Fire is the most significant natural disturbance agent in the MSdm biogeoclimatic subzone and has a determinant role in the dynamics of lodgepole pine (Pinus contorta ssp. latifolia Engelm.ex S.Wats.) dominated forests. Fire severity is a controversial term that usually refers to a qualitative measure of the fire effects on soil and vegetation and ultimately on ecosystem sustainability. The main objective of the thesis was to evaluate methods for quantifying and modelling the effects of fire severity on live biomass and dead organic matter and post-fire coarse woody debris (CWD) dynamics. A review of the representation of fire in models was conducted and several of the most commonly used fire models in North America have been described in terms of fire severity representation. The potential for developing the fire severity concept as a fire effects descriptor in an ecosystem management model were assessed. Severity matrices summarizing the probabilities of occurrence for fires of varying severity were constructed for two sites in the MSdm biogeoclimatic subzone of British Columbia, using weather data and past fire records. These matrices provide information to improve fire representation in the ecosystem based model FORECAST by quantifying the effects of fire severity on dead and live biomass components. Although this represents only a preliminary step, the severity matrix approach appears toprovide a viable methodology for improving the representation of fire effects in FORECAST. Patterns of post-fire coarse woody debris (CWD) accumulation were also assessed in the context of model development. Data were collected from a chronosequence of fire affected sites in the MSdm subzone of the TFL 49 Kelowna. The ability of the FORECAST model to simulate accumulation patterns in CWD and soil organic matter and nitrogen following fire was tested by comparing model outputs with field data. The evaluation of the model against chronosequence-derived data highlighted the fact that caution needs to be taken when using such data for model testing. The very slow recruitment pattern for new CWD illustrates the need to retain sources of CWD recruitment following fire by not salvage logging all killed trees and/or surviving live trees. / Forestry, Faculty of / Graduate

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Controlling for the wide variability in the physical health status of geriatric populations is important as severity of illness is known to both moderate and suppress relationships examined in psychosocial research. The purpose of the present investigation was to develop a uniform, easily administered quantitative index of illness severity, composed of disease-specific scales, that was independent of psychosocial factors and appropriate for use with a geriatric population. As well, the aim was to collect preliminary data on the reliability and validity of the scale. The development of the Severity of Illness-Geriatric (SOI­G) scale involved the adaptation of a previously developed severity of illness instrument Severity of Renal Disease Scale (SORDS). <p>The present investigation involved five programmatically linked studies. Study 1 involved the determination of the items to be included on SOI-G while Study 2 defined the severity criteria for each item. In Study 3, five geriatric specialists scaled each level of each item on the same underlying threat to life scale. There was a high level of initial agreement between the raters supporting the reliability of the severity values. The final scale consisted of 32 items. <p>In Study 4, archival data was collected on 61 patients admitted to the geriatric unit of a rehabilitation hospital. The SOI-G was compared to the Cumulative Illness Rating Scale-Geriatric (CIRS-G) and a global severity rating. <p>SOI-G inter-rater reliability estimates were low (likely due to rater error) but promising. SOI-G demonstrated support for content validity, face validity, and construct validity but evidence for convergent validity was not established. SOI-G scores were sensitive to differences among patients with respect to discharge outcome. The utility of SOI-G as a moderator variable in psychosocial research with the elderly could not be explored in Study 5 due to a limited sample size. <p>It was concluded that the present investigation demonstrated the potential usefulness of SOI-G in psychosocial research with the elderly but further research is needed before definitive conclusions can be made. The SOI-G offers researchers a tool for controlling disease variability that is not measured by psychological tests but must be accounted for in research designs.

Controlling for the wide variability in the physical health status of geriatric populations is important as severity of illness is known to both moderate and suppress relationships examined in psychosocial research. The purpose of the present investigation was to develop a uniform, easily administered quantitative index of illness severity, composed of disease-specific scales, that was independent of psychosocial factors and appropriate for use with a geriatric population. As well, the aim was to collect preliminary data on the reliability and validity of the scale. The development of the Severity of Illness-Geriatric (SOI­G) scale involved the adaptation of a previously developed severity of illness instrument Severity of Renal Disease Scale (SORDS). <p>The present investigation involved five programmatically linked studies. Study 1 involved the determination of the items to be included on SOI-G while Study 2 defined the severity criteria for each item. In Study 3, five geriatric specialists scaled each level of each item on the same underlying threat to life scale. There was a high level of initial agreement between the raters supporting the reliability of the severity values. The final scale consisted of 32 items. <p>In Study 4, archival data was collected on 61 patients admitted to the geriatric unit of a rehabilitation hospital. The SOI-G was compared to the Cumulative Illness Rating Scale-Geriatric (CIRS-G) and a global severity rating. <p>SOI-G inter-rater reliability estimates were low (likely due to rater error) but promising. SOI-G demonstrated support for content validity, face validity, and construct validity but evidence for convergent validity was not established. SOI-G scores were sensitive to differences among patients with respect to discharge outcome. The utility of SOI-G as a moderator variable in psychosocial research with the elderly could not be explored in Study 5 due to a limited sample size. <p>It was concluded that the present investigation demonstrated the potential usefulness of SOI-G in psychosocial research with the elderly but further research is needed before definitive conclusions can be made. The SOI-G offers researchers a tool for controlling disease variability that is not measured by psychological tests but must be accounted for in research designs.

