Blockchain Papers

Tomas Sander, Amnon Ta‐Shma, Moti Yung

No abstract is available for this record.

Jim Mignano

Bitcoin is the first digital medium to allow global, "purely peer-to-peer" exchange. At the height of the Great Recession, Bitcoin's pseudonymous creator introduced the electronic cash to sidestep political and economic institutions. Today, it is praised as an opportunity for the unbanked, a liberating force, and a pioneering technology. It is also infamously associated with volatility, illicit activities, and profligate energy consumption. Bitcoin has also flown under the radar of political science, whereas computer scientists, economists, and legal scholars have written extensively about it. To address the gap in the literature, I describe Bitcoin as an actor in global affairs, explain how Bitcoin and blockchain technology work, and discuss why Bitcoin is relevant to political science as the archetypal case of blockchain technology. I argue that Bitcoin is a form of contentious politics uniquely suited to the twenty-first century. Examining Bitcoin as a form of contentious politics sheds light on how a purportedly borderless technology has actually fared in subverting state authority: not entirely well. Nonetheless, Bitcoin has succeeded in at least two respects: it is an unprecedented form of untraceable electronic cash that coordinates unrivaled levels of computing resources from voluntary contributors and it has become a resilient, global social movement. As an archetype of blockchain technology, Bitcoin inspires research of blockchain's capacity to facilitate collective action, uses in international cooperation and competition, and prospects for human development. The thesis concludes with a set of implications for blockchain research and policy.

Yevgeniy Dodis, Shai Halevi, Tal Rabin

Abstract. In this work we use cryptography to solve a game-theoretic problem which arises naturally in the area of two party strategic games. The standard game-theoretic solution concept for such games is that of an equilibrium, which is a pair of “self-enforcing ” strategies making each player’s strategy an optimal response to the other player’s strategy. It is known that for many games the expected equilibrium payoffs can be much higher when a trusted third party (a “mediator”) assists the players in choosing their moves (correlated equilibria), than when each player has to choose its move on its own (Nash equilibria). It is natural to ask whether there exists a mechanism that eliminates the need for the mediator yet allows the players to maintain the high payoffs offered by mediator-assisted strategies. We answer this question affirmatively provided the players are computationally bounded and can have free communication (so-called “cheap talk”) prior to playing the game. The main building block of our solution is an efficient cryptographic protocol to the following Correlated Element Selection problem, which is of independent interest. Both Alice and Bob know a list of pairs (a1, b1)... (an, bn) (possibly with repetitions), and they want to pick a random index i such that Alice learns only ai and Bob learns only bi. Our solution to this problem has constant number of rounds, negligible error probability, and uses only very simple zero-knowledge proofs. We then show how to incorporate our cryptographic protocol back into a game-theoretic setting, which highlights some interesting parallels between cryptographic protocols and extensive form games. 1

Usman Khalil, Owais Ahmed Malik, Wee-Hong Ong, Mueen Uddin

The concept of smart city architecture requires a comprehensive solution that can combine real-time response applications for cyber-physical systems. However, the architecture faces challenges that can obstruct the operations in terms of systems, processes, and data flow as far as the breach risk is concerned. Though the field has been researched with the existence of centralized and distributed architectures to support smart cities. Research gaps regarding security concerns, platform assistance, and resource management continue to persist. This research article presents a novel blockchain-based architecture that proposes expansion in the non-fungible tokens (NFTs) to cater to the expansion of IoT-enabled smart assets. It enables NFTs to employ fog computing for all users and smart devices connected to a fog node in a cyber-physical system. The proposed expansion suggested in Non-Fungible Tokens (NFTs) for IoT assets representation in a cyber-physical system, provides devices and user identification and authentication functionality. The proposed NFT architecture has been designed to provide a smart city solution for cyber-physical systems that ensures robust security features (such as CIA) by introducing new attributes and functions for Owner, User, Fog, and IoT device/s authentication. The validation and rigor of the security services, efficiency, and latency have been achieved by deployments on private and public ledgers. The efficiency, and cost-effectiveness of the suggested functions and components have been evaluated in terms of evaluation cost and time complexity which resulted in promising results, obtained and validated on a testnet. The evaluation cost for the devised mint component was approximately 81%, and devised approve() was approximately 23% more efficient than other solutions.

