carcass and meat quality in light lambs from different fat classes in the EU carcass classification system.

PubMed

Sañudo, C; Alfonso, M; Sánchez, A; Delfa, R; Teixeira, A

2000-09-01

Ninety commercial lamb carcasses were analysed according to the four different fat classes in the light lamb European classification system. Shoulder fat increased 3%, muscle decreased 2% and bone decreased 1% for each class increase. No significant differences were found among fat classes regarding pH, WHC, cooking losses, juiciness, myoglobin content, meat colour measured immediately after cutting (L*, a*, b*), odour intensity or flavour quality. Some differences were found in colour evolution through ageing. Shear force decreased and tenderness and flavour intensity increased with fat class but this effect was only significant in the leanest animals.

Behavioural impairment in reef fishes caused by ocean acidification at CO2 seeps

NASA Astrophysics Data System (ADS)

Munday, Philip L.; Cheal, Alistair J.; Dixson, Danielle L.; Rummer, Jodie L.; Fabricius, Katharina E.

2014-06-01

Experiments have shown that the behaviour of reef fishes can be seriously affected by projected future carbon dioxide (CO2) concentrations in the ocean. However, whether fish can acclimate to elevated CO2 over the longer term, and the consequences of altered behaviour on the structure of fish communities, are unknown. We used marine CO2 seeps in Papua New Guinea as a natural laboratory to test these questions. Here we show that juvenile reef fishes at CO2 seeps exhibit behavioural abnormalities similar to those seen in laboratory experiments. Fish from CO2 seeps were attracted to predator odour, did not distinguish between odours of different habitats, and exhibited bolder behaviour than fish from control reefs. High CO2 did not, however, have any effect on metabolic rate or aerobic performance. Contrary to expectations, fish diversity and community structure differed little between CO2 seeps and nearby control reefs. Differences in abundances of some fishes could be driven by the different coral community at CO2 seeps rather than by the direct effects of high CO2. Our results suggest that recruitment of juvenile fish from outside the seeps, along with fewer predators within the seeps, is currently sufficient to offset any negative effects of high CO2 within the seeps. However, continuous exposure does not reduce the effect of high CO2 on behaviour in natural reef habitat, and this could be a serious problem for fish communities in the future when ocean acidification becomes widespread as a result of continued uptake of anthropogenic CO2 emissions.

Efficacy of the combined application of chitosan and Locust Bean Gum with different citrus essential oils to control postharvest spoilage caused by Aspergillus flavus in dates.

PubMed

Aloui, Hajer; Khwaldia, Khaoula; Licciardello, Fabio; Mazzaglia, Agata; Muratore, Giuseppe; Hamdi, Moktar; Restuccia, Cristina

2014-01-17

This study reports the efficacy of the combined application of chitosan (CH) and Locust Bean Gum (LBG) in combination with different citrus essential oils (EOs) to inhibit Aspergillus flavus in vitro and on artificially infected dates for a storage period of 12 days. The effect of these treatments on the fruits' sensory characteristics was evaluated to verify the complete absence of off-odours and off-flavours. Bergamot EO was the most effective in reducing mycelial growth, followed by bitter orange EO. Both bergamot and bitter orange oils significantly reduced conidial germination and a complete inhibition was obtained at concentrations higher than 2%. The mixtures based on CH-2% (v/v) bergamot EO or CH-2% (v/v) bitter orange EO proved to be the most effective coatings to reduce conidial germination resulting in an 87-90% inhibition compared with the control. In fruit decay assays coatings based on CH incorporating citrus oils were able to reduce fungal decay in the range of 52-62% at day 12. The study results and the complete absence of off-flavours and off-odours demonstrate the potential of CH coatings carrying citrus EOs at sub-inhibitory concentrations to control postharvest growth of A. flavus in dates. Copyright © 2013 Elsevier B.V. All rights reserved.

Refining the dual olfactory hypothesis: pheromone reward and odour experience.

PubMed

Martínez-García, Fernando; Martínez-Ricós, Joana; Agustín-Pavón, Carmen; Martínez-Hernández, Jose; Novejarque, Amparo; Lanuza, Enrique

2009-06-25

In rodents, sexual advertisement and gender recognition are mostly (if not exclusively) mediated by chemosignals. Specifically, there is ample evidence indicating that female mice are 'innately' attracted by male sexual pheromones that have critical non-volatile components and are detected by the vomeronasal organ. These pheromones can only get access to the vomeronasal organ by active pumping mechanisms that require close contact with the source of the stimulus (e.g. urine marks) during chemoinvestigation. We have hypothesised that male sexual pheromones are rewarding to female mice. Indeed, male-soiled bedding can be used as a reinforcer to induce conditioned place preference, provided contact with the bedding is allowed. The neural mechanisms of pheromone reward seem, however, different from those employed by other natural reinforcers, such as the sweetness or postingestive effects of sucrose. In contrast to vomeronasal-detected male sexual pheromones, male-derived olfactory stimuli (volatiles) are not intrinsically attractive to female mice. However, after repeated exposure to male-soiled bedding, intact female mice develop an acquired preference for male odours. On the contrary, in females whose accessory olfactory bulbs have been lesioned, exposure to male-soiled bedding induces aversion to male odorants. These considerations, together with data on the different properties of olfactory and vomeronasal receptors, lead us to make a proposal for the complementary roles that the olfactory and vomeronasal systems play in intersexual attraction and in other forms of intra- or inter-species communication.

The relation between self-reported worry and annoyance from air and road traffic.

PubMed

van den Berg, Frits; Verhagen, Claudia; Uitenbroek, Daan

2015-02-25

Negative perceptions such as fear or worry are known to be an important determinant of annoyance. Annoyance caused by noise and odour has been analysed in relation to worry about safety or health due to environmental hazards, using responses to a health survey. In the survey area high environmental impacts come from air and road traffic. The survey results show a correlation between worry due to the airport or passing aircraft and noise and odour annoyance from aircraft (correlation coefficient (c.c.) close to 0.6). For the relation between worry about a busy street and annoyance from road traffic the correlation is lower (c.c. 0.4-0.5). Worries about different situations, such as living below sea level, close to an airport, busy street or chemical industry, are highly correlated (c.c. 0.5-0.9), also for situations that are not obviously related. Personal factors can also lead to more worry: being female, above 35 years of age, having a high risk for anxiety/depression and being in bad health increase the odds for being worried. The results thus suggest that worry about safety or health is correlated to both personal and environmental factors.

Efficacy of pink guava pulp as an antioxidant in raw pork emulsion.

PubMed

Joseph, Serlene; Chatli, Manish K; Biswas, Ashim K; Sahoo, Jhari

2014-08-01

Lipid oxidation-induced quality problems can be minimized with the use of natural antioxidants. The antioxidant potential of pink guava pulp (PGP) was evaluated at different levels (0%; C, 5.0%; T-1, 7.5%; T-2 and 10.0%; T-3) in the raw pork emulsion during refrigerated storage of 9 days under aerobic packaging. Lycopene and β-carotene contents increased (P < 0.05) with PGP levels. The redness (a*) increased (P < 0.05), whereas L*decreased (P < 0.05) with the incorporation of PGP. The visual colour and odour scores were greater (P < 0.05) in PGP-treated products than control. Percent metmyoglobin formation was greater (P < 0.05) in the control than PGP-treated products, and increased (P < 0.05) during storage in all the treatments. Overall, peroxide value, thiobarbituric acid reactive substances and free fatty acid values were lower (P < 0.05) in PGP-treated raw emulsion than control throughout storage period. Our results indicated that pink guava pulp can be utilized as antioxidants in raw pork products to minimize lipid oxidation, off-odour development, and surface discolouration.

Impact of processing on odour-active compounds of a mixed tomato-onion puree.

PubMed

Koutidou, Maria; Grauwet, Tara; Van Loey, Ann; Acharya, Parag

2017-08-01

Gas chromatography-olfactometry revealed thirty-two odour-active compounds in a heat-processed tomato-onion puree, among which twenty-seven were identified by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOF MS). Based on the results of two olfactometric methods, i.e. detection frequency and aroma extract dilution analysis, the most potent aroma components include: dipropyl disulfide, S-propyl thioacetate, dimethyl trisulfide, 1-octen-3-one, methional, dipropyl trisulfide, 4,5-dimethylthiazole, 2-phenylacetaldehyde and sotolone. Processing of mixed vegetable systems can add complexity in their aroma profiles due to (bio)chemical interactions between the components. Therefore, the impact of different processing steps (i.e. thermal blanching, all-in-one and split-stream processes) on the volatile profile and aroma of a mixed tomato-onion puree has been investigated using a GC-MS fingerprinting approach. Results showed the potential to control the aroma in a mixed tomato-onion system through process-induced enzymatic modulations for producing tomato-onion food products with distinct aroma characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2014-01-01

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

The Relation between Self-Reported Worry and Annoyance from Air and Road Traffic

PubMed Central

van den Berg, Frits; Verhagen, Claudia; Uitenbroek, Daan

2015-01-01

Negative perceptions such as fear or worry are known to be an important determinant of annoyance. Annoyance caused by noise and odour has been analysed in relation to worry about safety or health due to environmental hazards, using responses to a health survey. In the survey area high environmental impacts come from air and road traffic. The survey results show a correlation between worry due to the airport or passing aircraft and noise and odour annoyance from aircraft (correlation coefficient (c.c.) close to 0.6). For the relation between worry about a busy street and annoyance from road traffic the correlation is lower (c.c. 0.4–0.5). Worries about different situations, such as living below sea level, close to an airport, busy street or chemical industry, are highly correlated (c.c. 0.5–0.9), also for situations that are not obviously related. Personal factors can also lead to more worry: being female, above 35 years of age, having a high risk for anxiety/depression and being in bad health increase the odds for being worried. The results thus suggest that worry about safety or health is correlated to both personal and environmental factors. PMID:25723645

Sweet attraction: sugarcane pollen-associated volatiles attract gravid Anopheles arabiensis.

PubMed

Wondwosen, Betelehem; Birgersson, Göran; Tekie, Habte; Torto, Baldwyn; Ignell, Rickard; Hill, Sharon R

2018-02-21

Anopheles arabiensis is a key vector for the transmission of human malaria in sub-Saharan Africa. Over the past 10,000 years, humans have successfully cultivated grasses and altered the landscape, creating An. arabiensis favourable environments that contain excellent habitats for both larvae and adults. Sugarcane is the most expanding agricultural system in sub-Saharan Africa, and is linked to the increased threat of malaria in rural communities. The prolific production and wind dispersal of sugarcane pollen, together with standing pools of water, often provide, as a result of irrigation, a nutrient-rich environment for the offspring of gravid malaria mosquitoes. In the present study, sugarcane pollen-associated volatiles from two cultivars are shown to attract gravid An. arabiensis in a still air two-port olfactometer and stimulate egg laying in an oviposition bioassay. Through combined gas chromatography and electroantennographic detection, as well as combined gas chromatography and mass spectrometric analyses, we identified the bioactive volatiles and generated a synthetic blend that reproduced the full behavioural repertoire of gravid mosquitoes in the Y-tube assay. Two subtractive odour blends, when compared with the full blend, were significantly more attractive. These three and four-component subtractive blends share the compounds (1R)-(+)-α-pinene, nonanal and benzaldehyde, of which, (1R)-(+)-α-pinene and nonanal are found in the attractive odour blends from rice plants and maize pollen. In pairwise comparisons, the rice synthetic odour blend was more attractive to gravid mosquitoes than either of the pollen blends, whereas the pollen blends did not differ in attraction. The attraction of gravid females to sugarcane pollen volatiles demonstrated in this study, together with the previously found grass-associated volatiles, raise the potential of developing a bioactive chimeric blend to attract gravid malaria mosquitoes. This is discussed in relation to the development of novel and cost-effective vector control measures.

[An odour of disease and decay: the nose as a diagnostic instrument].

PubMed

Bomers, Marije K; Smulders, Yvo M

2015-01-01

Infectious diseases and cancer change a patient's metabolism and hence the metabolic compounds produced. The composition of volatile organic compounds (VOCs) in exhaled breath or urine or stool samples can therefore be characteristic of a particular disease. In recent years many studies have been conducted into the training of animals, including dogs, to recognise diseases by smell. Besides trained animals, electronic noses (e-noses) are also being developed. These devices can identify disease-specific odour profiles in VOCs. Although the results of research in the field of scent diagnosis are promising, the medical community remains largely sceptical. We discuss applications of scent detection as a diagnostic tool in modern medicine.

A Simple Compression Scheme Based on ASCII Value Differencing

NASA Astrophysics Data System (ADS)

Tommy; Siregar, Rosyidah; Lubis, Imran; Marwan E, Andi; Mahmud H, Amir; Harahap, Mawaddah

2018-04-01

ASCII characters have a different code representation where each character has a different numeric value between the characters to each other. The characters is usually used as a text message communication has the representation of a numeric code to each other or have a small difference. The value of the difference can be used as a substitution of the characters so it will generate a new message with a size that is a little more. This paper discusses the utilization value of the difference of characters ASCII in a message to a much simpler substitution by using a dynamic-sized window in order to obtain the difference from ASCII value contained on the window as the basis in determining the bit substitution on the file compression results.

Increasing Electronic Nose Recognition Ability by Laser Irradiation

NASA Astrophysics Data System (ADS)

Alejandra, Massacane; Juan, Vorobioff; Karina, Pierpauli; Norberto, Boggio; Silvia, Reich; Carlos, Rinaldi; Alfredo, Boselli; Alberto, Lamagna; Laura, Azcárate M.; Jorge, Codnia; Francisco, Manzano

2009-05-01

We present a method to increase the capability of an electronic nose to discriminate between a priori similar odours. We analyze the case of olive oil because it is well known that the characteristics of its aroma impair in many cases the discrimination between different kinds of olive oils especially when they are from similar geographic regions. In the present work we study how to improve the electronic nose performance for the above mentioned discrimination by the use of two IR laser wavelengths for vaporization.

Facial patterns in a tropical social wasp correlate with colony membership

NASA Astrophysics Data System (ADS)

Baracchi, David; Turillazzi, Stefano; Chittka, Lars

2016-10-01

Social insects excel in discriminating nestmates from intruders, typically relying on colony odours. Remarkably, some wasp species achieve such discrimination using visual information. However, while it is universally accepted that odours mediate a group level recognition, the ability to recognise colony members visually has been considered possible only via individual recognition by which wasps discriminate `friends' and `foes'. Using geometric morphometric analysis, which is a technique based on a rigorous statistical theory of shape allowing quantitative multivariate analyses on structure shapes, we first quantified facial marking variation of Liostenogaster flavolineata wasps. We then compared this facial variation with that of chemical profiles (generated by cuticular hydrocarbons) within and between colonies. Principal component analysis and discriminant analysis applied to sets of variables containing pure shape information showed that despite appreciable intra-colony variation, the faces of females belonging to the same colony resemble one another more than those of outsiders. This colony-specific variation in facial patterns was on a par with that observed for odours. While the occurrence of face discrimination at the colony level remains to be tested by behavioural experiments, overall our results suggest that, in this species, wasp faces display adequate information that might be potentially perceived and used by wasps for colony level recognition.

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

PubMed

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

2015-09-11

Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (-)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite "supersensitivity" to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 10(8)-fold differential sensitivity of ΔD mice to (-)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >10(10)-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (-)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This "enantiomer odour discrimination paradox" indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification.

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

PubMed Central

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

2015-01-01

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

Neural responses during the anticipation and receipt of olfactory reward and punishment in human.

PubMed

Zou, Lai-Quan; Zhou, Han-Yu; Zhuang, Yuan; van Hartevelt, Tim J; Lui, Simon S Y; Cheung, Eric F C; Møller, Arne; Kringelbach, Morten L; Chan, Raymond C K

2018-03-01

Pleasure experience is an important part of normal healthy life and is essential for general and mental well-being. Many neuroimaging studies have investigated the underlying neural processing of verbal and visual modalities of reward. However, how the brain processes rewards in the olfactory modality is not fully understood. This study aimed to examine the neural basis of olfactory rewards in 25 healthy participants using functional magnetic resonance imaging (fMRI). We developed an Olfactory Incentive Delay (OLID) imaging task distinguishing between the anticipation and receipt of olfactory rewards and punishments. We found that the pallidum was activated during the anticipation of both olfactory rewards and punishments. The bilateral insula was activated independently from the odours' hedonic valence during the receipt phase. In addition, right caudate activation during the anticipation of unpleasant odours was correlated with self-reported anticipatory hedonic traits, whereas bilateral insular activation during the receipt of pleasant odours was correlated with self-reported consummatory hedonic traits. These findings suggest that activity in the insula and the caudate may be biomarkers of anhedonia. These findings also highlight a useful and valid paradigm to study the neural circuitry underlying reward processing in people with anhedonia. Copyright © 2018 Elsevier Ltd. All rights reserved.

Residents' concerns and attitudes toward a municipal solid waste landfill: integrating a questionnaire survey and GIS techniques.

PubMed

Che, Yue; Yang, Kai; Jin, Yan; Zhang, Weiqian; Shang, Zhaoyi; Tai, Jun

2013-12-01

The ever-growing industry of municipal solid waste (MSW) disposal appeals to the growing need for disposal facilities, and MSW treatment facilities are increasingly an environmental and public health concern. Residents living near MSW management facilities are confronted with various risk perceptions, especially odour. In this study, in an effort to assist responsible decision-makers in better planning and managing such a project, a structured questionnaire was designed and distributed to assess the nearby residents' concerns and attitudes surrounding the Laogang Landfill in Shanghai. Geographic information system techniques and relevance analysis were employed to conduct the spatial analysis of physical perceptions, especially odour annoyance. The findings of the research indicate that a significant percentage of the responding sample was aware of the negative impacts of landfills on the environment and public health, and residents in close proximity preferred to live farther from the landfill. The results from the spatial analysis demonstrated a definite degree of correlation between odour annoyance and distance to the facility and proved that the benefits of the socially disadvantaged have been neglected. The research findings also direct attention to the important role of public participation, information disclosure, transparency in management, and mutual communication to avoid conflicts and build social trust.

Social cichlid fish change behaviour in response to a visual predator stimulus, but not the odour of damaged conspecifics.

