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It is only recently that studies have explored the use of olfaction in birds. Birds are now known to use odour cues for navigation, and locating food. Odours produced by the birds themselves can also function in nest recognition and even mate choice. The odours of most birds stem from the preen wax produced by the uropygial or preen gland. The wax is comprised of a complex mixture of esters and volatiles, and is known to vary in some species with age, sex, season, or environmental conditions. Its function has been associated with feather maintenance, but it may also play a role in sexual selection and chemical communication. In this thesis, I used the preen gland and its preen wax to perform comparative studies on the evolution of odours between island birds and their continental relatives. I used the birds of the Oceania region as a model system, where most passerines originated from continental Australia but have colonised numerous surrounding islands such as New Zealand and New Caledonia. As islands generally lack mammalian predators, and have less parasites and less interspecific competition than continents, these differences in environmental conditions likely shaped functional differences in the preen gland and its products. I measured the size of the preen gland and collected preen wax from a variety of forest passerines in Australia, New Zealand and New Caledonia. I found that island birds have larger preen glands and therefore likely produce more preen wax than their continental relatives. I also found that the preen wax composition differed among species, with a shift to birds on islands producing disproportionately lighter and more volatile compounds. I suggest that selection favoured the gain of more volatile molecules in island birds as they were released from the constraint to camouflage their odours that is imposed by mammalian predators on continental areas. It is possible that this also allowed greater communication through olfactory channels in island birds, and such communication is enhanced through the use of more volatile compounds. To support this hypothesis I showed that the South Island robin (Petroica australis) was able to detect and react to the odour of a conspecific (odours produced by preen wax) in the absence of any visual cues. From a conservation perspective, increased volatility of the preen waxes of island birds might place them at increased risk from introduced mammalian predators that use olfaction to locate their prey. However, in both laboratory tests using Norway rats (Rattus norvegicus), a common exotic predator, and in field trials using rodent tracking tunnels, I found only limited evidence to suggest the odour of island birds places them at greater risk, and more experiments are needed to test this hypothesis. Finally, my findings of more conspicuous odours in island birds suggest new avenues of research for their conservation, including whether island species that seem especially prone to predation have preen waxes (and thus odours) that are also especially attractive to exotic mammalian predators. Conservation programmes to protect endangered island birds may even benefit from considering whether olfactory cues can be minimised as a method of reducing predation risk.

During storage of grain, there may have significant damage to its quality due to unfavorable physical and biological interactions and thus requires continuous monitoring. Therefore, an easy, cost-effective and environmentally friendly method is necessary for efficient monitoring of stored-grain. Arrays of sensors are being used for classifying liquors, perfumes, quality of food products mimicking mammalian olfactory systems. Monitoring of stored grain is a new application of sensor arrays. The main objective was to fabricate a carbon black polymer sensor array which can easily monitor incipient grain spoilage by detecting spoiling stored grain volatiles (benzene derivatives and aliphatic hydrocarbon derivatives) with minimum interference from relative humidity. Various aspects of a good sensor were analyzed using statistical analysis (RSD, LDA, PCA, t-test). The developed sensor array can identify red flour beetle-infected and uninfected wheat and fungal volatiles at ambient conditions as well as some stored grain conditions (MC 16%, RH 52%).