Jon F. Merz, Mildred K. Cho, Maxine Robertson, Debra G. B. Leonard

No abstract is available for this record.

Nick Szabo

Smart contracts combine protocols with user interfaces to formalize and secure relationships over computer networks. Objectives and principles for the design of these systems are derived from legal principles, economic theory, and theories of reliable and secure protocols. Similarities and differences between smart contracts and traditional business procedures based on written contracts, controls, and static forms are discussed. By using cryptographic and other security mechanisms, we can secure many algorithmically specifiable relationships from breach by principals, and from eavesdropping or malicious interference by third parties, up to considerations of time, user interface, and completeness of the algorithmic specification. This article discusses protocols with application in important contracting areas, including credit, content rights management, payment systems, and contracts with bearer.

Authors unavailable

No abstract is available for this record.

Sultan Gurban Niftaliyev

The price increase in the cryptocurrency market over the past 1 year has resulted in a further increase in the interest of ordinary citizens and amateur investors in digital assets. At the same time, the increase in prices has motivated people to invest in cryptocurrencies. At the moment, the main questions that interest investors are: how are the commissions charged during the purchase and cashing of cryptocurrencies and in what form is tax paid on cryptocurrency income. Considering these factors, the information contained in this article about the commissions charged during cryptocurrency trading and the mechanism of taxation of cryptocurrency income is quite relevant.

Rza Hasanli, Mahir Dursun

Abstract — The volatile nature of cryptocurrency markets has spurred interest in predictive models to aid investment and trading strategies. This study extends previous works by incorporating all available technical indicators, leveraging the TA library, and evaluating multiple deep learning architectures for Bitcoin price prediction. Using daily OHLC data for Bitcoin (BTC) sourced from Yahoo Finance, we implement Transformer-based Multi-Head Attention with GRU and LSTM layers, along with standalone LSTM and GRU models. These architectures are compared in terms of predictive accuracy to identify the most effective approach for capturing market dynamics. Our results provide a comprehensive analysis of model performance, highlighting the potential of advanced neural network architectures and technical indicators for improving cryptocurrency price prediction.

Rza Hasanli, Mahir Dursun

Abstract— Cryptocurrency markets have experienced rapid growth, attracting attention from investors, traders, and researchers. Accurate price prediction is critical for effective risk management and investment strategies. This paper proposes a hybrid deep learning model that combines Transformer Encoder and Gated Recurrent Unit (GRU) architectures with technical indicators to predict cryptocurrency prices. The model uses daily OHLC data and selected technical indicators, achieving strong predictive performance on BTC-USD, ETH-USD, and BNB-USD. The results demonstrate that the model accurately captures price trends with low prediction errors, achieving RMSE and MAPE values of 2607.32 and 3.70% for BTC-USD, 205.86 and 6.02% for ETH-USD, and 21.45 and 4.09% for BNB-USD, respectively. These findings highlight the model’s potential for developing adaptive trading strategies and advancing decision-making in cryptocurrency markets.

Joe Kilian

No abstract is available for this record.

Zvi Griliches. Chicago

No abstract is available for this record.

Rafail Ostrovsky, Ramarathnam Venkatesan, Moti Yung

No abstract is available for this record.

Toshiya Itoh, Kouichi Sakurai, Hiroki Shizuya

No abstract is available for this record.

