This dissertation deals with spectral measurements of solar radiation in the visible and near infrared wavelength range. The data were collected during a field campaign on the Cape Verde Islands in January / February 2008 within the DFG research group SAMUM 2 (Saharan Mineral Dust Experiment). During this campaign airborne measurements of upward radiances and irradiances were performed over aerosol layers. Since the Cape Verde Islands are in the advection area of air masses from the Sahara region northeast of the islands and from regions with bush fires from the southeast, the sampled aerosol mainly consists of mineral dust, biomass burning smoke or a mixture of both. These radiation measurements and airborne lidar measurements of aerosol extinction coefficients were used to calculate the dust radiative forcing at the top of atmosphere with an one-dimensional radiative transfer model. This required the spectral surface albedo and aerosol optical properties, determined by model retrievals. The dependence of the calculated dust radiative forcing on the aerosol optical thickness was used to distinguish between aerosol distributions with mineral dust only or mixed with biomass burning smoke. This mainly model-based method was compared with another mainly measurement-based method, which requires the net radiation at the flight altitude and its dependence on the aerosol optical thickness to distinguish between the different aerosol distributions. The mainly model-based method shows no differences between the calculated radiative forcings of aerosols mainly consisting of mineral dust and those mixed with biomass burning smoke due to high uncertainties. In contrast to the mainly model-based method, the mainly measurement-based method shows clear differences between aerosols with and without biomass burning smoke. Thus the mainly measurement-based method is the preferred method, because it omits the retrieval of the aerosol optical properties, which leads to high uncertainties, in contrast to the mainly model-based method.

Within the context of global climate change and soaring energy prices, people are searching for inexpensive and renewable sources of energy; therefore, burning wood for home heating is increasing. Woodsmoke contains substances known to harm human health and is a major contributor to air pollution in many parts of the world; yet there is limited research into the health effects of woodsmoke and existing research suffers from methodological constraints. As a result, there is interest in producing robust woodsmoke exposure estimates for health research and air quality management purposes. Studying health and the environment is inherently spatial; however, research related to air pollution and health tends to be aspatial. As investigators begin to understand the influence of spatial processes on research findings, the importance of adopting a spatial approach to modelling exposure and health risk is becoming apparent. This thesis describes a spatially explicit model for predicting fine particulate matter (PM2.5) attributable to woodsmoke from residential heating in Victoria, British Columbia, Canada. Spatially resolved measurements of PM2.5 were collected for 32 evenings during the winter heating seasons of 2004/05, 2005/06, 2006/07 using a nephelometer installed in a passenger vehicle. Positional data were collected concurrently using a Global Positioning System (GPS). Levoglucosan, a chemical unique to woodsmoke, was measured to confirm the presence of woodsmoke in the measured PM2.5. The spatial scale for the analysis of woodsmoke data was determined using semivariograms to identify the maximum distance of spatial dependence in the data which typically occurred near 2700m. Different spatial approaches for modelling woodsmoke concentrations were evaluated both qualitatively in terms of transferability, meeting statistical assumptions, and potential for exposure misclassification; and quantitatively to assess the association between the model’s predicted PM2.5 concentrations and observed PM2.5. The baseline model characterized exposure based on the PM2.5 value from the closest fixed monitor (R=0.51, α=0.05). The Krigged model produced a seasonal average surface based on nephelometer measurements and showed the weakest performance (R=0.25, α=0.05). The regression models predicted concentrations of woodsmoke based on predictor variables available from census data, typically used in health research, and spatial property assessment data (SPAD), an underused data source at a finer spatial resolution. Different approaches to regression modelling were investigated. A regression model already developed for Victoria performed the best quantitatively (R=0.84, α=0.05); however, qualitative considerations precluded it from being selected as an appropriate model. A quantitatively (R=0.62, α=0.05) and qualitatively robust regression model was developed using SPAD (M6). SPAD improved the spatial resolution and model performance over census data. Removing spatial and temporal autocorrelation in the data prior to modelling produced the most robust model as opposed to modelling spatial effects post regression. A Bayesian approach to M6 was applied; however, model performance remained unchanged (R=0.62, α=0.05). The spatial distribution of susceptibility to health problems associated with woodsmoke was derived from census data relating to population, age and income. Intersecting the exposure model with population susceptibility in a Geographic Information System (GIS) identified areas at high risk for health effects attributable to woodsmoke.