A previous study showed that addition of β-cyclodextrin to goat milk made a difference to its flavour, but in an undescribed way. Cyclodextrins (CDs, comprising α- β- and γ-CD) may be able to bind the free branched chain fatty acids in goat milk responsible for the largely undesirable ‘goaty’ flavour. The primary aim was to test the effect of CDs on this flavour in goat milk and its products with a view to marketing goat milk products with reduced flavour intensity. A secondary aim was to test the effect of β-CD on skatole flavour, a characteristic flavour of milk from pasturefed ruminants. Study design and methods: The present study evaluates addition of mainly β-CD to goat milk, cow milk and their products to reduce undesirable flavours. The methods applied were mainly ranking and hedonic assessment in sensory experiments. The tests done were with CDs added to buffers and milks, some of which were flavour-enhanced with 4-methyloctanoic acid as a representative goaty fatty acid, or with skatole. Goat milk yoghurts were also tested. Free fatty acid concentrations, which may be affected by CD binding, were measured after separating cream and skim milk. The methods applied were standard dairy procedures: titration of free fatty acids in milk fat and the copper-salt method for measuring fatty acids in skim milk. A fungal lipase was added to milks to accelerate fat hydrolysis (lipolysis). This was done to increase the concentration of free fatty acids for several experimental purposes. Some minor experiments studies were also done, for example the comparative effect of lipases on goat milk and cow milk, and the lipolytic activity at different temperatures over different times. Results: The results of skatole experiments were inconclusive. The odour of 4-methyloctanoic acid was reduced in acidic buffers by addition of α- and β-CD, particularly the former. Alpha and β-CD were both effective in goaty flavour reduction in goat milk. γ-CD was not effective. In all this work differences were statistically significant to varying levels. Goaty flavour was reduced by addition of β-CD to goat milk yoghurt, but only when added before fermentation (P < 0.001), not after (P = 0.09). The liking scores for goat milk yoghurts for both plain and flavoured yoghurts increased with β-CD treatment (both P < 0.001 for 59 panellists). The chemistry experiments revealed a reduction of free fatty acid concentration in the fat phase when β-CD treatment was added to full cream cow milk. However, analysis of skim milk did not show a corresponding increase in concentration. Further experiments are required to reveal the fate of the ‘missing’ fatty acids. Conclusion: Overall it was shown that under certain conditions, CDs were effective in reducing goaty flavour in milk and yoghurts. Whereas CDs are approved for addition to foods in many countries – including the bellwether U.S.A. – formal approval by Food Standards Australia New Zealand has not yet been finalized. When it is, the way should be clear to market a range of more consumer-acceptable goat milk products in New Zealand as a primary market. In short, this research has significant commercial relevance.

Doctor of Philosophy (PhD) / Abstract Olfactory tasks are used very often with laboratory animals in studies of the neurobiology of learning and memory. Rats and mice are extremely sensitive in their detection and discrimination of odours, learn olfactory tasks rapidly, and can display higher order cognitive functions in olfactory tasks. This cognitive capacity may rival the ability of primates to learn analogous tasks with visual cues and most likely reflects strong anatomical connections between the olfactory bulbs and higher brain regions such as the piriform cortex, orbitofrontal cortex and hippocampus. The current thesis explored olfactory discrimination learning and performance in rats and had two principal aims. The first part of the thesis was oriented around odour masking phenomena in rats: the ability of one odour in a mixture to suppress detection of a second odour in that mixture. A specialized behavioural paradigm was developed to allow the study of odour masking in the rat. The second part of the thesis was pharmacological and determined whether the acquisition, reversal and performance of olfactory discriminations, and analogous auditory discriminations, are affected by two commonly used classes of drugs (benzodiazepines and cannabinoids). Together, these studies attempt to gain a better understanding of the nature of olfactory discrimination learning in rats, by using both psychophysical and pharmacological approaches, and to develop behavioural paradigms which may be used in future psychophysical and pharmacological studies. Following an introduction and review of olfactory and auditory studies in rat (Chapter 1), odour masking phenomena were studied in Chapter 2. The aliphatic aldehydes butanal (C4) and heptanal (C7) were used in the study. Aldehydes were of interest as this class of odorants abound in nature and may be important for rodents’ species-specific communication. Thirsty rats were initially trained to discriminate C4 and C7 in the olfactometer, using a go/no-go olfactory discrimination task. This involved rats learning to nose poke in an odour port and to lick a tube for a water reward on presentation of the rewarded component S+, while withholding licking at the tube when the