Information-adaptive clinical trials: a selective recruitment design

We propose a novel adaptive design for clinical trials with time-to-event outcomes and covariates (which may consist of or include biomarkers). Our method is based on the expected entropy of the posterior distribution of a proportional hazards model. The expected entropy is evaluated as a function of a patient's covariates, and the information gained due to a patient is defined as the decrease in the corresponding entropy. Candidate patients are only recruited onto the trial if they are likely to provide sufficient information. Patients with covariates that are deemed uninformative are filtered out. A special case is where all patients are recruited, and we determine the optimal treatment arm allocation. This adaptive design has the advantage of potentially elucidating the relationship between covariates, treatments, and survival probabilities using fewer patients, albeit at the cost of rejecting some candidates. We assess the performance of our adaptive design using data from the German Breast Cancer Study group and numerical simulations of a biomarker validation trial

Existence of global weak solutions to some regularized kinetic models for dilute polymers

Published versio

Farming the Program: Rent-seeking Behavior Among Farmers and the Associated Deadweight Loss

Farm Management,

The Incidence of U.S. Agricultural Subsidies on Farmland Rental Rates

Each year U.S. farmers receive more subsidies than needy families receive through welfare assistance or post-secondary students receive through student aid grants. Yet, who benefits from agricultural subsidies is an open question. Economic theory predicts the entire subsidy incidence should be on the farmland owners. Since non-farmers own nearly half of all farmland, this implies that a substantial portion of all subsidies accrue to non-farmers while a significant share of all farmers receive no benefits. Using a complementary set of policy quasiexperiments, I find that farmers who rent the land they cultivate capture 75 percent of the subsidy, leaving just 25 percent for landowners. This finding contradicts the prediction from neoclassical models. The standard prediction may not hold due to less than perfect competition in the farmland rental market; the share captured by landowners increases with local measures of competitiveness in the farm land rental market.Agricultural and Food Policy, Environmental Economics and Policy, Land Economics/Use,

Cash Flow and Agricultural Investments: Evidence from a Natural Experiment

Agricultural Finance,

Developing an early childhood teacher workforce development strategy for rural and remote communities

The North West Early Childhood and Primary Teacher Workforce Development Strategy offers students in the Pilbara and Kimberley the opportunity to enrol in a Western Australian University’s fully accredited Bachelor of Education (Early Childhood and Primary) part time and externally – so they can continue to live and work in their communities. The Western Australian Department of Education and Training (WA DET) and the Commonwealth Government Department of Education, Employment and Workplace Relations (DEEWR) have funded the project, enabling the University to provide mentoring support and provision for Recognition of Prior Learning, on a case-by-case basis, depending on their individual experience and levels of skill. On completion of the course students will be fully qualified to teach from Kindergarten to Year 7. Added to this they will be able to bring their own knowledge of their unique communities, languages and cultures to their teaching

Design and application of squeeze film dampers for turbomachinery stabilization

The steady-state transient response of the squeeze film damper bearing was investigated. Both the steady-state and transient equations for the hydrodynamic bearing forces are derived; the steady-state equations were used to determine the damper equivalent stiffness and damping coefficients. These coefficients are used to find the damper configuration which will provide the optimum support characteristics based on a stability analysis of the rotor-bearing system. The effects of end seals and cavitated fluid film are included. The transient analysis of rotor-bearing systems was conducted by coupling the damping and rotor equations and integrating forward in time. The effects of unbalance, cavitation, and retainer springs are included. Methods of determining the stability of a rotor-bearing system under the influence of aerodynamic forces and internal shaft friction are discussed