Dusko Knezevic

The aim of the paper is to conduct a research on an impact of blockchain technology platform on the financial sector through cryptocurrency, and an impact on other industries.. The subject of research is not only this technology but also its commercial exploitation. In order to understand the platform, the starting point of this research is an analysis of how the technology functions, after that the advantages for business and economic transaction are identified, and finally the paper deals with an impact of new technology on business, above all on financial operations. The basic hypothesis is that blockchain has achieved a great impact on financial sector, also it has the potential to radically change only the financial sector but also the way we buy and sell, our interaction with the authorities as a way of verifying the ownership from the authorship and the organic food production. Using the available data and synthesis of knowledge from the fields of technology, economics, finance, and politics, 4 scenarios were set up for the future of underlying technology. The scenario approach combined with trend analysis in order to prove the starting hypothesis with high reliability. The research results show that the technology being investigated already has a profound impact on the financial sector, that it is in the initial phase of changing many industries, with the likelihood that they will change them significantly in the next five to ten years. Businesses increasingly discover the power of this technology to exploit the benefits of the Fourth Technological Revolution.

Donald Beaver

No abstract is available for this record.

Abraham Pizam, Julianne Pokela

No abstract is available for this record.

Authors unavailable

No abstract is available for this record.

B. Balamurugan, T. Poongodi, M. R. Manu, S. Karthikeyan · 5 authors

The moving image archive of the US Agency for International Development (USAID) includes a copy of the film The Double Day (1975), cataloged in the series Moving Images Relating to International Development Programs and Activities, 1979–1991, a collection of more than eight hundred titles “created to provide information on assistance programs supported by the Agency for International Development (AID).”1 Yet, The Double Day does not, in fact, directly depict or engage with any specific development or aid initiative. Instead, the film—directed by US-based Brazilian filmmaker Helena Solberg as part of the International Women’s Film Project collective and described as “the first Latin American feminist documentary”—examines the gendered dynamics of paid and unpaid labor through the testimonies of women from Argentina, Bolivia, Venezuela, and Mexico.2 Its presence in the USAID archive is likely a consequence of its funding history, having received support from the Inter-American Foundation, a USAID-affiliated entity; the development agencies of Denmark, Norway, and Sweden; the United Nations Development Program; and US philanthropist Calvin Cafritz.3These transnational funding structures not only enabled the film’s production but also determined its archival destination, which renders legible its place within the history of international development.4 The Double Day’s institutional trajectory reflects the shifting configurations of aid, gender, and media during a historic moment when women were being repositioned at the center of what Arturo Escobar has described as development’s “regimes of visuality.”5 Especially relevant to The Double Day’s production and exhibition was the international institutional framework of Women in Development (WID). Emerging in the early 1970s and culminating in United Nations’ proclamation of 1975 as International Women’s Year, WID emphasized women’s participation in the global economy as both an index and mechanism of development. Indeed, The Double Day premiered at the World Conference of the International Women’s Year, held in Mexico City.6 Within this context, the film forms part of a broader trajectory of media use by international organizations that intensified during the 1970s—as best exemplified by Media Habitat, a collection of 236 documentary films commissioned by the United Nations to represent urban and rural development initiatives for the 1976 Habitat Conference on Human Settlements in Vancouver. As a policy-shaping initiative, Media Habitat primarily featured films from the Global South intended not only to illustrate but also to help codify standardized audiovisual markers of “underdevelopment” that determined access to the emerging global economic order and to international aid.7Framed in relation to these international institutions and their operations, The Double Day could similarly be considered “development media”—exemplifying the type of nonfiction media produced and distributed outside of the commercial film circuits whose aspects and subcategories have been variously described in scholarship as nontheatrical, useful, sponsored, institutional, industrial, educational, or nonprofessional/amateur.8 Scholars working in this area have emphasized the institutional contexts of such media’s production and exhibition infrastructures as shaping its instrumentalized effects. From a feminist perspective, such an approach is crucial to grappling with the broader question of how “gender impacts [these works’] shape, content, and trajectories.”9 Yet we also argue that, taken in isolation, the institutional and infrastructural contexts are insufficient to account for the complex relationship between media and development, potentially not only limiting our understanding of the reach and impact of development but also distorting our interpretive conclusions. For example, to categorize The Double Day as “development media” is to overlook the film’s place within Solberg’s directorial oeuvre, as well as within the histories of both transnational women’s filmmaking and radical Latin American documentary cinema to which it simultaneously belongs. Such exclusive framing is especially limiting given