PubMed

O'Connor, Constance M; Reddon, Adam R; Odetunde, Aderinsola; Jindal, Shagun; Balshine, Sigal

2015-12-01

Predation is one of the primary drivers of fitness for prey species. Therefore, there should be strong selection for accurate assessment of predation risk, and whenever possible, individuals should use all available information to fine-tune their response to the current threat of predation. Here, we used a controlled laboratory experiment to assess the responses of individual Neolamprologus pulcher, a social cichlid fish, to a live predator stimulus, to the odour of damaged conspecifics, or to both indicators of predation risk combined. We found that fish in the presence of the visual predator stimulus showed typical antipredator behaviour. Namely, these fish decreased activity and exploration, spent more time seeking shelter, and more time near conspecifics. Surprisingly, there was no effect of the chemical cue alone, and fish showed a reduced response to the combination of the visual predator stimulus and the odour of damaged conspecifics relative to the visual predator stimulus alone. These results demonstrate that N. pulcher adjust their anti-predator behaviour to the information available about current predation risk, and we suggest a possible role for the use of social information in the assessment of predation risk in a cooperatively breeding fish. Copyright © 2015. Published by Elsevier B.V.

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

PubMed

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

2015-09-11

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

Superior Orthonasal but Not Retronasal Olfactory Skills in Congenital Blindness

PubMed Central

Gagnon, Lea; Ismaili, Abd Rahman Alaoui; Ptito, Maurice; Kupers, Ron

2015-01-01

Sight is undoubtedly important for finding and appreciating food, and cooking. Blind individuals are strongly impaired in finding food, limiting the variety of flavours they are exposed to. We have shown before that compared to sighted controls, congenitally blind individuals have enhanced olfactory but reduced taste perception. In this study we tested the hypothesis that congenitally blind subjects have enhanced orthonasal but not retronasal olfactory skills. Twelve congenitally blind and 14 sighted control subjects, matched in age, gender and body mass index, were asked to identify odours using grocery-available food powders. Results showed that blind subjects were significantly faster and tended to be better at identifying odours presented orthonasally. This was not the case when odorants were presented retronasally. We also found a significant group x route interaction, showing that although both groups performed better for retronasally compared to orthonasally presented odours, this gain was less pronounced for blind subjects. Finally, our data revealed that blind subjects were more familiar with the orthonasal odorants and used the retronasal odorants less often for cooking than their sighted counterparts. These results confirm that orthonasal but not retronasal olfactory perception is enhanced in congenital blindness, a result that is concordant with the reduced food variety exposure in this group. PMID:25822780

Computer-controlled stimulation for functional magnetic resonance imaging studies of the neonatal olfactory system

PubMed Central

Arichi, T; Gordon-Williams, R; Allievi, A; Groves, AM; Burdet, E; Edwards, AD

2013-01-01

Aim Olfactory sensation is highly functional early in human neonatal life, with studies suggesting that odours can influence behaviour and infant–mother bonding. Due to its good spatial properties, blood oxygen level–dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) has the potential to rapidly advance our understanding of the neural activity which underlies the development of olfactory perception in this key period. We aimed to design an ‘olfactometer’ specifically for use with neonatal subjects for fMRI studies of odour perception. Methods We describe a fully automated and programmable, fMRI compatible system capable of presenting odorant liquids. To prevent contamination of the system and minimize between-subject infective risk, the majority of the olfactometer is constructed from single-use, readily available clinical equipment. The system was used to present the odour of infant formula milk in a validation group of seven neonatal subjects at term equivalent postmenstrual age (median age 40 weeks). Results A safe, reliable and reproducible pattern of stimulation was delivered leading to well-localized positive BOLD functional responses in the piriform cortex, amygdala, thalamus, insular cortex and cerebellum. Conclusions The described system is therefore suitable for detailed studies of the ontology of olfactory sensation and perception during early human brain development. PMID:23789919

Pollinator-prey conflicts in carnivorous plants: When flower and trap properties mean life or death

PubMed Central

El-Sayed, Ashraf M.; Byers, John A.; Suckling, David M.

2016-01-01

Insect-pollinated carnivorous plants are expected to have higher fitness if they resolve pollinator-prey conflicts by sparing insects pollinating their flowers while trapping prey insects. We examined whether separation between flowers and traps of the carnivorous sundew species or pollinator preferences for colours of flowers enable these plants to spare pollinators. In addition, we collected odours from flowers and traps of each carnivorous species in order to identify volatile chemicals that are attractive or repellent to pollinators and prey insects. In Drosera spatulata and D. arcturi, no volatiles were detected from either their flowers or traps that could serve as kairomone attractants for insects. However, behavioural experiments indicated white colour and spatial separation between flowers and traps aid in reducing pollinator entrapment while capturing prey. In contrast, D. auriculata have flowers that are adjacent to their traps. In this species we identified chemical signals emanating from flowers that comprised an eight-component blend, while the plant’s traps emitted a unique four-component blend. The floral odour attracted both pollinator and prey insects, while trap odour only attracted prey. This is the first scientific report to demonstrate that carnivorous plants utilize visual, spatial, and chemical signals to spare flower visitors while trapping prey insects. PMID:26888545

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

PubMed Central

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

2015-01-01

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

Different roles of the posterior inferior frontal gyrus in Chinese character form judgment differences between literate and illiterate individuals.

PubMed

Wu, Jinglong; Wang, Bin; Yan, Tianyi; Li, Xiujun; Bao, Xuexiang; Guo, Qiyong

2012-01-11

In the present study, we used event-related functional magnetic resonance imaging (fMRI) to explore the different roles of the posterior inferior frontal gyrus (pIFG) in Chinese character form judgment between literate and illiterate subjects. Using event-related fMRI, 24 healthy right-handed Chinese subjects (12 literates and 12 illiterates) were asked to perform Chinese character and figure form judgment tasks. The blood oxygen level-dependent (BOLD) differences in pIFG were examined with general linear modeling (GLM). We found differences in reaction times and accuracy between subjects as they performed these tasks. These behavioral differences reflect the different cognitive demands of character form judgment for literate and illiterate individuals. The results showed differences in the BOLD response patterns in the pIFG between the two discrimination tasks and the two subject groups. A comparison of the character and figure tasks showed that literate and illiterate subjects had similar BOLD responses in the inferior frontal gyrus. However, differences in behavioral performance suggest that the pIFG plays a different role in Chinese character form judgment for each subject group. In literate subjects, the left pIFG mediated access to phonology in achieving Chinese character form judgment, whereas the right pIFG participated in the processing of the orthography of Chinese characters. In illiterate subjects, the bilateral frontal gyrus participated in the visual-spatial processing of Chinese characters to achieve form judgment. Copyright © 2011 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2015-01-01

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

New antiaxillary odour deodorant made with antimicrobial Ag-zeolite (silver-exchanged zeolite).

PubMed

Nakane, T; Gomyo, H; Sasaki, I; Kimoto, Y; Hanzawa, N; Teshima, Y; Namba, T

2006-08-01

The causative substances for axillary osmidrosis, which are often found in apocrine sweat, are the decomposed/denatured products of short-chain fatty acid and other biological metabolite compounds produced by axillary-resident bacteria. Conventional underarm deodorants suppress the process of odour production mostly by the following mechanism: (1) suppression of perspiration, (2) reduction in numbers of resident bacteria, (3) deodorization and (4) masking. The most important and effective method to reduce odour is to suppress the growth of resident bacteria with antimicrobials, which have several drawbacks, especially in their safety aspect. To solve these problems, we focused on Ag-zeolite (silver-exchanged zeolite) that hold stable Ag, an inorganic bactericidal agent, in its structure, and therefore, poses less risk in safety. Its bactericidal effect on skin-resident bacteria was found to be excellent and comparable with that of triclosan, a most frequently used organic antimicrobial in this product category. The dose-response study of Ag-zeolite powder spray (0-40 w/w%) using 39 volunteers revealed that 5-40 w/w% Ag-zeolite could show a sufficient antimicrobial effect against skin-resident bacteria. The comparison study using 0.2 w/w% triclosan as the control and 10 w/w% Ag-zeolite indicated that: (1) one application of the powder spray containing 10 w/w% Ag-zeolite could show a sufficient antimicrobial effect against the resident bacteria and its effect continued for 24 h, (2) a powder spray containing 0.2 w/w% triclosan was unable to show a sufficient antimicrobial effect, and (3) no adverse event was observed. These studies show that Ag-zeolite has a superior antimicrobial ability that is rarely found in conventional antimicrobials used in deodorant products and a strong antiaxillary odour deodorant ability because of its long-lasting effect. During clinical study, patch tests with humans and other clinical studies of this product showed no adverse events related to the treatment with the Ag-zeolite product.

Profiling the scent of weathered training aids for blood-detection dogs.

PubMed

Chilcote, Baree; Rust, LaTara; Nizio, Katie D; Forbes, Shari L

2018-03-01

At outdoor crime scenes, cadaver-detection and blood-detection dogs may be tasked with locating blood that is days, weeks or months old. Although it is known that the odour profile of blood will change during this time, it is currently unknown how the profile changes when exposed to the environment. Such variables must be studied in order to understand when the odour profile is no longer detectable by the scent-detection dogs and other crime scene tools should be implemented. In this study, blood was deposited onto concrete and varnished wood surfaces and weathered in an outdoor environment over a three-month period. Headspace samples were collected using solid phase microextraction (SPME) and analysed using comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC×GC-TOFMS). The chemical odour profiles were compared with the behavioural responses of cadaver-detection and blood-detection dogs during training. Data interpretation using principal component analysis (PCA) and hierarchical cluster analysis (HCA) established that the blood odour could no longer be detected using SPME-GC×GC-TOFMS after two months of weathering on both surfaces. Conversely, the blood-detection dogs had difficulty locating the blood samples after one month of weathering on concrete and after one week of weathering on varnished wood. The scent-detection dogs evaluated herein had not been previously exposed to environmentally weathered blood samples during training. Given that this study was conducted to test the dogs' baseline abilities, it is expected that with repeated exposure, the dogs' capabilities would likely improve. The knowledge gained from this study can assist in providing law enforcement with more accurate training aids for blood-detection dogs and can improve their efficiency when deployed to outdoor crime scenes. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Group discriminatory power of handwritten characters

NASA Astrophysics Data System (ADS)

Tomai, Catalin I.; Kshirsagar, Devika M.; Srihari, Sargur N.

2003-12-01

Using handwritten characters we address two questions (i) what is the group identification performance of different alphabets (upper and lower case) and (ii) what are the best characters for the verification task (same writer/different writer discrimination) knowing demographic information about the writer such as ethnicity, age or sex. The Bhattacharya distance is used to rank different characters by their group discriminatory power and the k-nn classifier to measure the individual performance of characters for group identification. Given the tasks of identifying the correct gender/age/ethnicity or handedness, the accumulated performance of characters varies between 65% and 85%.

Rank-frequency relation for Chinese characters

NASA Astrophysics Data System (ADS)

Deng, Weibing; Allahverdyan, Armen E.; Li, Bo; Wang, Qiuping A.

2014-02-01

We show that the Zipf's law for Chinese characters perfectly holds for sufficiently short texts (few thousand different characters). The scenario of its validity is similar to the Zipf's law for words in short English texts. For long Chinese texts (or for mixtures of short Chinese texts), rank-frequency relations for Chinese characters display a two-layer, hierarchic structure that combines a Zipfian power-law regime for frequent characters (first layer) with an exponential-like regime for less frequent characters (second layer). For these two layers we provide different (though related) theoretical descriptions that include the range of low-frequency characters (hapax legomena). We suggest that this hierarchic structure of the rank-frequency relation connects to semantic features of Chinese characters (number of different meanings and homographies). The comparative analysis of rank-frequency relations for Chinese characters versus English words illustrates the extent to which the characters play for Chinese writers the same role as the words for those writing within alphabetical systems.

Sugar-fermenting yeast as an organic source of carbon dioxide to attract the malaria mosquito Anopheles gambiae

PubMed Central

2010-01-01

Background Carbon dioxide (CO2) plays an important role in the host-seeking process of opportunistic, zoophilic and anthropophilic mosquito species and is, therefore, commonly added to mosquito sampling tools. The African malaria vector Anopheles gambiae sensu stricto is attracted to human volatiles augmented by CO2. This study investigated whether CO2, usually supplied from gas cylinders acquired from commercial industry, could be replaced by CO2 derived from fermenting yeast (yeast-produced CO2). Methods Trapping experiments were conducted in the laboratory, semi-field and field, with An. gambiae s.s. as the target species. MM-X traps were baited with volatiles produced by mixtures of yeast, sugar and water, prepared in 1.5, 5 or 25 L bottles. Catches were compared with traps baited with industrial CO2. The additional effect of human odours was also examined. In the laboratory and semi-field facility dual-choice experiments were conducted. The effect of traps baited with yeast-produced CO2 on the number of mosquitoes entering an African house was studied in the MalariaSphere. Carbon dioxide baited traps, placed outside human dwellings, were also tested in an African village setting. The laboratory and semi-field data were analysed by a χ2-test, the field data by GLM. In addition, CO2 concentrations produced by yeast-sugar solutions were measured over time. Results Traps baited with yeast-produced CO2 caught significantly more mosquitoes than unbaited traps (up to 34 h post mixing the ingredients) and also significantly more than traps baited with industrial CO2, both in the laboratory and semi-field. Adding yeast-produced CO2 to traps baited with human odour significantly increased trap catches. In the MalariaSphere, outdoor traps baited with yeast-produced or industrial CO2 + human odour reduced house entry of mosquitoes with a human host sleeping under a bed net indoors. Anopheles gambiae s.s. was not caught during the field trials. However, traps baited with yeast-produced CO2 caught similar numbers of Anopheles arabiensis as traps baited with industrial CO2. Addition of human odour increased trap catches. Conclusions Yeast-produced CO2 can effectively replace industrial CO2 for sampling of An. gambiae s.s.. This will significantly reduce costs and allow sustainable mass-application of odour-baited devices for mosquito sampling in remote areas. PMID:20973963

Acquisition of Chinese characters: the effects of character properties and individual differences among second language learners

PubMed Central

Kuo, Li-Jen; Kim, Tae-Jin; Yang, Xinyuan; Li, Huiwen; Liu, Yan; Wang, Haixia; Hyun Park, Jeong; Li, Ying

2015-01-01

In light of the dramatic growth of Chinese learners worldwide and a need for cross-linguistic research on Chinese literacy development, this study drew upon theories of visual complexity effect (Su and Samuels, 2010) and dual-coding processing (Sadoski and Paivio, 2013) and investigated (a) the effects of character properties (i.e., visual complexity and radical presence) on character acquisition and (b) the relationship between individual learner differences in radical awareness and character acquisition. Participants included adolescent English-speaking beginning learners of Chinese in the U.S. Following Kuo et al. (2014), a novel character acquisition task was used to investigate the process of acquiring the meaning of new characters. Results showed that (a) characters with radicals and with less visual complexity were easier to acquire than characters without radicals and with greater visual complexity; and (b) individual differences in radical awareness were associated with the acquisition of all types of characters, but the association was more pronounced with the acquisition of characters with radicals. Theoretical and practical implications of the findings were discussed. PMID:26379562

A Chinese Character Teaching System Using Structure Theory and Morphing Technology

PubMed Central

Sun, Linjia; Liu, Min; Hu, Jiajia; Liang, Xiaohui

2014-01-01

This paper proposes a Chinese character teaching system by using the Chinese character structure theory and the 2D contour morphing technology. This system, including the offline phase and the online phase, automatically generates animation for the same Chinese character from different writing stages to intuitively show the evolution of shape and topology in the process of Chinese characters teaching. The offline phase builds the component models database for the same script and the components correspondence database for different scripts. Given two or several different scripts of the same Chinese character, the online phase firstly divides the Chinese characters into components by using the process of Chinese character parsing, and then generates the evolution animation by using the process of Chinese character morphing. Finally, two writing stages of Chinese characters, i.e., seal script and clerical script, are used in experiment to show the ability of the system. The result of the user experience study shows that the system can successfully guide students to improve the learning of Chinese characters. And the users agree that the system is interesting and can motivate them to learn. PMID:24978171

When should fig fruit produce volatiles? Pattern in a ripening process

NASA Astrophysics Data System (ADS)

Borges, Renee M.; Ranganathan, Yuvaraj; Krishnan, Anusha; Ghara, Mahua; Pramanik, Gautam

2011-11-01

Ripe fruit need to signal their presence to attract dispersal agents. Plants may employ visual and/or olfactory sensory channels to signal the presence of ripe fruit. Visual signals of ripe fruit have been extensively investigated. However, the volatile signatures of ripe fruit that use olfactorily-oriented dispersers have been scarcely investigated. Moreover, as in flowers, where floral scents are produced at times when pollinators are active (diurnal versus nocturnal), whether plants can modulate the olfactory signal to produce fruit odours when dispersers are active in the diel cycle is completely unknown. We investigated day-night differences in fruit odours in two species of figs, Ficus racemosa and Ficus benghalensis. The volatile bouquet of fruit of F. racemosa that are largely dispersed by bats and other mammals was dominated by fatty acid derivatives such as esters. In this species in which the ripe fig phase is very short, and where the figs drop off soon after ripening, there were no differences between day and night in fruit volatile signature. The volatile bouquet of fruit of F. benghalensis that has a long ripening period, however, and that remain attached to the tree for extended periods when ripe, showed an increase in fatty acid derivatives such as esters and of benzenoids such as benzaldehyde at night when they are dispersed by bats, and an elevation of sesquiterpenes during the day when they are dispersed by birds. For the first time we provide data that suggest that the volatile signal produced by fruit can show diel differences based on the activity period of the dispersal agent.

Sampling diverse characters improves phylogenies: Craniodental and postcranial characters of vertebrates often imply different trees.

PubMed

Mounce, Ross C P; Sansom, Robert; Wills, Matthew A

2016-03-01

Morphological cladograms of vertebrates are often inferred from greater numbers of characters describing the skull and teeth than from postcranial characters. This is either because the skull is believed to yield characters with a stronger phylogenetic signal (i.e., contain less homoplasy), because morphological variation therein is more readily atomized, or because craniodental material is more widely available (particularly in the palaeontological case). An analysis of 85 vertebrate datasets published between 2000 and 2013 confirms that craniodental characters are significantly more numerous than postcranial characters, but finds no evidence that levels of homoplasy differ in the two partitions. However, a new partition test, based on tree-to-tree distances (as measured by the Robinson Foulds metric) rather than tree length, reveals that relationships inferred from the partitions are significantly different about one time in three, much more often than expected. Such differences may reflect divergent selective pressures in different body regions, resulting in different localized patterns of homoplasy. Most systematists attempt to sample characters broadly across body regions, but this is not always possible. We conclude that trees inferred largely from either craniodental or postcranial characters in isolation may differ significantly from those that would result from a more holistic approach. We urge the latter. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

The Fragrant Chemist

ERIC Educational Resources Information Center

Ward, P.

