The growing season for vegetable crops is limited by freezing temperatures in arid high elevation climates such as northern Utah. Logan, Utah (41.73 N, 111.83 W, 1382 m elevation) has a short, variable growing season with an average frost-free period of 135 days. Extending the growing season provides growers with an opportunity to extend revenue into a normally unproductive period and benefit from out-of-season price premiums. High tunnels have been used to effectively extend the growing season for numerous crops by providing cold temperature protection. However, limited high tunnel research has been performed in arid high elevation regions that experience extreme temperature fluctuations. The use of high tunnels was investigated in North Logan, Utah to extend the growing season for tomatoes and lettuce. In 2009 and 2010, supplemental heating under low tunnels within high tunnels was investigated to provide early season cold temperature protection for tomatoes. Sunbrite tomatoes were transplanted into four high tunnels over three planting dates. Tomatoes were subjected to supplemental heating treatments including soil warming cables alone or in conjunction with 40-watt incandescent lights for air heating. The highest early season and overall yield was achieved with the 17 Mar. planting date. Early season yield was significantly less for the latest planting date (7 Apr.) compared to the 17 Mar. and 30 Mar. planting dates. Early season yield was significantly greater for treatment plots with soil plus air heating, and soil heating alone significantly improved total yield. The use of a vertical structure within a high tunnel was investigated to improve productivity for lettuce. Parris Island Cos lettuce was consecutively transplanted from spring 2008 to spring 2010 in a high tunnel at the same site. The vertical growing system allowed for 31 plants*m-2 in south oriented gutters, and 45 plants*m-2 in east/west oriented gutters compared to 25 plants*m-2 in the ground including space for maintenance. Root zone temperatures in the gutters fluctuated widely in response to air temperatures, and super-optimal soil temperatures impeded growth. Productivity (g*m-2) in the gutters was only significantly greater than productivity in the ground soil during the spring and fall months when soil and air temperatures were not frequently below 0 °C or above 24 °C. This thesis includes both research results and extension factsheets intended for growers interested in high tunnel production of tomato and lettuce.

Allergic diseases are chronic inflammatory conditions, characterised by eosinophil inflammation systemically and in target organs, where cytotoxic granule proteins are responsible for tissue injury. Allergic rhinitis is known to be a risk factor for the development of asthma, yet not all with rhinitis develop asthma. The overall aim was to investigate the involvement of eosinophils in allergic rhinitis and allergic asthma in vivo and in experimental settings, with a focus on differences between rhinitis and asthma. Birch pollen allergy was used as a model and patients were studied during pollen season and after nasal and bronchial allergen challenge. During pollen season and at baseline, allergic rhinitis and allergic asthma had the same degree of systemic eosinophil inflammation. Despite this, impairment in lung function during season and increased bronchial responsiveness at baseline were more common in the asthmatics. Systemic inflammation was more pronounced after seasonal exposure than after experimental challenge. Allergic rhinitis and allergic asthma had the same degree of eosinophil airway inflammation after bronchial challenge, but only the asthmatics had increased bronchial responsiveness measured as PD20 for birch allergen. Allergen primed eosinophils were investigated in vitro for C3b-induced degranulation after seasonal and experimental challenge. The released amount of eosinophil granule proteins was within the same range for all three allergen challenge models with just minor differences in propensity for degranulation between rhinitics and asthmatics. Signalling through PI3K for degranulation was studied with the specific inhibitor Wortmannin. PI3K signalling for eosinophil degranulation was clearly involved in allergic rhinitis and allergic asthma irrespective of the model for allergen exposure. Asthmatics demonstrated less inhibition of degranulation through PI3K during pollen season, indicating that other pathways contribute to eosinophil degranulation in allergic asthmatics. Conclusion: Allergic rhinitis and allergic asthma present with the same degree of systemic and local eosinophil inflammation. The eosinophils are primed for degranulation equally and follow the same pathway through PI3K for degranulation. Our data indicates that eosinophil inflammation per se is not sufficient for the development of asthma.

