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This research aims at developing a better understanding of commuters preferences and mode switching behaviour towards local transit for work trips. The proposed methodological approach incorporates three main stages. The first introduces a conceptual framework for modal shift maximized transit route design model that extends the use of demand models beyond forecasting transit ridership to the operational extent of transit route design. The second deals with designing and implementing a socio-psychometric COmmuting Survey for MOde Shift (COSMOS). Finally, the third stage focuses on developing econometric choice models of mode switching behaviour towards public transit. Advanced mode shift models are developed using state-of-the-art methodology of combining Revealed Preference (RP) and Stated Preference (SP) information. The results enriched our understanding of mode switching behaviour and revealed some interesting findings. Some socio-psychological variables have shown to have strong influence on mode shift and improved the models in terms of fitness and statistical significance. In an indication of the superiority of the car among other travel options, strong car use habit formation was realized for car drivers, making it hard to persuade them to switch to public transit. Further, unlike conventional choice models, the developed mode shift models showed that travel cost and in-vehicle travel time are of lower importance compared to other transit Level of Service (LOS) attributes such as waiting time, service reliability, number of transfers, transit technology, and crowding level. The results also showed that passengers are more likely to shift to rail-based modes (e.g. LRT and subway) than rubber-tyred modes (e.g. BRT). On the other hand, the availability of park-and-ride facilities as well as both schedule and real-time information provision did not appear to be significant for mode switching to public transit for work trips. This research provides evidence that mode shift is a complex process which involves socio-psychological variables beside common socio-demographic and modal attributes. The developed mode switching models present a new methodologically sound tool for evaluating the impacts of alternative transit service designs on travel behaviour. Such tool is more desirable for transit service planning than the traditional ones and can aid in precisely estimating transit ridership.

This research aims at developing a better understanding of commuters preferences and mode switching behaviour towards local transit for work trips. The proposed methodological approach incorporates three main stages. The first introduces a conceptual framework for modal shift maximized transit route design model that extends the use of demand models beyond forecasting transit ridership to the operational extent of transit route design. The second deals with designing and implementing a socio-psychometric COmmuting Survey for MOde Shift (COSMOS). Finally, the third stage focuses on developing econometric choice models of mode switching behaviour towards public transit. Advanced mode shift models are developed using state-of-the-art methodology of combining Revealed Preference (RP) and Stated Preference (SP) information. The results enriched our understanding of mode switching behaviour and revealed some interesting findings. Some socio-psychological variables have shown to have strong influence on mode shift and improved the models in terms of fitness and statistical significance. In an indication of the superiority of the car among other travel options, strong car use habit formation was realized for car drivers, making it hard to persuade them to switch to public transit. Further, unlike conventional choice models, the developed mode shift models showed that travel cost and in-vehicle travel time are of lower importance compared to other transit Level of Service (LOS) attributes such as waiting time, service reliability, number of transfers, transit technology, and crowding level. The results also showed that passengers are more likely to shift to rail-based modes (e.g. LRT and subway) than rubber-tyred modes (e.g. BRT). On the other hand, the availability of park-and-ride facilities as well as both schedule and real-time information provision did not appear to be significant for mode switching to public transit for work trips. This research provides evidence that mode shift is a complex process which involves socio-psychological variables beside common socio-demographic and modal attributes. The developed mode switching models present a new methodologically sound tool for evaluating the impacts of alternative transit service designs on travel behaviour. Such tool is more desirable for transit service planning than the traditional ones and can aid in precisely estimating transit ridership.

Living environments are seldom, if ever, devoid of all background auditory stimuli. However, the relationship between particular structural components of acoustic backgrounds and cognitive task performance remains unclear. Two experiments were completed to examine the influence of sound on a visual selective attention task. Participants performed the Stroop task (Stroop, 1935) while silence or background acoustic patterns of various complexities were presented over headphones. No effect of background sound on performance was found. A post-hoc analysis indicated that in comparison with participants who do not regularly listen to music while studying, participants who regularly listen to music while studying performed better on the Stroop task when a structured auditory pattern that included variation in both frequency and time interval was presented in the background. These results indicate that distinct structural components of background auditory sequences may interact with individual characteristics to influence cognitive performance on a task involving selective attention.