1973-01-01

The chemist plays an important role in perfumery. There are scientific problems involved in relating odour to structure, including analysis of essential oils, quality control, and synthetic chemistry. (DF)

Feeding Behaviour of Cynopterus sphinx (Pteropodidae) Under Captive Conditions.

PubMed

Shafie, Nur Juliani; Rahman, Nor Amira; Sah, Shahrul Anuar Mohd; Rosely, Nik Fadzly Nik; Sufian, Maryam

2014-12-01

We examined the olfactory and visual abilities of megachiropteran bats, Cynopterus sphinx, for discrimination of the odour and shape of the banana fruit, Musa sp. We conducted the experiments in captive conditions by offering a selection of ripe bananas, blended bananas and artificial bananas. The behaviour of the bats was observed visually, and the percentage of activity and rest, duration of the first foraging bout, number of feeding attempts and the average duration of successful attempts was recorded for each bat. The bats exhibited an increased number of visits to ripe bananas and blended banana fruits. However, the artificial fruit did not evoke any response. Our study suggests that odour cues are more important than visual cues for the location of fruits by C. sphinx.

Pheromonal regulation of male mouse ultrasonic courtship (Mus musculus).

PubMed

Nyby, J; Wysocki, C J; Whitney, G; Dizinno, G

1977-05-01

Biochemicals from several sites on the body of female house mice (Mus musculus) were found to elicit 70-kHz ultrasonic calls from male mice. Experiment 1 demonstrated that an anaesthetized female wrapped in an odour-impermeable plastic bag elicited ultrasounds from males when either the front or rear of their body was left exposed. In experiment 2 cotton swabs rubbed on the face and cheeks of females but not from males elicited ultrasonic calls from males. The results of experiment 3 suggested that female vaginal odours also elicit calls. Experiments 4 and 5 demonstrated that males will also emit ultrasounds in response to female but not male urine. The source and chemical nature of this 'ultrasound-releasing pheromone' remain to be discovered.

Combined non-adaptive light and smell stimuli lowered blood pressure, reduced heart rate and reduced negative affect.

PubMed

Dong, Shan; Jacob, Tim J C

2016-03-15

Bright light therapy has been shown to have a positive impact on seasonal affective disorder (SAD), depression and anxiety. Smell has also has been shown to have effects on mood, stress, anxiety and depression. The objective of this study was to investigate the effect of the combination of light and smell in a non-adaptive cycle. Human subjects were given smell (lemon, lavender or peppermint) and light stimuli in a triangular wave (60scycle) for 15min. Blood pressure and heart rate were monitored before and after each session for 5 consecutive days and a Profile of Mood States (POMS) test was administered before and after the sensory stimulation on days 1, 3 and 5. The light-smell stimulus lowered blood pressure, both systolic and diastolic, and reduced heart rate for all odours compared to control. Of the two sensory stimuli, the odour stimulus contributed most to this effect. The different aromas in the light-smell combinations could be distinguished by their different effects on the mood factors with lemon inducing the greatest mood changes in Dejection-Depression, Anger-Hostility, Tension-Anxiety. In conclusion, combined light and smell stimulation was effective in lowering blood pressure, reducing heart rate and improving mood. The combination was more effective than either smell or light stimuli alone, suggesting that a light-smell combination would be a more robust and efficacious alternative treatment for depression, anxiety and stress. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Social learning improves survivorship at a life-history transition.

PubMed

Manassa, R P; McCormick, M I

2013-04-01

During settlement, one of the main threats faced by individuals relates to their ability to detect and avoid predators. Information on predator identities can be gained either through direct experience or from the observation and/or interaction with others, a process known as social learning. In this form of predator recognition, less experienced individuals learn from experienced members within the social group, without having to directly interact with a predator. In this study, we examined the role of social learning in predator recognition in relation to the survival benefits for the damselfish, Pomacentrus wardi, during their settlement transition. Specifically, our experiments aimed to determine if P. wardi are capable of transmitting the recognition of the odour of a predator, Pseudochromis fuscus, to conspecifics. The experiment also examined whether there was a difference in the rate of survival between individuals that directly learnt the predator odour and those which acquired the information through social learning compared to naïve individuals. Results show that naïve P. wardi are able to learn a predator's identity from experienced individuals via social learning. Furthermore, survival between individuals that directly learnt the predator's identity and those that learnt through social learning did not significantly differ, with fish from both treatments surviving at least five times better than controls. These results demonstrate that experience may play a vital role in determining the outcome of predator-prey interactions, highlighting that social learning improves the ability of prey to avoid and/or escape predation at a life-history transition.

REVIEW ARTICLE: A taste sensor

NASA Astrophysics Data System (ADS)

Toko, Kiyoshi

1998-12-01

A multichannel taste sensor, namely an electronic tongue, with global selectivity is composed of several kinds of lipid/polymer membranes for transforming information about substances producing taste into electrical signals, which are input to a computer. The sensor output exhibits different patterns for chemical substances which have different taste qualities such as saltiness, sourness and bitterness, whereas it exhibits similar patterns for chemical substances with similar tastes. The sensor responds to the taste itself, as can be understood from the fact that taste interactions such as the suppression effect, which appears for mixtures of sweet and bitter substances, can be reproduced well. The suppression of the bitterness of quinine and a drug substance by sucrose can be quantified. Amino acids can be classified into several groups according to their own tastes on the basis of sensor outputs. The tastes of foodstuffs such as beer, coffee, mineral water, milk, sake, rice, soybean paste and vegetables can be discussed quantitatively using the taste sensor, which provides the objective scale for the human sensory expression. The flavour of a wine is also discriminated using the taste-odour sensory fusion conducted by combining the taste sensor and an odour-sensor array using conducting polymer elements. The taste sensor can also be applied to measurements of water pollution. Miniaturization of the taste sensor using FET produces the same characteristics as those of the above taste sensor by measuring the gate-source voltage. Use of the taste sensor will lead to a new era of food and environmental sciences.

On the information content of discrete phylogenetic characters.

PubMed

Bordewich, Magnus; Deutschmann, Ina Maria; Fischer, Mareike; Kasbohm, Elisa; Semple, Charles; Steel, Mike

2017-12-16

Phylogenetic inference aims to reconstruct the evolutionary relationships of different species based on genetic (or other) data. Discrete characters are a particular type of data, which contain information on how the species should be grouped together. However, it has long been known that some characters contain more information than others. For instance, a character that assigns the same state to each species groups all of them together and so provides no insight into the relationships of the species considered. At the other extreme, a character that assigns a different state to each species also conveys no phylogenetic signal. In this manuscript, we study a natural combinatorial measure of the information content of an individual character and analyse properties of characters that provide the maximum phylogenetic information, particularly, the number of states such a character uses and how the different states have to be distributed among the species or taxa of the phylogenetic tree.

Visual field differences in visual word recognition can emerge purely from perceptual learning: evidence from modeling Chinese character pronunciation.

PubMed

Hsiao, Janet Hui-Wen

2011-11-01

In Chinese orthography, a dominant character structure exists in which a semantic radical appears on the left and a phonetic radical on the right (SP characters); a minority opposite arrangement also exists (PS characters). As the number of phonetic radical types is much greater than semantic radical types, in SP characters the information is skewed to the right, whereas in PS characters it is skewed to the left. Through training a computational model for SP and PS character recognition that takes into account of the locations in which the characters appear in the visual field during learning, but does not assume any fundamental hemispheric processing difference, we show that visual field differences can emerge as a consequence of the fundamental structural differences in information between SP and PS characters, as opposed to the fundamental processing differences between the two hemispheres. This modeling result is also consistent with behavioral naming performance. This work provides strong evidence that perceptual learning, i.e., the information structure of word stimuli to which the readers have long been exposed, is one of the factors that accounts for hemispheric asymmetry effects in visual word recognition. Copyright © 2011 Elsevier Inc. All rights reserved.

Gender differences and the effect of contextual features on game enjoyment and responses.

PubMed

Lin, Shu-Fang

2010-10-01

This article explores the effect of gender and contextual features on emotional reactions, identification toward game characters, and game enjoyment. Two aspects of contextual features are specifically examined: the moral justification of game characters and violence. An experiment was conducted by allowing participants to play either a morally justified character of a non-violent game, a morally justified character of a violent game, or a morally unjustified character of a violent game. The results show that participants felt less guilty and identified with the characters more when playing the morally justified characters of the non-violent game. Furthermore, males and females demonstrate different patterns of enjoyment to different contextual features of video games. The implications of these findings and directions for future research are discussed.

Parametric and genetic analysis of Drosophila appetitive long-term memory and sugar motivation.

PubMed

Colomb, J; Kaiser, L; Chabaud, M-A; Preat, T

2009-06-01

Distinct forms of memory can be highlighted using different training protocols. In Drosophila olfactory aversive learning, one conditioning session triggers memory formation independently of protein synthesis, while five spaced conditioning sessions lead to the formation of long-term memory (LTM), a long-lasting memory dependent on de novo protein synthesis. In contrast, one session of odour-sugar association appeared sufficient for the fly to form LTM. We designed and tuned an apparatus that facilitates repeated discriminative conditioning by alternate presentations of two odours, one being associated with sugar, as well as a new paradigm to test sugar responsiveness (SR). Our results show that both SR and short-term memory (STM) scores increase with starvation length before conditioning. The protein dependency of appetitive LTM is independent of the repetition and the spacing of training sessions, on the starvation duration and on the strength of the unconditioned stimulus. In contrast to a recent report, our test measures an abnormal SR of radish mutant flies, which might initiate their STM and LTM phenotypes. In addition, our work shows that crammer and tequila mutants, which are deficient for aversive LTM, present both an SR and an appetitive STM defect. Using the MB247-P[switch] system, we further show that tequila is required in the adult mushroom bodies for normal sugar motivation.

Effect of the antioxidants composition in diet on the sensory and physical properties of frozen farmed Coho salmon (Oncorhynchus kisutch).

PubMed

Rodríguez, Alicia; Latorre, Mónica; Gajardo, Mónica; Bunger, Andrea; Munizaga, Alejandro; López, Luis; Aubourg, Santiago P

2015-04-01

Great attention has been paid to the antioxidants present in farmed fish feeds, with the replacement of synthetic antioxidants by natural ones being a main objective. In the present study, Coho salmon (Oncorhynchus kisutch) was fed a conventional diet that was enriched with different kinds of antioxidants: synthetic antioxidants (butylated-hydroxy toluene and ethoxyquin; diet I), a tocopherols-rich mixture (diet II) and a tocopherols-rosemary extract mixture (diet III). A comparative study of the sensory and physical changes observed in the corresponding frozen products was undertaken. After 18 months at -18 °C, fish previously fed on diet I showed higher putrid and rancid odours and rancid taste scores, while lower mean typical odour and taste values were attained. Dripping and expressible moisture values obtained for diet II-fish were lower when compared with their counterparts belonging to the diet I; additionally, microstructure analysis revealed that Z-lines integration was better preserved in fish corresponding to diets II and III. Diet II has been recognised as being the most profitable to be employed to maintain the sensory and physical properties of the frozen product when long-term storage is considered. Further research is to be continued to optimise the natural antioxidants profile. © 2014 Society of Chemical Industry.

Mechanisms underlying the control of responses to predator odours in aquatic prey.

PubMed

Mitchell, Matthew D; Bairos-Novak, Kevin R; Ferrari, Maud C O

2017-06-01

In aquatic systems, chemical cues are a major source of information through which animals are able to assess the current state of their environment to gain information about local predation risk. Prey use chemicals released by predators (including cues from a predator's diet) and other prey (such as alarm cues and disturbance cues) to mediate a range of behavioural, morphological and life-history antipredator defences. Despite the wealth of knowledge on the ecology of antipredator defences, we know surprisingly little about the physiological mechanisms that control the expression of these defensive traits. Here, we summarise the current literature on the mechanisms known to specifically mediate responses to predator odours, including dietary cues. Interestingly, these studies suggest that independent pathways may control predator-specific responses, highlighting the need for greater focus on predator-derived cues when looking at the mechanistic control of responses. Thus, we urge researchers to tease apart the effects of predator-specific cues (i.e. chemicals representing a predator's identity) from those of diet-mediated cues (i.e. chemicals released from a predator's diet), which are known to mediate different ecological endpoints. Finally, we suggest some key areas of research that would greatly benefit from a more mechanistic approach. © 2017. Published by The Company of Biologists Ltd.

A procedure for the sensory evaluation of Salama da sugo, a typical fermented sausage produced in the Emilia Romagna Region, Italy.

PubMed

Coloretti, Fabio; Grazia, Luigi; Gardini, Fausto; Lanciotti, Rosalba; Montanari, Chiara; Tabanelli, Giulia; Chiavari, Cristiana

2015-03-30

Salama da sugo is a fermented sausage from the Ferrara tradition (Italy, Emilia-Romagna region), subjected to a long ripening period (4-6 months) and characterised by a high content of wine and spices in the mixture. It can be consumed after cooking and it is served with its sugo, i.e. the liquid extracted by cooking process. The aim of this work was to set up a method for the sensory profile of Salama da sugo as a request for Protected Geographical Indication (PGI) has been made to the European Commission. A system of sample preparation that provides for the precooking in an autoclave and cooking in boiling water was set up. A specific sheet for sensory evaluation of Salama da sugo has been created and reports 23 descriptors identified during the lexicon development. The differences in sensory profile of four samples were evaluated and principal component analysis highlighted the more discriminant parameters, i.e. odour intensity, wine odour, spicy aroma, fat/lean connection, sweet, bitter, juiciness, chewiness and pricking. The proposed method allows the standardisation of sensory profiling of Salama da sugo, and is also to verify compliance with the specification PGI. © 2014 Society of Chemical Industry.

Character trees from transcriptome data: Origin and individuation of morphological characters and the so-called "species signal".

PubMed

Musser, Jacob M; Wagner, Günter P

2015-11-01

We elaborate a framework for investigating the evolutionary history of morphological characters. We argue that morphological character trees generated by phylogenetic analysis of transcriptomes provide a useful tool for identifying causal gene expression differences underlying the development and evolution of morphological characters. They also enable rigorous testing of different models of morphological character evolution and origination, including the hypothesis that characters originate via divergence of repeated ancestral characters. Finally, morphological character trees provide evidence that character transcriptomes undergo concerted evolution. We argue that concerted evolution of transcriptomes can explain the so-called "species signal" found in several recent comparative transcriptome studies. The species signal is the phenomenon that transcriptomes cluster by species rather than character type, even though the characters are older than the respective species. We suggest the species signal is a natural consequence of concerted gene expression evolution resulting from mutations that alter gene regulatory network interactions shared by the characters under comparison. Thus, character trees generated from transcriptomes allow us to investigate the variational independence, or individuation, of morphological characters at the level of genetic programs. © 2015 Wiley Periodicals, Inc.

Effects of visual and verbal interference tasks on olfactory memory: the role of task complexity.

PubMed

Annett, J M; Leslie, J C

1996-08-01

Recent studies have demonstrated that visual and verbal suppression tasks interfere with olfactory memory in a manner which is partially consistent with a dual coding interpretation. However, it has been suggested that total task complexity rather than modality specificity of the suppression tasks might account for the observed pattern of results. This study addressed the issue of whether or not the level of difficulty and complexity of suppression tasks could explain the apparent modality effects noted in earlier experiments. A total of 608 participants were each allocated to one of 19 experimental conditions involving interference tasks which varied suppression type (visual or verbal), nature of complexity (single, double or mixed) and level of difficulty (easy, optimal or difficult) and presented with 13 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Both recognition and recall performance showed an overall effect for suppression nature, suppression level and time of testing with no effect for suppression type. The results lend only limited support to Paivio's (1986) dual coding theory, but have a number of characteristics which suggest that an adequate account of olfactory memory may be broadly similar to current theories of face and object recognition. All of these phenomena might be dealt with by an appropriately modified version of dual coding theory.

Volatile organic components migrating from plastic pipes (HDPE, PEX and PVC) into drinking water.

PubMed

Skjevrak, Ingun; Due, Anne; Gjerstad, Karl Olav; Herikstad, Hallgeir

2003-04-01

High-density polyethylene pipes (HDPE), crossbonded polyethylene pipes (PEX) and polyvinyl chloride (PVC) pipes for drinking water were tested with respect to migration of volatile organic components (VOC) to water. The odour of water in contact with plastic pipes was assessed according to the quantitative threshold odour number (TON) concept. A major migrating component from HDPE pipes was 2,4-di-tert-butyl-phenol (2,4-DTBP) which is a known degradation product from antioxidants such as Irgafos 168(R). In addition, a range of esters, aldehydes, ketones, aromatic hydrocarbons and terpenoids were identified as migration products from HDPE pipes. Water in contact with HDPE pipes was assessed with respect to TON, and values > or =4 were determined for five out of seven brands of HDPE pipes. The total amount of VOC released to water during three successive test periods were fairly constant for the HDPE pipes. Corresponding migration tests carried out for PEX pipes showed that VOC migrated in significant amounts into the test water, and TON >/=5 of the test water were observed in all tests. Several of the migrated VOC were not identified. Oxygenates predominated the identified VOC in the test water from PEX pipes. Migration tests of PVC pipes revealed few volatile migrants in the test samples and no significant odour of the test water.

Sniffing out the truth: clinical diagnosis using the electronic nose.

PubMed

Pavlou, A K; Turner, A P

2000-02-01

Recently the use of smell in clinical diagnosis has been rediscovered due to major advances in odour sensing technology and artificial intelligence (AI). It was well known in the past that a number of infectious or metabolic diseases could liberate specific odours characteristic of the disease stage. Later chromatographic techniques identified an enormous number of volatiles in human clinical specimens that might serve as potential disease markers. "Artificial nose" technology has been employed in several areas of medical diagnosis, including rapid detection of tuberculosis (TB), Helicobacter pylori (HP) and urinary tract infections (UTI). Preliminary results have demonstrated the possibility of identifying and characterising microbial pathogens in clinical specimens. A hybrid intelligent model of four interdependent "tools", odour generation "kits", rapid volatile delivery and recovery systems, consistent low drift sensor performance and a hybrid intelligent system of parallel neural networks (NN) and expert systems, have been applied in gastric, pulmonary and urine diagnosis. Initial clinical tests have shown that it may be possible in the near future to use electronic nose technology not only for the rapid detection of diseases such as peptic ulceration, UTI, and TB but also for the continuous dynamic monitoring of disease stages. Major advances in information and gas sensor technology could enhance the diagnostic power of future bio-electronic noses and facilitate global surveillance models of disease control and management.

Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

PubMed Central

Lefèvre, Thierry; Gouagna, Louis-Clément; Dabiré, Kounbobr Roch; Elguero, Eric; Fontenille, Didier; Renaud, François; Costantini, Carlo; Thomas, Frédéric

2010-01-01

Background Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso. Methodology/Principal Findings We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes. Conclusions/Significance These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures. PMID:20209056

Using Stroke Removal to Investigate Chinese Character Identification during Reading: Evidence from Eye Movements

ERIC Educational Resources Information Center

Yan, Guoli; Bai, Xuejun; Zang, Chuanli; Bian, Qian; Cui, Lei; Qi, Wei; Rayner, Keith; Liversedge, Simon P.

2012-01-01

We explored the effect of stroke removal from Chinese characters on eye movements during reading to examine the role of stroke encoding in character identification. Experimental sentences were comprised of characters with different proportions of strokes removed (15, 30, and 50%), and different types of strokes removed (beginning, ending, and…

Mammalian social odours: attraction and individual recognition

PubMed Central

Brennan, Peter A; Kendrick, Keith M

2006-01-01

Mammalian social systems rely on signals passed between individuals conveying information including sex, reproductive status, individual identity, ownership, competitive ability and health status. Many of these signals take the form of complex mixtures of molecules sensed by chemosensory systems and have important influences on a variety of behaviours that are vital for reproductive success, such as parent–offspring attachment, mate choice and territorial marking. This article aims to review the nature of these chemosensory cues and the neural pathways mediating their physiological and behavioural effects. Despite the complexities of mammalian societies, there are instances where single molecules can act as classical pheromones attracting interest and approach behaviour. Chemosignals with relatively high volatility can be used to signal at a distance and are sensed by the main olfactory system. Most mammals also possess a vomeronasal system, which is specialized to detect relatively non-volatile chemosensory cues following direct contact. Single attractant molecules are sensed by highly specific receptors using a labelled line pathway. These act alongside more complex mixtures of signals that are required to signal individual identity. There are multiple sources of such individuality chemosignals, based on the highly polymorphic genes of the major histocompatibility complex (MHC) or lipocalins such as the mouse major urinary proteins. The individual profile of volatile components that make up an individual odour signature can be sensed by the main olfactory system, as the pattern of activity across an array of broadly tuned receptor types. In addition, the vomeronasal system can respond highly selectively to non-volatile peptide ligands associated with the MHC, acting at the V2r class of vomeronasal receptor. The ability to recognize individuals or their genetic relatedness plays an important role in mammalian social behaviour. Thus robust systems for olfactory learning and recognition of chemosensory individuality have evolved, often associated with major life events, such as mating, parturition or neonatal development. These forms of learning share common features, such as increased noradrenaline evoked by somatosensory stimulation, which results in neural changes at the level of the olfactory bulb. In the main olfactory bulb, these changes are likely to refine the pattern of activity in response to the learned odour, enhancing its discrimination from those of similar odours. In the accessory olfactory bulb, memory formation is hypothesized to involve a selective inhibition, which disrupts the transmission of the learned chemosignal from the mating male. Information from the main olfactory and vomeronasal systems is integrated at the level of the corticomedial amygdala, which forms the most important pathway by which social odours mediate their behavioural and physiological effects. Recent evidence suggests that this region may also play an important role in the learning and recognition of social chemosignals. PMID:17118924

A pharmacological profile of the aldehyde receptor repertoire in rat olfactory epithelium

PubMed Central

Araneda, Ricardo C; Peterlin, Zita; Zhang, Xinmin; Chesler, Alex; Firestein, Stuart

2004-01-01

Several lines of evidence suggest that odorants are recognized through a combinatorial process in the olfactory system; a single odorant is recognized by multiple receptors and multiple odorants are recognized by the same receptor. However few details of how this might actually function for any particular odour set or receptor family are available. Approaching the problem from the ligands rather than the receptors, we used the response to a common odorant, octanal, as the basis for defining multiple receptor profiles. Octanal and other aldehydes induce large EOG responses in the rodent olfactory epithelium, suggesting that these compounds activate a large number of odour receptors (ORs). Here, we have determined and compared the pharmacological profile of different octanal receptors using Ca2+ imaging in isolated olfactory sensory neurones (OSNs). It is believed that each OSN expresses only one receptor, thus the response profile of each cell corresponds to the pharmacological profile of one particular receptor. We stimulated the cells with a panel of nine odorants, which included octanal, octanoic acid, octanol and cinnamaldehyde among others (all at 30μm). Cluster analysis revealed several distinct pharmacological profiles for cells that were all sensitive to octanal. Some receptors had a broad molecular range, while others were activated only by octanal. Comparison of the profiles with that of the one identified octanal receptor, OR-I7, indicated several differences. While OR-I7 is activated by low concentrations of octanal and blocked by citral, other receptors were less sensitive to octanal and not blocked by citral. A lower estimate for the maximal number of octanal receptors is between 33 and 55. This large number of receptors for octanal suggests that, although the peripheral olfactory system is endowed with high sensitivity, discrimination among different compounds probably requires further central processing. PMID:14724183

Effects of sex and gonadectomy on social investigation and social recognition in mice.

PubMed

Karlsson, Sara A; Haziri, Kaltrina; Hansson, Evelyn; Kettunen, Petronella; Westberg, Lars

2015-11-25

An individual's ability to recognise and pay attention to others is crucial in order to behave appropriately in various social situations. Studies in humans have shown a sex bias in sociability as well as social memory, indicating that females have better face memory and gaze more at the eyes of others, but information about the factors that underpin these differences is sparse. Our aim was therefore to investigate if sociability and social recognition differ between female and male mice, and if so, to what extent gonadal hormones may be involved. Intact and gonadectomised male and female mice were assessed for sociability and social recognition using the three-chambered sociability paradigm, as well as the social discrimination test. Furthermore, we conducted a novel object recognition test, a locomotor activity test and an odour habituation/dishabituation test. The present study showed that the ability to recognise other individuals is intact in males with and without gonads, as well as in intact females, whereas it is hampered in gonadectomised females. Additionally, intact male mice displayed more persistent investigatory behaviour compared to the other groups, although the intact females showed elevated basal locomotor activity. In addition, all groups had intact object memory and habituated to odours. Our results suggest that intact male mice investigate conspecifics more than females do, and these differences seem to depend upon circulating hormones released from the testis. As these results seem to contrast what is known from human studies, they should be taken into consideration when using the three-chambered apparatus, and similar paradigms as animal models of social deficits in e.g. autism. Other behavioural tests, and animal models, may be more suitable for translational studies between patients and experimental animals.

Differences in the Portrayal of Health Risk Behaviors by Black and White Characters in Popular Films.

PubMed

Ellithorpe, Morgan E; Bleakley, Amy; Hennessy, Michael; Weitz, Ilana; Jamieson, Patrick; Khurana, Atika

2017-06-01

Adolescent exposure to risk in film has been associated with behavior. We coded Black and White character involvement in sex, violence, alcohol use, and tobacco use, and combinations of those behaviors in popular mainstream and Black-oriented films (film n = 63, character n = 426). Health risk portrayals were common, with the majority of characters portraying at least one. Black characters were more likely than Whites to portray sex and alcohol use, while White characters were more likely to portray violence. Within-segment combinations of sex and alcohol were more prevalent for Black characters, while violence and alcohol were more prevalent for Whites. Throughout a film, Black characters were more likely than White characters to portray sex and alcohol, sex and tobacco, and alcohol and tobacco. Risky behaviors are prevalent, but types portrayed differ between Black and White characters. This may have implications for health disparities in Black and White adolescents.

Differences in the Portrayal of Health Risk Behaviors by Black and White Characters in Popular Films

PubMed Central

ELLITHORPE, MORGAN E.; BLEAKLEY, AMY; HENNESSY, MICHAEL; WEITZ, ILANA; JAMIESON, PATRICK; KHURANA, ATIKA

2017-01-01

Adolescent exposure to risk in film has been associated with behavior. We coded Black and White character involvement in sex, violence, alcohol use, and tobacco use, and combinations of those behaviors in popular mainstream and Black-oriented films (film n = 63, character n = 426). Health risk portrayals were common, with the majority of characters portraying at least one. Black characters were more likely than Whites to portray sex and alcohol use, while White characters were more likely to portray violence. Within-segment combinations of sex and alcohol were more prevalent for Black characters, while violence and alcohol were more prevalent for Whites. Throughout a film, Black characters were more likely than White characters to portray sex and alcohol, sex and tobacco, and alcohol and tobacco. Risky behaviors are prevalent, but types portrayed differ between Black and White characters. This may have implications for health disparities in Black and White adolescents. PMID:28481166

Sex-Dependent Effects of Prenatal Stress on Social Memory in Rats: A Role for Differential Expression of Central Vasopressin-1a Receptors.

PubMed

Grundwald, N J; Benítez, D P; Brunton, P J

2016-04-01

Prenatal stress (PNS) affects a number of traits in the offspring, including stress axis regulation, emotionality and cognition; however, much less is known about the effects of PNS on social memory and the underlying central mechanisms. In the present study, we investigated social preference, social memory under basal and stress conditions and olfactory memory for social and nonsocial odours in the adult offspring of dams exposed to social stress during late pregnancy. Given the key roles that the central oxytocin and vasopressin systems play in facilitating social memory, we further investigated the effects of PNS on the central expression of mRNA for oxytocin (Oxtr) and vasopressin-1a (Avpr1a) receptors. PNS did not affect social preference in either sex; however, social memory was impaired under basal conditions in PNS females but not PNS males. Accordingly, Avpr1a mRNA expression in the lateral septum and bed nucleus of stria terminalis (BNST) was unaltered in males but was significantly lower in PNS females compared to controls. No differences in Oxtr mRNA expression were detected between control and PNS offspring in either sex in any of the brain regions examined. Social memory deficits in PNS females persisted when social odours were used; however, this does not appear to be a result of impaired olfaction because memory for nonsocial odours was similar in control and PNS females. Under acute stress conditions, deficits in social memory were observed in both male and female control offspring; however, PNS males were unaffected. Moreover, acute stress facilitated social memory in PNS females and this was associated with an up-regulation of Avpr1a mRNA in the lateral septum and BNST. Our data support a role for altered signalling via central Avpr1a in PNS-induced sex-dependent changes in social memory and may have implications for understanding the aetiology of neurodevelopmental disorders characterised by social behaviour deficits in humans. © 2015 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.

Evaluation of low density polyethylene and nylon for delivery of synthetic mosquito attractants

PubMed Central

2012-01-01

Background Synthetic odour baits present an unexploited potential for sampling, surveillance and control of malaria and other mosquito vectors. However, application of such baits is impeded by the unavailability of robust odour delivery devices that perform reliably under field conditions. In the present study the suitability of low density polyethylene (LDPE) and nylon strips for dispensing synthetic attractants of host-seeking Anopheles gambiae mosquitoes was evaluated. Methods Baseline experiments assessed the numbers of An. gambiae mosquitoes caught in response to low density polyethylene (LDPE) sachets filled with attractants, attractant-treated nylon strips, control LDPE sachets, and control nylon strips placed in separate MM-X traps. Residual attraction of An. gambiae to attractant-treated nylon strips was determined subsequently. The effects of sheet thickness and surface area on numbers of mosquitoes caught in MM-X traps containing the synthetic kairomone blend dispensed from LDPE sachets and nylon strips were also evaluated. Various treatments were tested through randomized 4 × 4 Latin Square experimental designs under semi-field conditions in western Kenya. Results Attractant-treated nylon strips collected 5.6 times more An. gambiae mosquitoes than LDPE sachets filled with the same attractants. The attractant-impregnated nylon strips were consistently more attractive (76.95%; n = 9,120) than sachets containing the same attractants (18.59%; n = 2,203), control nylon strips (2.17%; n = 257) and control LDPE sachets (2.29%; n = 271) up to 40 days post-treatment (P < 0.001). The higher catches of mosquitoes achieved with nylon strips were unrelated to differences in surface area between nylon strips and LDPE sachets. The proportion of mosquitoes trapped when individual components of the attractant were dispensed in LDPE sachets of optimized sheet thicknesses was significantly higher than when 0.03 mm-sachets were used (P < 0.001). Conclusion Nylon strips continuously dispense synthetic mosquito attractants several weeks post treatment. This, added to the superior performance of nylon strips relative to LDPE material in dispensing synthetic mosquito attractants, opens up the opportunity for showcasing the effectiveness of odour-baited devices for sampling, surveillance and control of disease vectors. PMID:22992518

Evaluation of low density polyethylene and nylon for delivery of synthetic mosquito attractants.

PubMed

Mukabana, Wolfgang R; Mweresa, Collins K; Omusula, Philemon; Orindi, Benedict O; Smallegange, Renate C; van Loon, Joop Ja; Takken, Willem

2012-09-19

Synthetic odour baits present an unexploited potential for sampling, surveillance and control of malaria and other mosquito vectors. However, application of such baits is impeded by the unavailability of robust odour delivery devices that perform reliably under field conditions. In the present study the suitability of low density polyethylene (LDPE) and nylon strips for dispensing synthetic attractants of host-seeking Anopheles gambiae mosquitoes was evaluated. Baseline experiments assessed the numbers of An. gambiae mosquitoes caught in response to low density polyethylene (LDPE) sachets filled with attractants, attractant-treated nylon strips, control LDPE sachets, and control nylon strips placed in separate MM-X traps. Residual attraction of An. gambiae to attractant-treated nylon strips was determined subsequently. The effects of sheet thickness and surface area on numbers of mosquitoes caught in MM-X traps containing the synthetic kairomone blend dispensed from LDPE sachets and nylon strips were also evaluated. Various treatments were tested through randomized 4 × 4 Latin Square experimental designs under semi-field conditions in western Kenya. Attractant-treated nylon strips collected 5.6 times more An. gambiae mosquitoes than LDPE sachets filled with the same attractants. The attractant-impregnated nylon strips were consistently more attractive (76.95%; n = 9,120) than sachets containing the same attractants (18.59%; n = 2,203), control nylon strips (2.17%; n = 257) and control LDPE sachets (2.29%; n = 271) up to 40 days post-treatment (P < 0.001). The higher catches of mosquitoes achieved with nylon strips were unrelated to differences in surface area between nylon strips and LDPE sachets. The proportion of mosquitoes trapped when individual components of the attractant were dispensed in LDPE sachets of optimized sheet thicknesses was significantly higher than when 0.03 mm-sachets were used (P < 0.001). Nylon strips continuously dispense synthetic mosquito attractants several weeks post treatment. This, added to the superior performance of nylon strips relative to LDPE material in dispensing synthetic mosquito attractants, opens up the opportunity for showcasing the effectiveness of odour-baited devices for sampling, surveillance and control of disease vectors.

Modified mosquito landing boxes dispensing transfluthrin provide effective protection against Anopheles arabiensis mosquitoes under simulated outdoor conditions in a semi-field system.

PubMed

Andrés, Marta; Lorenz, Lena M; Mbeleya, Edgar; Moore, Sarah J

2015-06-24

Efforts to control malaria vectors have primarily focused on scaling-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying. Although highly efficient against indoor-biting and indoor-resting vectors, these interventions have lower impact on outdoor-biting mosquitoes. Innovative vector control tools are required to prevent outdoor human-mosquito contacts. In this work, the potential of spatial repellents, delivered in an active system that requires minimal user compliance, to provide personal protection against exophagic mosquitoes active in the early evening was explored. A device previously used as an odour-baited lure and kill apparatus, the mosquito landing box (MLB), was modified to dispense the volatile synthetic pyrethroid, transfluthrin, as a spatial repellent. The MLB has an active odour-dispensing mechanism that uses a solar-powered fan and switches on at dusk to provide long duration dispensing of volatile compounds without the need for the user to remember to employ it. Two MLBs were located 5 m from a human volunteer to investigate the repellent effects of a transfluthrin 'bubble' created between the MLBs. Transfluthrin was emanated from polyester strips, hanging inside the MLB odour-dispensing unit. A fully randomized cross-over design was performed in a large, semi-field, screened cage to assess the effect of the repellent against laboratory-reared Anopheles arabiensis mosquitoes under ambient outdoor conditions. The knock-down capacity of the transfluthrin-treated strips was also evaluated at different time points up to 3 weeks after being impregnated to measure duration of efficacy. The protective transfluthrin bubble provided 68.9% protection against An. arabiensis bites under these simulated outdoor conditions. Volatile transfluthrin caused low mortality among mosquitoes in the semi-field system. Transfluthrin-treated strips continued to knock down mosquitoes in laboratory tests, 3 weeks after impregnation, although this effect diminished with time. Modified MLBs can be used as efficient and long-lasting dispensers of volatile spatial repellents such as transfluthrin, thereby providing high levels of protection against outdoor-biting mosquitoes in the peri-domestic space. They have a potential role in combatting outdoor malaria transmission without interfering with effective indoor interventions such as LLINs.

Unveiling the osmophores of Philodendron adamantinum (Araceae) as a means to understanding interactions with pollinators.