This dissertation performs a comprehensive analysis of the effect of different environmental, demographic and vehicle variables on the severity of two-vehicle crashes. The limitations associated with previous studies have been addressed by using a large crash database, properly defining the independent variables, using appropriate statistical models, and by considering the effect of factors normally unaccounted for such as crash type, impact speed, and weight or height incompatibilities between the two vehicles.The use of multinomial logit models at the individual occupant and crash levels provides the flexibility to evaluate variables that have opposing effects at different injury levels (such as airbags). Alternative formulations with interaction terms and with instrumental variables are included. An analysis of marginal probabilities and costs is also provided, which is particularly useful when discussing potential safety treatments with transportation officials, politicians and other decision makers.The findings from the different models are consistent and suggest that the type of crash has a great impact on severity. Age is the most significant demographic variable, with children and older occupants being least and most likely to be injured, respectively. Behavior also seems to be critical, as the use of seatbelts greatly decreases occupant injuries. Heavier vehicles increase the safety of its occupants but decrease the safety of occupants of the other vehicle. The effect of vehicle type is not as significant as weight, with the exception of pickups, which are both more crashworthy and more aggressive than passenger cars. Further research is needed on the effects of airbags and impaired driving, as the analyses conducted have been inconclusive.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / The percentage of the U.S. population aged 65 years or older is increasing rapidly. Statistics also show this age group was 14.9 percent of the population in 2015 and is expected to be 20.7 to 21.4 percent for the years 2030–2050. Kansas has similar statewide trends with its aging population. Therefore, identifying issues, concerns, and factors associated with severity of older-driver crashes in Kansas is necessary. The Kansas Crash Analysis and Reporting System (KCARS) database maintained by Kansas Department of Transportation was used in this study to identify older-driver crash characteristics, compare older drivers with all drivers, and develop crash severity models. According to KCARS data, older drivers were involved in more than one in five fatal injuries out of all drivers in Kansas from 2010 to 2014. When compared with all drivers, older drivers were overly represented in fatal and incapacitating injuries. The percentage of older-driver fatal injuries was more than the twice that of all drivers. When compared with all drivers, older drivers were involved more often in crashes at four-way intersections, on straight and level roads, in daylight hours, and at a stop or yield signs. An in-depth crash severity analysis was carried out for the older drivers involved in crashes. Three separate binary logistic regression models were developed for single-vehicle crashes where only the older driver was present (Model A), single-vehicle crashes involving an older driver with at least one passenger (Model B), and multi-vehicle crashes involving at least one older driver (Model C). From the crash severity analysis, it was found that left turns were significant in changing the crash severity for Model A, but it was not significant in model B, meaning that older drivers may be safer with passengers. For Model B, none of the passenger attributes were significant, though it was originally developed to identify passenger attributes. Gender of the older driver was not significant in any model. For all models, variables such as safety equipment use, crash location, weather conditions, driver ejected or trapped, and light conditions distinguished crash severity. Furthermore, for Model A, variables such as day of the week, speed, accident class, and maneuver, distinguished crash severity. Moreover, accident class, surface type, and vehicle type changed crash severity in Model B. Number of vehicles, speed, collision type, maneuver, and two-lane roads were significant in Model C. A road-user survey was also conducted to identify habits, needs, and concerns of Kansas' aging road users since it was not advisable to conclude safety factors solely on crash data. The probability of occurrence was calculated by taking the weighted average of answers to a question. Then a contingency table analysis was carried out to identify relationships among variables. For older drivers, seatbelt use as a driver had the highest probability of occurrence. Driving in heavy traffic, merging into traffic, moving away from traffic, and judging gaps were dependent on age group. Findings of this research gave an understanding of older-driver crashes and associated factors. Since more than 85 percent of crash contributory causes were related to drivers, driver awareness programs, driver licensing restrictions, providing public transportation, and law enforcement can be used as countermeasures. Accordingly, results of this study can be used to enhance older-driver safety and awareness programs.

Fire activity, in terms of intensity, frequency, and total area burned, is expected to increase with a changing climate. A challenge for landscape-level assessment of fire effects, often termed burn severity, is that current remote sensing assessments provide very little information regarding tree/vegetation physiological performance and recovery, limiting our understanding of fire effects on ecosystem services such as carbon storage/cycling. In this paper, we evaluated whether spectral indices common in vegetation stress and burn severity assessments could accurately quantify post-fire physiological performance (indicated by net photosynthesis and crown scorch) of two seedling species, Larix occidentalis and Pinus contorta. Seedlings were subjected to increasing fire radiative energy density (FRED) doses through a series of controlled laboratory surface fires. Mortality, physiology, and spectral reflectance were assessed for a month following the fires, and then again at one year post-fire. The differenced Normalized Difference Vegetation Index (dNDVI) spectral index outperformed other spectral indices used for vegetation stress and burn severity characterization in regard to leaf net photosynthesis quantification, indicating that landscape-level quantification of tree physiology may be possible. Additionally, the survival of the majority of seedlings in the low and moderate FRED doses indicates that fire-induced mortality is more complex than the currently accepted binary scenario, where trees survive with no impacts below a certain temperature and duration threshold, and mortality occurs above the threshold.