Background Anthropogenic air pollution is a global health problem estimated to contribute to millions of premature deaths. Exposure to biomass smoke is common due to varying sources, such as wildfires, indoor cooking over open fires, and residential heating from wood stoves. In urban environments transportation and industry rely heavily on the combustion of fossil fuels yet environmental policies increasingly support a shift to renewable fuels such as biodiesel. It has not been investigated how either wood smoke or biodiesel exhaust affect human health in general or the cardiovascular system in particular. We hypothesized that wood smoke exposure would induce acute cardiovascular impairment via similar underlying mechanisms as have been established for petrodiesel exhaust exposure. We also hypothesized that replacing petrodiesel with biodiesel, as a blend or pure biodiesel, would generate an exhaust profile with a less harmful effect on the cardiovascular system than petrodiesel exhaust. Methods In four separate studies healthy non-smoking subjects were exposed to different air pollutants in controlled exposure chambers followed by clinical investigations of the cardiovascular system. All studies were performed as randomized controlled trials in a crossover fashion with each individual acting as her own control. In study I healthy volunteers were exposed to wood smoke at a target concentration of particulate matter (PM) 300 µg/m3 for three hours followed by measures of blood pressure, heart rate variability and central arterial stiffness. In study II subjects were exposed to wood smoke at a target concentration of PM 1000 µg/m3 for one hour followed by measures of thrombus formation using the Badimon technique and vasomotor function using forearm venous occlusion plethysmography. In study III subjects were exposed to petrodiesel exhaust and a 30% rapeseed methyl ester (RME30) biodiesel blend for one hour at a target concentration of PM 300 µg/m3. Following exposure, thrombus formation and vasomotor function were assessed as in study II. In study IV subjects were exposed to petrodiesel exhaust at a target concentration of PM 300 μg/m3for one hour and pure rapeseed methyl ester (RME100) exhaust generated at identical running conditions of the engine. Following exposure, thrombus formation and vasomotor function were assessed as in study II and III. Results In study I fourteen subjects (8 males) were exposed to wood smoke at P M 294±36 μg/m3. Compared to filtered air exposure, measures of central arterial stiffness were increased and heart rate variability was decreased following wood smoke exposure. No effect was seen on blood pressure. In study II sixteen males were exposed to wood smoke at PM 899±100 μg/m3. We found no evidence of increased thrombus formation or impaired vasomotor function following wood smoke exposure. In study III sixteen subjects (14 males) were exposed to petrodiesel exhaust (PM 314±27 µg/m3) and RME30 exhaust (PM 309±30 µg/m3). Thrombus formation and vasomotor function were equal following either exposure. In study IV nineteen males were exposed to petrodiesel exhaust (PM 310±34 µg/m3, 1.7±0.3 x105 particles/cm3) and RME100 exhaust (PM 165±16 µg/m3, 2.2±0.1 x105 particles/cm3). As in study III, thrombus formation and vasomotor function were identical following both exposures. Conclusions We have for the first time demonstrated that wood smoke exposure can increase central arterial stiffness and decrease heart rate variability in healthy subjects. We did not, however find evidence of increased thrombus formation and impaired vasomotor function following wood smoke exposure at a higher concentration for a shorter time period. We have, for the first time, demonstrated that exhaust from RME biodiesel induced acute adverse cardiovascular effects of increased thrombus formation and impaired vasomotor function in man. These effects are on par with those seen following exposure to petrodiesel exhaust, despite marked physicochemical differences of the exhaust characteristics.