PubMed

Gonçalves-Souza, Patrícia; Schlindwein, Clemens; Dötterl, Stefan; Paiva, Elder Antônio Sousa

2017-03-01

Araceae species pollinated by nocturnal Cyclocephalini beetles attract their pollinators by inflorescence scents. In Philodendron , despite the intense odour, the osmophores exhibit no definite morphological identity, making them difficult to locate. This may explain why structural studies of the scent-releasing tissue are not available so far. Several approaches were employed for locating and understanding the osmophores of Philodendron adamantinum . A sensory test allowed other analyses to be restricted to fertile and sterile stamens as odour production sites. Stamens were studied under light and electron microscopy. Dynamic headspace and gas chromatography-mass spectrometry were used to collect and analyse scents from different zones of the inflorescence. The epidermal cells of the distal portion of fertile stamens and staminodes are papillose and, similar to the parenchyma cells of this region, have dense cytoplasm and large nuclei. In these cells, the composition of organelles is compatible with secretory activity, especially the great number of mitochondria and plastids. In this portion, lipid droplets that are consumed concomitantly with the release of odour were observed. Quantitative scent analyses revealed that the scent, with a predominance of dihydro-β-ionone, is mainly emitted by the fertile and sterile staminate zones of the spadix. An amorphous substance in the stomata pores indicates that the components are secreted and volatilized outside of the osmophore under thermogenic heat. Despite the difficulty in locating osmophores in the absence of morphological identity and inefficiency of neutral red staining, the osmophores of P. adamantinum have some features expected for these structures. The results indicate a functional link between thermogenesis and volatilization of osmophore secretions to produce olfactory signals for attracting specialized beetle pollinators. These first experimental data about the precise location of osmophores in Philodendron will stimulate studies in related species that will allow future comparison and the establishment of patterns of functional morphology. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Molecular Cloning and Characterization of O-Methyltransferase from Mango Fruit (Mangifera indica cv. Alphonso).

PubMed

Chidley, Hemangi G; Oak, Pranjali S; Deshpande, Ashish B; Pujari, Keshav H; Giri, Ashok P; Gupta, Vidya S

2016-05-01

Flavour of ripe Alphonso mango is invariably dominated by the de novo appearance of lactones and furanones during ripening. Of these, furanones comprising furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) and mesifuran (2,5-dimethyl-4-methoxy-3(2H)-furanone) are of particular importance due to their sweet, fruity caramel-like flavour characters and low odour detection thresholds. We isolated a 1056 bp complete open reading frame of a cDNA encoding S-adenosyl-L-methionine-dependent O-methyltransferase from Alphonso mango. The recombinantly expressed enzyme, MiOMTS showed substrate specificity towards furaneol and protocatechuic aldehyde synthesizing mesifuran and vanillin, respectively, in an in vitro assay reaction. A semi-quantitative PCR analysis showed fruit-specific expression of MiOMTS transcripts. Quantitative real-time PCR displayed ripening-related expression pattern of MiOMTS in both pulp and skin of Alphonso mango. Also, early and significantly enhanced accumulation of its transcripts was detected in pulp and skin of ethylene-treated fruits. Ripening-related and fruit-specific expression profile of MiOMTS and substrate specificity towards furaneol is a suggestive of its involvement in the synthesis of mesifuran in Alphonso mango. Moreover, a significant trigger in the expression of MiOMTS transcripts in ethylene-treated fruits point towards the transcriptional regulation of mesifuran biosynthesis by ethylene.

The esthetic preference of Chinese typefaces--an event-related potential study.

PubMed

Li, Rui; Qin, Ruilin; Zhang, Junsong; Wu, Junjie; Zhou, Changle

2015-02-19

Emotional stimuli such as pictures, logos, geometric shapes, etc can evoke human esthetic preference from previous neuroesthetic studies. Chinese characters can be considered as emotional stimuli as they have an important property: typeface. Intuitively, the emotional meaning of Chinese characters can cause esthetic preference. However, whether a typeface can cause esthetic preference or not from an empirical perspective is still unknown. To address this issue, participants׳ event-related potential (ERP) waves are recorded while they are presented a series of Chinese characters in different typefaces. Participants are asked to distinguish specific target from the others. Afterwards, from the Chinese characters presented in this task, participants are asked individually to select the characters they like the most and dislike the most. By recording the ERP responses (a response of implicit preference to Chinese characters themselves) during the experiment to different typefaces of Chinese characters, we find a significant difference between disliked and all characters in the frontal-central area in the 200-300 ms window after the stimulus׳ onset. In the 400-600 ms window, after the stimulus׳ onset, a significant bias for disliked characters emerges in frontal, central, parietal and occipital areas. Our results suggest that people could make a rapid, implicit esthetic preference for the typefaces of Chinese characters. Copyright © 2014. Published by Elsevier B.V.

[Comparative analysis of agronomic and qualitative characters in different lines of Dendrobium denneanum].

PubMed

He, Tao; Deng, Li; Lin, Yuan; Li, Bo; Yang, Xiaofan; Wang, Fang; Chun, Ze

2010-08-01

To provide theoretical basis for breeding good variety of Dendrobium denneanum, agronomic and qualitative characters of 4 different lines and relationships among them were studied. The stem length, stem diameter, leaf length, leaf width, length/ width ratio and leaf area were measured. The single fresh and dry stem was weighed and drying rate was calculated. The contents of polysaccharides and total alkaloids were determined by sulfuric acid-phenol colorimetry and acid-dye colorimetry, respectively. The correlations between characters were analyzed. The results showed that differences in major agronomic characters between four lines were significant. The plant types of dq-1 and dq-2 were higher, dq-3 was medium and dq-4 was lower. The fresh weigh of stem and content of polysaccharides were the highest in dq-2, 7.81 g and 14.33%. While the highest content of total alkaloids and was 0. 486% in dq-3. There were significant correlations between agronomic characters, but these characters had low or non correlations with qualitative characters such as polysaccharides and total alkaloids. It was shown that the content of polysaccharides and total alkaloids were significantly different among 4 lines of D. denneanum, which could be selected for different uses.

Sequence Comparisons of Odorant Receptors among Tortricid Moths Reveal Different Rates of Molecular Evolution among Family Members

PubMed Central

Carraher, Colm; Authier, Astrid; Steinwender, Bernd; Newcomb, Richard D.

2012-01-01

In insects, odorant receptors detect volatile cues involved in behaviours such as mate recognition, food location and oviposition. We have investigated the evolution of three odorant receptors from five species within the moth genera Ctenopseustis and Planotrotrix, family Tortricidae, which fall into distinct clades within the odorant receptor multigene family. One receptor is the orthologue of the co-receptor Or83b, now known as Orco (OR2), and encodes the obligate ion channel subunit of the receptor complex. In comparison, the other two receptors, OR1 and OR3, are ligand-binding receptor subunits, activated by volatile compounds produced by plants - methyl salicylate and citral, respectively. Rates of sequence evolution at non-synonymous sites were significantly higher in OR1 compared with OR2 and OR3. Within the dataset OR1 contains 109 variable amino acid positions that are distributed evenly across the entire protein including transmembrane helices, loop regions and termini, while OR2 and OR3 contain 18 and 16 variable sites, respectively. OR2 shows a high level of amino acid conservation as expected due to its essential role in odour detection; however we found unexpected differences in the rate of evolution between two ligand-binding odorant receptors, OR1 and OR3. OR3 shows high sequence conservation suggestive of a conserved role in odour reception, whereas the higher rate of evolution observed in OR1, particularly at non-synonymous sites, may be suggestive of relaxed constraint, perhaps associated with the loss of an ancestral role in sex pheromone reception. PMID:22701634

Anoxic control of odour and corrosion from sewer networks.

PubMed

Yang, W; Vollertsen, J; Hvitved-Jacobsen, T

2004-01-01

Anoxic processes can effectively control odour and corrosion in sewer networks. However, the absence of fundamental knowledge on the kinetics of anoxic transformation of sewage prevents the engineering applications of anoxic control in sewers. This paper focuss on a basic understanding of the anoxic transformations needed for a conceptual simulation of the water phase processes. Experiments conducted in batch reactors have shown that nitrite builds up in wastewater during denitrification. Part of the nitrate-reducing biomass is capable of utilizing nitrite after nitrate is depleted. Compared with aerobic transformation, anoxic processes have low values of maximum growth rate of the biomass and also a low endogenous respiration rate. Heterotrophic yield determined under anoxic conditions, at level of 0.25 mmol e-eq (mmol e-eq)(-1), accounted for less than 40% of the corresponding aerobic values.

Kin recognition in zebrafish: a 24-hour window for olfactory imprinting

PubMed Central

Gerlach, Gabriele; Hodgins-Davis, Andrea; Avolio, Carla; Schunter, Celia

2008-01-01

Distinguishing kin from non-kin profoundly impacts the evolution of social behaviour. Individuals able to assess the genetic relatedness of conspecifics can preferentially allocate resources towards related individuals and avoid inbreeding. We have addressed the question of how animals acquire the ability to recognize kin by studying the development of olfactory kin preference in zebrafish (Danio rerio). Previously, we showed that zebrafish use an olfactory template to recognize even unfamiliar kin through phenotype matching. Here, we show for the first time that this phenotype matching is based on a learned olfactory imprinting process in which exposure to kin individuals on day 6 post fertilization (pf) is necessary and sufficient for imprinting. Larvae that were exposed to kin before or after but not on day 6 pf did not recognize kin. Larvae isolated from all contact with conspecifics did not imprint on their own chemical cues; therefore, we see no evidence for kin recognition through self-matching in this species. Surprisingly, exposure to non-kin odour during the sensitive phase of development did not result in imprinting on the odour cues of unrelated individuals, suggesting a genetic predisposition to kin odour. Urine-born peptides expressed by genes of the immune system (MHC) are important messengers carrying information about ‘self’ and ‘other’. We suggest that phenotype matching is acquired through a time-sensitive learning process that, in zebrafish, includes a genetic predisposition potentially involving MHC genes expressed in the olfactory receptor neurons. PMID:18544507

Kin recognition in zebrafish: a 24-hour window for olfactory imprinting.

PubMed

Gerlach, Gabriele; Hodgins-Davis, Andrea; Avolio, Carla; Schunter, Celia

2008-09-22

Distinguishing kin from non-kin profoundly impacts the evolution of social behaviour. Individuals able to assess the genetic relatedness of conspecifics can preferentially allocate resources towards related individuals and avoid inbreeding. We have addressed the question of how animals acquire the ability to recognize kin by studying the development of olfactory kin preference in zebrafish (Danio rerio). Previously, we showed that zebrafish use an olfactory template to recognize even unfamiliar kin through phenotype matching. Here, we show for the first time that this phenotype matching is based on a learned olfactory imprinting process in which exposure to kin individuals on day 6 post fertilization (pf) is necessary and sufficient for imprinting. Larvae that were exposed to kin before or after but not on day 6 pf did not recognize kin. Larvae isolated from all contact with conspecifics did not imprint on their own chemical cues; therefore, we see no evidence for kin recognition through self-matching in this species. Surprisingly, exposure to non-kin odour during the sensitive phase of development did not result in imprinting on the odour cues of unrelated individuals, suggesting a genetic predisposition to kin odour. Urine-born peptides expressed by genes of the immune system (MHC) are important messengers carrying information about 'self' and 'other'. We suggest that phenotype matching is acquired through a time-sensitive learning process that, in zebrafish, includes a genetic predisposition potentially involving MHC genes expressed in the olfactory receptor neurons.

Alarm Pheromones and Chemical Communication in Nymphs of the Tropical Bed Bug Cimex hemipterus (Hemiptera: Cimicidae)

PubMed Central

Liedtke, H. Christoph; Åbjörnsson, Kajsa; Harraca, Vincent; Knudsen, Jette T.; Wallin, Erika A.; Hedenström, Erik; Ryne, Camilla

2011-01-01

The recent resurge of bed bug infestations (Cimex spp.; Cimicidae) and their resistance to commonly used pesticides calls for alternative methods of control. Pheromones play an important role in environmentally sustainable methods for the management of many pest insects and may therefore be applicable for the control of bed bugs. The tropical bed bug, Cimex hemipterus, is a temporary ectoparasite on humans and causes severe discomfort. Compared to the common bed bug, Cimex lectularius, little is known about the chemical signalling and pheromone-based behaviour of the tropical species. Here, we show that the antennal morphology and volatile emission of C. hemipterus closely resembles those of C. lectularius and we test their behavioural responses to conspecific odour emissions. Two major volatiles are emitted by male, female and nymph C. hemipterus under stress, (E)-2-hexenal and (E)-2-octenal. Notably, nymph emissions show contrasting ratios of these compounds to adults and are further characterized by the addition of 4-oxo-(E)-2-hexenal and 4-oxo-(E)-2-octenal. The discovery of this nymph pheromone in C. hemipterus is potentially the cause of a repellent effect observed in the bio-tests, where nymph odours induce a significantly stronger repellent reaction in conspecifics than adult odours. Our results suggest that pheromone-based pest control methods developed for C. lectularius could be applicable to C. hemipterus, with the unique nymph blend showing promising practical properties. PMID:21479180

Location of and landing on a source of human body odour by female Culex quinquefasciatus in still and moving air.

PubMed

Lacey, Emerson S; Cardé, Ring T

2012-06-01

The orientation to and landing on a source of human odour by female Culex quinquefasciatus Say (Diptera: Culicidae) is observed in a wind tunnel without an airflow or with a laminar airflow of 0.2 m s -1 . Odours from human feet are collected by 'wearing' clean glass beads inside a stocking and presenting beads in a Petri dish in a wind tunnel. Mosquitoes are activated by brief exposure to a 1 L min -1 jet of 4% CO 2 positioned 10 cm from the release cage. In moving air at 0.2 m s -1 , a mean of 3.45 ± 0.49 landings are observed in 10 min trials (5 mosquitoes per trial), whereas 6.50 ± 0.96 landings are recorded in still air. Furthermore, 1.45 ± 0.31mosquitoes are recorded on beads at any one time in moving air (a measure of individuals landing versus one landing multiple times) compared to 3.10 ± 0.31 in still air. Upwind flight to beads in moving air is demonstrated by angular headings of flight immediately prior to landing, whereas approaches to beads in still air are oriented randomly. The mean latency until first landing is 226.7 ± 17.98 s in moving air compared to 122.5 ± 24.18 in still air. Strategies used to locate a prospective host at close range in still air are considered.

Validation of bovine oestrous-specific synthetic molecules with trained scent dogs; similarities between natural and synthetic oestrous smell.

PubMed

Fischer-Tenhagen, C; Johnen, D; Le Danvic, C; Gatien, J; Salvetti, P; Tenhagen, B A; Heuwieser, W

2015-02-01

Oestrous detection is crucial for successful dairy cow reproduction. Bulls identify cows in oestrus by oestrous-specific odours especially in urine and vaginal fluid. These have been used to train dogs to detect cows in heat. To improve and simplify the dog training, a spray containing synthetic oestrous molecules was developed. The objective of this study was to test the spray on similarities to the natural substance thus to assess its suitability as a training substance for heat detection dogs. Ten privately owned dogs of various breeds were trained. Dogs should be trained either to differentiate natural vaginal fluid from cows in oestrus and dioestrus (n = 5), or spray with or without synthetic oestrous molecules (n = 5). Dogs trained on natural fluid and on spray could detect the oestrous odour they had been trained on with an overall accuracy of 69.0% and 82.4%, respectively (p = 0.019). To validate the synthetic molecules, dogs trained with synthetic molecules had to detect oestrous odour in natural fluid without further training (accuracy 37.6%). Dogs trained on natural fluid detected the synthetic molecules with an accuracy of 50.0% (50% vs 37.4%, p < 0.05). Dogs can recognize natural vaginal fluid from cows in oestrus after they have been trained with synthetic oestrous molecules, but accuracy needs to be improved. © 2014 Blackwell Verlag GmbH.

Chemosensory assessment of sperm competition levels and the evolution of internal spermatophore guarding

PubMed Central

Carazo, P; Font, E; Alfthan, B

2006-01-01

Males of many species adjust their reproductive behaviour according to the perceived risk of sperm competition. Although this phenomenon is widespread in insects and other animals, the mechanisms that allow mates to assess sperm competition levels remain largely unexplored. In this study, we analysed the mating behaviour of pairs of Tenebrio molitor beetles under three odour treatments representing increasing levels of sperm competition risk (SCR) and sperm competition intensity (SCI). Copula duration and male and female post-copulatory behaviour varied significantly with odour treatment. Both copula duration and post-copulatory associations (PCAs) increased significantly in odour treatments reflecting high male density. To our knowledge, this is the first study to report that insects may assess the actual density of potential competitors at the time of mating, a cue to SCR and SCI, on the basis of chemical cues. In T. molitor, males inhibit sperm release from the spermatophore of a rival male when remating takes place at short intervals. We show that, when sperm competition levels are high, PCAs increase female remating interval just above that necessary to prevent spermatophore inhibition by rival males. This finding strongly suggests that strategic male behaviour plays a ‘spermatophore guarding’ role in this species. Although common in insects with external spermatophore transfer, spermatophore guarding is not expected in species with rapid ejaculate transfer and internal spermatophore delivery. Our results reveal that spermatophore guarding may evolve, even under these circumstances, as an evolutionary response to short-term spermatophore inhibition or displacement mechanisms. PMID:17148255

The development and discussion of computerized visual perception assessment tool for Chinese characters structures - Concurrent estimation of the overall ability and the domain ability in item response theory approach.

PubMed

Wu, Huey-Min; Lin, Chin-Kai; Yang, Yu-Mao; Kuo, Bor-Chen

2014-11-12

Visual perception is the fundamental skill required for a child to recognize words, and to read and write. There was no visual perception assessment tool developed for preschool children based on Chinese characters in Taiwan. The purposes were to develop the computerized visual perception assessment tool for Chinese Characters Structures and to explore the psychometrical characteristic of assessment tool. This study adopted purposive sampling. The study evaluated 551 kindergarten-age children (293 boys, 258 girls) ranging from 46 to 81 months of age. The test instrument used in this study consisted of three subtests and 58 items, including tests of basic strokes, single-component characters, and compound characters. Based on the results of model fit analysis, the higher-order item response theory was used to estimate the performance in visual perception, basic strokes, single-component characters, and compound characters simultaneously. Analyses of variance were used to detect significant difference in age groups and gender groups. The difficulty of identifying items in a visual perception test ranged from -2 to 1. The visual perception ability of 4- to 6-year-old children ranged from -1.66 to 2.19. Gender did not have significant effects on performance. However, there were significant differences among the different age groups. The performance of 6-year-olds was better than that of 5-year-olds, which was better than that of 4-year-olds. This study obtained detailed diagnostic scores by using a higher-order item response theory model to understand the visual perception of basic strokes, single-component characters, and compound characters. Further statistical analysis showed that, for basic strokes and compound characters, girls performed better than did boys; there also were differences within each age group. For single-component characters, there was no difference in performance between boys and girls. However, again the performance of 6-year-olds was better than that of 4-year-olds, but there were no statistical differences between the performance of 5-year-olds and 6-year-olds. Results of tests with basic strokes, single-component characters and compound characters tests had good reliability and validity. Therefore, it can be apply to diagnose the problem of visual perception at preschool. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of goat milk or milk replacer diet on meat quality and fat composition of suckling goat kids.