Peanut allergy is a public health concern which affects a significant proportion of the population. Accidental exposure to peanut can cause severe and fatal reactions in peanut allergic individuals and currently their only safeguard is to practise careful avoidance. Identification and protection of at-risk members of the allergic population is critical in managing this life-threatening condition. This thesis produces key data to enable this. A prospective study was performed on 60 peanut allergic participants to determine thresholds of reactivity to peanut using oral challenges with incrementally increasing amounts of peanut protein. Following a double-blind placebo-controlled peanut challenge, participants received three further peanut challenges, two with co-factors: sleep deprivation and exercise, and one without. Severity was measured using a numerical scale derived from symptoms and serum tryptase was measured at each challenge. A total of 187 challenges were performed. Findings were that the median amount of peanut protein which induces a reaction in 10% of the population (ED10) was 12.3mg (95% CI 7.3,20.4) equivalently this suggests that 90% of the allergic population will not react to doses below this level. Both sleep deprivation and exercise have a significant effect on lowering reaction threshold (ED10), by 5 times and 2.5 times respectively. Separately there is a reduction in threshold with successive challenges. Co-factors also significantly increased symptom severity during challenge reactions. In particular sleep deprivation significantly increased the severity of gastrointestinal symptoms suggesting that a stressful stimulus may affect intestinal permeability. Evidence was provided for the importance of asthma as a risk factor which increased the severity of respiratory symptoms during reaction. Using a novel visual analogue scale for measuring the participant’s perception of severity, a poor correlation was observed between the participant’s perception of the reaction and the overall numerical severity score, suggesting that participants misperceive severe symptoms. This thesis provides the first data showing that symptom patterns in repeated challenges show a high degree of homogeneity within individuals, but importantly that this symptom homogeneity is also observed across individuals. Lastly the utility of serum tryptase in identifying food allergic reactions has been disputed previously. This thesis provides evidence of its value and identifies a rise cut-off of 30% as being diagnostic of a food allergic reaction, but cautions that acute levels must be compared with baseline as this rise may occur within the normal range.

Young children between the ages of two and six years often exhibit partword, whole word. and phrases repetitions as their language develops. This is also the age range when stutterertng most frequently appears. Consequently. speech-language pathologists need diagnostic criteria and evaluation tools to distinguish between the incipient stutterer and the normally disfluent child. Today a widely used evaluation tool is the Stuttering Severity Instrument (SSI) (Riley, 1972, 1980). The SSI is designed to provide a severity level based upon the parameters of frequency. duration. and physical concomitants. Riley (1972) first designed the SSI to not include monosyllabic word repetitions in the frequency count: however. he revised the SSI in 1980 to include monosyllabic word repetitions without providing new normative data nor standardization. It was questionable as to whether the SSI was a sufficiently sensitive means to determine stuttering severity for young children and to whether or not it was strengthened or weakened by the addition of whole monosyllabic words.

Crime severity has been found to be one of the best predictors of sentencing decisions (Darley, Carlsmith, & Robinson, 2000). There is however a dearth of research examining the effect of offender and victim ethnicity on perceptions of crime seriousness, and the few studies that do exist have produced equivocal findings. Some studies find an effect of victim ethnicity (e.g., Cohen-Raz, Bozna, & Glicksohn, 1997), some studies find no significant effects of offender nor victim ethnicity (e.g., Benjamin, 1989), and some studies only find effects under certain conditions, such as when the crime is of low seriousness (e.g., Herzog, 2003a). The present study was conducted in an attempt to clarify these convoluted findings by using measures of modern and old-fashioned prejudice. Whereas old-fashioned prejudice refers to the belief that an out group is in someway inferior, modern prejudice refers to the view that a minority group no longer faces discrimination or that the minority group is being too pushy when advocating for equal rights (McConahay, 1983). Using a sample of undergraduate psychology students, it was found that when the crime was perceived as being quite severe, harsher punishments were recommended for the offender. Further to this, participants scoring high in modern prejudice perceived crimes to be more severe and recommended longer sentences in certain offender-victim ethnicity conditions than participants scoring low in modern prejudice. However, contrary to the hypotheses, no significant differences were found between high and low old-fashioned prejudice participants. Perceived offender responsibility and stability were also found to affect perceptions of crime severity and recommended punishment. When an offence was described as being stable (i.e., the offender had committed similar crimes in the past), participants rated the crime as being more severe and recommended a harsher punishment than when it was the offenders first offence. Additionally, when participants attributed responsibility for the crime to the offender, crime severity ratings were higher and recommended punishments were longer. The implications of these results are discussed and recommendations for future research are put forward.