Blockchain Papers

Celeste-Marie Bernier

Material proofs or Imaginary Property? Complex intellectual, historical and cultural relationships have always existed between the experimentation with rhetoric and the spectacle of the slave body in abolitionist literature. This article debates the challenges the eighteenth and nineteenth century writers offered to the widespread representation of the slave body within mainstream North American, British and Caribbean abolitionist discourse. The commitment of writers such as Robert Wedderburn, Phillis Wheatley, David Walker and Jupiter Hammon to experimental language and subject-matter testifies to the existence of a radical literary tradition much earlier than the popularly examined mid-nineteenth century authors, including Frederick Douglass and Harriet Jacobs. These earlier figures were intent, not only upon extending the permissible boundaries of abolitionist representation, but also in staking a claim for the politically liberating potential of the literary imagination in a fight for the right to aesthetic experimentation.

Kun Peng, Colin Boyd, Ed Dawson

The batch verification technique of Bellare et al. is extended to verification of several frequently employed zero-knowledge proofs. The new techniques are correct, sound, efficient, and can be widely applied. Specific applications are discussed in detail, including batch ZK proof and verification of validity of encryption (or reencryption) and batch ZK proof and verification of validity of decryption. Considerable efficiency improvements are gained in these two applications without compromising security. As a result, efficiency of the practical cryptographic systems (such as mix networks) based on these two applications is dramatically improved.

Bernard Chazelle

No abstract is available for this record.

John Loughlin

Subnational Government: The French Experience is the most comprehensive and up to date treatment in English of the transformation of local governance in France since the 1982 decentralization reforms. It places these reforms and their consequences in the historical context of French nation-building, socio-economic changes within France and in relation to international trends in territorial governance. The book argues that we are witnessing a transformation of the classical Jacobin unitary state and the end of the old system of central-local relations which underpinned this. It examines the evolution of the municipalities and the attempts to overcome the problem of their vast number through various forms of association. It analyses the struggle for dominance between the departments and regions, the link between decentralization and reform of the state, the role of politicians and of electoral systems and it is all financed. The book combines meticulous empirical research with clear theoretical analysis.