other, unrewarded, aldehyde (S-) was presented. Odour mixtures (C4C7 or C7C4) were then introduced into the task as an additional non-rewarded condition (mixture S-). The concentration of the non-rewarded aldehyde in the mixture was then systematically decreased, while the concentration of the rewarded aldehyde was kept constant. When the non-rewarded aldehyde reached a critical low level in the mixture, rats started to make responses to the non-rewarded mixture (false alarms) showing that the S+ odour was suppressing the S- odour in the mixture, so the mixture was being responded to in the same manner as the S+ odour presented alone. Results also showed asymmetric suppression in the mixture condition, such that butanal suppressed detection of heptanal at a much lower concentration than vice versa. A second experiment demonstrated that when both butanal and heptanal were present in a binary mixture at the same concentration (10-6 volume %), rats responded to the mixture as if only butanal was present. Our findings are in agreement with human studies showing component interactions in binary mixtures of aldehydes. The molecular feature of carbon chain length appears to be a critical factor in determining the outcome of interactions between aldehydes at peripheral olfactory receptors, with smaller chain aldehydes better able to compete for receptor occupancy. Subsequent chapters explored the effects of two classes of commonly used drugs - benzodiazepines and cannabinoids - on olfactory and auditory discrimination in rats. Animal models such as the radial arm maze, Morris water maze and object recognition test are routinely used to test adverse and facilitatory effects of drugs on cognition in rodents. However, comparatively few pharmacological studies employ olfactory or auditory go/no-go paradigms. Thus, an important part of the present thesis was to assess the viability of using such paradigms in detecting pharmacological effects, and to identify whether such effects may be modality specific (i.e. whether a drug has a greater effect on olfactory or auditory tasks). In Chapter 3, the effects of benzodiazepines on olfactory discrimination tasks were explored. Rats were injected with the benzodiazepine drugs midazolam or diazepam and tested on discrimination tasks involving either the auditory and olfactory modality. Results showed that midazolam (0.5–2 mg/kg sc) did not affect the performance of a well-learned two-odour olfactory discrimination task, and moderately facilitated the performance of a go/no-go auditory discrimination task. On the contrary, midazolam (1 mg/kg) impaired the acquisition of a novel go/no-go olfactory discrimination task, as well as the reversal of a previously well-learned olfactory discrimination. However, midazolam did not affect the acquisition or reversal of an equivalent auditory discrimination task. The olfactory bulb and the piriform cortex are intimately involved in associative learning and behavioural aspects of olfactory performance, and have high concentrations of benzodiazepine receptors. These may therefore be possible neural substrates for the disruptive effects of benzodiazepines on olfactory learning. Findings from Chapter 4 indicated that the prototypical cannabinoid agonist delta-9-tetrahydrocanabinol (Δ9 THC) (0.3, 1 and 3 mg/kg) impairs auditory discrimination performance, but had no effect on equivalent olfactory discriminations. This is in marked contrast to the effects of benzodiazepines. Residual effects were observed, such that auditory discrimination performance was still impaired on the day following Δ9 THC administration. Delta-9-tetrahydrocanabinol effects were prevented by co-administration of the cannabinoid antagonist rimonabant (3 mg/kg). In addition, the anandamide hydrolysis inhibitor URB597 (0.1 and 0.3 mg/kg), which boosts levels of endogenous cannabinoids in the synapse, also impaired auditory discrimination performance, and this effect was also reversed by rimonabant. This study also assessed the effects of Δ9 THC (0.3, 1 and 3 mg/kg) and URB597 (0.1 and 0.3 mg/kg) on acquisition and reversal of novel olfactory discriminations. Results showed that Δ9 THC impairs olfactory reversal learning without affecting acquisition of the original discrimination. It is argued that this reversal deficit may be part of a wider capacity for cannabinoids to impair cognitive flexibility. The final Chapter (General Discussion) discusses the relevance and implications of the combined findings. The results add significantly to our current understanding of perceptual, learning and memory processes involving the olfactory modality in rats. With respect to olfactory perception, this thesis introduced a new behavioural paradigm, which can be used to assess component suppression in mixtures, and may be of use in future psychophysical studies involving rodents or other species. With respect to learning and memory, the thesis provides novel information on the disruptive effects of benzodiazepines and cannabinoids on olfactory and auditory tasks. It is concluded that go/no-go olfactory and auditory discrimination tasks in rats can provide a useful platform for assessing the disruptive and modality-specific effects of drugs on learning, performance and cognitive flexibility. Future studies might expand the range of drugs tested on these paradigms and might consider chronic as well as acute drug effects.

