If We Pay Football Players, Why Not Kidney Donors

Ethicists who oppose compensating kidney donors claim they do so because kidney donation is risky for the donor’s health, donors may not appreciate the risks and may be cognitively biased in other ways, and donors may come from disadvantaged groups and thus could be exploited. However, few ethical qualms are raised about professional football players, who face much greater health risks than kidney donors, have much less counseling and screening concerning that risk, and who often come from racial and economic groups deemed disadvantaged. It thus seems that either ethicists—and the law—should ban both professional football and compensated organ donation, allow both, or allow compensated organ donation but prohibit professional football. The fact that we choose none of those options raises questions about the wisdom of the compensation ba

If We Pay Football Players, Why Not Kidney Donors

Ethicists who oppose compensating kidney donors claim they do so because kidney donation is risky for the donor’s health, donors may not appreciate the risks and may be cognitively biased in other ways, and donors may come from disadvantaged groups and thus could be exploited. However, few ethical qualms are raised about professional football players, who face much greater health risks than kidney donors, have much less counseling and screening concerning that risk, and who often come from racial and economic groups deemed disadvantaged. It thus seems that either ethicists—and the law—should ban both professional football and compensated organ donation, allow both, or allow compensated organ donation but prohibit professional football. The fact that we choose none of those options raises questions about the wisdom of the compensation ba

Substructure Discovery Using Minimum Description Length and Background Knowledge

The ability to identify interesting and repetitive substructures is an essential component to discovering knowledge in structural data. We describe a new version of our SUBDUE substructure discovery system based on the minimum description length principle. The SUBDUE system discovers substructures that compress the original data and represent structural concepts in the data. By replacing previously-discovered substructures in the data, multiple passes of SUBDUE produce a hierarchical description of the structural regularities in the data. SUBDUE uses a computationally-bounded inexact graph match that identifies similar, but not identical, instances of a substructure and finds an approximate measure of closeness of two substructures when under computational constraints. In addition to the minimum description length principle, other background knowledge can be used by SUBDUE to guide the search towards more appropriate substructures. Experiments in a variety of domains demonstrate SUBDUE's ability to find substructures capable of compressing the original data and to discover structural concepts important to the domain. Description of Online Appendix: This is a compressed tar file containing the SUBDUE discovery system, written in C. The program accepts as input databases represented in graph form, and will output discovered substructures with their corresponding value.Comment: See http://www.jair.org/ for an online appendix and other files accompanying this articl

A Primer on Kidney Transplantation: Anatomy of the Shortage

Kidneys are unique among the solid organs due to the combination of the low risk of living donation, the feasibility of sustaining life on dialysis for several years following kidney failure, and Medicare coverage of dialysis and transplantation for kidney patients. Despite these advantages, thousands of Americans die each year while waiting for a kidney transplant, and the waiting list grows each year. In this kidney transplantation primer, we provide a quantitative description of the kidney shortage and discuss future trends and possible solutions. We demonstrate that the current system provides only about half as many kidneys as are needed for transplantation and the gap cannot be eliminated through an increase in deceased donation alone, because most kidneys from suitable deceased donors are already procured. The prospects for increasing living donations under the current system are also dim. Donations from living kidney donors have declined from their 2003 peak and nearly all living kidney donations are directed by the donor, usually to family members, rendering the current account of living kidney donation as “altruistic” somewhat misleading. For all of these reasons, we believe the time is ripe to reconsider financial incentives for kidney donation. Needless to say, a system that provided financial rewards for living donors could produce unsavory consequences, and would have to be carefully designed and managed. But without such a system, the most likely version of the future is a continuation of unnecessarily high rates of death and disability from kidney failure

If We Allow Football Players and Boxers to be Paid for Entertaining the Public, Why Don’t We Allow Kidney Donors to be Paid for Saving Lives?

We contrast the compensation ban on organ donation with the legal treatment of football, boxing, and other violent sports where both acute and chronic injuries to participants are common. Our claim is that there is a stronger case for compensating kidney donors than for compensating participants in violent sports. If this proposition is accepted, one implication is that there are only three logically consistent positions: allow compensation for both kidney donation and for violent sports; allow compensation for kidney donation but not for violent sports; or allow compensation for neither. Our current law and practice is perverse in endorsing a fourth regime, allowing compensation for violent sports but not kidney donation. We base our argument chiefly on the medical risk to participants, the consent process, social justice concerns, and social welfare considerations. The medical risks to a professional career in football, boxing, and other violent sports are much greater both in the near and long term than the risks of donating a kidney. On the other hand, the consent and screening process in professional sports is not as developed as in kidney donation. The social justice concerns stem from the fact that most players are black and some come from impoverished backgrounds. Finally, the net social benefit from compensating kidney donors – namely, saving thousands of lives each year and reducing the suffering of 100,000 more receiving dialysis – far exceeds the net social benefit of entertaining the public through professional sports. In sum, the arguments against compensating kidney donors apply with equal or greater force to compensating athletes in these sport

Adaptive Parallel Iterative Deepening Search

Many of the artificial intelligence techniques developed to date rely on heuristic search through large spaces. Unfortunately, the size of these spaces and the corresponding computational effort reduce the applicability of otherwise novel and effective algorithms. A number of parallel and distributed approaches to search have considerably improved the performance of the search process. Our goal is to develop an architecture that automatically selects parallel search strategies for optimal performance on a variety of search problems. In this paper we describe one such architecture realized in the Eureka system, which combines the benefits of many different approaches to parallel heuristic search. Through empirical and theoretical analyses we observe that features of the problem space directly affect the choice of optimal parallel search strategy. We then employ machine learning techniques to select the optimal parallel search strategy for a given problem space. When a new search task is input to the system, Eureka uses features describing the search space and the chosen architecture to automatically select the appropriate search strategy. Eureka has been tested on a MIMD parallel processor, a distributed network of workstations, and a single workstation using multithreading. Results generated from fifteen puzzle problems, robot arm motion problems, artificial search spaces, and planning problems indicate that Eureka outperforms any of the tested strategies used exclusively for all problem instances and is able to greatly reduce the search time for these applications

Energy efficient engine. Volume 2. Appendix A: Component development and integration program

The large size and the requirement for precise lightening cavities in a considerable portion of the titanium fan blades necessitated the development of a new manufacturing method. The approach which was selected for development incorporated several technologies including HIP diffusion bonding of titanium sheet laminates containing removable cores and isothermal forging of the blade form. The technology bases established in HIP/DB for composite blades and in isothermal forging for fan blades were applicable for development of the manufacturing process. The process techniques and parameters for producing and inspecting the cored diffusion bonded titanium laminate blade preform were established. The method was demonstrated with the production of twelve hollow simulated blade shapes for evaluation. Evaluations of the critical experiments conducted to establish procedures to produce hollow structures by a laminate/core/diffusion bonding approach are included. In addition the transfer of this technology to produce a hollow fan blade is discussed

Streamlining the walls of an empty two-dimensional flexible-walled test section

The techniques used to find aerodynamically straight wall contours in a test section of a transonic wind tunnel are discussed. The walls were defined as aerodynamically straight up to Mach 0.9