Frank H Hamilton

“As it is now, the unfortunate patient tries to retrieve his bad luck by levying upon the hard working surgeon without risking or staking anything for the chance of testing what may prove to be no case at all … The suit depletes the surgeon's pocket and ruins his reputation. To pay is ruinous, to defend is ruinous, and to live in constant dread is ruinous … The plaintiff carries around a lame leg with the surgeon's money to support it, and the surgeon carries around a lame reputation with nothing to support it.” These comments appeared in the Boston Medical and Surgical Journal on January 9, 1879.7 They point out that patients in the United States were as litigious in the 19th century as they are today, and most of the cases involved the end results of the treatment of fractures and dislocations.1 Four years prior to being elected president, Abraham Lincoln successfully defended two physicians sued by a patient whose fractured leg had healed with some shortening.4 That the results of treatment were often poor (and sometimes disastrous) is not surprising as anesthesia was not introduced until 1846, antisepsis and asepsis until 1867-1885, and X-rays until 1895. Reports on the end results of the treatment of fractures were limited, vague, and anecdotal, and provided no information on what result could be anticipated in an “average case.” This is why the publication by Frank Hastings Hamilton (Fig. 1) of statistical tables that detailed the end results in a large group of patients with a wide variety of fractures was so important. These tables served as a standard against which an individual case could be compared and “had an incalculable influence on the results of suits for malpractice.”5 Originally published piecemeal in the Transactions of the American Medical Association, they were collected into a single volume in 1855.2 It is the preface to that collection that is presented here. Hamilton was born in Vermont in 1813. He was educated in Schenectady, New York and obtained a bachelor of arts degree from Union College in 1830. He began to study medicine as a preceptee, attended the College of Physicians and Surgeons of Fairfield, New York, and received the degree of doctor of medicine from the University of Pennsylvania in 1833. He entered practice and taught at medical schools in Fairfield and Geneva. After an extended trip to Europe, where he visited the major clinics and hospitals, he became a professor of surgery at the medical school in Buffalo, New York, which opened in 1847. An early advocate of the use of ether anesthesia, Hamilton had a varied surgical practice. In 1854 he performed the first cross-leg pedicle graft.6 The majority of his practice involved the treatment of skeletal injuries. In 1859 he followed his colleague, Austin Flint, to the Long Island College of Medicine. A short time later the first edition of A Practical Treatise on Fractures and Dislocations appeared.3 This contained a good deal of material gleaned from his fracture tables and from his observations made during his foreign travels. It is noteworthy as being the first textbook in English to completely cover the subject. After a period of distinguished service in the Medical Corps during the Civil War, Hamilton returned to New York where he became a professor of surgery at Bellevue Hospital. An indication of his reputation can be seen in that he was called as a consultant after President Garfield had been shot. Hamilton died in 1886 from the effects of pulmonary tuberculosis. Leonard F. Peltier, MD, PhD I propose to deduce from my own experience, and from the experience of other surgeons, as recorded in this report, the true prognosis of fractures. This I shall endeavor to do with care and fidelity, avoiding, on the one hand, if possible, the error of encouraging the practitioner with a prognosis too favorable, and, on the other, the equal wrong of leaving him to expect too little. To this end, I shall draw from my hospital and private records such cases as have come under my immediate care, describing, as briefly as will be consistent with my purpose, all those circumstances connected with each fracture which might in any way modify the result, together with the plan of treatment, and finally, the precise amount and character of the imperfection, or maiming, if any, which remains. I shall not, however, confine myself to my own cases; but, so far as I am able, I shall record the cases which have been treated by other regularly qualified surgeons, and which have subsequently passed under my own observation. This is necessary not only as a vindication of my own practice and reputation, of which one must naturally feel jealous, but more especially that my conclusions may have, what you have a right to demand for them, the weight of authority. I shall, therefore, ask the liberty of reporting the practice of my contemporaries, and of mentioning their names, that you may judge for yourselves whether they constitute proper representatives of the present condition of our art. Of this, I trust, no one will complain, since without such permission I would not have ventured upon the duty assigned me, nor do I believe any one else would have consented to have occupied my place. It is certain that, up to this moment, no one has volunteered to state fully what have been the results in his own practice, or in the practice of the hospital, or other similar institutions, which have been under his immediate charge. In hospital records, you may find patients admitted with fractures, and reported as “dead,” or as dismissed “cured,” with the occasional interpolation of “a good leg;” and, upon these records, tables have been constructed to determine the average fatality of such accidents, and the probabilities of cure; but I have not yet seen any published reports declaring what was