Blockchains as Infrastructure and Semicommons

Blockchains are not self-executing machines. They are resource systems designed by people, maintained by people, and governed by people. Their technical protocols help to solve some difficult problems in shared resource management, but behind those protocols there are always communities of people struggling with familiar challenges in governing their provision and use of common infrastructure. In this Article, we describe blockchains as shared, distributed transactional ledgers using two frameworks from commons theory. Brett Frischmann’s theory of infrastructure provides an external view, showing how blockchains provide useful, generic infrastructure for recording transactions and why that infrastructure is most naturally made available on common, nondiscriminatory terms. Henry Smith’s theory of semicommons provides an internal view, showing how blockchains intricately combine private resources (such as physical hardware and on-chain assets) with common resources (such as the shared transactional ledger and the blockchain protocol itself). We then detail how blockchains struggle with many of the governance challenges that these frameworks predict, requiring blockchain communities to engage in extensive off-chain governance work to coordinate their uses and achieve consensus. Blockchains function as infrastructure and semicommons not in spite of the human element, but because of it

Catalytic abatement of trichloroethylene over Mo and/or W-based bronzes

[EN] In this paper we present the results of the synthesis, characterization and catalytic behaviour of Mo(W)¿Nb¿V¿O mixed metal oxides bronzes for the catalytic oxidation of trichloroethylene. The catalysts were prepared hydrothermally with different Mo/W/Nb/V/P atomic ratio and heat-treated at 500 and 700 °C. They were characterized by several techniques as N2-adsorption, X-ray diffraction, FTIR, SEM-EDS, temperature programmed desorption, temperature programmed reduction, UV¿vis, Fourier transformed infrared spectroscopy of adsorbed pyridine and 18O/16O isotope exchange. X-ray diffraction patterns (XRD) of samples heat-treated at 500 °C suggest the presence of a semi-crystalline material with a diffraction peak at ca. 2¿ = 22.2°, while XRD patterns of samples heat-treated at 700 °C show the formation of a tetragonal tungsten bronze (TTB) structure. The activity for the catalytic abatement of trichloroethylene strongly depends on the heat-treatment temperature and the catalyst composition. Thus, samples with W/(Mo + W) atomic ratios of 0.25-0.75 and heat-treated at 500 °C are the most active ones. The enhanced activity has been related to the remarkable higher surface area of the catalyst and to the catalyst composition which influences the acid characteristics as well as the reducibility and reoxidation of the catalysts. The importance of the oxygen dissociation on the catalyst surface and the diffusion of oxygen species through the catalyst are also discussed.The authors wish to thank DGICYT in Spain (Project CTQ2009-14495 and CSD2009-00050-CONSOLIDER/INGENIO 2010) and Universitat Politecnica de Valencia for the financial support. N.B.R. acknowledges Catedra Cemex Sostenibilidad (UPV) for a fellowship. M.D.S. acknowledges Universitat Politecnica de Valencia for a fellowship.Blanch Raga, N.; Soriano Rodríguez, MD.; Palomares Gimeno, AE.; Concepción Heydorn, P.; Martínez Triguero, LJ.; López Nieto, JM. (2013). Catalytic abatement of trichloroethylene over Mo and/or W-based bronzes. Applied Catalysis B: Environmental. 130-131:36-43. https://doi.org/10.1016/j.apcatb.2012.10.016S3643130-13

Anglo-Iraqi relations 1945-1958

SIGLEAvailable from British Library Document Supply Centre-DSC:DX207515 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Speculation, Embedding, and Food Prices: A Cointegration Analysis

The disparity between massive volatility in food prices and relatively slow changes in agricultural supply and demand since the beginning of the food crisis in 2007 has focused attention on the potential effects of financial speculators in food markets. The challenge of identifying the effects of such speculators has been complicated by a number of factors, key among which has been the criteria used to define speculative activity. This paper provides a more targeted analysis of one particular kind of speculator, and builds on a combination of sociological and econometric analysis to identify their presence in commodity markets during the food crisis

The Emergence of Blockchain: Institutions, Open Source Technology and the Social Organization of Early-Stage Digital Transformation

Blockchain technology has emerged from the shadow of Bitcoin to become a central component of 21st century digital transformation, and has become a focus of experimentation by actors ranging from the world’s oldest central banks to startups spanning nearly every industry sector. This combination of novelty and seeming ubiquity means that blockchain technology provides an unusual opportunity to study digital transformation in its pre-settlement stage. This dissertation approaches digital transformation as a question of social organization, and asks how people organize to implement a novel technology when both the technology and the social organization around it are in flux. I explore this question of techno-social organization at the macro and meso levels using a combination of computational and qualitative digital methodologies. At the macro level, my analysis is based on a unique data set I have constructed of roughly 5,000 blockchain implementations and an interpretive data science approach I developed to classify these implementations in the absence of a “ground truth” pre-existing framework. I develop a three-level taxonomy of implementations that I then use to ask how an emergent general purpose technology interacts with higher-level, institutionalized social structures such as institutions and established economic domains. I find that the technology’s generality of purpose is embodied by three clusters: programmable money, tokenization and computational infrastructure. I also find that its widespread adoption is driven by three patterns of reinvention whose differences result largely from variation in the alignment between the functions of the technology and the core institutions in the domains in which it is being applied. At the meso level I use comparative case studies and algorithmic ethnography to study how people organize to implement a new technology. My analysis at the meso level is divided into classic questions of coordination and control or governance. I find that coordination uses both established and 21st century organizational forms as component microstructures that are recombined in novel ways. In studying governance, I find that the institutionalization of open source processes has, together with the technology itself, enabled the emergence of a new, digital form of institution-building

Tubulointerstitial lupus nephritis

Background: Isolated or predominant tubulointerstitial lupus nephritis is rare. Case Presentation: Here we report the case of a thirty eight years old male who was diagnosed with systemic lupus erythematosus (SLE) according to clinical and laboratory criteria and presented with impaired renal function and non nephrotic range proteinuria. Renal biopsy revealed normal glomeruli but interstitial momonuclear cell infiltration. Immunohiostochemistry (IHC) showed immune deposits in the tubular basement membranes (TBMs), and the peritubular capillary basement membranes (PTCBMs). He was started on high dose oral steroids, which were gradually tapered over one month. His renal functions improved over few days and normalized by the end of the first month of treatment. He was continued on low dose steroids and azathioprine with no evidence of relapse. Conclusions: Predominant tubulointerstitial lupus can occur, although rarely; and it runs a favorable course with good response to treatment

Blockchains as Infrastructure and Semicommons

Blockchains are not self-executing machines. They are resource systems designed by people, maintained by people, and governed by people. Their technical protocols help to solve some difficult problems in shared resource management, but behind those protocols there are always communities of people struggling with familiar challenges in governing their provision and use of common infrastructure. In this Article, we describe blockchains as shared, distributed transactional ledgers using two frameworks from commons theory. Brett Frischmann’s theory of infrastructure provides an external view, showing how blockchains provide useful, generic infrastructure for recording transactions and why that infrastructure is most naturally made available on common, nondiscriminatory terms. Henry Smith’s theory of semicommons provides an internal view, showing how blockchains intricately combine private resources (such as physical hardware and on-chain assets) with common resources (such as the shared transactional ledger and the blockchain protocol itself). We then detail how blockchains struggle with many of the governance challenges that these frameworks predict, requiring blockchain communities to engage in extensive off-chain governance work to coordinate their uses and achieve consensus. Blockchains function as infrastructure and semicommons not in spite of the human element, but because of it