PubMed

Bañón, S; Vila, R; Price, A; Ferrandini, E; Garrido, M D

2006-02-01

The effects of a diet with goat milk "GM" or milk replacer "MR" on the meat quality and fat composition of suckling Murciano-Granadina kids were studied. MR consisted of powdered skimmed milk, coconut oil and fat, and cereal products and by-products. Raw meat quality (moisture, protein, lipids, ash, collagen, cholesterol, haem pigments, CIELab colour, pH and water retention capacity), fatty acid "FA" composition and eating quality of cooked meat (odour, flavour and texture) were determined. Diet had only a slight effect on raw meat quality but had a pronounced effect on fatty acid composition and eating quality of cooked meat. MR diet increased the water/protein proportion in the muscle. The saturated/unsaturated FA ratio in GM and MR fat was 0.94 and 2.27, respectively. The major FA in GM and MR fat were C16:0 and C18:1, respectively. Short-chain C4-C12 hardly accumulated in the adipose tissue of suckling kid, increasing the relative percentages of C14-C20. This effect was more pronounced in MR fat, due to the fact that MR contained more short-chain fatty acids than GM. MR diet gave cooked meat a more intense characteristic goat meat odour and flavour, more tenderness and more juiciness than the natural suckling diet. This fact could be related to differences in meat and fat composition.

Chemical properties and sensory quality of ice cream fortified with fish protein.

PubMed

Shaviklo, Gholam Reza; Thorkelsson, Gudjon; Sveinsdottir, Kolbrun; Rafipour, Fereidon

2011-05-01

Fish protein powder is a functional ingredient that can be used for enhancing the nutritional value of food products. In this study the effect of fortification with different levels of fish protein powder (FP) on chemical properties and sensory quality of Persian ice cream with 0, 30 and 50 g kg(-1) FP during storage at - 18 °C for 4 months was investigated. Ice creams fortified with 50 and 30 g kg(-1) FP had significantly higher protein and solid-non-fat content than ice cream with 0% FP or 83, 69 and 51 g kg(-1) protein and 215, 204 and 181 g kg(-1) solid non-fat, respectively. All products had the same levels of fat, lactose, acidity and pH. They had similar sensory quality after production except for colour, but sensory properties of fortified samples changed significantly after 2 months of storage. Colour faded, cohesiveness decreased, sandiness/coarseness increased, sweetness decreased and fish flavour and off-odour increased. The control ice cream scored highest for additives odour and flavour. Development of ice cream fortified with fish protein powder could be an effective way to enhance nutritional and functional value of ice cream. But studies on storage stability, consumers' acceptance and attitudes are recommended if companies are planning to do so. Copyright © 2011 Society of Chemical Industry.

New icing media for quality enhancement of chilled hake (Merluccius merluccius) using a jumbo squid (Dosidicus gigas) skin extract.

PubMed

Ezquerra-Brauer, Josafat Marina; Miranda, José M; Chan-Higuera, Jesús Enrique; Barros-Velázquez, Jorge; Aubourg, Santiago P

2017-08-01

An advanced strategy for chilled fish preservation, based on the inclusion in ice of an extract of jumbo squid (Dosidicus gigas) skin (JSS), is proposed. Aqueous solutions including acetic acid-ethanol extracts of JSS were tested at two different concentrations as icing media, with the effects on the quality evolution of chilled hake (Merluccius merluccius) being monitored. A significant inhibition (P < 0.05) of microbial activity (aerobes, psychrotrophs, Enterobacteriaceae, proteolytic bacteria; pH, trimethylamine) was obtained in hake corresponding to the icing batch including the highest JSS concentration. Additionally, fish specimens from such icing conditions showed an inhibitory effect (P < 0.05) on lipid hydrolysis development, while no effect (P > 0.05) was depicted for lipid oxidation. Sensory analysis (skin and mucus development; eyes; gills; texture; external odour; raw and cooked flesh odour; flesh taste) indicated a shelf life extension of chilled hake stored in ice including the highest JSS concentration. A profitable use of JSS, an industrial by-product during jumbo squid commercialisation, has been developed in the present work, which leads to a remarkable microbial inhibition and a significant shelf life extension of chilled hake. In agreement with previous research, ommochrome pigments (i.e. lipophilic-type compounds) would be considered responsible for this preservative effect. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

A mathematical model of chemoreception for odours and taste.

PubMed

Maurin, Francis

2002-04-07

We propose a mathematical model based on the occupation theory and on the hypothesis that, for a given stimulus, there exist two kinds of receptors. The receptors of the first kind react by a two-step process, first forming an intermediate inactive compound which is then changed into an active depolarizing form (this scheme was already used by Del Castillo & Katz, 1957). In the same way, the receptors of the second kind react by a two-step process, first forming an intermediate inactive compound which is then changed into an active hyperpolarizing form. The response is assumed to be proportional to the difference between the fraction of the active depolarizing compound and that of the active hyperpolarizing compound. The present paper deals only with the time course of the intensity of the response: in the first part, when a continuous flow of stimulus is applied and in the second part, when this continuous flow is removed. It does not deal with the quality and the discrimination of odours. The proposed mathematical model accounts for the depolarizing responses (which are the most frequent ones), the hyperpolarizing responses, the mixed responses reported by Patte et al. (1989), the off-responses reported by Takagi & Shibuya (1959) and for their variability, and the latent period in the olfactory response (Ottoson, 1974). Copyright 2002 Elsevier Science Ltd. All rights reserved.

Integration of advanced oxidation processes at mild conditions in wet scrubbers for odourous sulphur compounds treatment.

PubMed

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

2014-08-01

The effectiveness of different advanced oxidation processes on the treatment of a multicomponent aqueous solution containing ethyl mercaptan, dimethyl sulphide and dimethyl disulphide (0.5 mg L(-1) of each sulphur compound) was investigated with the objective to assess which one is the most suitable treatment to be coupled in wet scrubbers used in odour treatment facilities. UV/H2O2, Fenton, photo-Fenton and ozone treatments were tested at mild conditions and the oxidation efficiency obtained was compared. The oxidation tests were carried out in magnetically stirred cylindrical quartz reactors using the same molar concentration of oxidants (hydrogen peroxide or ozone). The results show that ozone and photo-Fenton are the most efficient treatments, achieving up to 95% of sulphur compounds oxidation and a mineralisation degree around 70% in 10 min. Furthermore, the total costs of the treatments taking into account the capital and operational costs were also estimated for a comparative purpose. The economic analysis revealed that the Fenton treatment is the most economical option to be integrated in a wet scrubber to remove volatile organic sulphur compounds, as long as there are no space constraints to install the required reactor volume. In the case of reactor volume limitation or retrofitting complexities, the ozone and photo-Fenton treatments should be considered as viable alternatives. Copyright © 2014 Elsevier Ltd. All rights reserved.

Is transport distance correlated with animal welfare and carcass quality of reindeer (Rangifer tarandus tarandus)?

PubMed

Laaksonen, Sauli; Jokelainen, Pikka; Pusenius, Jyrki; Oksanen, Antti

2017-03-15

Slaughter reindeer are exposed to stress caused by gathering, handling, loading and unloading, and by conditions in vehicles during transport. These stress factors can lead to compromised welfare and trauma such as bruises or fractures, aspiration of rumen content, and abnormal odour in carcasses, and causing condemnations in meat inspection and lower meat quality. We investigated the statistical association of slaughter transport distance with these indices using meat inspection data from years 2004-2016, including inspection of 669,738 reindeer originating from Finnish reindeer herding areas. Increased stress and decreased welfare of reindeer, as indicated by higher incidence of carcass condemnation due to bruises or fractures, aspiration of rumen content, or abnormal odour, were positively associated with systems involving shorter transport distances to abattoirs. Significant differences in incidence of condemnations were also detected between abattoirs and reindeer herding cooperatives. This study indicates that in particular the short-distance transports of reindeer merit more attention. While the results suggest that factors associated with long distance transport, such as driver education, truck design, veterinary supervision, and specialist equipment, may be favourable to reducing pre-slaughter stress in reindeer when compared with short distance transport systems, which occur in a variety of vehicle types and may be done by untrained handlers. Further work is required to elucidate the causal factors to the current results.

Flavour identification in frontotemporal lobar degeneration.

PubMed

Omar, Rohani; Mahoney, Colin J; Buckley, Aisling H; Warren, Jason D

2013-01-01

Deficits of flavour processing may be clinically important in frontotemporal lobar degeneration (FTLD). To examine flavour processing in FTLD. We studied flavour identification prospectively in 25 patients with FTLD (12 with behavioural variant frontotemporal dementia (bvFTD), eight with semantic variant primary progressive aphasia (svPPA), five with non-fluent variant primary progressive aphasia (nfvPPA)) and 17 healthy control subjects, using a new test based on cross-modal matching of flavours to words and pictures. All subjects completed a general neuropsychological assessment, and odour identification was also assessed using a modified University of Pennsylvania Smell Identification Test. Brain MRI volumes from the patient cohort were analysed using voxel-based morphometry to identify regional grey matter associations of flavour identification. Relative to the healthy control group, the bvFTD and svPPA subgroups showed significant (p<0.05) deficits of flavour identification and all three FTLD subgroups showed deficits of odour identification. Flavour identification performance did not differ significantly between the FTLD syndromic subgroups. Flavour identification performance in the combined FTLD cohort was significantly (p<0.05 after multiple comparisons correction) associated with grey matter volume in the left entorhinal cortex, hippocampus, parahippocampal gyrus and temporal pole. Certain FTLD syndromes are associated with impaired flavour identification and this is underpinned by grey matter atrophy in an anteromedial temporal lobe network. These findings may have implications for our understanding of abnormal eating behaviour in these diseases.

Most Likely to Succeed: Seeking Self-Knowledge in the Company of Characters

ERIC Educational Resources Information Center

Gardoqui, Kate Ehrenfeld

2012-01-01

In this article, the author describes several innovative activities for engaging students in studies of literary characters: voting on superlatives for characters, creating characters' Facebook profiles, and composing creative dialogs in which characters from different works meet each other. The author points out that it is this self-knowledge…

A Study of Character among Collegiate Athletes

ERIC Educational Resources Information Center

Heupel, Jill D.

2017-01-01

The idea that sport builds character has been around for a long time. However, sports may not build the type of character once thought. Character of athletes was defined based on differing views held by sport scholars, coaches, athletes, and sport enthusiast. Sport scholars tend to view character of athletes from a moral perspective. Coaches,…

Neural basis of hierarchical visual form processing of Japanese Kanji characters.

PubMed

Higuchi, Hiroki; Moriguchi, Yoshiya; Murakami, Hiroki; Katsunuma, Ruri; Mishima, Kazuo; Uno, Akira

2015-12-01

We investigated the neural processing of reading Japanese Kanji characters, which involves unique hierarchical visual processing, including the recognition of visual components specific to Kanji, such as "radicals." We performed functional MRI to measure brain activity in response to hierarchical visual stimuli containing (1) real Kanji characters (complete structure with semantic information), (2) pseudo Kanji characters (subcomponents without complete character structure), (3) artificial characters (character fragments), and (4) checkerboard (simple photic stimuli). As we expected, the peaks of the activation in response to different stimulus types were aligned within the left occipitotemporal visual region along the posterior-anterior axis in order of the structural complexity of the stimuli, from fragments (3) to complete characters (1). Moreover, only the real Kanji characters produced functional connectivity between the left inferotemporal area and the language area (left inferior frontal triangularis), while pseudo Kanji characters induced connectivity between the left inferotemporal area and the bilateral cerebellum and left putamen. Visual processing of Japanese Kanji takes place in the left occipitotemporal cortex, with a clear hierarchy within the region such that the neural activation differentiates the elements in Kanji characters' fragments, subcomponents, and semantics, with different patterns of connectivity to remote regions among the elements.

Character combinations, convergence and diversification in ectoparasitic arthropods.

PubMed

Poulin, Robert

2009-08-01

Different lineages of organisms diversify over time at different rates, in part as a consequence of the characteristics of the species in these lineages. Certain suites of traits possessed by species within a clade may determine rates of diversification, with some particular combinations of characters acting synergistically to either limit or promote diversification; the most successful combinations may also emerge repeatedly in different clades via convergent evolution. Here, the association between species characters and diversification is investigated amongst 21 independent lineages of arthropods ectoparasitic on vertebrate hosts. Using nine characters (each with two to four states) that capture general life history strategy, transmission mode and host-parasite interaction, each lineage was described by the set of character states it possesses. The results show, firstly, that most possible pair-wise combinations of character states have been adopted at least once, sometimes several times independently by different lineages; thus, ectoparasitic arthropods have explored most of the life history character space available to them. Secondly, lineages possessing commonly observed combinations of character states are not necessarily the ones that have experienced the highest rates of diversification (measured as a clade's species-per-genus ratio). Thirdly, some specific traits are associated with higher rates of diversification. Using more than one host per generation, laying eggs away from the host and intermediate levels of fecundity are features that appear to have promoted diversification. These findings indicate that particular species characters may be evolutionary drivers of diversity, whose effects could also apply in other taxa.

A Missing Piece of the Contemporary Character Education Puzzle: The Individualisation of Moral Character

ERIC Educational Resources Information Center

Chen, Yi-Lin

2013-01-01

The different sorts of virtuous people who display various virtues to a remarkable degree have brought the issue of individualisation of moral character to the forefront. It signals a more personal dimension of character development which is notoriously ignored in the current discourse on character education. The case is made that since in…

Inversion effect in the visual processing of Chinese character: an fMRI study.

PubMed

Zhao, Jizheng; Liu, Jiangang; Li, Jun; Liang, Jimin; Feng, Lu; Ai, Lin; Tian, Jie

2010-07-05

Chinese people engage long-term processing of characters. It has been demonstrated that the presented orientation affects the perception of several types of stimuli when people have possessed expertise with them, e.g. face, body, and scene. However, the influence of inversion on the neural mechanism of Chinese character processing has not been sufficiently discussed. In the present study, a functional magnetic resonance imaging (fMRI) experiment is performed to examine the effect of inversion on Chinese character processing, which employs Chinese character, face and house as stimuli. The region of interest analysis demonstrates inversion leads to neural response increases for Chinese character in left fusiform character-preferential area, bilateral fusiform object-preferential area and bilateral occipital object-preferential area, and such inversion-caused changes in the response pattern of characters processing are highly similar to those of faces processing but quiet different from those of houses processing. Whole brain analysis reveals the upright characters recruit several language regions for phonology and semantic processing, however, the inverted characters activated extensive regions related to the visual information processing. Our findings reveal a shift from the character-preferential processing route to the generic object processing steam within visual cortex when the characters are inverted, and suggest that different mechanisms may underlie the upright and the inverted Chinese character, respectively. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Olfactory lateralization in the chick.

PubMed

Vallortigara, G; Andrew, R J

1994-04-01

Chicks using their right nostril (and so with direct olfactory input to the right hemisphere), and presented simultaneously with two objects identical in visual appearance with the rearing object, and differing only in odour, chose that which smelled like the rearing object. Chicks using the left nostril chose equally readily but at random. Earlier work, using similar tests, has shown special interest of the right hemisphere in change in visual properties of familiar stimuli, suggesting that analysis of a wide range of properties of a familiar stimulus may be an important function of the right hemisphere in the chick, with consequent detection of novelty.

Improving semi-text-independent method of writer verification using difference vector

NASA Astrophysics Data System (ADS)

Li, Xin; Ding, Xiaoqing

2009-01-01

The semi-text-independent method of writer verification based on the linear framework is a method that can use all characters of two handwritings to discriminate the writers in the condition of knowing the text contents. The handwritings are allowed to just have small numbers of even totally different characters. This fills the vacancy of the classical text-dependent methods and the text-independent methods of writer verification. Moreover, the information, what every character is, is used for the semi-text-independent method in this paper. Two types of standard templates, generated from many writer-unknown handwritten samples and printed samples of each character, are introduced to represent the content information of each character. The difference vectors of the character samples are gotten by subtracting the standard templates from the original feature vectors and used to replace the original vectors in the process of writer verification. By removing a large amount of content information and remaining the style information, the verification accuracy of the semi-text-independent method is improved. On a handwriting database involving 30 writers, when the query handwriting and the reference handwriting are composed of 30 distinct characters respectively, the average equal error rate (EER) of writer verification reaches 9.96%. And when the handwritings contain 50 characters, the average EER falls to 6.34%, which is 23.9% lower than the EER of not using the difference vectors.

Writing affects the brain network of reading in Chinese: a functional magnetic resonance imaging study.

PubMed

Cao, Fan; Vu, Marianne; Chan, Derek Ho Lung; Lawrence, Jason M; Harris, Lindsay N; Guan, Qun; Xu, Yi; Perfetti, Charles A

2013-07-01

We examined the hypothesis that learning to write Chinese characters influences the brain's reading network for characters. Students from a college Chinese class learned 30 characters in a character-writing condition and 30 characters in a pinyin-writing condition. After learning, functional magnetic resonance imaging collected during passive viewing showed different networks for reading Chinese characters and English words, suggesting accommodation to the demands of the new writing system through short-term learning. Beyond these expected differences, we found specific effects of character writing in greater activation (relative to pinyin writing) in bilateral superior parietal lobules and bilateral lingual gyri in both a lexical decision and an implicit writing task. These findings suggest that character writing establishes a higher quality representation of the visual-spatial structure of the character and its orthography. We found a greater involvement of bilateral sensori-motor cortex (SMC) for character-writing trained characters than pinyin-writing trained characters in the lexical decision task, suggesting that learning by doing invokes greater interaction with sensori-motor information during character recognition. Furthermore, we found a correlation of recognition accuracy with activation in right superior parietal lobule, right lingual gyrus, and left SMC, suggesting that these areas support the facilitative effect character writing has on reading. Finally, consistent with previous behavioral studies, we found character-writing training facilitates connections with semantics by producing greater activation in bilateral middle temporal gyri, whereas pinyin-writing training facilitates connections with phonology by producing greater activation in right inferior frontal gyrus. Copyright © 2012 Wiley Periodicals, Inc.

Observations on the effects of odours on the homeopathic response.