Fluids such as smoke, water and fire are simulated for both Computer Graphics applications and engineering fields such as Mechanical Engineering. Generally, Fluid Dynamics is used for the achievement of realistic-looking fluid simulations. However, the complexity of these calculations makes it difficult to achieve high performance. With the advances in graphics hardware, it has been possible to provide programmability both at the vertex and the fragment level, which allows for faster simulations of complex fluids and other events. In this thesis, one gaseous fluid, smoke is simulated in three dimensions by solving Navier-Stokes Equations (NSEs) using a semi-Lagrangian unconditionally stable method. Simulation is performed both on Central Processing Unit (CPU) and Graphics Processing Unit (GPU). For the programmability at the vertex and the fragment level, C for Graphics (Cg), a platform-independent and architecture neutralshading language, is used. Owing to the advantage of programmability and parallelism of GPU, smoke simulation on graphics hardware runs significantly faster than the corresponding CPU implementation. The test results prove the higher performance of GPU over CPU for running three dimensional fluid simulations.

Research on sex and gender in chronic obstructive pulmonary disease (COPD) has primarily focused on differences in pulmonary function. Detailed gender- and sex-based analyses of other aspects of COPD, including epidemiology, risk factors other than cigarette smoke, pathophysiology, and measurement tools are warranted. In Chapter Two we analyzed administrative health services data to compare the prevalence, mortality and use of drugs and spirometry in men and women with COPD. Contrary to recent predictions, we did not detect a dramatic increase in the prevalence or mortality of COPD over time in women compared to men. We discuss how different coding practices in medical billing can impact the results. In Chapter Three we examined sex differences in COPD phenotypes. We hypothesized that male smokers would have more emphysema whereas female smokers would have more airway wall remodeling using data from high resolution computed tomography (HRCT) scans. We did detect more emphysema in male smokers but there was no evidence of increased airway remodeling in women. We discuss the limits of HRCT to detect airway differences in women and men. In Chapter Four we examined the use of HRCT in assessing emphysema. We hypothesized that the computer-derived estimates of emphysema (the fractal value and the % low attenuation area (%LAA)) would differentiate COPD from non-COPD as accurately as the radiologist’s emphysema scores, and would provide similar predictions in both men and women. Instead, we found that the subjective rating of emphysema best differentiated COPD, and the fractal value (a measure of emphysematous lesion size) better differentiated COPD compared with an established objective measurement, the %LAA. These results were generally the same in men and women. In Chapter Five we examined characteristics of COPD in women exposed to biomass smoke. We hypothesized that biomass smoke would induce an airway disease-predominant phenotype. We found that women with biomass smoke-exposed COPD had greater airway remodeling and less emphysema than women with tobacco smoke-exposed COPD. In summary, these findings suggest that sex and gender differences are present in COPD epidemiology and pathophysiology. However, current research measurement tools may limit the ability to accurately measure these differences.

Coconut (Cocos nucifera L.) is native to the regions between 20oN and 20oS of the Equator, where it plays a significant socioeconomic role in the local communities. There it is referred to as ’The Tree of Life’, a eulogistic epithet describing its versatile use - more than 100 edible and non-edible products can be produced from it. Therefore the coconut palm is grown in about 90 tropical countries on more than 10 millions ha of land (Hamon et al., 1999). Although coconut has a high local socioeconomic reputation, its production is experiencing many problems and consequently the area planted with this crop is declining. The conventional breeding approach using seed to replant land is very expensive due to the low production of seed for planting, and even when elite germplasm is available it takes decades to multiply up enough planting material for new areas (Adkins et al., 1999). Hence over the past 40 years research has been directed towards developing a new technique for the micropropagation of coconut using somatic embryogenic approach. Throughout this time however one conclusion is repeatedly made – coconut is very recalcitrant to somatic embryogenesis. And although the many obstacles to this are slowly being reduced, in order to successfully micropropagate coconut on a large scale bottlenecks in the protocol still exist, and those include inconsistency of the embryogenic response by explanted tissues, poor somatic embryo maturation and germination, low regeneration rate of the new plantlets and long time required to produce plants (1.5 years) (Samosir et al., 1998). These bottlenecks and other problems were researched in the present study with the aim of trying to speed up the efficiency of coconut somatic embryogenesis