the exact amount and value of the “cure”-how much the bone was shortened, or bent, or otherwise maimed and deformed. In short, they still fail to inform us what are the “deformities after fractures,” which, under fair treatment, may reasonably be expected. Dr. Wallace published, in 1839, a statistical account of the eighteen hundred fractures which had been treated in the Pennsylvania Hospital from its foundation up to the year 1838; and Dr. Norris published, soon after, a similar report of the fractures treated in the same institution between the years 1830 and 1839, inclusive; but neither of these gentlemen make any reference to a shortening, or to any degree of deformity which may have occurred in the cases reported as cured. Dr. Peirson, in his report of the statistical tables of all the fractures which had occurred in the Massachusetts General Hospital up to the year 1840, notices, under the head of “Remarks,” many interesting facts, such as delayed or non-union, the occurrence of ulcers, gangrene, &c. &c.; but there is nothing exactly pertinent to the subject of our inquiry. Dr. Lente, who has recorded the statistics of fractures treated at the New York Hospital for the twelve years preceding 1851, has attempted to supply the deficiency, which he declares does exist in the hospital records, upon this subject, by his own “personal experience of several years in the practice of the hospital, and by conversation with other surgeons who have been connected with it.” But he has limited his statements to what he believes to have been the average results, as regards shortening, in the treatment of fractures of the femur. The statistics furnished by Lonsdale, of the Middlesex Hospital of London, and by Fricke, of the General Hospital at Hamburg, are equally silent upon the subject of deformities or shortening. The same disinclination to approach this subject is manifested by those who have written special or general treatises upon fractures, and who, with the single exception of Malgaigne, will be found either to have ignored prognosis altogether, or they have seemed to speak of it only casually, and without any numerical basis for their calculations, since, among writers of equal experience and reputation, there exist the widest discrepancies of opinion. An example will illustrate what I have said. Chelius, writing of fractures of the thigh-bone, says: “Fracture of the thigh-bone is always a severe accident, as the broken bones are retained in proper contact with great difficulty. The cure takes place most commonly with deformity and shortening of the limb, especially in oblique fractures, and those which occur in the upper and lower third of the thigh-bone.” To which Mr. South, the translator, and Surgeon to St. Thomas's Hospital, appends the following note: “In simple fractures of the thigh-bone, except with great obliquity, I have rarely found difficulty in retaining the broken ends in place, and in effecting the union without deformity, and with very little, and sometimes without any, shortening. For the contrary results the medical attendant is mostly to be blamed, as they are usually consequent on his own carelessness or ignorance.” (Chelius's Surgery, by South, American edition, vol. i. p. 627.) Even Malgaigne, to whose recent work, entitled, Traité des Fractures et des Luxations, I shall hereafter have frequent occasion to refer, and who speaks generally with a precision which indicates a careful observation of the facts, does not intimate the existence of any exact records, either in his own practice or in the practice of others, from which his conclusions have been deduced. In looking for an explanation of this seeming indifference, or palpable ignorance, upon a subject of such manifest importance both to surgeons and to their patients, I find several probable causes. I suppose that most practical surgeons have a tolerably correct appreciation of prognosis in fractures. I say tolerably, because I wish to imply a qualification. I do not think that a majority of even “practical” surgeons have a full appreciation of the subject. I am frank to confess that, until I commenced these investigations, I had not any just notions of the frequency of deformities after fractures. Nor can I now understand how any surgeon, who does not carefully measure limbs with a rule or with a graduated tapeline, can have possessed himself of any very accurate information upon that point. Yet I appeal to surgeons whether this has been their constant or even their general practice? or whether they have not usually adopted, in measuring the lower extremities, that more simple, yet always unreliable method of placing the limbs parallel, knee to knee and heel to heel? or whether they have not as often contented themselves with the averment of the patient himself, that the limb was perfect? and, indeed, whether, in case of a fractured arm or radius and ulna, they have, in one case out of ten, instituted any sort of inquiry or examination by which their relative length might be determined?