that women globally were disproportionately engaged in nonfiction production throughout the twentieth century—sometimes by political choice but more often due to structural exclusions from fiction filmmaking. Even in nonfiction historiography, however, institutional media has remained particularly marginal, reinforcing hierarchies that separate such works from the aesthetic and authorial frameworks through which film history has been constructed.10 This marginalization not only tends to erase women’s contributions but also presumes a “weak” or derivative authorship, rendering these films unworthy of the interpretive attention needed to apprehend their aesthetic and political complexity.11 The same dynamic is likely to structure assumptions about “development media” as well.Categorizing The Double Day exclusively within this category would further prompt us to assume top-down institutional analyses that have been characteristic of both institutional media methodologies and the scholarship on development at large. This, in turn, would risk obscuring this film’s radical Marxist approach to women’s labor as well as its concrete contribution to activism and its attendant grassroot structures. In Mexico City, The Double Day became a catalyst for feminist solidarity in practice when one of the film’s protagonists, Bolivian activist and trade unionist Domitila Barrios de Chungara, was invited to participate in the Tribune of Non-Governmental Organizations held alongside the official UN conference.12 There, Barrios de Chungara challenged Western feminist priorities by reframing the debate around labor, class, and imperialism, helping to articulate a shared Third World feminist agenda that significantly departed from the developmentalist vision of the United Nations and USAID.13 Seen through the lens of activist media, The Double Day helped forge transnational solidarity networks by enabling information exchange across the diverse voices that shaped its making—from the women featured in the film to the activists who circulated it—revealing a considerably more dynamic interplay between institutional and grassroots or contingent media practices.Moreover, the film’s Latin American context—reflected in Solberg’s formation in Brazil as the only woman in Cinema Novo, its focus on women from across the region, and its premiere and key reception in Mexico City—requires grappling with the regional specificities of the very notion of development in its multiple iterations.14 Far from being an epistemological and political framework imposed solely by the Global North, both the practices of development and the theoretical foundations of developmentalism (understood as a broad and polysemic set of discourses) were shaped through the active participation of Latin American economists.15 Within this iteration, underdevelopment, as a constitutive notion of developmentalism, became central to a distinctly critical strand, which by the late 1960s became known as the dependency theory.16 This same approach is reflected in some of the best-known Latin American radical film manifestos of the time, arising precisely from the same milieus to which Solberg belonged.17These various considerations of the film’s history illustrate the methodological challenges confronting feminist scholars seeking to assess the impact of development on media projects, theories, and practices. To disregard the developmentalist context of such works by emphasizing their political aesthetics and affects risks reproducing a romanticized narrative of heroic resistance (albeit from a feminist perspective). Yet to engage exclusively with their institutional and material infrastructures risks naturalizing developmentalism’s political and epistemological foundations at the expense of the goals and beliefs of the many women who participated in these projects. The contradictions and ambivalences that animate such histories call for feminist frameworks capable of holding both institutional complicity and radical possibility in view.This challenge resonates with ongoing debates about the politics of the archive and what Allyson Field has termed “the practice of informed speculation.”18 As she reminds us, feminist, queer, and decolonial methodologies have long taught us to “press at the limits” of the archive to “inoculate our scholarship against our evidence’s afflictions.”19 The concern that the evidence we draw on in our analysis reproduces the very structures and blind spots of the dominant ideology and therefore shapes and delimits our interpretation becomes particularly urgent when engaging the developmentalist media corpus. Informed speculation offers an alternative by inviting the experimental, creative, and speculative rewriting of history, mobilizing the archive “in a project that runs counter to the original purpose, or the imperative to preserve, or the conditions that led to erasure.”20 Yet, as Field cautions, such speculative gestures must remain grounded in a deep and “intimate familiarity with the archive” that we are working with and against. Building on this imperative, we suggest that the developmentalist archive, in particular, demands expansion and critical reconsideration in ways that unsettle the very disciplinary frameworks through which it has been studied as well as the larger institutional contexts for such knowledge production.Our focus on The Double Day in the opening of this introduction thus foregrounds the entanglements of institutional and grassroots forces, local and international contexts, structural and interpersonal relations, and creative and economic factors that have shaped not only this film but the broader ecosystem of development media projects—and their preservation—over time. Addressing such a constellation involves transgressing methodologically entrenched divisions between political economy and aesthetics, between material infrastructures and affective regimes; reckoning with divergent periodizations across film history and world economics; and situating these within the local