process. Hence this thesis had the objectives to identify a starting protocol for coconut somatic embryogenesis; to select an appropriate for aim that explant; to optimize the production of embryogenic callus; to increase the rate of initiating coconut somatic embryos; to improve the maturation of somatic embryos and their germination efficiency; and to optimize the regeneration rate of the new plantlets. In order to identify a starting protocol, preliminary work was conducted, where existing protocols for coconut somatic embryogenesis were compared in their efficiency to induce somatic embryos. The protocol that stood out as the best in producing most embryogenic callus and subsequently embryos, as well as having the least dead (in culture) explants, was that of Nikmatullah (2001). Therefore the latter was chosen to be used as a starting protocol for this study. New sources of explants were investigated during the current work as well, using tissues from different parts of in vitro derived 8 months old coconut plantlets. Those however have shown to be unsuitable for somatic embryogenesis, since only non-embryogenic callus was developed by some of the inoculated tissues. The immature inflorescence explants were superior in producing embryogenic callus and somatic embryos; therefore they were selected as the preferred explant source to use in the next steps of the current study. Optimizing the production of embryogenic callus was the first issue to address during the core work of this project. As a result of that the culture conditions were considerably improved by using vessels with larger headspace-medium ratio (3:1), as well as by selecting younger immature inflorescences and transversely segmenting the top half of the inflorescence spikes into smaller size (1 mm) sections. Further improvement was possible by studying the make up of the callus growth media. Amongst the administered for that purpose substances the applied together polyamines spermine (0.10 µM) and putrescine (7.5 mM) have proven to play a notably positive role in the induction of callus from coconut immature inflorescence explants. Thidiazuron (TDZ, 10 µM) too has shown a potential to improve the efficiency of the initial stage of coconut somatic embryogenesis, but only when applied in conjunction with other cytokinins (eg. BAP and 2iP). Smoke-saturated-water (SSW, 10 %) could only slightly diminish the amount of necrotising cultured explants, and high 2,4-D concentrations could not support the induction of callus from immature coconut inflorescences. Collectively taken, as a result of this current study the production of callus was improved by 300 %. The rate of coconut somatic embryos formation was as well significantly increased (over 300 %), by the simultaneous application of suspension culture step, spermine (0.01 µM), SSW (10 %) and high auxin concentration (500 µM). Nevertheless the presence of TDZ and other cytokinins in the medium, as well as the absence of activated charcoal, were found to be unable to positively influence the somatic embryogenesis process. Despite the considerable improvements made in the efficiency of inducing callus and initiating embryos, the poor maturation and germination (eg. 5 %, Verdeil et. al., 1999) of somatic embryos still remained a bottleneck to the whole somatic embryogenesis procedure. Therefore further work was conducted in that direction and discovered that embryo maturation and germination rate can be elevated to 55 % by administering ancymidol (30 µM) to the somatic embryo maturation medium. This plant retardant has exhibited here three potential modes of action towards the cultured coconut somatic embryos: a) as a promoter of somatic embryo maturation and germination; b) as a preventor of pre-germination death of the somatic embryos; and c) as a preserver of non-germinating somatic embryos, that still can possess the potential to germinate in the future. The work during the next step of the process – regeneration of the new plantlets – has shown that the omission of plant growth regulators from the media was crucial for the development of germinated embryos into new plantlets, where otherwise no plant regeneration occurred at all. The achieved here plantlet regeneration rate in the PGR-free medim was 56 %, which is higher than the previously reported 20 % regeneration rate (Verdeil et al., 1994) for coconut plantlets produced from immature inflorescences explants. As a result of this current work a new method was developed for somatic embryogenesis of coconut from immature inflorescences explants (Fig. 9.2). The overall efficiency of this protocol is over three times higher than that of the starting protocol (Nikmatullah, 2001) selected during the preliminary work. Furthermore, when using this new method the entire duration for regenerating clonal coconut plantlets (up to the stage of first root and shoot emerging) takes up to 8 months, which is the shortest reported time for producing coconut plantlets via somatic embryogenesis (eg. 36 months from inflorescences explants (Verdeil et. al., 1999) and 18 months from sliced zygotic explants (Samosir, 1999, Fig. 9.2), presenting an additional valuable advantage of this newly developed method, from the perspective of the potential to micropropagate coconut on a commercial scale.