* I address hospital surgeons as well as surgeons in private practice. Let them answer to themselves these interrogatories. If such examinations can be shown to have occasionally been made, we still venture to affirm that, in no instance, for any considerable length of time, have regular records of exact results been kept. Nor do I expect that, upon my humble remonstrance, such records, fairly made, will hereafter be kept. Surgeons who have the charge of public hospitals understand that the eyes of their pupils, their governors, their confrères, and of the public even are upon them, and it is attributing to them nothing more than a common frailty to charge that they dare not record faithfully their results in the treatment of fractures. To be honest in the admission of shortcomings in a branch of our art, where the difficulties are so little understood by those who constitute themselves our judges, would be suicidal. Do you not see that jealous and designing colleagues would have no such discreditable results? Pupils would draw unfavorable comparisons, and desert the wards where failures were so common; rival hospitals would secretly or openly seize upon such records to their own advantage; and the patients themselves would, no doubt, often return the diligence, skill, and honesty of their surgeons with imprecations and prosecutions. There is, gentlemen, no lack of charity in these suppositions. We are to take men as they are, and as they are well enough known to be, and not as we would have them; and it is in vain to deny that such are the fair risks which strict honesty in this matter must incur. The instinct of self-preservation, therefore, prompts to silence, or to the most favorable representations. Students will continue to go out from our hospitals with a belief that perfect union of broken bones is the rule, and that exceptions imply generally unskilful management; and if, when hereafter they have themselves occasion to treat a fractured femur, the result falls short of their standard of perfect success, they, taught also by the same instinct of self-preservation which actuated their teachers, will conceal the truth from others, and even from themselves, if possible. Nay, I fear that sometimes, under the same urgent promptings, and where the moral sense is not superior to all other considerations, they may hesitate to regard the sanctity of an oath! How else shall we explain the testimony of that man who, with uplifted hand, affirms that he has “seen and treated ten fractures of the femur, in adult persons, and not one of them is in any way shortened or deformed?” Or what less charitable construction will you place upon the published averment of a hospital surgeon in a neighboring province, who, in his remarks upon my “fracture tables,” as reported by my late pupil, Dr. Boardman, some years ago, declares that he has lately treated at the hospital under his care one case of fractured inferior maxilla; three cases of broken clavicles, two of which were at the outer third; seven of fractured femur, one of which was compound and one comminuted; eight cases of fracture of the tibia and fibula, two of which were comminuted and one compound-in all nineteen cases, and that, with the exception of one who died, every case resulted in a perfect cure? It is more than probable that the writer will not escape similar criticisms hereafter, and that his report may be regarded as giving a true representation of American surgery, but as scarcely applicable to the surgery of others. In reply to a sentiment so illiberal, I beg to say, in anticipation, that having myself visited a majority of the large hospitals of Great Britain, and very many upon the continent of Europe, and having observed carefully their methods of treatment, and, in some measure, noticed their success, I am prepared to affirm that, in so far as I have yet seen, the practice of American surgeons, in the management of fractures, compares favorably with that of any other people. The English themselves are constantly proclaiming their deficiency in this department of surgery. It is now more than one hundred years since Pott, then Surgeon to St. Bartholomew's Hospital, inquired of his brethen if it was not “notorious” that in England broken thighs and legs were “often, very often, left deformed, crooked, and shortened?” But, notwithstanding Pott believed that he had discovered the true cause of these deformities, and had devised a remedy which must in future secure to his countrymen comparative eminence in this branch, yet today Mr. Skey, the very distinguished successor of Mr. Pott in the same great hospital, finds occasion to say: “One is therefore at a loss to find any apology for those surgeons to whose want of care, and even of humanity, may be attributed the numerous examples of distorted and contracted members, which have cast a reproach on the surgery of Great Britain.” (Skey's Operative Surgery, American edition, p. 140.) For myself, while I take these admissions as evidence that Americans are quite as expert in the dressing of broken bones as the English, I am nevertheless much more charitable to their failures than they are themselves. To me these admissions only confirm a long-nourished conviction that neither in Great Britain nor in the United States, nor in any other part of the world, has the art of treating fractures attained that degree of perfection which surgeons have almost universally claimed for it. If my reviewers deny the correctness of my conclusions, I trust they will do me the justice to accompany their denial with proofs of the same specific character, and obtained in the same careful manner, with those evidences which I shall present. Finally, no man can be more sensible than myself of the imperfect manner in which I have accomplished the duty which you have imposed upon me, and especially since, while I have only contributed a limited experience to the elucidation of a very important subject-the subject of Prognosis in Fractures-I have, to an extent still more limited, contributed suggestions or experience in relation to better or more successful modes of treatment. Yet I trust no one will, for that cause, censure an humble beginning. Others may yet complete what I have only commenced. “Admit that bones and patients are and always have been contumacious and refractory.” What then? “What good,” do you ask, “can be accomplished by exposing our failures, unless we have found the remedy, in which alone the world can claim a final interest?” I reply, that the first step towards improvement in any art or science must be the faithful exposure of its wants and deficiencies.