The contrast between the familiar social space and the world beyond has been widely recognised as an organising principle in medieval literature, in which the natural and the supernatural alike are set off against human society as alien and hostile. However, the study of this antithesis has typically been restricted to the spatial aspect whereas the literature often exhibits seasonal patterns as well. This dissertation modifies the existing paradigm to accommodate the temporal dimension, demonstrating that winter stands out as a season in which the autonomy of the human domain is drawn into question in both Anglo-Saxon and early Scandinavian literature. In Old English poetry, winter is invoked as a landscape category connoting personal affliction and hostility, but it is rarely used to evoke a cyclical chronology. Old Icelandic literature likewise employs winter as a spatial category, here closely associated with the dangerous supernatural. However, Old Icelandic prose furthermore give winter a place in the annual progression of the seasons, which structures all but the most legendary of the sagas. Accordingly, the winter halfyear stands out as the near-exclusive domain of revenant hauntings and prophecy. These findings stand in stark contrast to the state of affairs in Middle English poetry, which associates diverse kinds of adventure and supernatural interaction with florid landscapes of spring and summer, and Maytime forests in particular. Even so, the seasonal imagery in <em>Sir Gawain and the Green Knight</em> makes clear that Middle English poets could use the contrastive functions of winter to no less effect than authors in neighbouring corpora. In partial explanation of authorial choices in this regard, it is proposed that winter settings are employed especially where a strong empathic response is desired of the audience.

The contrast between the familiar social space and the world beyond has been widely recognised as an organising principle in medieval literature, in which the natural and the supernatural alike are set off against human society as alien and hostile. However, the study of this antithesis has typically been restricted to the spatial aspect whereas the literature often exhibits seasonal patterns as well. This dissertation modifies the existing paradigm to accommodate the temporal dimension, demonstrating that winter stands out as a season in which the autonomy of the human domain is drawn into question in both Anglo-Saxon and early Scandinavian literature. In Old English poetry, winter is invoked as a landscape category connoting personal affliction and hostility, but it is rarely used to evoke a cyclical chronology. Old Icelandic literature likewise employs winter as a spatial category, here closely associated with the dangerous supernatural. However, Old Icelandic prose furthermore give winter a place in the annual progression of the seasons, which structures all but the most legendary of the sagas. Accordingly, the winter halfyear stands out as the near-exclusive domain of revenant hauntings and prophecy. These findings stand in stark contrast to the state of affairs in Middle English poetry, which associates diverse kinds of adventure and supernatural interaction with florid landscapes of spring and summer, and Maytime forests in particular. Even so, the seasonal imagery in <em>Sir Gawain and the Green Knight</em> makes clear that Middle English poets could use the contrastive functions of winter to no less effect than authors in neighbouring corpora. In partial explanation of authorial choices in this regard, it is proposed that winter settings are employed especially where a strong empathic response is desired of the audience.

A suitable climate, varied scenic terrain, and proximity of communities along Ontario’s system of 39,742 km of snowmobile trails have provided for domestic and international snowmobile tourism. Outdoor winter tourism in many parts of the world has been identified to be at risk to changes in global climate. The Intergovernmental Panel on Climate Change in its Fourth Assessment Report (AR4) reported a global increase of temperature of 0.74 degrees Celsius for the period 1906 to 2005 and estimates that by the end of the 21st century the global mean temperature will increase between 1.8 degrees Celsius to 4.0 degrees Celsius. Temperature increases of only a few degrees may contribute to variances in snow-based tourism reliant on the reliability of natural snow cover. This study examines the spatial and temporal impacts of climate change scenarios upon snowmobile season length and operations within the snowmobile industry in the Province of Ontario Canada to six climate change scenarios for the 21st century. Snowmobile trail operations in Ontario are reliant upon a minimum natural snow cover of 15 cm for smooth terrain trails and 30 cm to 60 cm for rough terrain trails, temperatures less than 0 degrees Celsius and, human and financial capital. Three or more consecutive snowmobile seasons with ≤ 28 days have been identified as having serious implications for human and financial capital necessary to develop and maintain the snowmobile trail system. As early as the 2020s, north eastern snowmobile districts are projected to be least vulnerable to changes in climate with the longest snowmobile seasons > 28 days, while south central snowmobile districts are projected to be the most vulnerable to changes in climate with the shortest snowmobile seasons of < 28 days. Snowmobile trail managers identified possible strategies to adapt to a changing climate (2020s to 2080s) including: pre-season preparation of the terrain including early season packing of snow cover, re-location of the most vulnerable snowmobile trails, and strengthening inter-district alliances.

