Current Proposals (current + proposal)

Distribution by Scientific Domains


Selected Abstracts


Proposing magnetic nanoparticle hyperthermia in low-field MRI

CONCEPTS IN MAGNETIC RESONANCE, Issue 1 2010
Pádraig Cantillon-Murphy
Abstract This work examines feasibility, practical advantages, and disadvantages of a combined MRI/magnetic particle hyperthermia (MPH) system for cancerous tumor treatment in low perfusion tissue. Although combined MRI/hyperthermia systems have been proposed and constructed, the current proposal differs because the hyperthermia system would be specifically designed to interact with the magnetic nanoparticles injected at the tumor site. The proposal exploits the physical similarities between the magnetic nanoparticles currently employed for MPH and those used as superparamagnetic iron oxide (SPIO) contrast agents in MR imaging. The proposal involves the addition of a rotating magnetic field RF hyperthermia source perpendicular to the MRI B0 field which operates in a similar manner to the MRI RF excitation field, B1, but at significantly higher frequency and field strength such that the magnetic nanoparticles are forced to rotate in its presence. This rotation is the source of increases in temperature which are of therapeutic benefit in cancer therapy. For rotating magnetic fields with amplitudes much smaller than B0, the nanoparticles' suspension magnetization rapidly saturates with increasing B0. Therefore, the proposal is best suited to low-field MRI systems when magnetic saturation is incomplete. In addition, careful design of the RF hyperthermia source is required to ensure no physical or RF interference with the B1 field used for MRI excitation. Notwithstanding these caveats, the authors have shown that localized steady-state temperature rises in small spherical tumors of up to 10°C are conceivable with careful selection of the nanoparticle radius and concentration, RF hyperthermia field amplitude and frequency. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 36,47, 2010. [source]


Incorporating Collateral Value Uncertainty in Loss Given Default Estimates and Loan-to-value Ratios

EUROPEAN FINANCIAL MANAGEMENT, Issue 3 2003
Esa Jokivuolle
Abstract We present a model of risky debt in which collateral value is correlated with the possibility of default. The model is then used to study the expected loss given default, primarily as a function of collateral. The results obtained could prove useful for estimating losses given default in many popular models of credit risk which assume them constant. We also examine the problem of determining sufficient collateral to secure a loan to a desired extent. In addition to bank practitioners, regulators might find our analysis useful in reviewing banks' lending standards relative to current collateral values. In particular, the current proposals for The New (Basel) Capital Accord involve options for the use of banks' own loss given default estimates which might benefit from the analysis in this paper. [source]


Nationalism in Winter Sports Judging and Its Lessons for Organizational Decision Making

JOURNAL OF ECONOMICS & MANAGEMENT STRATEGY, Issue 1 2006
Eric Zitzewitz
This paper exploits nationalistic biases in Olympic winter sports judging to study the problem of designing a decision-making process that uses the input of potentially biased agents. Judges score athletes from their own countries higher than other judges do, and they appear to vary their biases strategically in response to the stakes, the scrutiny given the event, and the degree of subjectivity of the performance aspect being scored. Ski jumping judges display a taste for fairness in that they compensate for the nationalistic biases of other panel members, while figure skating judges appear to engage in vote trading and bloc judging. Career concerns create incentives for judges: biased judges are less likely to be chosen to judge the Olympics in ski jumping but more likely in figure skating; this is consistent with judges being chosen centrally in ski jumping and by national federations in figure skating. The sports truncate extreme scores to different degrees; both ski jumping and, especially, figure skating are shown to truncate too aggressively. Extreme truncation not only discards information, but may also make the vote trading in figure skating easier to implement. These findings have implications for both the current proposals for reforming the judging of figure skating and for designing decision making in organizations more generally. [source]


Constructing Compliance: Game Playing, Tax Law, and the Regulatory State

LAW & POLICY, Issue 1 2007
SOL PICCIOTTO
This article proposes a rethinking of approaches to compliance, extending perspectives that view regulation as an interactive or reflexive process mediated by sociolinguistic practices. These suggest that the meaning of rules is not fixed ex ante, but may emerge and change through such interactions, which therefore actually help to construct what it means to comply. The analysis supports proposals to base tax law on purposive general principles combined with detailed rules. However, it suggests that this should be the approach adopted for the tax code as a whole, instead of focusing mainly on the merits of a general anti-avoidance principle, as some of the recent debates have done. The article explores the question of interpretation of rules and the problem of avoidance and game playing. It reexamines the issue of the indeterminacy of rules and relocates it within the context of professional and regulatory practices, suggesting that it is these interactions that construct the meaning of rules and hence of compliance. The analysis is applied to income taxation, to sketch out how the international tax system has been constructed through the interaction of contending views of fairness in the allocation of tax jurisdiction, while in the process becoming refined into a formalist and technicist process of game playing. It argues that the central factor in this process has been the inherent contestability of the core concepts of international taxation, the rules on corporate residence and source of income. The article concludes by considering some of the current proposals for improving tax compliance, in particular by reducing complexity, improving clarity, and the use of broad principles. [source]


"Health Courts" and Accountability for Patient Safety

THE MILBANK QUARTERLY, Issue 3 2006
MICHELLE M. MELLO
Proposals that medical malpractice claims be removed from the tort system and processed in an alternative system, known as administrative compensation or ,health courts,' attract considerable policy interest during malpractice ,crises,' including the current one. This article describes current proposals for the design of a health court system and the system's advantages for improving patient safety. Among these advantages are the cultivation of a culture of transparency regarding medical errors and the creation of mechanisms to gather and analyze data on medical injuries. The article discusses the experiences of foreign countries with administrative compensation systems for medical injury, including their use of claims data for research on patient safety; choices regarding the compensation system's relationship to physician disciplinary processes; and the proposed system's possible limitations. [source]