Reducing Tumour Volume Uncertainty for the Benefit of Radiation Therapy Cancer Patients

The efficacy of radiotherapy is dependent on its precision and accuracy. Increasingly conformal, modulated radiation fields can be reproducibly delivered to small, complex volumes within the human body. However, treatment is not without uncertainty. This thesis focuses on limitations in radiotherapy accuracy due to uncertainty in delineation of the volume requiring treatment

WILLINGNESS TO PAY FOR LOCAL COHO SALMON ENHANCEMENT IN COASTAL COMMUNITIES

Salmon restoration and enhancement are dominant environmental policy issues in Oregon and Washington. In response to salmon species listings under the Endangered Species Act, salmon protection and recovery actions are being implemented throughout the Pacific Northwest at substantial opportunity costs. In this paper, we examine the willingness to pay (WTP) of coastal residents for local coho salmon enhancement programs. A contingent valuation study is completed using survey responses from five rural, coastal communities of Oregon and Washington, where coho salmon are prevalent. Our empirical results indicate that coastal residents are willing to pay for local coho salmon enhancement and that WTP varies considerably with individual opinions of the merit of the enhancement program.Resource /Energy Economics and Policy,

Leptophilic Dark Matter with Z′Z' interactions

We consider a scenario where dark matter (DM) interacts exclusively with Standard Model (SM) leptons at tree level. Due to the absence of tree-level couplings to quarks, the constraints on leptophilic dark matter arising from direct detection and hadron collider experiments are weaker than those for a generic WIMP. We study a simple model in which interactions of DM with SM leptons are mediated by a leptophilic $Z'$ boson, and determine constraints on this scenario arising from relic density, direct detection, and other experiments. We then determine current LHC limits and project the future discovery reach. We show that, despite the absence of direct interactions with quarks, this scenario can be strongly constrained.Comment: 12 pages, 15 figure

Bereavement among Urban University Students: The Role of Meaning Making in Adjustment to Loss

Employing Neimeyer\u27s theory of meaning reconstruction as a guiding framework, this study examined meaning making in a diverse sample of bereaved university students. The aims of this study were to 1) identify types of meanings made about loss, 2) examine socio-demographic and bereavement-related characteristics that might influence meaning making, and 3) investigate associations between types of meanings and post-loss psychological adjustment. Participants were 229 students from an urban commuter university. This was a cross-sectional study, employing self-report data collected on a secure, Web-based system. Participants were 18 years or older and had experienced the loss of a friend or family member within the last three years. Bereavement-related meaning making was assessed using four measures of sense-making, cognitive appraisal, religious/spiritual meaning, and impact on identity. Participants were diverse in age (18 - 61 years, M = 24.18), race (55% White/Caucasian, 15.3% Asian, 14.4% Latino/a, 14.4% Black/African American, and 10.4% multi-racial/other), and religious background (25% atheist, 28% agnostic, 53% affiliated with a religion, and 6% spiritual/not religious). The majority lost a family member (66.7%), rather than a friend. Cause of death was due to natural (64.5%) or unnatural/violent causes and the mean time since death was 17.2 months. Principal components analysis identified five interpretable factors of meaning making: 1) personal growth, 2) positive reframing, 3) spiritual/religious meaning, 4) causal attribution, and 5) rumination/impact on identity. After controlling for covariates, each of the factors was regressed onto positive affect (PANAS), depression (CES-D), posttraumatic stress (PCL-S), and prolonged grief (PGD-13). Results of this study indicated that bereaved students made positive and negative secular and religious meanings about loss. Meaning making factors were influenced by socio-demographic and bereavement-related characteristics, in particular a closer relationship with the deceased, cause of death due to unnatural/violent causes, and younger age of the deceased when he or she died. These characteristics may make it more difficult for survivors to make sense and find meaning in a loss. Difficulty making sense was associated with higher distress, including symptoms of depression, PTSD, and prolonged grief as well as lower positive affect. Future studies are warranted to examine specific cultural influences and the clinical significance of ascribing meaning to loss among underserved groups