Michał Jerzmanowski, Malhar Nabar

This paper studies the effects of stock market valuation on research investment, the rate of innovation, and welfare. In the presence of financing constraints for R&D investment, episodes of high market valuation can ease these constraints and raise the economy-wide investment in R&D and the rate of innovation. If the decentralized equilibrium rate of innovation is inefficiently low, then such episodes may lead to an increase in aggregate welfare even if the higher valuation is not entirely justified by fundamentals. We present a Schumpeterian-style growth model with a costly financial intermediation process to characterize the relationship between market value, entry of new firms, and the aggregate rate of innovation. We use the model to measure the welfare consequences of a stock market run-up that may only partly be justified by fundamentals. In particular, we apply the model to the US economy in the 1990s and calibrate the impact of the NASDAQ boom on the rate of innovation, growth and welfare. The welfare effect depends on the underlying change in fundamentals. We find that with an acceleration in US trend productivity growth from a pre-1995 rate of 1.4% to a rate of 2.0% per annum, the NASDAQ boom will have resulted in a net welfare gain of 0.55%. If the new growth rate is as high as 3%, the net gain was 1.35% of the present discounted value of consumption.

Oded Goldreich, Silvio Micali, Avi Wigderson

No abstract is available for this record.

Gilles Brassard, Claude Crépeau

A zero-knowledge interactive proof is a protocol by which Alice can convince a polynomially-bounded Bob of the truth of some theorem without giving him any hint as to how the proof might proceed. Under cryptographic assumptions, we give a general technique for achieving this goal for every problem in NP. This extends to a presumably larger class, which combines the powers of non-determinism and randomness. Our protocol is powerful enough to allow Alice to convince Bob of theorems for which she does not even have a proof: it is enough for Alice to convince herself probabilistically of a theorem, perhaps thanks to her knowledge of some trap-door information, in order for her to be able to convince Bob as well, without compromising the trap-door in any way. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Nelly Catalina Barbieri

The present work tries to evaluate the present Law of Municipal Co-participation of the Province of Buenos Aires from the point of view of the capacity of financing of the cost of the municipal health sector in the Province of Buenos Aires. The "health component" explains the 37% of the distribution of the co-participable mass. The implicit "prices" of the selected variables, influence the "what" and "how" to produce goods in health. This is why the controversies between the fiscal objectives shaped in the normative variant of the method and the assigning eficiency of the sector, as well as the fairness in health, central objectives of the sanitary policy, are put in evidence. As a conclusion and after analysing the results of the distribution, I attempt to demonstrate that in a system of distribution of funds, where variables that try to partially measure the activity of a government function are included, where the criterion to repay the cost of the decentralized public services reigns, in the specific case of health it transforms into a signal that confirms and deepens the assigning inefficiency and the inequality in the distribution.

Arlene Urdaneta Quintero

During the first months of 1864, the construction process of Zulia as a sovereign state was initiated affirming the principles of federation, supported since the beginnings of the republic. The federalists had to establish a new order resulting from a consensus among the local powers that had agreed on a new pact of association. Organizing a “society of societies” implied adapting political tradition to the needs for decentralizing the State to benefit the new sovereign, autonomous entities. Achievements in legal-political organization and use of power by the sovereign government of Zulia showed the extent of the federal state in Venezuela.

Weili Ding, Ming Lu

No abstract is available for this record.

Don Perugini, Dennis Jarvis, Stefan Reschke, Don Gossink

Military operations typically involve cooperation of various military, government and commercial organizations from various nations. In order to coordinate these autonomous organizations, a social mechanism is required that facilitates deliberative planning and task allocation in decentralized, open and dynamic environments, and enables agreements via a legal contracting process. In this paper, we present (a component of) such a mechanism, called the legal agreement protocol (LAP). Agents that plan using LAP must plan with partial observability that is the customer is only aware of proposals (capabilities) that suppliers choose to send. This makes it difficult for the customer to determine the (minimum/average) expected cost of any unallocated sub-tasks in its search. In this paper, we present and compare various heuristics that allow the customer to dynamically determine the expected cost for sub-tasks as proposals are received during planning. We show that different heuristics have tradeoffs in terms of quality of solution and search effort (efficiency of search and quantity of communication). The number of distributed agents involved in planning also influences the effort required to search. More agents increase communication, but provide more information (observability) about agents' capabilities to be utilized by the heuristics

Mamuka Djibuti, Natia Rukhadze, David R. Hotchkiss, Thomas P. Eisele · 5 authors

No abstract is available for this record.

