Assignment (MPhil)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--Catholic University of America, 1927. / Vita. Bibliography: p. 55-56.

Thesis (Ph. D.)--Catholic University of America, 1927. / Vita. Bibliography: p. 55-56.

No description available.

Magister Scientiae Dentium - MSc(Dent) / Restorative dentistry aims to replace lost or damaged tooth structure with durable and life-like alternatives. To accommodate the inherent limitations and weakness of the restorative materials, preparation techniques often require the sacrifice of healthy tooth structure to create enough restorative space. This can lead to weakening of the remaining tooth structure, with subsequent damage or catastrophic failure. When using indirect restoratives, the development of adhesive luting agents (adhesive cements) and stronger allporcelain restorations (lithium disilicate) has contributed to the development of “minimally invasive” preparation techniques and concepts such as cavity design optimization (CDO) and bio-substitution. With these techniques, resin materials are combined with ceramic restoratives in an attempt to not only produce strong restorations, but also increase the longevity of the remaining tooth. The clinician needs to therefore find the ideal preparation design that combine such materials to produces a clinically performing restoration while increasing the strength and longevity of the underlying tooth.

This study examines the effect of pensions on the timing of retirement, focusing on the differences between defined benefit (DB) plans and defined contribution (DC) plans. I find that DC plans have different effects on the accumulation of retirement wealth, the incentives for retirement and the risk of retirement benefits than DB plans. Thereby, DC plans have different effects from DB plans on the decision to retire. This paper is the first empirical study to investigate the effect of longevity risk in pension plans on retirement. It is an important addition to the literature on retirement behavior since longevity risk will become more important as individuals have longer life expectancies and bear more longevity risk due to increasing likelihood of coverage by DC plans or Social Security personal accounts. Previous research has found that DB plans have an age-incentive effect on retirement. That is, the structure of DB plans may induce individuals to retire at a specific age. By contrast, the structure of DC plans does not have age-incentive effects. Thereby, individuals with DC plans may retire either earlier or later on average than individuals with DB plans because of the absence of age-related incentives in DC plans. To shed further light on these issues, this study introduces risk factors, and particularly longevity risk, to an option value model of the retirement decision. Longevity risk is important to DC participants since DC plans usually offer a lump-sum benefit at retirement. Since payouts are not guaranteed over life expectancy, retirees with DC plans bear a greater risk of outliving their resources, i.e., longevity risk. The additional risks in DC plans may make workers save more, and retire later. This paper extends a standard intertemporal model of consumption and retirement by incorporating risk factors for different pension types into the retirement decision problem. Comparative statics from the optimal solution show that increases in risk factors (i.e. longevity risk) during retirement induce workers with DC plans to retire later than workers with defined benefit (DB) plans. This study then test the predictions of this model empirically, using the data from the Health and Retirement Study (HRS). Empirical results confirm the predictions of the theoretical model. First, workers with DC plans expect to retire later than workers with DB plans. Next, increase in pension option value, measured as the difference between the maximum pension value and the pension value of 1992, decreases the probability of retirement, thereby increasing the expected retirement wage. By contrast, greater pension wealth increases the probability of retirement, reducing the expected retirement age. Considering that pension wealth in DC plans is about half of pension wealth in DB plans, it is reasonable to conclude that workers with DC plans retire later than workers with DB plans. Finally, longevity risk, as measured by the Annuity Equivalent Wealth (AEW), decreases probability of retirement, increasing the expected retirement age.

Diss. Linköping : Linköpings universitet, 2007.

Dissertation (Ph.D.).--University of Texas Graduate School of Biomedical Sciences at San Antonio, 2008. / Vita. Includes bibliographical references.

Dissertation (Ph.D.) --University of Texas Graduate School of Biomedical Sciences at San Antonio, 2008. / Vita. Includes bibliographical references.

Master of Science / Department of Animal Sciences and Industry / Robert L. Weaber / Feet and leg soundness is an important trait for beef producers as it has an impact on cow longevity and animal well-being. The objective of this study was to investigate genetic parameter estimates for feet and leg traits, understand the relationship between feet and leg traits and Stayability EPD, and develop a scoring method for feet and leg traits in Red Angus cattle. Cattle were scored on 14 subjective traits: Body Condition Score (BCS), Front Hoof Angle (FA), Front Heel Depth (FHD), Front Hoof Claw Shape (FC), Rear Hoof Angle (RA), Rear Heel Depth (RHD), Rear Hoof Claw Shape (RC), Foot Size (FS), Hoof Orientation (HO), Knee Orientation (KO), Front Side View (FSV), Rear Leg Side View (RS), Rear Leg Hind View (RH), Composite Score (CS). Red Angus cattle (n=1885) were scored for all 14 traits by trained evaluators. All traits except CS were scored with the assumed optimum level being in the middle with undesirable scores being located on the extremes. Scores were observed on a scale of 1-100 and analyzed, then scores were simplified to 1-9 where scores were collapsed by 10’s into bins, starting at 10 since there were no scores observed below that point and the rubric used did not have an associated phenotype below that point. A three-generation pedigree file was obtained from the Red Angus Association of America (RAAA) that contained 13,306 animals, as well as a performance file on all animals observed in the study. Data were modeled using multiple linear bivariate animal models with additive and residual random effects, and age and contemporary group (herd-year) as fixed effects. Genetic parameters were estimated with ASREML4.0. Heritability estimates on the 1-9 scale for BCS, FA, FHD, FC, RA, RHD, RC, FS, HO, KO, FSV, RS, RH, and CS were 0.13, 0.18, 0.12, 0.08, 0.17, 0.24, 0.15, 0.29, 0.15, 0.15, 0.11, 0.29, 0.11, and 0.09 respectively. In general, feet and leg traits were lowly to moderately heritable, and are similar when compared to estimates for the same traits scored on a 1-100 scale. This informs a less granular and more simplified scale of measurement can be an appropriate method of feet and leg trait classification. Front hoof angle, FHD, RA, and RHD were all highly genetically correlated (r = 0.83 - 0.97), suggesting that angle and heel depth are controlled by many of the same genes. Front claw shape and RC were highly genetically correlated (r = 0.80) with each other but were not as significantly correlated with FA, FHD, RA, RHD (r = -0.43 to 0.38). This suggests that hoof angle/depth should be measured separately from claw shape. Rear leg side view, and RH had a strong correlation (r = 0.69). Strong correlations between FSV, HO, and KO also existed, yet there was noticeable variation among point estimates and standard error. Six traits on the 1-9 scale were selected to generate estimated breeding values (EBV’s) based on their heritability and correlation with other traits; BCS RHD, RC, FS, RSV, RH. A linear model was used to determine breeding values for BCS, RHD, RC, FS, FSV and RH. Those breeding values were regressed on Stayability EPD. When fixed effects of herd, age and year born were accounted for, RC (P < 0.0001), RSV (P = 0.0517), and FS (P = 0.086) had relationships as predictor variables for Stayability EPD. The use of feet and leg traits as predictor variables for improved Stayability EPD can be achieved with a simplified scoring system (1-9 vs. 1-100) in Red Angus cattle. By narrowing the number of traits needed to measure with a more simplified scoring method should allow for more rapid adoption among current beef cattle producers. A greater number of observations could be useful to validate these results and provide more accurate point estimates for feet and leg trait heritabilities and correlations.