specificities of women’s movements and international institutional programs. It also demands attentiveness to the coexistence of multiple, and sometimes competing, understandings of development—each historically, geographically, and ideologically situated.We imagine this special issue as an opening toward a critical dialogue, not only about how such an approach might be enacted in practice but also about the far-reaching ways development paradigms have shaped both our objects of study and the contours of the field itself. The decision to center institutionally sponsored films across all the essays in this issue is deliberate and enables us to highlight institutional critique as a vital methodological imperative within our analytical framework. Created within the frameworks of international organizations, state agencies, or NGOs, these films’ histories make legible the institutional logics that underwrite their production. Yet our critique does not stop at these specific entities. Rather, we argue for a broader interrogation of the political conditions and institutional infrastructures that shape media and knowledge production more generally. This includes contemporary corporations embedded in the digital platform economy, from streaming services to the rapid expansion of AI. Equally critical is a reflexive examination of academia itself, where departments of economics, political science, and centers for development have played a formative role in producing and legitimizing developmentalist theories and policy frameworks. While the humanities and arts have at times offered critical alternatives, they have also frequently mirrored and reinforced many of the same developmentalist assumptions. A feminist analysis of the nexus between development and media must therefore unsettle not only dominant archives but also the institutional and disciplinary foundations of our own scholarly practices.As scholars, we share the complex position of navigating the same tensions between institutional complicity and emancipatory aspiration as many of the media-makers whose work we study. Mirroring our subjects is also the transnational, collective mode of this special issue’s own production as it emerges from an ongoing informal working group we have sustained over several years. While relying on institutional and disciplinary affordances—such as university funding for conferences or access to academic publishing platforms—we have been working toward creating a community that exceeds, and often resists, the prevailing logics of our academic institutions. Our aim has been to create a space for shared inquiry and mutual support that pushes back against disciplinary siloing and technocratic neoliberal assessment modes of both labor and knowledge production—and this certainly extends to our experience collaborating with the journal editors throughout the publication process. Our goal has been to examine both the persistence and variability of developmentalism, understood as what Gustavo Esteva calls a “powerful but fragile semantic constellation,” as a conceptual formation that has historically inspired, legitimized, and mobilized media projects across Asia, Africa, and Latin America.21 And gendered biopolitics, from population control to gender mainstreaming, have remained integral to development policies and media practices, recurring across formats from institutional newsreels to film festivals.We share the conviction that, far beyond the history of nonfiction institutional media, development (as both a broad ideological project and a network of material and institutional practices) and developmentalism (as a set of discourses and theoretical models associated with development) have exerted a far-reaching influence on film and media cultures at large. As such, they must be treated as a major force in shaping global film and media systems and also the many ongoing assumptions behind their critical discourses. The discipline of communication studies was founded on modernization theory governed by Cold War goals of dissemination of Western liberal democracy around the world, while “an area studies framework allowed compartmentalizing Western and non-Western outcomes of technologies that were always claimed to be universal.”22 Despite critique from postcolonial and critical race studies, many of these frameworks have remained foundational for media theory.23 In historical scholarship, as we increasingly move beyond “modernity” as a dominant conceptual anchor, engaging with practices and discourses of development opens more precise analytical pathways. These film and media’s entanglements with the logics of and economic and the associated with as well as their conceptual underdevelopment, and impact in as diverse as and of media aesthetic and paradigms in film and film and funding are developmentalist assumptions to the they to underwrite the narrative and logics of and global media from the structure of the film to the cultures of argue that a examination of the historical entanglements between film and developmentalist aesthetics, modes of as well as infrastructures and critical the and that our contemporary media is a of the historical contours of development as a field of inquiry embedded within a of some of the methodologies by the featured in this special a of this complex history, to the larger at in media, development, and gender all its development a it as an of be with practices as divergent as and in In as we work on this the of the of the USAID the ideological that have the history of international the and of this on the global its a from development as a global practice and as an institutional and which over the has as a with its own media Yet or does not erase the historical impact of these the contradictions they have reflected and over the as the of development several crucial to the economic theories of development initiatives to and through the of the development an international policy framework at from the Global to the of the Global the by the political role of and the of