Giovanni Facchini, Cecilia Testa

No abstract is available for this record.

Mercedes Canavesio, Ernesto Martínez

No abstract is available for this record.

Allen Repko

Abstract Curriculum that is truly interdisciplinary reflects the emerging consensus definition of interdisciplinarity and addresses the core elements of interdisciplinarity. These elements include (1) addressing a complex problem or focus question that cannot be resolved by using a single disciplinary approach, (2) drawing on insights generated by disciplines, interdisciplines, or schools of thought, including non-disciplinary knowledge formations, (3) integrating insights, and (4) producing an interdisciplinary understanding of the problem or question. Integrating these dements into curriculum at all levels should reduce much of the semantic evasiveness surrounding the term interdisciplinary, foster integrative learning, and enhance meaningful assessment of interdisciplinary courses and programs. Introduction Writing in the Chronicle of Higher Education, Jeffrey N. Wasserstrom (2006, January 20) complains that interdisciplinarity has become so fuzzy that a university's commitment to it is close to meaningless (p. B5). If programs claiming to be interdisciplinarity are fuzzy in their understanding of what interdisciplinarity is, then their curriculum will not provide the proven educational outcomes for students that interdisciplinarity promises. This, in turn, will severely compromise meaningful assessment of these programs. Klein (1999) argues in Mapping Interdisciplinary Studies that interdisciplinary curriculum must make sense locally and yet, to achieve quality, also ought to be informed by research and the national conversation (p. 16). interdisciplinary curriculum, therefore, requires familiarity with the extensive literature on interdisciplinarity. This literature addresses theory, research process, innovative pedagogies, assessment, institutional context, and faculty support strategies, and can be mined profitably for core design elements that typically characterize interdisciplinarity curriculum. Two essays by Newell provide a good place to start: Designing Interdisciplinary (1994) provides a step-by-step guide to designing interdisciplinary courses, examines their theoretical rationale, and identifies expected learning outcomes; and Powerful Pedagogies (2001b) examines new assessment techniques, educational benefits of integrative learning, and ancillaries to formal courses such as learning communities, experiential learning, and study abroad. The essays in Interdisciplinary General Education: Questioning Outside the Lines edited by Seabury (1999) explain how to design general education curricula that will build students' integrative skills. Davis (1995) in Interdisciplinary Courses and Team Teaching: New Arrangements for Learning traces the development of five interdisciplinary courses at the University of Denver from conception and planning to evaluation and revision. The essays in Innovations in Interdisciplinary Teaching edited by Haynes (2002) provide invaluable insights into interdisciplinary teaching, learning, and curriculum design for new and experienced faculty. The Association for Integrative Studies (AIS) website offers a wealth of information on curricula design, including papers, syllabi, back issues of Issues in Integrative Studies, and useful links. Designers of interdisciplinary curriculum should also consult recent work on interdisciplinary assessment, the psychology of cognitive interdisciplinarity, and the interdisciplinary research process. Until recently, interdisciplinary assessment lacked clear guidelines, meaning that faculty and administrators had to rely on discipline-based measures that privileged tests as proof that a student had command of key concepts and skills (Klein, 1999, pp. 18-19). Works by Field, Lee, and Field (1994), Farmer and Napieralski (1997), Schilling (2001), McGann (2001), Tommerup (2001), Field and Stowe (2002), and Wolfe and Haynes (2003), as well as the several reports by Harvard University's Project Zero, document the shift from quantitative to qualitative approaches, from summative to formative evaluation, and from reliance on inputs to emphasis on outcomes. …