PubMed

McGuigan, Moira

2014-07-01

Samuel Hahnemann described incidences where the homeopathic response was disrupted by noxious smells in the environment. An earlier paper proposed that homeopathic medicines may be sensed by vomeronasal cells (VNCs) i.e. microvillus or brush cells in the vomeronasal organ (VNO), the taste buds and associated with the trigeminal nerve and nervus terminalis. This paper proposes an extension to the theory and suggests that a subset of solitary chemosensory cells (SCCs) in the diffuse chemosensory system (DCS) that is morphologically similar to VNCs might also be receptive to homeopathic medicines. The types of odours that may interfere with this process are described. Two clinical cases of disruption of the homeopathic response are given as examples, showing that successful re-establishment of remedy action can be produced by timely repetition of the medicine. The ramifications on clinical homeopathic practice are discussed. Copyright © 2014 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Possible health and safety problems in the use of novel plant essential oils and extracts in aromatherapy.

PubMed

Lis-Balchin, M

1999-12-01

Aromatherapy is a branch of complementary or alternative therapy which is increasing in popularity, yet has scant scientific credibility. Aromatherapy should be defined as treatment using odours and practised as such. However, essential oils are usually used in conjunction with massage and often combined with counselling of some kind. The use of most commonly-used essential oils in massage is seldom dangerous, as they have low systemic toxicity, especially when used at 2% dilution (provided they are not adulterated); however their safety during pregnancy, childbirth and babies has not been clearly demonstrated. Sensitisation, however, is a growing concern. Some aromatherapists are now introducing novel plant essential oils, extracts and phytols into their massage routine many of which have no odour and are potentially toxic. The possible dangers of these plant products are therefore discussed using specific example.

Verification of key odorants in rose oil by gas chromatography-olfactometry/aroma extract dilution analysis, odour activity value and aroma recombination.

PubMed

Xiao, Zuobing; Li, Jing; Niu, Yunwei; Liu, Qiang; Liu, Junhua

2017-10-01

Rose oil is much too expensive but very popular. It's well known that the flower oil's aroma profile hasn't been intensively investigated. In order to verify the aroma profile of rose oil, the synthetic blend of odorants was prepared and then compared with the original rose oil using electronic nose analysis (ENA) combined with quantitative descriptive analysis (QDA). The odorants from rose oils were screened out by Gas Chromatography-Olfactometry/aroma extract dilution analysis (GC-O/AEDA) combined with odour activity value (OAV). Both ENA and QDA indicated the recombination model derived from OAV and GC-O/AEDA closely resembled the original rose oil. The experiment results show that rose oxide, linalool, α-pinene, β-pinene, nonanal, heptanal citronellal, phenyl ethyl alcohol, benzyl alcohol, eugenol, methyl eugenol, β-citronellol, hexyl acetate, β-ionone, nerol, etc. are very important constituent to rose oil aroma profile.

Eye movement control in reading unspaced text: the case of the Japanese script.

PubMed

Kajii, N; Nazir, T A; Osaka, N

2001-09-01

The present study examines the landing-site distributions of the eyes during natural reading of Japanese script: a script that mixes three different writing systems (Kanji, Hiragana, and Katakana) and that misses regular spacing between words. The results show a clear preference of the eyes to land at the beginning rather than the center of the word. In addition, it was found that the eyes land on Kanji characters more frequently than on Hiragana or Katakana characters. Further analysis for two- and three-character words indicated that the eye's landing-site distribution differs depending on type of the characters in the word: the eyes prefer to land at the word beginning only when the initial character of the word is a Kanji character. For pure Hiragana words, the proportion of initial fixations did not differ between character positions. Thus, as already indicated by Kambe (National Institute of Japanese Language Report 85 (1986) 29), the visual distinctiveness of the three Japanese scripts plays a role in guiding eye movements in reading Japanese.

Kannada character recognition system using neural network

NASA Astrophysics Data System (ADS)

Kumar, Suresh D. S.; Kamalapuram, Srinivasa K.; Kumar, Ajay B. R.

2013-03-01

Handwriting recognition has been one of the active and challenging research areas in the field of pattern recognition. It has numerous applications which include, reading aid for blind, bank cheques and conversion of any hand written document into structural text form. As there is no sufficient number of works on Indian language character recognition especially Kannada script among 15 major scripts in India. In this paper an attempt is made to recognize handwritten Kannada characters using Feed Forward neural networks. A handwritten Kannada character is resized into 20x30 Pixel. The resized character is used for training the neural network. Once the training process is completed the same character is given as input to the neural network with different set of neurons in hidden layer and their recognition accuracy rate for different Kannada characters has been calculated and compared. The results show that the proposed system yields good recognition accuracy rates comparable to that of other handwritten character recognition systems.

The dark cube: dark and light character profiles.

PubMed

Garcia, Danilo; Rosenberg, Patricia

2016-01-01

Background. Research addressing distinctions and similarities between people's malevolent character traits (i.e., the Dark Triad: Machiavellianism, narcissism, and psychopathy) has detected inconsistent linear associations to temperament traits. Additionally, these dark traits seem to have a common core expressed as uncooperativeness. Hence, some researchers suggest that the dark traits are best represented as one global construct (i.e., the unification argument) rather than as ternary construct (i.e., the uniqueness argument). We put forward the dark cube (cf. Cloninger's character cube) comprising eight dark profiles that can be used to compare individuals who differ in one dark character trait while holding the other two constant. Our aim was to investigate in which circumstances individuals who are high in each one of the dark character traits differ in Cloninger's "light" character traits: self-directedness, cooperativeness, and self-transcendence. We also investigated if people's dark character profiles were associated to their light character profiles. Method. A total of 997 participants recruited from Amazon's Mechanical Turk (MTurk) responded to the Short Dark Triad and the Short Character Inventory. Participants were allocated to eight different dark profiles and eight light profiles based on their scores in each of the traits and any possible combination of high and low scores. We used three-way interaction regression analyses and t-tests to investigate differences in light character traits between individuals with different dark profiles. As a second step, we compared the individuals' dark profile with her/his character profile using an exact cell-wise analysis conducted in the ROPstat software (http://www.ropstat.com). Results. Individuals who expressed high levels of Machiavellianism and those who expressed high levels of psychopathy also expressed low self-directedness and low cooperativeness. Individuals with high levels of narcissism, in contrast, scored high in self-directedness. Moreover, individuals with a profile low in the dark traits were more likely to end up with a profile high in cooperativeness. The opposite was true for those individuals with a profile high in the dark traits. The rest of the cross-comparisons revealed some of the characteristics of human personality as a non-linear complex dynamic system. Conclusions. Our study suggests that individuals who are high in Machiavellianism and psychopathy share a unified non-agentic and uncooperative character (i.e., irresponsible, low in self-control, unempathetic, unhelpful, untolerant), while individuals high in narcissism have a more unique character configuration expressed as high agency and, when the other dark traits are high, highly spiritual but uncooperative. In other words, based on differences in their associations to the light side of character, the Dark Triad seems to be a dyad rather than a triad.

The dark cube: dark and light character profiles

PubMed Central

2016-01-01

Background. Research addressing distinctions and similarities between people’s malevolent character traits (i.e., the Dark Triad: Machiavellianism, narcissism, and psychopathy) has detected inconsistent linear associations to temperament traits. Additionally, these dark traits seem to have a common core expressed as uncooperativeness. Hence, some researchers suggest that the dark traits are best represented as one global construct (i.e., the unification argument) rather than as ternary construct (i.e., the uniqueness argument). We put forward the dark cube (cf. Cloninger’s character cube) comprising eight dark profiles that can be used to compare individuals who differ in one dark character trait while holding the other two constant. Our aim was to investigate in which circumstances individuals who are high in each one of the dark character traits differ in Cloninger’s “light” character traits: self-directedness, cooperativeness, and self-transcendence. We also investigated if people’s dark character profiles were associated to their light character profiles. Method. A total of 997 participants recruited from Amazon’s Mechanical Turk (MTurk) responded to the Short Dark Triad and the Short Character Inventory. Participants were allocated to eight different dark profiles and eight light profiles based on their scores in each of the traits and any possible combination of high and low scores. We used three-way interaction regression analyses and t-tests to investigate differences in light character traits between individuals with different dark profiles. As a second step, we compared the individuals’ dark profile with her/his character profile using an exact cell-wise analysis conducted in the ROPstat software (http://www.ropstat.com). Results. Individuals who expressed high levels of Machiavellianism and those who expressed high levels of psychopathy also expressed low self-directedness and low cooperativeness. Individuals with high levels of narcissism, in contrast, scored high in self-directedness. Moreover, individuals with a profile low in the dark traits were more likely to end up with a profile high in cooperativeness. The opposite was true for those individuals with a profile high in the dark traits. The rest of the cross-comparisons revealed some of the characteristics of human personality as a non-linear complex dynamic system. Conclusions. Our study suggests that individuals who are high in Machiavellianism and psychopathy share a unified non-agentic and uncooperative character (i.e., irresponsible, low in self-control, unempathetic, unhelpful, untolerant), while individuals high in narcissism have a more unique character configuration expressed as high agency and, when the other dark traits are high, highly spiritual but uncooperative. In other words, based on differences in their associations to the light side of character, the Dark Triad seems to be a dyad rather than a triad. PMID:26966650

Olfactory discrimination training up-regulates and reorganizes expression of microRNAs in adult mouse hippocampus.

PubMed

Smalheiser, Neil R; Lugli, Giovanni; Lenon, Angela L; Davis, John M; Torvik, Vetle I; Larson, John

2010-02-26

Adult male mice (strain C57Bl/6J) were trained to execute nose-poke responses for water reinforcement; then they were randomly assigned to either of two groups: olfactory discrimination training (exposed to two odours with reward contingent upon correctly responding to one odour) or pseudo-training (exposed to two odours with reward not contingent upon response). These were run in yoked fashion and killed when the discrimination-trained mouse reached a learning criterion of 70% correct responses in 20 trials, occurring after three sessions (a total of approximately 40 min of training). The hippocampus was dissected bilaterally from each mouse (N = 7 in each group) and profiling of 585 miRNAs (microRNAs) was carried out using multiplex RT-PCR (reverse transcription-PCR) plates. A significant global up-regulation of miRNA expression was observed in the discrimination training versus pseudo-training comparison; when tested individually, 29 miRNAs achieved significance at P = 0.05. miR-10a showed a 2.7-fold increase with training, and is predicted to target several learning-related mRNAs including BDNF (brain-derived neurotrophic factor), CAMK2b (calcium/calmodulin-dependent protein kinase IIβ), CREB1 (cAMP-response-element-binding protein 1) and ELAVL2 [ELAV (embryonic lethal, abnormal vision, Drosophila)-like; Hu B]. Analysis of miRNA pairwise correlations revealed the existence of several miRNA co-expression modules that were specific to the training group. These in vivo results indicate that significant, dynamic and co-ordinated changes in miRNA expression accompany early stages of learning.

Visual Field Differences in Visual Word Recognition Can Emerge Purely from Perceptual Learning: Evidence from Modeling Chinese Character Pronunciation

ERIC Educational Resources Information Center

Hsiao, Janet Hui-wen

2011-01-01

In Chinese orthography, a dominant character structure exists in which a semantic radical appears on the left and a phonetic radical on the right (SP characters); a minority opposite arrangement also exists (PS characters). As the number of phonetic radical types is much greater than semantic radical types, in SP characters the information is…

Relationships between volatile compounds and sensory characteristics in virgin olive oil by analytical and chemometric approaches.

PubMed

Procida, Giuseppe; Cichelli, Angelo; Lagazio, Corrado; Conte, Lanfranco S

2016-01-15

The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph-mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green-fruity' and 'sweet') and olfactory perception. Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. © 2015 Society of Chemical Industry.

Guatemalan potato moth Tecia solanivora distinguish odour profiles from qualitatively different potatoes Solanum tuberosum L.

PubMed

Karlsson, Miriam Frida; Birgersson, Göran; Witzgall, Peter; Lekfeldt, Jonas Duus Stevens; Nimal Punyasiri, P A; Bengtsson, Marie

2013-01-01

Guatemalan potato moth, Tecia solanivora, lay eggs in the soil nearby potato Solanum spp. and larvae feed on the tubers. We investigated the oviposition behaviour of T. solanivora females and the survival of larval offspring on healthy vs. stressed, i.e. light exposed and/or damaged potato tubers. In choice tests, females laid significantly more eggs in response to potato odour of healthy tubers and female oviposition preference correlated with higher larval survival. Survival of larvae was negatively correlated with the tuber content of the steroid glycoalkaloids α-solanine and α-chaconine: healthy potatoes contained lower amounts than stressed tubers, ranging from 25 to 500 μg g⁻¹ and from 30 to 600 μg g⁻¹, respectively. Analysis of volatile compounds emitted by potato tubers revealed that stressed tubers could clearly be distinguished from healthy tubers by the composition of their volatile profiles. Compounds that contributed to this difference were e.g. decanal, nonanal, isopropyl myristate, phenylacetaldehyde, benzothiazole, heptadecane, octadecane, myristicin, E,E-α-farnesene and verbenone. Oviposition assays, when female moths were not in contact with the tubers, clearly demonstrated that volatiles guide the females to lay fewer eggs on stressed tubers that are of inferior quality for the larvae. We propose that volatiles, such as sesquiterpenes and aldehydes, mediate oviposition behaviour and are correlated with biosynthetically related, non-volatile compounds, such as steroidal glycoalkaloids, which influence larval survival. We conclude that the oviposition response and larval survival of T. solanivora on healthy vs. stressed tubers supports the preference performance hypothesis for insect herbivores. Copyright © 2012 Elsevier Ltd. All rights reserved.

Performance-Driven Hybrid Full-Body Character Control for Navigation and Interaction in Virtual Environments

NASA Astrophysics Data System (ADS)

Mousas, Christos; Anagnostopoulos, Christos-Nikolaos

2017-06-01

This paper presents a hybrid character control interface that provides the ability to synthesize in real-time a variety of actions based on the user's performance capture. The proposed methodology enables three different performance interaction modules: the performance animation control that enables the direct mapping of the user's pose to the character, the motion controller that synthesizes the desired motion of the character based on an activity recognition methodology, and the hybrid control that lies within the performance animation and the motion controller. With the methodology presented, the user will have the freedom to interact within the virtual environment, as well as the ability to manipulate the character and to synthesize a variety of actions that cannot be performed directly by him/her, but which the system synthesizes. Therefore, the user is able to interact with the virtual environment in a more sophisticated fashion. This paper presents examples of different scenarios based on the three different full-body character control methodologies.

Mathematical morphology-based shape feature analysis for Chinese character recognition systems

NASA Astrophysics Data System (ADS)

Pai, Tun-Wen; Shyu, Keh-Hwa; Chen, Ling-Fan; Tai, Gwo-Chin

1995-04-01

This paper proposes an efficient technique of shape feature extraction based on the application of mathematical morphology theory. A new shape complexity index for preclassification of machine printed Chinese Character Recognition (CCR) is also proposed. For characters represented in different fonts/sizes or in a low resolution environment, a more stable local feature such as shape structure is preferred for character recognition. Morphological valley extraction filters are applied to extract the protrusive strokes from four sides of an input Chinese character. The number of extracted local strokes reflects the shape complexity of each side. These shape features of characters are encoded as corresponding shape complexity indices. Based on the shape complexity index, data base is able to be classified into 16 groups prior to recognition procedures. The performance of associating with shape feature analysis reclaims several characters from misrecognized character sets and results in an average of 3.3% improvement of recognition rate from an existing recognition system. In addition to enhance the recognition performance, the extracted stroke information can be further analyzed and classified its own stroke type. Therefore, the combination of extracted strokes from each side provides a means for data base clustering based on radical or subword components. It is one of the best solutions for recognizing high complexity characters such as Chinese characters which are divided into more than 200 different categories and consist more than 13,000 characters.

[Eye movement study in multiple object search process].

PubMed

Xu, Zhaofang; Liu, Zhongqi; Wang, Xingwei; Zhang, Xin

2017-04-01

The aim of this study is to investigate the search time regulation of objectives and eye movement behavior characteristics in the multi-objective visual search. The experimental task was accomplished with computer programming and presented characters on a 24 inch computer display. The subjects were asked to search three targets among the characters. Three target characters in the same group were of high similarity degree while those in different groups of target characters and distraction characters were in different similarity degrees. We recorded the search time and eye movement data through the whole experiment. It could be seen from the eye movement data that the quantity of fixation points was large when the target characters and distraction characters were similar. There were three kinds of visual search patterns for the subjects including parallel search, serial search, and parallel-serial search. In addition, the last pattern had the best search performance among the three search patterns, that is, the subjects who used parallel-serial search pattern spent shorter time finding the target. The order that the targets presented were able to affect the search performance significantly; and the similarity degree between target characters and distraction characters could also affect the search performance.

Educating Moral People: A Caring Alternative to Character Education.

ERIC Educational Resources Information Center

Noddings, Nel

An alternative to character education is care ethics. The ethics of care can be seen as fundamentally relational, not individual-agent-based in the way of virtue ethics, and the ethics of care is more indirect than character education. After an introductory chapter that outlines the similarities and differences between character education and care…

Representations of deaf characters in children's picture books.

PubMed

Golos, Debbie B; Moses, Annie M

2011-01-01

Picture books can influence how children perceive people of different backgrounds, including people with disabilities whose cultures differ from their own. Researchers have examined the portrayal of multicultural characters with disabilities in children's literature. However, few have specifically considered the portrayal of deaf characters, despite increased inclusion of deaf characters in children's literature over the past two decades. The present study analyzed the portrayal of deaf characters in picture books for children ages 4-8 years. A content analysis of 20 children's picture books was conducted in which the books were analyzed for messages linked to pathological and cultural categories. Results indicated that these books did not portray Deaf characters from a cultural perspective but, rather, highlighted aspects of deafness as a medical condition, one that requires fixing and that perpetuates stereotypes of deafness as a disability.

Volcanic ash clouds; a continuing threat to international aviation

USGS Publications Warehouse

Scarone, H.

1987-01-01

Suddenly, an acrid odour began to pervade the aircraft, an eerie bluish glow lit up the edges of the wings, and in the cockpit the familiar hum of static started to break up the high-frequency communications. Then it happened.

Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda)

PubMed Central

Golovatch, Sergei; Wesener, Thomas; Tian, Mingyi

2017-01-01

Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life. PMID:28178274

Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda).

PubMed

Liu, Weixin; Golovatch, Sergei; Wesener, Thomas; Tian, Mingyi

2017-01-01

Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life.

A survey on levels and seasonal changes of assimilable organic carbon (AOC) and its precursors in drinking water.