the International the on was challenged by dependency theory and at development as global structural the neoliberal of the the Programs by the and World imposed and as conditions for and forms of assistance became known as the major markers for international development development has moving beyond economic to such as the Human Development and the Development and from international organizations such as the United Nations to a broader network of These frameworks increasingly of and liberal of and with what in many ways to various while the of the to development’s epistemological more scholarship has toward a of its and material the field has to a of and critical by and scholars, which development as a dynamic of conceptual and political to these the studies in this special issue call for sustained analysis in place of In we draw from a of and that in of of gender and to this special issue engage that and from Mexico to contemporary specific local historical of global distinctly feminist methodologies as well as attention to studies that this issue a in the global history of development on and documentary work in Mexico how early women infrastructures as of while US films an early of state and transnational on a outside the Global as the of developmentalist both the and markers of development media, its to the and Latin central grounded in archival also women’s in transnational and the methodological of archives on study of the series to a a digital media not by but by women not as but as subjects and within circuits of neoliberal and the aesthetics and of how development’s has models of to contemporary neoliberal paradigms of and analysis how digital and gender and practices, discourses on and their of these essays the of some of the historical of developmentalist as the question of the role of the state within such on a notion of economic as a and the dominant of development that the state as the for and through infrastructural projects. This understanding of development was shared across both of the as well as in the Third The United and the increasingly mobilized international in the of the modes of international at the postcolonial of policy and ideological These programs were at the expansion of their and of while with the and decolonial of The conceptual between modernization and development that the Cold in of and hierarchies of that long and As an of postcolonial their role as of international aid concern about the of Western development projects. In alternative across the Global South that to structural between and through policies of and In many they were further the global structures. In Latin for example, this approach was through organizations such as the United Nations for Latin and the both developmentalist projects and their have taken many forms historically, and they have and they have been to a of projects, and postcolonial and development has been and in ways and with frequently political While many of these alternative frameworks the embedded in dominant Western they often technocratic and assumptions. gender and gender as for the of to be shaped by This becomes particularly in the media that of development where women frequently a crucial associated with and women were as both the subjects and of their participation in the and labor often as the index of In this study of from the 1970s how women were as of this as these about women’s urban and recurring and of a within the own of and critique that official examination of archives and enables a feminist interrogation of their mobilizing a of the in the of contribution to this issue similarly the of a dynamic within as well as across ideological the of women’s and the media of the and as active in labor and as integral to the technocratic women became of as their labor remained a of and analysis and archival with attention to the specific of and It also transnational that as a and affective a nexus of and practices through which gender, media, and developmentalism one film not as a but as part of the of alongside and work a broader concern of this special media as a of developmentalist projects. The debates the World and which international such as the United Nations and a critical historical for such primarily by postcolonial and of the for the of media and communication infrastructures in as to counter Western The a between and economic how systems of media and reinforced global hierarchies of and in an agenda that supported and alternative media infrastructures across postcolonial contexts, the framework gender as an analytical This “gender in the 1970s by of the Women in Development in relation to The Double its political critique of with its broader to center women in development policy through and This was also in of media, which was shaped by its international reach and audiovisual production and and and Yet, as WID institutional it also to the and of the women’s development programs often by in These were by a of studies, and on and the to of women’s presence and through the of their economic and In this on the filmmaker this history directly by the and of for women by the WID framework during the with and agencies the of and against Women in at the of the neoliberal turn, when institutional media often the only to access and support to projects. The an by this dynamic as of the from the Global South are to engage with the developmentalist assumptions funding models that their similarly the as a in developmentalist media history by the of and centers on the Film a between of and the attention toward the and labor by and work was foundational the of and the of audiovisual aid, as both a of development projects and a critical for their the in this issue argue for a with media, gender, and developmentalism as an field of that is and shaped by feminist and methodologies and that challenge the entanglements between academic knowledge production and and technocratic development And while methodological these dynamics at the structural the of feminist in media and cinema by this the very a