Nikša Nikolić

Human resource, one of the most important development resources of the world, is undoubtedly a basic precondition for entering the society of knowledge. The quality of human knowledge is determined by the quality of the educational system that enables knowledge, skill and competence acquisition required in the labor market. Quality educational system must be based on the quality financing. One of the problems that emerge is a disproportion between the educational needs and the possibilities of their financing. This problem is present in all countries, thus it shows that it is about educational financing crisis. Encountered with numerous severe consequences of this crisis, the countries undertake different measures, which basically represent the essence of the educational process reform. Public education financing reform measures are directed towards activating trade mechanism and financing decentralization. Croatia is not the exception where the education financing crisis is also pronounced and where numerous reform measures have been undertaken in order to surpass the crisis. This paper examines the measures which are directed towards the decentralization of education financing in Croatia.

Teshome Yizengaw

Abstract Higher education participation in Ethiopia is very low (about 1.5 per cent) and is the major source of the critical shortage of educated and skilled human resource. The higher education system in Ethiopia is moving away from exclusive and dismally low enrolments towards increasing participation. To expand access, to redress inequitable subsidies by taxpayers to a small proportion of the age cohort and to diversify revenue the introduction of cost sharing is necessitated to supplement public finance. Cost sharing serves as an alternative non‐governmental source supplementing revenue opening more opportunities and making students responsible citizens and customers. It also has a profound effect on improving the management and academic efficiency of the higher education institutions. In the expanding system, covering the full tuition and food and room cost for a small proportion of the age cohort from the taxpayers’ money is inappropriate and inequitable distribution of resources. A significant number of students are enrolled in fee‐paying programs in public and private institutions. A modified model of the Australian type Graduate Tax, as a more attractive, simple and manageable scheme is adopted in the Ethiopian higher education landscape. The scheme is expected to ensure equitable access to students of any background, as there is no need to stipulate income of parents to arrive at the repayment amounts. Immediate removal of all subsidies to food and room, calculating appropriate tuition fees and costs, provision of every citizen a tax identification number (TIN) and decentralization and strengthening the tax collection and information system are essential for successful implementation of cost sharing in Ethiopia. These improvements enhance the confidence of both public and university community and improves cost recovery.

Nikos Komninos, Dimitrios D. Vergados, Christos Douligeris

Abstract An ad hoc network is a collection of nodes that do not need to rely on a predefined infrastructure to keep the network connected. Nodes communicate amongst each other using wireless radios and operate by following a peer‐to‐peer network model. In this article, we propose a multifold node authentication approach for protecting mobile ad hoc networks. The security requirements for protecting data link and network layers are identified and the design criteria for creating secure ad hoc networks using multiple authentication protocols are analysed. Such protocols, which are based on zero‐knowledge and challenge‐response techniques, are presented through proofs and simulation results. Copyright © 2007 John Wiley & Sons, Ltd.

Allan B. de Guzman

No abstract is available for this record.

René García, Éric Renault, Georges Tsafack

Value at risk (VaR) is a central concept in risk management. As stressed by Artzner et al. (1999, Coherent measures of risk, Math. Finance 9(3) 203–228), VaR may not possess the subadditivity property required to be a coherent measure of risk. The key idea of this paper is that, when tail thickness is responsible for violation of subadditivity, eliciting proper conditioning information may restore VaR rationale for decentralized risk management. The argument is threefold. First, since individual traders are hired because they possess a richer information on their specific market segment than senior management, they just have to follow consistently the prudential targets set by senior management to ensure that decentralized VaR control will work in a coherent way. The intuition is that if one could build a fictitious conditioning information set merging all individual pieces of information, it would be rich enough to restore VaR subadditivity. Second, in this decentralization context, we show that if senior management has access ex post to the portfolio shares of the individual traders, it amounts to recovering some of their private information. These shares can be used to improve backtesting to check that the prudential targets have been enforced by the traders. Finally, we stress that tail thickness required to violate subadditivity, even for small probabilities, remains an extreme situation because it corresponds to such poor conditioning information that expected loss appears to be infinite. We then conclude that lack of coherence of decentralized VaR management, that is VaR nonsubadditivity at the richest level of information, should be an exception rather than a rule.