Odours caused by intensive piggery operations have become a major environmental issue in the piggery industry in Australia. Effluent ponds are the major source of odours in typical piggeries. It is assumed that the odour emissions from ponds are mainly driven by pond loading rate. However, there are few data to corroborate this concept. Allied to this is the need for a convenient and low cost method of odour measurement, which can be used as an alternative method for current olfactometry. The present odour measurement methods using olfactometry is time-consuming, expensive and often impractical because of its fundamental problem of using subjective human panels. In addition, one of the major problems in odour measurement lies in the air sampling method. Wind tunnels have been accepted as a preferred method for the sampling of odour from area sources. However, current wind tunnels do not consider meteorological factors, which directly affect the odour emission rates. A machine-based odour quantification method and a novel wind tunnel were developed and evaluated in this Ph D study. These methods were then used in a demonstration trial to investigate the effects of pond loading rate on odour emissions. The AromaScan A32S electronic nose, and an artificial neural network were used to develop the machine based odour quantification method. The sensor data analysed by the AromaScan were used to train an ANN, to correlate the responses to the actual odour concentration provided by a human olfactometry panel. Preprocessing techniques and different network architectures were evaluated through network simulation to find an optimal artificial neural network model. The simulation results showed that the two-layer back-propagation neural network can be trained to predict piggery odour concentrations correctly with a low mean squared error. The trained ANN was able to predict the odour concentration of nine unknown air samples with a value for the coefficient of correlation, r2 of 0.59. A novel wind tunnel was developed for odour sampling. The USQ wind tunnel was designed to have a capability to control wind speed and airflow rate. The tunnel was evaluated in terms of the aerodynamics of the airflow inside the tunnel, nd the gas recovery efficiency rate, in order to further improve the performance of the wind tunnel. The USQ wind tunnel showed that sample recovery efficiencies ranging from 61.7 to 106.8%, while the average result from the entire trial was 81.1%. The optimal sample recovery efficiency of the tunnel was observed to be 88.9% from statistical analysis. Consequently, it can be suggested that the tunnel will give estimates of the odour emission rate with significant level of precision. However, the tunnel needs to be calibrated to compensate for the error caused by different airflow rates and odour emission rates. In addition, the installation of a perforated baffle upstream of the sampling section was suggested to improve its performance. To investigate the relationship between the pond loading rate and odour emission rate, replicable experimental studies were conducted using a novel experimental facility and the machine based odour quantification method. The experimental facility consisted of reactor vessels to simulate the operation of effluent ponds and the USQ wind tunnel for odour sampling. A strong relationship between organic loading rate (OLR) and physical and chemical parameters was observed except pH and NH3-N. The pH was not affected by OLR due to the buffering capacity of piggery effluent. EC and COD were suggested as indicators to estimate the operating condition of the piggery effluent ponds because the regression results show that these two parameters can be predicted accurately by OLR. The time averaged odour emission rates from the reactor vessels showed a strong relationship with OLR. Consequently, it can be concluded that heavily loaded effluent ponds would produce more odours. The effect of hydraulic retention time (HRT) was examined. The HRT was increased from 30 days to 60 days, resulting in a significant decrease in odour emission rates from the reactor vessels. This decrease ranged from 59.1% to 54.9%, with an average of 57.1%. Therefore, it can be concluded that the increasing HRT will decrease the odour emission rate. This trial confirmed the value of the project methodology in obtaining unambiguous data on odour emission processes. However, more data are required for a wider range of OLR, HRT and other pertained variables before a usable model can be formulated.

Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-26Bitstream added on 2014-06-13T20:34:29Z : No. of bitstreams: 1 villamilmontero_da_me_botfca.pdf: 420966 bytes, checksum: 543e6e7fd9117a39d9d9c563ac346c9d (MD5) / As flores das espécies do gênero Passiflora têm recebido especial atenção por sua extraordinária beleza e complexidade da corola além de suas intensas fragrâncias. A presença de tecidos secretores de compostos voláteis (CVS) nas flores de Passiflora é muito variável, têm grande importância ecológica e prospecção econômica. Atualmente, só se tem registro dos CVs das fragrâncias florais de algumas poucas espécies, obtidos por meio de diferentes metodologias, com resultados variáveis. Durante os anos 2011 e 2012 foi desenvolvida uma pesquisa em parceria UNESP/FCA - Botucatu e Instituto Agronômico de Campinas (IAC) para estudar parâmetros da biologia floral e obter a primeira coleção brasileira dos perfis químicos das fragrâncias florais de cinco espécies de Passiflora L. (Passiflora edulis Sims., P. alata Curtis., P. cincinnata Mast., P. coccinea Aubl. e P. quadrangularis L.). As cinco espécies foram cultivadas em ambiente protegido. Os compostos voláteis das fragrâncias das flores de cada espécie foram capturados com a técnica de Headspace dinâmico (HSD) e as fragrâncias avaliadas através de teste olfativo. A análise da composição química das fragrâncias foi conduzida em cromatógrafo a gás acoplado a espectrômetro de massas e a identificação dos constituintes químicos foi efetuada através dos índices de retenção (IR) seguido da análise comparativa dos espectros de massas com diferentes