Não custa resumo na publicação. / Abstract not avaible

Não custa resumo na publicação. / Abstract not avaible

Cognitive research with human non-smokers has demonstrated that nicotine generally enhances performance on tasks of attention but, working memory does not appear to be affected. In contrast, nicotine has been shown to produce robust enhancements of working memory in non-human animals. To address this disparity, the present study investigated the effects of nicotine (2mg, 4mg nicotine gum, and placebo) on the performance of 30 non-smokers (15 male) completing a working memory task developed for rodents (the odor span task, OST). Nicotine has been reported to enhance OST performance in rodents and the present study sought to determine whether the effect is generalizable to human performance. In addition to completing the OST, participants completed a cognitive battery of clinical and experimental tasks assessing working memory and attention. This allowed for a direct comparison of OST performance to other commonly used measures of human cognition. Findings showed that nicotine was associated with dose dependent enhancements in sustained attention, as evidenced by increased hit accuracy on the rapid visual information processing (RVIP) task. However, nicotine failed to produce main effects on OST performance or on alternative measures of working memory (digit span, spatial span, letter-number sequencing, 2-back) or attention (digits forward, 0-back). Interestingly, enhancement of RVIP performance occurred concomitant to significant reductions in self-reported attention/concentration. Human OST performance was significantly related to N-back performance and, as in rodents, OST accuracy declined with increasing memory load. Given the similarity of human and rodent OST performance and the strong association observed between OST and visual 0-back accuracy, the OST may be particular useful for preclinical studies of conditions characterized by inattention.

The flora of Aotearoa/ New Zealand has evolved in association with birds and lizards as the dominant frugivores and seed dispersers. There is a wide range of ripe fruit colours within the native fleshy-fruited plants spanning the visible light spectrum from red to violet, with the notable exception of green. The evolution of fleshy-fruit and fruiting related trait, may be a result of the selection pressures exerted by different frugivore guilds. This study was conducted to ascertain if endemic diurnal lizards, Oligosoma species (Scincidae: Lacertilia), display features associated with visual based foraging, colour sensitivity and colour preferences, which are necessary conditions to infer a co-evolutionary mutualism between fleshy-fruited plant species and lizards as seed dispersers, which may have influenced the evolution of fruit colour. Many lizards have exceptional colour vision, with the ability to see a wide range of the visual light spectrum from short wave ultra violet to long wave red. They are able to discriminate all aspects of colour: hue, brightness and saturation. Fruit colour within Coprosma (Rubiaceae), is extremely variable, between and within species. The study of fruit colour preferences within this genus and particularly within species with polymorphic fruit colour provides a valuable comparison of frugivore preference to fruit with little inter and intraspecific variation, therefore minimising potentially confounding factors due to phylogeny. Fruit-colour choice experiments were conducted offering fruit from two colour categories based on postulated frugivore preferences; red and red orange fruit has been associated with avian frugivores whilst white and pale fruit has been associated with lizard frugivory in New Zealand. Experiments were conducted both ex-situ, in environmentally controlled laboratories and in-situ at Macraes Flat, Otago. Pilot trials indicated that the background colour on which fruit were presented was important in fruit choice and consequentially, all fruit were offered on a background which provided contrast to both fruit colour categories. The laboratory trials showed some weak evidence for a preference of white and pale blue fruit however, in-situ trials showed a strong preference for white over red fruit. Field studies were conducted to ascertain the composition of fleshy-fruit in the diets of lizards and the results were consistent with those expected for a generalist omnivore; many of the small fruits available to lizards were consumed however, the results indicated that plant abundance does not adequately explain fruit consumption at this field site. A preference index showed that white and pale fruited plants, Melicytus alpinus and Coprosma spp., were preferred over more abundant orange and red fruited plants. Fruit odour was investigated to determine if fruit choice was mediated primarily by visual cues as opposed to odour cues. Fruit choice trials with the fruit concealed from view indicated that fruit choice was based primarily on visual cues in Oligosoma skinks. It is concluded that lizards demonstrate the necessary conditions to infer that as frugivores, they may have influenced the evolution of fruit colour and that within the open habitats of Aotearoa/ New Zealand, the shrubs, particularly the divaricate shrubs may have provided sufficient environmental conditions to establish a mutualism between plants and lizards resulting in the evolution of small, white and other low chroma fruits.