PubMed

Ohkouchi, Yumiko; Ly, Bich Thuy; Ishikawa, Suguru; Aoki, Yusuke; Echigo, Shinya; Itoh, Sadahiko

2011-10-01

In Japan, customers' concerns about chlorinous odour in drinking water have been increasing. One promising approach for reducing chlorinous odour is the minimization of residual chlorine in water distribution, which requires stricter control of organics to maintain biological stability in water supply systems. In this investigation, the levels and seasonal changes of assimilable organic carbon (AOC) and its precursors in drinking water were surveyed to accumulate information on organics in terms of biological stability. In tap water samples purified through rapid sand filtration processes, the average AOC concentration was 174 microgC/L in winter and 60 microgC/L in summer. This difference seemed to reflect the seasonal changes of AOC in the natural aquatic environment. On the other hand, very little or no AOC could be removed after use of an ozonation-biological activated carbon (BAC) process. Especially in winter, waterworks should pay attention to BAC operating conditions to improve AOC removal. The storage of BAC effluent with residual chlorine at 0.05-0.15 mgCl2/L increased AOC drastically. This result indicated the possibility that abundant AOC precursors remaining in the finished water could contribute to newly AOC formation during water distribution with minimized residual chlorine. Combined amino acids, which remained at roughly equivalent to AOC in finished water, were identified as major AOC precursors. Prior to minimization of residual chlorine, enhancement of the removal abilities for both AOC and its precursors would be necessary.

Reward deficits in behavioural variant frontotemporal dementia include insensitivity to negative stimuli.

PubMed

Perry, David C; Datta, Samir; Sturm, Virginia E; Wood, Kristie A; Zakrzewski, Jessica; Seeley, William W; Miller, Bruce L; Kramer, Joel H; Rosen, Howard J

2017-12-01

During reward processing individuals weigh positive and negative features of a stimulus to determine whether they will pursue or avoid it. Though patients with behavioural variant frontotemporal dementia display changes in their pursuit of rewards, such as food, alcohol, money, and sex, the basis for these shifts is not clearly established. In particular, it is unknown whether patients' behaviour results from excessive focus on rewards, insensitivity to punishment, or to dysfunction in a particular stage of reward processing, such as anticipation, consumption, or action selection. Our goal was to determine the nature of the reward deficit in behavioural variant frontotemporal dementia and its underlying anatomy. We devised a series of tasks involving pleasant, unpleasant, and neutral olfactory stimuli, designed to separate distinct phases of reward processing. In a group of 25 patients with behavioural variant frontotemporal dementia and 21 control subjects, diagnosis by valence interactions revealed that patients with behavioural variant frontotemporal dementia rated unpleasant odours as less aversive than did controls and displayed lower skin conductance responses when anticipating an upcoming aversive odour. Subjective pleasantness ratings and skin conductance responses did not differ between behavioural variant frontotemporal dementia and controls for pleasant or neutral smells. In a task designed to measure the effort subjects would expend to smell or avoid smelling a stimulus, patients with behavioural variant frontotemporal dementia were less motivated, and therefore less successful than control subjects, at avoiding what they preferred not to smell, but had equivalent success at obtaining stimuli they found rewarding. Voxel-based morphometry of patients with behavioural variant frontotemporal dementia revealed that the inability to subjectively differentiate the valence of pleasant and unpleasant odours correlated with atrophy in right ventral mid-insula and right amygdala. High pleasantness ratings of unpleasant stimuli correlated with left dorsal anterior insula and frontal pole atrophy. These findings indicate that insensitivity to negative information may be a key component of the reward-seeking behaviours in behavioural variant frontotemporal dementia, and may relate to degeneration of structures that are involved in representing the emotional salience of sensory information. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Transhistorical variations in personality and their association with experiences of parental rearing.

PubMed

Lundberg, M; Perris, C; Schlette, P; Adolfsson, R

1999-10-01

A population sample comprised of 765 subjects (367 males and 398 females), in the age range of 15-81 years, completed the EMBU, a reliable questionnaire aimed at assessing experiences of parental rearing, and the TCI, a self-report questionnaire aimed at assessing dimensions of temperament and character. The study had three main aims: 1) to verify, on a larger scale, previous findings suggesting the occurrence of significant associations between experiences of parental rearing and aspects of temperament and character, 2) to assess possible variations in temperament and character in cohorts of subjects who have grown up in different historical epochs, and 3) to investigate to what extent transgenerational differences in parental rearing are detectable in different associations with various dimensions of personality. Several, albeit small, significant and meaningful associations between experiences of parental rearing and both temperament and character dimensions have been found, adding support to the robustness of previously reported results obtained in an independent smaller series. Also, several significant differences among subjects in different age groups have been found, both concerning temperament variables and character dimensions. Finally, the results show that associations between experiences of parental rearing and dimensions of temperament and character are most pronounced in subjects belonging to the youngest cohort and almost nil in the cohort comprising the oldest subjects.

Effect of refractive error on temperament and character properties.

PubMed

Kalkan Akcay, Emine; Canan, Fatih; Simavli, Huseyin; Dal, Derya; Yalniz, Hacer; Ugurlu, Nagihan; Gecici, Omer; Cagil, Nurullah

2015-01-01

To determine the effect of refractive error on temperament and character properties using Cloninger's psychobiological model of personality. Using the Temperament and Character Inventory (TCI), the temperament and character profiles of 41 participants with refractive errors (17 with myopia, 12 with hyperopia, and 12 with myopic astigmatism) were compared to those of 30 healthy control participants. Here, temperament comprised the traits of novelty seeking, harm-avoidance, and reward dependence, while character comprised traits of self-directedness, cooperativeness, and self-transcendence. Participants with refractive error showed significantly lower scores on purposefulness, cooperativeness, empathy, helpfulness, and compassion (P<0.05, P<0.01, P<0.05, P<0.05, and P<0.01, respectively). Refractive error might have a negative influence on some character traits, and different types of refractive error might have different temperament and character properties. These personality traits may be implicated in the onset and/or perpetuation of refractive errors and may be a productive focus for psychotherapy.

DiscML: an R package for estimating evolutionary rates of discrete characters using maximum likelihood.

PubMed

Kim, Tane; Hao, Weilong

2014-09-27

The study of discrete characters is crucial for the understanding of evolutionary processes. Even though great advances have been made in the analysis of nucleotide sequences, computer programs for non-DNA discrete characters are often dedicated to specific analyses and lack flexibility. Discrete characters often have different transition rate matrices, variable rates among sites and sometimes contain unobservable states. To obtain the ability to accurately estimate a variety of discrete characters, programs with sophisticated methodologies and flexible settings are desired. DiscML performs maximum likelihood estimation for evolutionary rates of discrete characters on a provided phylogeny with the options that correct for unobservable data, rate variations, and unknown prior root probabilities from the empirical data. It gives users options to customize the instantaneous transition rate matrices, or to choose pre-determined matrices from models such as birth-and-death (BD), birth-death-and-innovation (BDI), equal rates (ER), symmetric (SYM), general time-reversible (GTR) and all rates different (ARD). Moreover, we show application examples of DiscML on gene family data and on intron presence/absence data. DiscML was developed as a unified R program for estimating evolutionary rates of discrete characters with no restriction on the number of character states, and with flexibility to use different transition models. DiscML is ideal for the analyses of binary (1s/0s) patterns, multi-gene families, and multistate discrete morphological characteristics.

Legal requirements and guidelines for the control of harmful laser generated particles, vapours and gases

NASA Astrophysics Data System (ADS)

Horsey, John

2015-07-01

This paper is a review of the Health and Safety laws and guidelines relating to laser generated emissions into the workplace and outside environment with emphasis on the differences between legal requirements and guideline advice. The types and nature of contaminants released by various laser processes (i.e. cutting, coding, engraving, marking etc) are discussed, together with the best methods for controlling them to within legal exposure limits. A brief description of the main extract air filtration techniques, including the principles of particulate removal and the action of activated carbon for gas/vapour/odour filtration, is given.

Presentation Factors in the Learning of Chinese Characters: The Order and Position of Hanyu Pinyin and English Translations

ERIC Educational Resources Information Center

Chung, Kevin K. H.

2007-01-01

The influence of different instructional presentations upon meaning and pronunciation acquisition in character learning was examined. High school students learned to identify a series of characters in terms of their associated pinyin and English translation prompts. Acquisition was shown to proceed more rapidly when the Chinese character was…

Pollination of Schisandra henryi (Schisandraceae) by Female, Pollen-eating Megommata Species (Cecidomyiidae, Diptera) in South-central China

PubMed Central

Yuan, Liang-Chen; Luo, Yi-Bo; Thien, Leonard B.; Fan, Jian-Hua; Xu, Huan-Li; Chen, Zhi-Duan

2007-01-01

Background and Aims The mutualistic interaction between insects and flowers is considered to be a major factor in the early evolution of flowering plants. The Schisandraceae were, until now, the only family in the ANITA group lacking information on pollination biology in natural ecosystems. Thus, the objective of this research was to document the pollination biology and breeding system of Schisandra henryi. Methods Field observations were conducted in three populations of S. henryi and the floral phenology, floral characters and insect activities were recorded. Floral fragrances were sampled in the field and analysed using TCT-GC-MS. Floral thermogenesis was measured with a TR-71U Thermo Recorder. Pollen loads and location of pollen grains on insect bodies (including the gut) were checked with a scanning electron microscope and under a light microscope. Key Results Schisandra henryi is strictly dioecious. Male flowers are similar to female flowers in colour, shape, and size, but more abundant than female flowers. The distance between tepals and the androecium or gynoecium is narrow. Neither male nor female flowers are fragrant or thermogenic. Schisandra henryi is pollinated only by adult female Megommata sp. (Cecidomyiidae, Diptera) that eat the pollen grains as extra nutrition for ovary maturation and ovipositing. Both male and female flowers attract the pollinators using similar visual cues and thus the female flowers use deceit as they offer no food. Conclusions Schisandra henryi exhibits a specialized pollination system, which differs from the generalized pollination system documented in other ANITA members. Pollen is the sole food resource for Megommata sp. and the female flowers of S. henryi attract pollinators by deceit. This is the first report of predacious gall midges utilizing pollen grains as a food source. The lack of floral thermogenesis and floral odours further enforces the visual cues by reducing attractants for other potential pollinators. PMID:17237212

Protective Behaviour of Citizens to Transport Accidents Involving Hazardous Materials: A Discrete Choice Experiment Applied to Populated Areas nearby Waterways

PubMed Central

de Bekker-Grob, Esther W.; Bergstra, Arnold D.; Bliemer, Michiel C. J.; Trijssenaar-Buhre, Inge J. M.; Burdorf, Alex

2015-01-01

Background To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens’ protective behaviour. However, quantitative studies investigating citizens’ protective behaviour in case of hazardous material transport accidents are scarce. Methods A discrete choice experiment was conducted among subjects (19–64 years) living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seeking shelter, or escaping. A panel error component model was used to quantify how different transport accident characteristics influenced subjects’ protective behaviour. Results The response was 44% (881/1,994). The predicted probability that a subject would stay ranged from 1% in case of a severe looking accident till 62% in case of a mild looking accident. All three transport accident characteristics proved to influence protective behaviour. Particularly a perception of strong ammonia or mercaptan odours and visible smoke/vapour close to citizens had the strongest positive influence on escaping. In general, ‘escaping’ was more preferred than ‘seeking shelter’, although stated preference heterogeneity among subjects for these protective behaviour options was substantial. Males were less willing to seek shelter than females, whereas elderly people were more willing to escape than younger people. Conclusion Various characteristics of transport accident involving hazardous materials influence subjects’ protective behaviour. The preference heterogeneity shows that information needs to be targeted differently depending on gender and age to prepare citizens properly. PMID:26571374

Research in Practice: Character Education.

ERIC Educational Resources Information Center

Lasley, Thomas J.; And Others

1996-01-01

Three articles explore character education from different perspectives: "Teaching Students to See Beyond Themselves" (Lasley, Biddle); "An Effective Character Education Model for a Diverse Student Population" (Cline, Necochea); and "Teaching as Modeling: The Impact of Teacher Behaviors upon Student Character…

Emotion and the humors: scoring and classifying major characters from Shakespeare's comedies on the basis of their language.

PubMed

Whissell, Cynthia

2010-06-01

The theory of humors, which was the prevalent theory of affect in Shakespeare's day, was used to explain both states (moods, emotions) and traits (personalities). This article reports humoral scores appropriate to the major characters of Shakespeare's comedies. The Dictionary of Affect in Language was used to score all words (N = 180,243) spoken by 105 major characters in 13 comedies in terms of their emotional undertones. These were translated into humoral scores. Translation was possible because emotional undertones, humor, and personality (e.g., Eysenck's model) are defined by various axes in the same two-dimensional space. Humoral scores differed for different types of characters, e.g., Shakespeare's lovers used more Sanguine language and his clowns more Melancholy language than other characters. A study of Kate and Petruchio from The Taming of the Shrew demonstrated state-like changes in humor for characters as the play unfolded.

Isolation, characterization and identification of pericarp-degrading bacteria for the production of off-odour-free white pepper from fresh berries of Piper nigrum L.

PubMed

Vinod, V; Kumar, A; Zachariah, T J

2014-04-01

To isolate, fermentatively evaluate and identify black pepper (Piper nigrum L.)-associated bacteria for the microbial decortication of fresh ripened berries and dried black pepper for preparation of off-odour-free white pepper. Among 45 bacterial isolates obtained from black pepper, seven of them were found to decorticate black pepper (>60%) and fresh pepper berries (98-100%) into white pepper within 5 days of immersion in bacterial suspension. The 16S rRNA genes (1500-bp amplicon) of these bacteria were sequenced, and species identity was established by closest match in GenBank. Superior-quality white pepper was obtained with Bacillus subtilis (IISR WP 33, 34, 38), Bacillus licheniformis (IISR WP 43), Acinetobacter baumanii (IISR WP 35), Klebsiella pneumoniae (IISR WP 19) and Microbacterium barkeri (IISR WP25). The bacterial isolates were found to secrete multiple hydrolytic enzymes such as cellulase, pectinase, amylase, protease and xylanase. Bacterial cultures were deposited with International Depository Authority at Microbial Type Culture Collection, India, as patent deposits as prescribed in Budapest Treaty for microbial deposits. The white pepper, thus obtained from bacterial decortication process, was free from off-odour compound, especially skatole. Other biochemical constituents such as oleoresin, piperine and essential oils were found in the acceptable range. The bacterial decortication did not affect inherent constituents of pepper such as essential oil constituents, oleoresin and piperine content. One of the most significant findings of the work is identification of specific bacterial species for decortication of fresh berries or black pepper berries into value-added white pepper. This work paved way for developing a technological process for microbial decortication of fresh/black pepper for the production of superior-quality white pepper. © 2014 The Society for Applied Microbiology.

Learning Temporal Patterns of Risk in a Predator-Diverse Environment

PubMed Central

Bosiger, Yoland J.; Lonnstedt, Oona M.; McCormick, Mark I.; Ferrari, Maud C. O.

2012-01-01

Predation plays a major role in shaping prey behaviour. Temporal patterns of predation risk have been shown to drive daily activity and foraging patterns in prey. Yet the ability to respond to temporal patterns of predation risk in environments inhabited by highly diverse predator communities, such as rainforests and coral reefs, has received surprisingly little attention. In this study, we investigated whether juvenile marine fish, Pomacentrus moluccensis (lemon damselfish), have the ability to learn to adjust the intensity of their antipredator response to match the daily temporal patterns of predation risk they experience. Groups of lemon damselfish were exposed to one of two predictable temporal risk patterns for six days. “Morning risk” treatment prey were exposed to the odour of Cephalopholis cyanostigma (rockcod) paired with conspecific chemical alarm cues (simulating a rockcod present and feeding) during the morning, and rockcod odour only in the evening (simulating a rockcod present but not feeding). “Evening risk” treatment prey had the two stimuli presented to them in the opposite order. When tested individually for their response to rockcod odour alone, lemon damselfish from the morning risk treatment responded with a greater antipredator response intensity in the morning than in the evening. In contrast, those lemon damselfish previously exposed to the evening risk treatment subsequently responded with a greater antipredator response when tested in the evening. The results of this experiment demonstrate that P. moluccensis have the ability to learn temporal patterns of predation risk and can adjust their foraging patterns to match the threat posed by predators at a given time of day. Our results provide the first experimental demonstration of a mechanism by which prey in a complex, multi-predator environment can learn and respond to daily patterns of predation risk. PMID:22493699

Anosmia in dementia is associated with Lewy bodies rather than Alzheimer's pathology

PubMed Central

McShane, R; Nagy, Z; Esiri, M; King, E; Joachim, C; Sullivan, N; Smith, A

2001-01-01

OBJECTIVES—To assess olfactory function of patients with dementia. Odour detection ability is impaired in clinical Parkinson's disease. Evidence of impaired detection in patients with clinically diagnosed Alzheimer's disease is inconsistent. No studies of olfaction have been neuropathologically validated.
METHODS—The olfactory function of 92 patients with dementia and 94 controls was assessed using a simple bedside test as part of the Oxford Project To Investigate Memory and Ageing (OPTIMA). Neuropathological assessment was made of cortical Lewy bodies and substantia nigra (SN) cell counts and of Alzheimer's disease in all 92 patients, 22 of whom had SN Lewy bodies and 43 of whom had only Alzheimer's disease.
RESULTS—Patients with Lewy bodies were more likely to be anosmic than those with Alzheimer's disease or controls. Patients with Alzheimer's disease were not more likely to be anosmic than controls. Nor was anosmia associated with degree of neurofibrillary tangles, as assessed by Braak stage. Among subjects with Lewy bodies, overall cortical Lewy body scores and Lewy body density in the cingulate were higher in those who were anosmic. Consensus clinical criteria for dementia with Lewy bodies had a sensitivity of 64% and specificity of 89%. In the absence of definite Alzheimer's disease, the criteria had sensitivity of 100%. In patients with definite Alzheimer's disease, anosmia was slightly more sensitive (55%) than the consensus criteria (33%). However, the addition of anosmia to the consensus criteria did not improve their overall performance.
CONCLUSION—Dementia with Lewy bodies is associated with impaired odour detection. Misdiagnosis may have accounted for some previous reports of impaired odour detection in Alzheimer's disease. Simple but more sensitive tests of anosmia are required if they are to be clinically useful in identifying patients with dementia with Lewy bodies.

 PMID:11385006