Coconut (Cocos nucifera L.) is native to the regions between 20oN and 20oS of the Equator, where it plays a significant socioeconomic role in the local communities. There it is referred to as ’The Tree of Life’, a eulogistic epithet describing its versatile use - more than 100 edible and non-edible products can be produced from it. Therefore the coconut palm is grown in about 90 tropical countries on more than 10 millions ha of land (Hamon et al., 1999). Although coconut has a high local socioeconomic reputation, its production is experiencing many problems and consequently the area planted with this crop is declining. The conventional breeding approach using seed to replant land is very expensive due to the low production of seed for planting, and even when elite germplasm is available it takes decades to multiply up enough planting material for new areas (Adkins et al., 1999). Hence over the past 40 years research has been directed towards developing a new technique for the micropropagation of coconut using somatic embryogenic approach. Throughout this time however one conclusion is repeatedly made – coconut is very recalcitrant to somatic embryogenesis. And although the many obstacles to this are slowly being reduced, in order to successfully micropropagate coconut on a large scale bottlenecks in the protocol still exist, and those include inconsistency of the embryogenic response by explanted tissues, poor somatic embryo maturation and germination, low regeneration rate of the new plantlets and long time required to produce plants (1.5 years) (Samosir et al., 1998). These bottlenecks and other problems were researched in the present study with the aim of trying to speed up the efficiency of coconut somatic embryogenesis process. Hence this thesis had the objectives to identify a starting protocol for coconut somatic embryogenesis; to select an appropriate for aim that explant; to optimize the production of embryogenic callus; to increase the rate of initiating coconut somatic embryos; to improve the maturation of somatic embryos and their germination efficiency; and to optimize the regeneration rate of the new plantlets. In order to identify a starting protocol, preliminary work was conducted, where existing protocols for coconut somatic embryogenesis were compared in their efficiency to induce somatic embryos. The protocol that stood out as the best in producing most embryogenic callus and subsequently embryos, as well as having the least dead (in culture) explants, was that of Nikmatullah (2001). Therefore the latter was chosen to be used as a starting protocol for this study. New sources of explants were investigated during the current work as well, using tissues from different parts of in vitro derived 8 months old coconut plantlets. Those however have shown to be unsuitable for somatic embryogenesis, since only non-embryogenic callus was developed by some of the inoculated tissues. The immature inflorescence explants were superior in producing embryogenic callus and somatic embryos; therefore they were selected as the preferred explant source to use in the next steps of the current study. Optimizing the production of embryogenic callus was the first issue to address during the core work of this project. As a result of that the culture conditions were considerably improved by using vessels with larger headspace-medium ratio (3:1), as well as by selecting younger immature inflorescences and transversely segmenting the top half of the inflorescence spikes into smaller size (1 mm) sections. Further improvement was possible by studying the make up of the callus growth media. Amongst the administered for that purpose substances the applied together polyamines spermine (0.10 µM) and putrescine (7.5 mM) have proven to play a notably positive role in the induction of callus from coconut immature inflorescence explants. Thidiazuron (TDZ, 10 µM) too has shown a potential to improve the efficiency of the initial stage of coconut somatic embryogenesis, but only when applied in conjunction with other cytokinins (eg. BAP and 2iP). Smoke-saturated-water (SSW, 10 %) could only slightly diminish the amount of necrotising cultured explants, and high 2,4-D concentrations could not support the induction of callus from immature coconut inflorescences. Collectively taken, as a result of this current study the production of callus was improved by 300 %. The rate of coconut somatic embryos formation was as well significantly increased (over 300 %), by the simultaneous application of suspension culture step, spermine (0.01 µM), SSW (10 %) and high auxin concentration (500 µM). Nevertheless the presence of TDZ and other cytokinins in the medium, as well as the absence of activated charcoal, were found to be unable to positively influence the somatic embryogenesis process. Despite the considerable improvements made in the efficiency of inducing callus and initiating embryos, the poor maturation and germination (eg. 5 %, Verdeil et. al., 1999) of somatic embryos still remained a bottleneck to the whole somatic