How we smell is important to a lot of people, as indicated by the high spending on perfumes. Most perfumes are categorized as feminine or masculine, and this gender categorization is an important factor when people purchase perfumes. This thesis explores odor perception and perfume preference when the person sniffing the perfume does not know the commercial gender categorization. Three psychophysical experiments were conducted, in which the participants scaled the femininity and masculinity of the perfumes, indicated preferences, and gender categorized the perfumes. The perfumes were presented both in glass bottles and when applied on human skin. Results of three experiments indicate that female and male participants (20–30 years old) preferred the same perfumes, both for themselves and for their potential partners. The preferred perfumes tended to be “unisex,” that is, perceived as neither strongly feminine nor strongly masculine. The participants did not succeed well in identifying the commercial gender categorizations of the perfumes, and they did not succeed in guessing the gender of the human when the perfumes were applied on human skin. The commercial gender associations of the perfumes only corresponded to how they were perceived in the case of extremely feminine or extremely masculine perfumes. I conclude that the gender categorizations of most perfumes are not related to how they are actually perceived. / <p>At the time of the doctoral defence the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p>

Livestock odour has been an obstacle for the development of livestock industry. Air dispersion models have been applied to predict odour concentrations downwind from the livestock operations. However, most of the air dispersion models were designed for industry pollutants and can only predict hourly average concentrations of pollutants. Currently, a livestock odour dispersion model that can consider the difference between livestock odour and traditional air pollutants and can account for the short time fluctuations is not available. Therefore, the objective of this research was to develop a dispersion model that is designed specifically for livestock odour and is able to consider the short time odour concentration fluctuations. A livestock odour dispersion model (LODM) was developed based on Gaussian fluctuating plume theory to account for odour instantaneous fluctuations. The model has the capability to predict mean odour concentration, instantaneous odour concentration, peak odour concentration and the frequency of odour concentration that is equal to or above a certain level with the input of hourly routine meteorological data.<p> LODM predicts odour frequency by a weighted odour exceeding half width method. A simple and effective method is created to estimate the odour frequency from multiple sources. Both Pasquill-Gifford and Hogstr¨¯m dispersion coefficients are applied in this model. The atmospheric condition is characterized by some derived parameters including friction velocity, sensible heat flux, M-O length, and mixing height. An advanced method adapted from AERMOD model is applied to derive these parameters. An easy to use procedure is generated and utilized to deal with the typical meteorological data input as ISC met file. LODM accepts and only requires routine meteorological data. It has the ability to process individual or multiple sources which could be elevated point sources, ground level sources, livestock buildings, manure storages, and manure land applications. It can also deal with constant and varied emission rates. Moreover, the model considers the relationships between odour intensity and odour concentrations in the model. Finally, the model is very easy to use with a friendly interface.<p> Model evaluations and validations against field plume measurement data and ISCST3 and CALPUFF models indicate that LODM can achieve fairly good odour concentration and odour frequency predictions. The sensitivity analyses demonstrate a medium sensitivity of LODM to the controllable odour source parameters, such as stack height, diameter, exit velocity, exit temperature, and emission rate. This shows that the model has a great potential for application on resolving odour issues from livestock operations. From that perspective, the most effective way to reduce odour problems from livestock buildings is to lessen the odour emission rate (e.g. biofiltration of exhaust air, diet changes).