bancos de dados especializados. Os resultados demonstraram que as espécies estudadas apresentam diferenças significativas na biologia floral, relacionados com o período de floração, desenvolvimento dos botões florais, numero e tamanho das flores produzidas. As composições químicas das fragrâncias florais das espécies estudadas têm grande diversidade interespecífica, assim como interessante potencial na... / The flowers of the species from the genus Passiflora have received special attention for its extraordinary beauty, complexity of the corona and for their intense fragrances. The presence of volatile compounds (VCs) secreting tissues in the flowers of Passiflora is highly variable and have major ecological and economic survey. Currently, there are records of the VCOs of floral fragrances from a few species, obtained by different methods with varying results. During the years 2011 and 2012 a research was carried out as a master´s dissertation in partnership between the UNESP-Botucatu/IAC, to study the floral behaviors and developed the first Brazilian collection of the chemical profiles from the floral fragrances of five species of Passiflora L. ( Passiflora edulis Sim, P. alata Curtis., P. cincinnata Mast., P. coccinea Aubl. and P. quadrangularis L.). The five species were grown in a greenhouse following specific recommendations. The fragrances of the flowers from each species were evaluated by sensory test and the VCOS were collected with the technique of Dynamic Headspace (DHS). The analyses of the chemical composition of fragrances were conducted using a gas chromatograph coupled to mass spectrometer. The identification of the chemical constituents was carried through the calculation of retention indices (RI) followed by comparative analysis of mass spectra with different specialized databases. The results of the flowering period, development of floral buds, size and number of flower produced showed significative differences between the studied species. Also, the chemical compositions of the floral fragrances from the studied species had large interspecific diversity, as well as interesting potential in the fragrance industry, particularly the floral fragrance of P. alata. The olfactive analysis revealed that this species is highly promissory due... (Complete abstract click electronic access below)

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21611号 / 理博第4518号 / 新制||理||1648(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 正高 信男, 准教授 後藤 幸織, 教授 髙井 正成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

In this study photocatalytic oxidation was investigated as a potential treatment method of VOC emissions from industrial plants. This was done by designing an experimental setup and a photocatalytic reactor for screening of photocatalysts (TiO2). The performance of commercial TiO2 and synthesized TiO2 (pure and Ni-doped) for degrading acetaldehyde when exposed to UV-C light was evaluated at fix reaction conditions. Also, procedure of coating TiO2 on aluminum and stainless steel as well as their stability performance was investigated in the study. For comparison of photocatalysts aluminum was chosen as support material since it showed highest stability at reaction conditions.  The results show that photocatalysts with a high anatase content and high specific surface area present enhanced photocatalytic performance. Commercial TiO2 show significantly higher photocatalytic performance than synthesized TiO2. This may be influenced by higher coating stability presented for commercial TiO2. For synthesized TiO2 non-doped samples present significantly higher performance than Ni-doped TiO2. However, because of coating instabilities it is difficult to determine if this was observed difference in performance was only caused by photocatalytic performance. / I detta arbete undersöktes fotokatalytisk oxidation som potentiell gasreningsteknik för industriella utsläpp av flyktiga organiska kolväten. En experimentell uppsättning konstruerades tillsammans med en fotokatalytisk reaktor designad för att jämföra olika fotokatalysatorers (TiO2) prestanda. Prestandan för både kommersiella fotokatalysatorer samt fotokatalysatorer syntetiserade i arbetet (TiO2 samt Ni-dopad TiO2) jämfördes för att bryta ned acetaldehyd under konstanta reaktionsförhållanden samt bestrålning av UV-C. Aluminum och rostfritt stål undersöktes som supportmaterial för TiO2. För undersökning av olika fotokatalytorers prestanda användes aluminum på grund av en högre stabilitet vid undersökta reaktionsförhållanden. Resultaten från jämförelsen av olika fotokatalysatorer visar att en hög andel anatas form av TiO2 samt en hög specifik ytarea ger en förbättrad fotokatalytisk prestanda. Kommersiell TiO2 visade signifikant högre fotokatalytisk effekt än syntetiserad TiO2. Detta kan bero på en högre stabilitet av TiO2-beläggning på aluminum för kommersiell TiO2 gentemot syntetiserad och inte nödvändigtvis bero av enbart fotokatalytisk aktivitet. För syntetiserad TiO2 visar dopning med Ni signifikant lägre aktivitet än för icke dopad TiO2. På grund av instabilitet i beläggningen av TiO2 på supportmaterialet kan en påverkan av detta inte uteslutas.

A variety of prey species are able to detect predators by odours emanating from their urine, feces, fur and anal glands. However, it is unknown whether the odour of a predator’s blood also contains information signalling “predator” to a prey. The aim of the present study was therefore to assess if blood odour from a cat elicits avoidance or anxiety responses in CD-1 mice (Mus musculus). A two-compartment test arena was used to assess place preference, motor activity and fecal excretions when the mice were simultaneously presented with cat blood and a blank control. Additionally, the mice were tested with horse blood and N-pentyl acetate, a fruity odour. The mice did not show avoidance of any of the three odours. Nevertheless, the mice were significantly less active when exposed to cat blood in comparison to horse blood, but did not increase defecation when exposed to cat blood. This suggests that the information mice get by the odour of cat blood did not contain the signal “predator”.