Designing a Compensated–Kidney Donation System

Osteochondral lesions of the talus (OLTs) are the third most common type of osteochondral lesion and can cause pain and instability of the ankle joint. Episurf Medical AB is a medical technology company that develops individualized implants for patients who are suffering from focal cartilage lesions. Episurf have recently started a project that aims to implement their implantation technique in the treatment of OLTs. This master thesis was a part of Episurf’s talus project and the main goal of the thesis was to find the optimal implantation angle of the Episurf implant when treating OLTs. The optimal implantation angle was defined as the angle that minimized the maximum equivalent (von Mises) strain acting on the implant shaft during the stance phase of a normal gait cycle. It is desirable to minimize the strain acting on the implant shaft, since a reduction of the strain can improve the longevity of the implant. To find the optimal implantation angle a finite element model of an ankle joint treated with the Episurf implant was developed. In the model an implant with a diameter of 12 millimeters was placed in the middle part of the medial side of the talar dome. An optimization algorithm was designed to find the implantation angle, which minimized the maximum equivalent strain acting on the implant shaft. The optimal implantation angle was found to be a sagittal angle of 12.5 degrees and a coronal angle of 0 degrees. Both the magnitude and the direction of the force applied to the ankle joint in the simulated stance phase seemed to influence the maximum equivalent strain acting on the implant shaft. A number of simplifications have been done in the simulation of this project, which might affect the accuracy of the results. Therefore it is recommended that further, more detailed, simulations based on this project are performed in order to improve the result accuracy.Fokala broskskador på talusbenet är den tredje vanligaste typen av fokala broskskador och kan ge upphov till smärta och instabilitet av fotleden. Episurf Medical AB är ett medicintekniskt företag som utvecklar individanpassade implantat för patienter med fokala broskskador. Episurf har nyligen påbörjat ett projekt där deras teknik ska användas i behandlingen av fokala broskskador på talusbenet. Den här masteruppsatsen var en del i Episurfs talusprojekt och dess huvudmål var att finna den optimala implantationsvinkeln av Episurfs implantat i behandlingen av fokala broskskador på talusbenet. Den optimala implanteringsvinkeln definierades som den vinkel som minimerade den effektiva von Mises-töjningen som verkade på implantatskaftet under stance-fasen i en normal gångcykel. Det är eftersträvansvärt att minimera belastningen på implantatskaftet eftersom en reducering av belastningen kan förbättra implantatets livslängd. En finita element-modell av en fotled behandlad med Episurfs implantat utvecklades för att för att finna den optimala implantationsvinkeln. I modellen placerades ett implantat med en diameter på 12 millimeter på mittendelen av talus mediala sida. En optimeringsalgoritm utformades för att finna implantationsvinkeln som minimerade den effektiva von Mises-töjningen på implantatskaftet. Den funna optimala implantationsvinkeln bestod av en vinkel på 12.5 grader i sagittalplan och en vinkel på 0 grader i koronalplan. Både storleken och riktningen på kraften som applicerats på fotleden under den simulerade stance-fasen av gångcykeln verkade påverka belastningen på implantatskaftet. Ett antal förenklingar har gjorts i projektets simuleringar, vilket kan påverka noggrannheten i resultatet. Därför rekommenderas att ytterligare, mer detaljerade simuleringar baserade på det här projektet görs för att förbättra resultatets noggrannhet

A Time-Series Analysis of U.S. Kidney Transplantation and the Waiting List: Donor Substitution Effects and "Dirty Altruism"

This paper provides an econometric analysis of the relationship between live and deceased (cadaveric) kidney donations for the United States for the period 1992:IV through 2006:II. Statistical analysis shows that increases in deceased donor transplants reduce future live donor grafts, controlling for both waiting list effects and exogenous trends. This result has important, and potentially dire, implications for efforts to reduce the organ shortage by increasing use of cadaver donors.Kidney Transplantations; Donor Substitution Effects; Dirty Altruism; Cointegration

Market Definition and the Economic Effects of Special Access Price Regulation

Market definition is an essential ingredient to competitive and regulatory analysis. Yet, there is significant disparity regarding the definition of the relevant geographic market for high-capacity circuits, commonly referred to as Special Access services. Given the present debate over expanding price regulation in this sector, the importance of market definition on the expected economic effects of regulation is worth evaluating. In this article, we demonstrate that if geographic markets are “location specific” and supplied by a monopolist as the proponents of regulation claim, then price regulation reduces economic welfare in all instances. That is, even with monopoly supply, regulation offers no improvement in economic welfare, meaning the debates over the extent of competition and profit margins in such markets are irrelevant. The effect of regulation is mostly to transfer profits from sellers to buyers, so the debate appears to be largely a squabble over rents. That said, every $1 of transfer costs more than$1 to society, so regulation reduces welfare. This analysis demonstrates that the present case for regulating high-capacity services is woefully inadequate and poorly conceived

A Policy Framework for Spectrum Allocation in Mobile Communications

With the National Broadband Plan\u27s promise of an additional 500 MHz of spectrum for commercial purposes, the question of how to allocate those resources among competing uses and users will dominate the communications policy debate over the coming years. In this Article, the Authors provide a theoretical analysis of some of the relevant tradeoffs involved in allocating spectrum among service providers, with a particular focus on incumbent exclusion rules such as spectrum caps. Two key assumptions center the analysis: (i) more firms implies lower prices (i.e., Cournot competition); and (ii) more spectrum permits more advanced services due to greater capacity and throughput. The derived theoretical tradeoff is straightforward: In a setting with many firms with little spectrum, there are low prices but relatively less advanced services; however, in a setting with fewer firms with larger allotments of spectrum, there may be higher prices but also more advanced services. The Authors\u27 analysis highlights several key components of the spectrum allocation decision. First, an incumbent-exclusion rule is not proentry, but instead seeks to select one form (price cutting) of entry over another (quality improving). Second, given the existing number of firms, the potential for sizeable competitive price effects is low. Third, the economic benefits of advanced wireless services are likely to be very high. Fourth, access to spectrum resources does not necessarily convey financial success, as spectrum is but one of many inputs necessary to provide service. In all, the Authors believe these facts, interpreted in the context of the theory, suggest incumbent exclusion rules are not welfare enhancing, at least in the United States

The Broadband Adoption Index: Improving Measurements and Comparisons of Broadband Deployment and Adoption

Countries around the world are increasingly concerned as to whether the adoption of broadband technology by their respective citizens is sufficient to support economic growth and social development. Unfortunately, such concerns are often expressed in terms of where a country ranks among its peers by means of raw adoption numbers. Such raw data are often misleading and incomplete. In this Article, we propose a different and more policy-relevant approach to adoption measurement. We develop a value-based Broadband Adoption Index (BAI) that compares the actual value to society that results from the adoption of broadband technology to a target level of adoption value. This target level will vary from country to country and is a function of the social value of broadband connectivity, measured as the difference in the social benefits and the costs of broadband. The BAI is specifically designed to accommodate and include the value of different connection modalities, like mobile broadband, into a single index-something that merely summing the number of connections cannot do. We believe that policymakers can adopt aspects of the BAI approach immediately, with particular attention to collecting and using proper information for policy decisions