A suitable climate, varied scenic terrain, and proximity of communities along Ontario’s system of 39,742 km of snowmobile trails have provided for domestic and international snowmobile tourism. Outdoor winter tourism in many parts of the world has been identified to be at risk to changes in global climate. The Intergovernmental Panel on Climate Change in its Fourth Assessment Report (AR4) reported a global increase of temperature of 0.74 degrees Celsius for the period 1906 to 2005 and estimates that by the end of the 21st century the global mean temperature will increase between 1.8 degrees Celsius to 4.0 degrees Celsius. Temperature increases of only a few degrees may contribute to variances in snow-based tourism reliant on the reliability of natural snow cover. This study examines the spatial and temporal impacts of climate change scenarios upon snowmobile season length and operations within the snowmobile industry in the Province of Ontario Canada to six climate change scenarios for the 21st century. Snowmobile trail operations in Ontario are reliant upon a minimum natural snow cover of 15 cm for smooth terrain trails and 30 cm to 60 cm for rough terrain trails, temperatures less than 0 degrees Celsius and, human and financial capital. Three or more consecutive snowmobile seasons with ≤ 28 days have been identified as having serious implications for human and financial capital necessary to develop and maintain the snowmobile trail system. As early as the 2020s, north eastern snowmobile districts are projected to be least vulnerable to changes in climate with the longest snowmobile seasons > 28 days, while south central snowmobile districts are projected to be the most vulnerable to changes in climate with the shortest snowmobile seasons of < 28 days. Snowmobile trail managers identified possible strategies to adapt to a changing climate (2020s to 2080s) including: pre-season preparation of the terrain including early season packing of snow cover, re-location of the most vulnerable snowmobile trails, and strengthening inter-district alliances.

This study examines potential livelihood outcomes from a recently established irrigation project in Ta Haen, Cambodia, in a sustainable livelihoods framework. The aim of this SAUCE irrigation project is to provide water for drinking and irrigation purposes with the goal of enhancing food by producing an extra rice harvest, the staple, per year. Field research conducted in December 2011 provided qualitative data from questionnaires, key informant interviews, and participant and direct observation, in addition to quantitative data from water quality analysis focusing on arsenic (a potential risk), pH, EC and temperature. Most of the people in the village did not obtain an extra rice harvest in this first year of the project. However, they did plant other crops along the Ta Haen riverbanks. Average arsenic concentration was 32 ppb, above WHO guideline value (10 ppb). However, dose response data is uncertain at levels below 50 ppb, which makes river water use acceptable given that this is a major water source for the community. Preliminary results suggest that project sustainability and positive livelihood outcomes depend upon improving overall agricultural and water management practices by addressing quality issues, rationing water, and removing invasive water hyacinths that affect water quantity.

The research presented here attempts to bridge science and policy through the quantification of climate change impacts and the analysis of a science-fed participatory process to face a sustainability challenge in the San Pedro Basin (Arizona). Paper 1 presents an assessment of a collaborative development process of a decision support system model between academia and a multi-stakeholder consortium created to solve water sustainability problems in a local watershed. This study analyzes how science-fed multi-stakeholder participatory processes lead to sustainability learning promoting resilience and adaptation. Paper 2 presents an approach to link an ensemble of global climate model outputs with a hydrological model to quantify climate change impacts in the hydrology of a basin, providing a range of uncertainty in the results. Precipitation projections for the current century from different climate models and IPCC scenarios are used to obtain recharge estimates as inputs to a groundwater model. Quantifying changes in the basin's water budget due to changes in recharge, evapotranspiration (ET) rates are assumed to depend only on groundwater levels. Picking on such assumption, Paper 3 explores the effects of a changing climate on ET. Using experimental eddy covariance data from three riparian sites, it analyzes seasonal controls on ET. An approach to quantify evapotranspiration rates and growing season length under warmer climates is proposed. Results indicate that although atmospheric demand will be greater, increasing pan and reference crop evaporation, ET rates at the studied field sites will remain unchanged due to stomatal regulation. However, the length of the growing season will increase, mainly with an earlier leaf-out and at a lesser level by a delayed growing season end. These findings - implying decreased aquifer recharge, increased riparian water use and a lesser water balance - are very relevant for water management in semi-arid regions. Paper 4, in which I am second author, explores the theory relating changes in area-average and pan evaporation. Using the same experimental data as Paper 3, it corroborates a previous theoretical relationship and discusses the validity of Bouchet's hypothesis.