Hops (Humulus lupulus L.) are primarily used to provide specific characteristics to beer, such as bitterness, aroma, flavor, and microbial stability. The chemical composition of hops, relative to how they are used during the brewing process, dictates the expression of these characteristics. Of the raw ingredients that go into making beer, hops are perhaps the most costly. Considerable resources are required to grow quality hops, and therefore, brewers and hop growers alike have a common goal of obtaining the highest quality hops possible. However, quality can be a relative term. While it is commonly agreed upon that high brewing values, such as α-acids and essential oil content, and robust structural integrity are indicators of quality hops, there are many opinions of the ideal aroma. Changes in the chemical composition of hops during plant maturation are a dynamic process requiring a comprehensive, in-depth chemical and sensory analysis in order to maximize the characteristics of interest to brewers. The complex aroma chemistry associated with hops in beer has been a confounding variable for the practical brewer, and a deeper understanding of hop aroma development during cultivation is needed. The effect of harvest date, location, and cultivar on key chemical components of Willamette and Cascade hops was investigated for the 2010 and 2011 growing seasons. Hops were harvested at 3 time points (Early, Typical, and Late), within a 3-week interval from 2 different farms in the Willamette Valley, Oregon. A split-plot experimental design for each cultivar was used; each farm represented a main plot and harvest years were designated as subplots. American Society of Brewing Chemist standard methods of analysis were used to measure moisture content, hop acids and their homologs, Hop Storage Index, total essential oil content and volatile profile by GC-FID. Additionally, difference testing, descriptive analysis, and consumer acceptance testing was conducted using beers brewed with either Typical or Late harvested Cascade hops from the 2010 harvest year. The response of analytes was dependent on the cultivar being examined, its location within the Willamette Valley, as well as days until harvest. Hop acids did not change appreciably during plant maturation for the period examined, while hop oil content increased hyperbolically to a plateau as the hops aged on the bine. Increases in oil quantity were strongly correlated (r > 0.90) with increases in α-pinene, β-pinene, myrcene, limonene, methyl heptanoate, and linalool concentrations. For Cascade, α-pinene, β-pinene, myrcene, limonene, ρ-cymene, caryophyllene, E, β-farnesene, and humulene all increased from Early to Typical points but no increase was observed between the Typical and Late time point. Linalool and methyl heptanoate increased between each time point while citral and humulene epoxide differed between Early harvest and Late harvest, but not between Early and Typical or Late and Typical harvests. For Willamette hops, α-pinene, β-pinene, myrcene, limonene, ρ-cymene, and linalool all increased between each time point. Caryophyllene, E β-farnesene, humulene, farnesol and citral all increased from Early harvest to Typical harvest but no difference was observed between Typical and Late. Clear sensory differences were found between beers brewed with Typical harvest Cascade hops and Late harvest Cascade hops, in terms of difference testing, descriptive analysis and consumer preference tests. / Graduation date: 2013

Livestock odour has been an obstacle for the development of livestock industry. Air dispersion models have been applied to predict odour concentrations downwind from the livestock operations. However, most of the air dispersion models were designed for industry pollutants and can only predict hourly average concentrations of pollutants. Currently, a livestock odour dispersion model that can consider the difference between livestock odour and traditional air pollutants and can account for the short time fluctuations is not available. Therefore, the objective of this research was to develop a dispersion model that is designed specifically for livestock odour and is able to consider the short time odour concentration fluctuations. A livestock odour dispersion model (LODM) was developed based on Gaussian fluctuating plume theory to account for odour instantaneous fluctuations. The model has the capability to predict mean odour concentration, instantaneous odour concentration, peak odour concentration and the frequency of odour concentration that is equal to or above a certain level with the input of hourly routine meteorological data.<p> LODM predicts odour frequency by a weighted odour exceeding half width method. A simple and effective method is created to estimate the odour frequency from multiple sources. Both Pasquill-Gifford and Hogstr¨¯m dispersion coefficients are applied in this model. The atmospheric condition is characterized by some derived parameters including friction velocity, sensible heat flux, M-O length, and mixing height. An advanced method adapted from AERMOD model is applied to derive these parameters. An easy to use procedure is generated and utilized to deal with the typical meteorological data input as ISC met file. LODM accepts and only requires routine meteorological data. It has the ability to process individual or multiple sources which could be elevated point sources, ground level sources, livestock buildings, manure storages, and manure land applications. It can also deal with constant and varied emission rates. Moreover, the model considers the relationships between odour intensity and odour concentrations in the model. Finally, the model is very easy to use with a friendly interface.<p> Model evaluations and validations against field plume measurement data and ISCST3 and CALPUFF models indicate that LODM can achieve fairly good odour concentration and odour frequency predictions. The sensitivity analyses demonstrate a medium sensitivity of LODM to the controllable odour source parameters, such as stack height, diameter, exit velocity, exit temperature, and emission rate. This shows that the model has a great potential for application on resolving odour issues from livestock operations. From that perspective, the most effective way to reduce odour problems from livestock buildings is to lessen the odour emission rate (e.g. biofiltration of exhaust air, diet changes).