Jiarun Hu, Qian Luo, Jiaen Zhang

Security breaches of the cryptocurrency exchanges usually cause the price fluctuation in the market. Approximately one hundred cryptocurrency thefts, including hacks and scams, has occurred since 2012 to 2018, half of which are hacks of Bitcoins. Based on the thirty Bitcoin hacks, this study portrays the general price pattern during the hack. And it illustrates the link between the size of the hack and the subsequent price change of Bitcoin. The tests reveal that the larger the volume of the hack, the stronger the price drop. However, a similar obvious relationship does not exist for the recovery of the price. The study might be the first piece of research focus on the hacks and the price pattern in a short time period.

Vasilis Kostakis, Chris Giotitsas

The still raging financial crisis of 2007–2008 has enabled the emergence of several alternative practices concerning the production, circulation, and use of money. This essay explores the political economy of the Bitcoin ecosystem. Specifically, we examine the context in which this digital currency is emerging as well as its nature, dynamics, advantages, and disadvantages. We conclude that Bitcoin, a truly interesting experiment, exemplifies “distributed capitalism” and should be mostly seen as a technological innovation. Rather than providing pragmatic answers and solutions to the current views on the financial crisis, Bitcoin provides some useful and timely questions about the principles and bases of the dominant political economy. A ECONOMIA POLÍTICA DO BITCOINResumoO aquecimento da crise financeira de 2007-2008 permitiu o surgimento de várias práticas alternativas em matéria de produção, circulação e uso do dinheiro. Este ensaio explora a economia política do ecossistema Bitcoin. Especificamente, vamos examinar o contexto em que essa moeda digital está emergindo, bem como a sua natureza, dinâmica, vantagens e desvantagens. Concluímos que Bitcoin, uma experiência verdadeiramente interessante, exemplifica "capitalismo distribuído" e deve ser visto principalmente como uma inovação tecnológica. Em vez de fornecer respostas e soluções pragmáticas para os pontos de vista atuais sobre a crise financeira, Bitcoin fornece algumas perguntas úteis e oportunas sobre os princípios e as bases da economia política dominante.