This research assessed the seasonal effects of contrasting tillage and crop rotation systems on soil ammonia oxidizing bacteria (AOB) and archaea (AOA). Four different cropping systems under till and no-till were analyzed in a 30 year-old agricultural field trial. Samples were collected during the 2010 growing season at times corresponding with agronomic events. Nucleic acids were preserved in the field and subsequently analyzed by quantitative real-time polymerase chain reactions (qPCR). Tillage decreased AOB activity and abundance in the plow layer (0-15 cm) immediately after fall moldboard plow events, but observed AOB dynamics at other times suggest tillage had a long-term distribution effect across depth (0-30 cm). AOA abundance was significantly greater in no-till plots at all times indicating tillage had longer-term effects on these communities. Crop rotation had minimal effect on AOB and AOA, but there was a noted yield advantage for corn following wheat, regardless of tillage treatment. / OMAFRA Highly Qualified Personnel Program, NSERC

This research project examined the role of environmental time cues and circadian rhythms in mediating seasonal adjustments in the body temperature and locomotoractivity patterns in the Australian sleepy lizard, Tiliqua rugosa (Gray 1827). The first component of this study investigated whether daily rhythms of behavioural thermoregulation and locomotor activity that T. rugosa displays in the field are endogenous circadian rhythms. In each season, there was significant variation in each of these rhythms in lizards released on laboratory thermal gradients under prevailing light-dark (LD) cycles. Both rhythms persisted when lizards were released in constant darkness (DD) and exhibited the same free-running period suggesting a single circadian pacemaker drives both rhythms. The first component of this study revealed that seasonal changes in the expression of daily behavioural thermoregulatory and locomotor activity rhythms are mediated by the circadian system in T. rugosa. The second component of this project comprised three experiments that determined the relative importance of 24 h LD and temperature cycles (TCs) in entraining the locomotor activity rhythm. In the first experiment, lizards were held under LD 12:12 and were subjected to either a TC of 33:15C in phase with the LD cycle or a reversed TC. Following LD 12:12, lizards were maintained under the same TCs but were subjected to DD. Activity was restricted to the thermophase in LD irrespective of the lighting regime and during the period of DD that followed, suggesting entrainment by the TC. In the second experiment, lizards were held under LD 12.5:11.5 and were subjected to one of three treatments; (1) constant 30C, (2) normal TC (30:20C), or (3) reversed TC. Following LD, all lizards were subjected to DD and constant 30C. Post-entrainment free-run records revealed that LD cycles and TCs both entrain locomotor activity rhythms of T. rugosa. Although there was large variation in the phasing of the rhythm in relation to the LD cycle in reversed TC lizards, TCs presented in phase with the LD cycle most accurately synchronised the rhythm to the photocycle. In the third experiment, lizards were held in DD at constant 30C before being subjected to a further period of DD and one of four treatments; (1) normal TC (06:00 h to 18:00 h thermophase), (2) delayed TC (12:00 h to 00:00 h thermophase), (3) advanced TC (00:00 h to 12:00 h thermophase) or (4) control (no TC, constant 30C). While control lizards continued to free-run in DD at constant temperature, locomotor rhythms of lizards subjected to TCs rapidly entrained to TCs irrespective of whether TCs were phase advanced or delayed by 6 h. The results of this experiment excluded the possibility that masking effects were responsible for locomotor responses of lizards to TCs. This study demonstrated that seasonal changes in the expression of this species‟ daily behavioural thermoregulatory and locomotor rhythms are mediated by a circadian system that is sensitive to both light and temperature. The sensitivity of the circadian system to temperature, in particular, may allow T. rugosa to restrict its activity to times of the year that are thermally favourable. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1521959 / Thesis(Ph.D.)-- University of Adelaide, School of Medical Sciences, 2010