From Stereogram to Surface: How the Brain Sees the World in Depth

When we look at a scene, how do we consciously see surfaces infused with lightness and color at the correct depths? Random Dot Stereograms (RDS) probe how binocular disparity between the two eyes can generate such conscious surface percepts. Dense RDS do so despite the fact that they include multiple false binocular matches. Sparse stereograms do so even across large contrast-free regions with no binocular matches. Stereograms that define occluding and occluded surfaces lead to surface percepts wherein partially occluded textured surfaces are completed behind occluding textured surfaces at a spatial scale much larger than that of the texture elements themselves. Earlier models suggest how the brain detects binocular disparity, but not how RDS generate conscious percepts of 3D surfaces. A neural model predicts how the layered circuits of visual cortex generate these 3D surface percepts using interactions between visual boundary and surface representations that obey complementary computational rules.Air Force Office of Scientific Research (F49620-01-1-0397); National Science Foundation (EIA-01-30851, SBE-0354378); Office of Naval Research (N00014-01-1-0624

Constructing an overall dynamical model for a system with changing design parameter properties

This study considers the identification problem for a class of non-linear parameter-varying systems associated with the following scenario: the system behaviour depends on some specifically prescribed parameter properties, which are adjustable. To understand the effect of the varying parameters, several different experiments, corresponding to different parameter properties, are carried out and different data sets are collected. The objective is to find, from the available data sets, a common parameter-dependent model structure that best fits the adjustable parameter properties for the underlying system. An efficient Common Model Structure Selection (CMSS) algorithm, called the Extended Forward Orthogonal Regression (EFOR) algorithm, is proposed to select such a common model structure. Two examples are presented to illustrate the application and the effectiveness of the new identification approach

Fees on Fees in Funds of Funds

Funds of funds are an increasingly popular avenue for hedge fund investment. Despite the increasing interest in hedge funds as an alternative asset class, the high degree of fund specific risk and the lack of transparency may give fiduciaries pause. In addition, many of the most attractive hedge funds are closed to new investment. Funds of funds resolve these issues by providing investors with diversification across manaager styles and professional oversight of fund operations that can provide the necessary degree of due diligence. In addition, many such funds hold shares in hedge funds otherwise closed to new investment allowing smaller investors access to the most sought-after managers. However, the diversification, oversight and access comes at the cost of a multiplication of fees paid by the investor. One would expect that the information advantage of funds of funds would more than compensate investors for these fees. Unfortunately, individual hedge funds dominate fund of funds on an after-fee return or Sharpe ratio basis. In this paper we argue that the disappointing after-fee performance of some fund of funds may be explained by the nature of this fee arrangement. Fund of funds providers pass on individual hedge fund incentive fees in the form of after-fee returns, although they are in a better position to hedge these fees than are their investors. We examine a new fee arrangement emerging in the industry that may provide better incentives at a lower cost to investors in these funds.

Haemostatic status in patients with ovarian cancer compared with patients with benign ovarian cysts and the study of the relationships between haemostatic levels in ovarian cancer patients with known survival outcome

Ph.DDOCTOR OF PHILOSOPH

"GREEN TAXES": IMPACTS ON NATIONAL INCOME, SOCIAL WELFARE, AND ENVIRONMENTAL QUALITY

Two taxation schemes were designed to be included in a multi-regional multi-sectoral General Equilibrium model for reducing the use of commercial fertilizers, with the goal of alleviating surface water pollution. Under the 500% tax rate, results showed that 0.1% of the national income was given up in order to exchange for a 3% reduction in the fertilizer application used as an intermediate input. Furthermore environmental quality would be improved by 3%, if a linear relationship existed between the changes in intermediate fertilizer use and the improvement in environmental quality.Environmental Economics and Policy,

Invasive fungal infections secondary to traumatic injury

Invasive fungal infection (IFI) is a rare but serious complication of traumatic injury. The purpose of this article is to review the epidemiology, natural history, mycology, risk factors, diagnosis, treatment, and outcomes associated with post-traumatic IFI in military and civilian populations. The epidemiology of post-traumatic IFI is poorly characterized, but incidence appears to be rising. Patients often suffer from severe injuries and require extensive medical interventions. Fungi belonging to the order Mucorales are responsible for most post-traumatic IFI in both civilian and military populations. Risk factors differ between these cohorts but include specific injury patterns and comorbidities. Diagnosis of post-traumatic IFI typically follows positive laboratory results in the appropriate clinical context. The gold standard of treatment is surgical debridement in addition to systemic antifungal therapy. Patients with post-traumatic IFI may be at greater risk of amputation, delays in wound healing, hospital complications, and death as compared to trauma patients who do not develop IFI. More research is needed to understand the factors surrounding the development and management of post-traumatic IFI to reduce the significant morbidity and mortality associated with this disease