Demba Niang

Decentralization in Senegal and its most visible pillar, municipalization, give rise to several issues. A<br />strong general sentiment exists that, once political quitus acquired, elected officials seem to content<br />themselves with the representative democracy that brought them to local power. In particular, these<br />issues are manifested by the populations' distrust of local public action and by social divisions, in which<br />underdevelopment remains very visible.<br />Several attempts at reform have been carried out between 1966 and 1996 with the laws on regionalization.<br />Local government authorities have conducted several experiments, often with foreign impetus,<br />particularly as a result of decentralized cooperation. Although it soon becomes clear that a considerable<br />part of this impetus comes from abroad, the experiment carried out in Saint Louis, with the help of<br />decentralized cooperation in the form of the Lille-Saint-Louis Partnership, demonstrated that it is possible<br />for local development to become a reality. Despite constraints faced by the city and its Institution, local<br />politicians expressed a willingness to relay outside impetus.<br />What lessons can be learned from this process?<br />To what extent do the funding and construction of infrastructures, mainly financed by foreign sources,<br />help strengthen the vision and abilities of elected officials to conduct development policy, while taking<br />into account the point of view and expectations of different social groups? On a more general level, how<br />do the systems set up in Saint Louis (Agence de Développement Communal or Municipal Development<br />Agency, and Conseils de Quartier or Neighbourhood Councils) encourage democratic, efficient and<br />transparent management by local government?<br />In examining these questions through a thesis, the goal was, on one hand, to build upon ten-years' field<br />experience in an academic framework and, on the other hand, to gain sufficient perspective in order to<br />problematize the various development practices induced by this experiment, in a context characterized<br />by an exceptionally complex game and system of actors. Working toward these two aims led to further<br />questioning of the transformations which Saint Louis has undergone and their impact on the ability of the<br />municipality to maintain control over communal development projects as contracting owner, which, along<br />with the strengthening of local democracy, seem essential foundations for a municipalization worthy of<br />such a name.

Juan Ramón Troncoso, Fernando Pérez‐González

Zero-knowledge watermark detectors presented to date are based on a linear correlation between the asset features and a given secret sequence. This detection function is susceptible of being attacked by sensitivity attacks, for which zero-knowledge does not provide protection. In this paper, an efficient zero-knowledge version of the Generalized Gaussian Maximum Likelihood (ML) detector is introduced. The inherent robustness that this detector presents against sensitivity attacks, together with the security provided by the zero-knowledge protocol that conceals the keys that could be used to remove the watermark or to produce forged assets, results in a robust and secure protocol. Two versions of the zero-knowledge detector are presented; the first one makes use of two new zero-knowledge proofs for modulus and square root calculation; the second is an improved version applicable when the spreading sequence is binary, and it has minimum communication complexity. Completeness, soundness and zero-knowledge properties of the developed protocols are proved, and they are compared with previous zero-knowledge watermark detection protocols in terms of receiver operating characteristic, resistance to sensitivity attacks and communication complexity.

Adam Wagstaff, Magnus Lindelöw

In many countries health services and/or health insurance are delivered but also partly financed by subnational entities that vary in their fiscal or financial capacity, e.g. local governments and social health insurance schemes. The central government typically mandates a specific (or at least minimum) level of benefit or expenditure per intended beneficiary, and sets rules about enrollment and coverage. It also typically contributes to the cost of the program, partly because the resources of subnational entities may be insufficient, on average, to meet the expenditure requirements, but partly for equity reasons. These two problems are typically addressed through tax-transfer schemes. In practice, there is considerable institutional heterogeneity across countries in the mix of vertical and horizontal schemes, and the way each works. In this Note, we show how the progressivity of health outlays by subnational entities can be decomposed into contributions from vertical and horizontal schemes, and how each of these can be further decomposed into contributions from taxes and transfers. We suggest that, in addition to providing a foundation for future empirical work, the decomposition provides some insights into the reasons for different institutional choices, and into the way vertical and horizontal tax-transfer schemes operate in practice.