The purpose of the present study was to determine olfactory detection thresholds in human subjects for a set of six sulfur-containing odorants which are known to be components of mammalian predator odors. Using a threealternative ascending staircase procedure, the olfactory sensitivity of 12 healthy adult human subjects, 6 males and 6 females was assessed with 2-propylthietane, 2,2-dimethylthietane, 3-mercapto-3-methylbutan-1-ol, 3-mercapto-3- methylbutyl formate, 3-methyl-1-butanethiol, and methyl-2-phenylethyl sulfide. The results showed that A) all six predator odorants were detected at concentrations below 1 ppb (parts per billion), and one of them (3-mercapto-3-methylbutyl formate) even at a concentration below 1 ppt (parts per trillion), B) structurally similar odorants yielded significantly different threshold values, and C) no significant sex differences were found in olfactory sensitivity with any of the six odorants. The findings obtained from the present study show that human subjects were not generally less sensitive to the predator odorants tested here compared to spider monkeys despite having a markedly lower number of olfactory receptor types. Further, they suggest that humans may be more sensitive to predator odorants compared to a variety of non-predator odorants. One possible explanation for the high olfactory sensitivity observed here is the fact that sulfur compounds typically can be detected at low concentrations. An alternative explanation derives from an evolutionary perspective as our human ancestors were a potential prey of large carnivores and  thus a high olfactory sensitivity for predator odors should be adaptive for humans.

Fumes emitted from coffee bean roasters contain various chemicals such as aldehydes, pyridine, volatile fatty acids, and ketones. These chemicals have high odor intensities and are sensitive to human breathing organs and eyes. In Taiwan, most of these fumes are not well controlled before venting to the atmosphere. This research attempted to eliminate these odorous and offensive chemicals by chemical scrubbing methods. Sodium hypochlorite oxidation followed by hydrogen peroxide reduction (hypochlorite-peroxide) was investigated first. After that, ozone oxidation followed by hydrogen peroxide reduction (ozone-peroxide) was also tried. In both methods, hydrogen peroxide acted as a reducing agent for the elimination of either residual chlorine or ozone emitted from the oxidation reaction. Experimental results indicated that both methods were effective. An oxidative scrubbing liquid with an initial effective chlorine content of 200 mg/L and a pH of 12, and an reducing scrubbing liquid with an initial hydrogen peroxide concentration of 1% and a pH of 12 could remove an average of 85% of total hydrogen carbons (THC) in the fume gas from a coffee bean roaster. With a dose of 10 ppm ozone in the fume gas to the oxidative scrubbing liquid (water only) followed by an reducing scrubbing liquid with an initial hydrogen peroxide concentration of 0.3% and a pH of 12, an average removal of 80% of the THC could be removed. An odor intensity (expressed by the dilution to threshold ratio) of 9,772 in the original fume could be reduced to as low as 31 by both methods. As indicated by the data from GC/MS (gas chromatography-mass spectrometry) analysis for the hypochlorite-peroxide method, acrolein, vinyl acetate, 2-butanone, and acetone in the roaster fume could almost completely be eliminated. Traces of chlorinated hydrocarbons as potential secondary pollutants were detected in the treated gases from the hypochlorite-peroxide scrubbing system. While by the ozone-peroxide one, satisfactory results were also obtained with no chlorinated hydrocarbons emitted. An economical analysis shows that the ozone-peroxide approach is a practical one for actual control applications.