The cotton fleahopper, Pseudatomoscelis seriatus (Reuter) is a widely distributed insect across the United States. Although, it feeds on several native wild hosts, its agricultural importance lies as an economic pest of cotton in several states in the southern United States. No studies have addressed intraspecific genetic and phenotypic variation of this insect pest at a large geographic scale. I examined genetic variation among cotton fleahopper populations associated with cotton in different geographic locations across the southern United States (Chapter II). Using dominant, neutral, nuclear molecular markers (AFLP, amplified fragment length polymorphism) and mitochondrial DNA sequences, I found that overall genetic differentiation among different geographic populations, collected from cotton in eleven cotton growing states, was low but significant. AFLP revealed the presence of three regional groups representing western (Arizona), central (Texas, Oklahoma, Arkansas, Louisiana, Mississippi and Alabama), and eastern (Florida, Georgia, South Carolina and North Carolina) populations. I examined if there were distinct lineages of cotton fleahoppers associated with three of its host plant species: cotton (Gossypium hirsutum), horsemint (Monarda punctata) and woolly croton (Croton capitatus) in five different locations of Texas by using AFLP markers (Chapter III). I found two distinct host-associated lineages at three locations and local panmixia in the other two locations. I tested if host preference of cotton fleahoppers were affected by geographic variation and prior experience. Conducting choice tests with a Y-tube olfactometer, I found that host preference in cotton fleahoppers for horsemint (one of its native host plants) is conserved and unaffected by individual?s prior experience with cotton (Chapter IV). Finally, I explored the role of host-plant species in morphological differentiation of the cotton fleahopper in two locations that differ in presence of distinct host-associated lineages. Using a geometric-morphometric approach, I detected significant effect of host plant and geography on body morphology and wing shape of cotton fleahopper populations (Chapter V). Length of antenna and rostrum were two important traits associated with morphological divergence of cotton and horsemint associated insect populations. Cotton associated individuals had relatively longer antenna and rostrum compared to individuals associated with horsemint.

<p>The mycorrhizal mutualism is one of the earliest and most influential of all terrestrial symbioses. As the primary method used by most plants to acquire nutrients from the soil, mycorrhizal fungi help to shape the structure and composition of many ecosystems. Ectomycorrhizal (EM) fungi play an especially significant role because most EM fungi prefer a limited number of host taxa, and EM plant species likewise associate with only a fraction of the available EM fungi. This host preference issue, combined with the high diversity of EM fungi in forest ecosystems, complicates interspecies competition both among fungi and among plants, because these plant and fungal communities interact.</p><p>Despite recent attempts at documenting mycorrhizal fungi in the context of ecological succession, many questions remain about the underlying causal relationships among EM fungi, soil conditions, and plant community assembly. The succession of mycorrhizal fungi often mirrors the succession of plants, and ectomycorrhizal (EM) community composition may affect the outcome of competition among trees during succession. In a pine-oak seral system, we tested the ability of <italic>Pinus taeda</italic> and <italic>Quercus alba</italic> seedlings to associate with EM fungi when planted under both conspecific and heterospecific adults. We found that EM communities under pine and oak canopy were distinct regardless of seedling identity, indicating that the fungal associations of adult trees determine which EM species are available in the soil. In addition, pine seedlings planted under oak canopy showed decreased mycorrhization and growth compared to those planted under pine canopy, while oak seedlings showed no negative effects of heterospecific planting. This impaired ability of pine seedlings to associate with the EM community established under oaks may deter pine recruitment and facilitate the late-seral replacement of pines with oaks.</p><p>While EM fungal communities correlate with the dominant species of host tree, soil properties do as well, making it difficult to establish causality among these three variables. Soil was collected from oak- and pine-dominated stands and dried to kill off mature mycelium, leaving only the spore bank as a source of inoculum for pine and oak seedlings. EM root tips were collected for molecular identification of fungal species based on ITS barcoding, and soil samples from field and laboratory conditions were analyzed for fungal diversity using 454 sequencing. We found a reduced influence of canopy type and a more pronounced influence of seedling identity when compared to the EM communities on seedlings planted in the field, suggesting that adult trees do alter the availability of fungi by directly promoting the growth of their preferred EM associates.</p><p>The availability of EM fungi can also affect seedlings at the interface between EM- an AM-dominated forest. We tested the hypothesis that seedlings of <italic>Dicymbe corymbosa</italic> which recruit outside of monodominant stands have limited access to EM symbionts compared with those which recruit inside <italic>D. corymbosa</italic> stands. EM root tips and rhizosphere soil were collected from seedlings along two transects inside monodominant stands and three transects in the transition zone into mixed forest dominated by AM associates. Seedlings inside monodominant stands yielded both a greater quantity of mycorrhized root tips and a higher diversity of EM species than transition zone seedlings. Of the fungal families commonly found on adult roots, the Boletaceae were notably underrepresented on all seedlings. In the transition zones, high-throughput sequencing of soil also detected a decrease in EM diversity with distance from the parent tree.</p><p>Seedlings of <italic>D. corymbosa</italic> may benefit from recruiting within monodominant stands by tapping into common mycorrhizal networks (CMNs) to acquire low-cost nitrogen and, potentially, photosynthates produced by conspecific adults. Leaves of stand adults, stand seedlings, and mixed-forest seedlings were collected for stable isotope analysis to track the transfer of nitrogen and carbon through CMNs. The &delta;<super>13</super>C and &delta;<super>15</super>N results contradicted each other, suggesting that more complicated interactions may be playing out among adults, seedlings, and fungi.</p> / Dissertation