William C. Hsiao, Alan Maynard

On behalf of the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Section on Disorders of the Spine and Peripheral Nerves, it is my great privilege to introduce these Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injuries. These guidelines represent the initial installment of a more comprehensive guidelines initiative from the Joint Section on behalf of all practicing neurosurgeons and their patients. The Section is grateful to the small working group who devoted considerable time and effort to the generation of this outstanding document. We would like to formally recognize the Joint Section on Trauma for their important collaboration on this project. The Section would also like to acknowledge and thank the parent organizations, the American Association of Neurological Surgeons and the Congress of Neurological Surgeons, for their guidance of and support for this project, most notably through the efforts of the American Association of Neurological Surgeons/ Congress of Neurological Surgeons Guidelines Committee. The Section is also deeply indebted to Michael Apuzzo and the staff of Neurosurgery for their advice and editorial assistance in preparing this document for publication. The application of Neurosurgery’ s rigorous peer-reviewed editorial process has clearly enhanced the quality, balance, and stature of this document. Perhaps most importantly, Neurosurgery has provided an extraordinary vehicle for the widespread dissemination and ultimate incorporation of these guidelines to improve the care and enhance the outcomes of patients with traumatic cervical spine and spinal cord injuries. One of the truly important functions of organized neurosurgery is the generation of evidenced-based clinical practice guidelines. Properly developed, such guidelines can answer important questions, resolve uncertainty, identify areas of deficient knowledge and opportunities for future scientific investigation, standardize treatment, and improve the quality of care and the outcomes for patients. The now widely disseminated head trauma guidelines, for example, have clearly made a difference in the outcomes of patients with severe head injury. Guidelines development is a highly structured process with rigorous methodological criteria and exacting standards. It is a time-, labor-, and resource-intensive process that has served as a significant obstacle to more widespread guidelines development throughout neurosurgery. In the past, clinical practice guidelines have been developed by publicly supported epidemiologists and methodologists who understood study design, data analysis, and the guidelines process, but not the disease. This absence of context and clinical perspective significantly limited the value and relevance of their results. Alternatively, clinician-generated guidelines often took the form of methodologically flawed consensus panels and expert opinion, also of limited value. The Joint Spine Section recognized the importance of evidence-based clinical practice guidelines and the challenges of their development. The appropriate clinical expertise, strict adherence to established methodological standards for guidelines development, and considerable resource investment for the development, dissemination, and maintenance of the guidelines documents were deemed crucial to our guidelines initiative. Cervical spine and spinal cord injury was chosen as the initial guidelines topic because of the personal, social, and economic devastation of these injuries, their complex nature, and the high level of uncertainty, as reflected in wide practice variations, as to the value and indications for many of the aspects of evaluation and treatment. The clinical practice guidelines contained in this supplement to Neurosurgery represent a remarkable effort. They address the key issues related to the evaluation and management of these complex conditions that are relevant to the treating physician. In every chapter, the pertinent issues are succinctly stated, the published data are comprehensively presented in the evidentiary tables, and the evidence is thoroughly discussed and critically evaluated throughout the text. The linkage between the quality of the evidence and the strength of the recommendations was not a “black box” process but an open, deliberative exercise by skilled experts guided by a rigorous set of standards. Despite the strength and potential value of this document, it is important to acknowledge the inherent limitations of clinical practice guidelines. This, or any other, evidence-based clinical practice guidelines document does not represent the definitive source of knowledge on the stated topic. Rather, it represents recommendations of varying strength and certainty based on an analysis of the best available published data. These data, however, are often conflicting, flawed, or incomplete, and there are unavoidable elements of potential bias from subjectivity, perspective, and experience of the individuals and group involved in the analysis and interpretation of these data. In essence, proof is a relative term based on the interpretation of evidence. Furthermore, it is subject to different standards. A relevant example comes from the field of jurisprudence, where the standard of proof (i.e., guilt) for criminal trials is “beyond a reasonable doubt,” whereas the standard for civil courts must simply reflect “a preponderance of evidence” or “more likely than not.” These different standards evolved because of the perceived different consequences of a wrongful verdict. Moreover, as Stephen Haines likes to note, the verdict “not guilty” does not mean innocent; it merely says not proved. Such are the vagaries associated with the interpretation of even scientific evidence. Principled people can look at the same evidence and come to different conclusions subject to their own personal perspective, experience, and stake in the result. Nevertheless, the Joint Section and Guidelines Development Group went to great lengths to identify and avoid—or at least minimize—these potential problems. The working group adopted the most widely recognized and rigorous standards for guidelines development. A diverse panel of experts with expertise in spine, trauma, and epidemiology brought relevant clinical, scientific, and methodological competence to enhance both the analytical and the deliberative aspects of this process. Periodic outside reviews were routinely obtained for topics or areas of contention or uncertainty to add additional perspective and balance. Above all, the process was accountable and transparent at every stage. Ultimately, we offer these guidelines as a living document to those professionals who treat patients with traumatic spinal injury. We hope each practitioner will critically evaluate these guidelines and come to his or her own conclusion on how, whether, and when to implement its recommendations. It may be used either as a reference or as a basis for standardized protocols of evaluation and management of the patients with traumatic spinal injury. For clinical and basic science researchers, we hope that it will identify and catalyze scientific investigation in areas of deficient knowledge. As a Section, we stand firmly behind this important document and will continuously update the recommendations as new knowledge and understanding is developed. We sincerely believe that these guidelines can improve the care and enhance the outcomes of patients with traumatic injuries to the cervical spine and spinal cord.

Svante Arrhénius

No abstract is available for this record.