embryogenesis procedure. Therefore further work was conducted in that direction and discovered that embryo maturation and germination rate can be elevated to 55 % by administering ancymidol (30 µM) to the somatic embryo maturation medium. This plant retardant has exhibited here three potential modes of action towards the cultured coconut somatic embryos: a) as a promoter of somatic embryo maturation and germination; b) as a preventor of pre-germination death of the somatic embryos; and c) as a preserver of non-germinating somatic embryos, that still can possess the potential to germinate in the future. The work during the next step of the process – regeneration of the new plantlets – has shown that the omission of plant growth regulators from the media was crucial for the development of germinated embryos into new plantlets, where otherwise no plant regeneration occurred at all. The achieved here plantlet regeneration rate in the PGR-free medim was 56 %, which is higher than the previously reported 20 % regeneration rate (Verdeil et al., 1994) for coconut plantlets produced from immature inflorescences explants. As a result of this current work a new method was developed for somatic embryogenesis of coconut from immature inflorescences explants (Fig. 9.2). The overall efficiency of this protocol is over three times higher than that of the starting protocol (Nikmatullah, 2001) selected during the preliminary work. Furthermore, when using this new method the entire duration for regenerating clonal coconut plantlets (up to the stage of first root and shoot emerging) takes up to 8 months, which is the shortest reported time for producing coconut plantlets via somatic embryogenesis (eg. 36 months from inflorescences explants (Verdeil et. al., 1999) and 18 months from sliced zygotic explants (Samosir, 1999, Fig. 9.2), presenting an additional valuable advantage of this newly developed method, from the perspective of the potential to micropropagate coconut on a commercial scale.

Burn injuries represent a major cause of mortality and morbidity as well as a significant drain on limited resources, particularly in the developing world. Advances in resuscitation, critical care, protective ventilatory strategies, earlier complete debridement complemented by more aggressive treatment of burn wound sepsis have reduced the mortality of thermal injuries. There has also been a move to focus on education and prevention campaigns, which have borne fruit and resulted in some reduction in the incidence of burns in the paediatric population. Burn care, once a Cinderella specialty, has become a well focused multi-disciplinary specialty in its own right. Burn injury is dissimilar to many forms of trauma. In major burns, the initial trauma may be limited to the skin alone or skin and lungs, but all organ systems are rapidly involved as the physiological derangement becomes systemic. The burden of this multi-system insult is substantial. Globally, the World Health Organisation estimated that fire-associated burns alone directly resulted in over 320,000 deaths in 2002, and in the USA, approximately 1million children sustain burns each year. Australasian guidelines suggest that all adult burns with greater than 15% total body surface area (TBSA) and >10% TBSA burn in children will require fluid resuscitation and possibly critical care support at some point in their hospitalisation. Mortality in these patients with severe burns follows a bimodal pattern of early and late deaths. Causes of early death comprise refractory shock, inability to obtain a safe airway or provide adequate oxygenation, co-existent trauma, non-survivable carboxyhaemoglobin poisoning, and decisions that injuries are non-compatible with recovery, leading to therapy withdrawal. With improved resuscitation strategies, 95% of patients survive the early resuscitation phase. Late deaths are secondary to sepsis normally associated with wound infection and multiple organ failure. The morbidity associated with burn injury continues well after the acute hospital admission, frequently for up to several years post burn injury, as is witnessed by prolonged rise in basal metabolic rate and worsening scar tissue1, 2. It has been calculated that in children approximately 60% of the cost of burn care occurs post wound closure; that is, dealing with the disabling and disfiguring contractures associated with hypertrophic scar3, 4. Hence, research and new modalities are being aimed at reducing cost of treatment and improving quality of life for survivors of burn injury. Thus, this PhD aims to reflect the multidisciplinary nature of modern day burn care, with the inclusion of seven published papers and one book chapter covering prevention and education relevant to paediatric burns, treatment and minimisation of wound infection , and scar minimisation, along with the first study into the relevance of fetal wound healing post burn injury.

Thesis (M.P.H.)--University of Adelaide, Dept. of Public Health, 2001. / Bibliography: leaves 92-98.

Thesis (M.S.)--University of Michigan, 1980.