This project was aimed at investigating behaviour and condition of the Yellow-breasted Boubou, Laniarius atroflavus, in response to habitat differences across core, edge and riparian Afro-montane forest habitats at the Ngel Nyaki Forest Reserve, Nigeria. This species is little known and conservation effort will require direction in identifying the habitat of best quality for their survival. The determination of habitat association using correspondence analysis of census data suggested strongest association with the riparian habitat, even though this habitat held the least overall avian biodiversity as determined from a modified Shannon index. L. atroflavus appeared not to hold territories in the core habitat. Territoriality, vocalisation and time budget showed trends indicating L. atroflavus were more abundant and fared better in the riparian habitat. In this habitat, there was a greater density of territories and a smaller mean territory size, better call quality in frequency bandwidth and duration, and increased displaying and foraging time in the riparian habitat. Difference in size, colour and growth-based measures of condition showed difference between sexes, but did not show a strong habitat effect – males were larger than females, yet females appeared to have better quality of yellow breast feathers for equal carotenoid concentration. The effect of nest predation risk as a predictor of habitat quality revealed nests in the riparian habitat had the greatest daily survival probability, and within this habitat nests established at lower heights survived longest. While the evidence pointed towards the riparian habitat being most suitable for L. atroflavus, this habitat sadly continues to suffer anthropogenic disturbance and this species’ IUCN listing as Least Concern was suspected be an over-estimation.

Many factors control, contribute to, stimulate and limit forage selection. It is apparent that cattle prefer certain cultivars compared to others. This study sought to test if cattle displayed preferences for certain cultivars over a two-year period in 2008 and 2009. Determining the effect of endophyte status on preference was another objective. Previous research showed rapid increase in the selection of preferred cultivars, i.e., diet learning. We attempted to replicate those results. Forty cultivars (34 tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) cultivars), two festuloliums (Festuca pratensis x Lolium perenne), two meadow fescue (Lolium pratense) and one meadow brome (Bromus biebersteinii), and one orchard grass (Dactylis glomerta L.)) were used to determine preference and to investigate factors contributing to preference. From this two-year study, we observed that cattle preferred certain cultivars compared to others, e.g. KYFA9819 > Latar-OG > Barfest-FL and AU-Triumph < 97TF1-EF < Seine, the most and least preferred cultivars, respectively. During drought conditions, both novel and toxic endophyte cultivars were preferred significantly (P < 0.05) to endophyte free counterparts. The cattle showed rejection of unpalatable grasses but did not clearly show learning to increase selection of desired cultivars.

This study investigates the determinants that influence adult Kentuckians’ preference to buy organic and/or locally grown food based on their age, gender, income, education level and metropolitan versus nonmetropolitan living status. Ajzen’s theory of planned behavior (TPB) provides the conceptual framework of the research and the appropriateness of the theory. Data for this analysis are from a 2009 Kentucky statewide survey. The analysis shows that: There is a significant difference in food purchasing habits of Metropolitan and Nonmetropolitan adult Kentuckians; the factors associated with the purchase of organic and locally grown foods are different; and, those who purchased locally grown and organic foods shared similar beliefs.

This thesis consists of four essays in resource and behavioral economics. Resource Extraction, Capital Accumulation and Time Horizon The paper shows that relaxing the standard infinite horizon assumption can explain the patterns of exhaustible resource extraction and prices for the last century. An empirical test proposes a time horizon of roughly 28 years to be most likely. Model calibration yields an oil price which fits the falling price after WWII and suggests that the sharply increasing price after 1998 is due to scarcity. Optimal Forest Rotation under Climate Change    The scenario of forests growing faster over time, due to climate change, is analyzed. It is shown numerically that ignoring future changes is highly likely to be accurate in terms of harvesting and will cause insignificant profit losses. Tragedy of the Commons versus the Love of Variety    The opposing effects of overharvesting of renewable resources when property rights are missing and increased consumption variety, both due to trade, are analyzed. Trade increases welfare if the resource has strong regenerative power. If, instead, the resource regenerates slowly, then sufficient increases in the number of trade partners harms welfare and the stock may even collapse. Correcting policies may be very harsh and still improve upon laissez faire. The Distribution of Revealed Preferences under Social Pressure    Stated preferences, such as declared political opinions, are studied when individuals make the trade off between being true to their real opinions and conforming to a social norm. In orthodox societies, individuals will tend to either conform fully or ignore the social norm while individuals in liberal societies will tend to compromise between the two extremes. The model sheds light on phenomena such as polarization, alienation and hypocrisy. Furthermore, it suggests that orthodoxy cannot be maintained under pluralism.