4,247 research outputs found

    Rethinking the scale, structure & scope of U.S. energy institutions

    Get PDF
    This essay notes some of the key institutions created in the twentieth century for the purpose of delivering energy in North America. Those institutions are being challenged by a combination of stresses in three interconnected areas: reliability, economics, and environmental sustainability. The essay argues that these three stresses create an “energy trilemma” requiring institutional reform. We suggest that new and modi½ed institutions can best be understood if we evaluate them along three dimensions: institutional scale, structure, and scope. We consider real-world examples of recent institutions in light of each of these dimensions and note both successes and concerns that those factors illuminate. We conclude by noting that some institutional changes will be organic and unplanned; but many others, including responses to climate change, will bene½t from conscious attention to scale, structure, and scope by those engaged in designing and building the energy institutions needed in the twenty-½rst century

    Global equality of resources and the problem of valuation

    Get PDF
    The principle that every individual on the planet has a claim to an equal share of Earth’s natural resources has an intuitive attraction. Yet the Principle of Natural Resource Equality is not without its problems. This article focuses on the problem of valuation. Unless and until its adherents are able to develop an adequate theoretical mechanism for determining the comparative value of two or more bundles of natural resources the principle lacks applicability and persuasive force. Three adequacy constraints on such a mechanism are presented and then applied to a theorisation of the Principle of Natural Resource Equality that I have already expounded elsewhere: Global Equality of Resources. In each case I try to argue that Global Equality of Resources could satisfy the adequacy constraint, provided that both this theory and the relevant constraint are properly understood

    Language and the Promised Land: Passage and Migration to a Spanish-Language ‘Third Place’

    Get PDF
    The Spanish-language anthology Caminos para la paz: Literatura israelí y árabe en castellano (Buenos Aires: Corregidor, 2007) [Paths towards/for Peace: Israeli and Arab literature in Castilian], compiled by Ignacio López-Calvo and Cristián Ricci, offers us a collection of over thirty reflections—some Jewish, others Muslim—about the millennial but also contemporary situation of two literally related and historic peoples in a language—Spanish—that seemingly allows them to inhabit the same, this time uncontested, space. Despite the potentially questionable title of the work, which couches the conflict as that of a nation-state versus a nation and/or two peoples contesting rights to one same land, the anthology makes a daring attempt to invite multi-positional authors to express themselves openly without fear about matters that, through a third language, appear to transcend their political and national boundaries. According to the compilers, the search for Muslim contributors to this collection was sometimes met with aggression and threats to capitulate. One coeditor explained that nearly midway through the project most of the non-North African, Muslim contributors backed out after being warned by naysayers of the negative consequences of their participation in this literary convivencia or coexistence. Those who eventually did contribute—some Muslims from the Middle East and North Africa (from Ceuta, Morocco or Tétouan), and a few more, Latin American Jewish immigrants to Israel (from Argentina, Chile, Mexico)—saw in this project “una oportunidad de regresar al hogar común del idioma [an opportunity to return to the common home of language]” (Ricci & López-Calvo, p. 12). Caminos para la paz represents a kind of \u27tierra (com)prometida,\u27 a socially and politically committed and promised land whose existence and survival goes beyond the disputed and bloodied land itself, one in which the writers (and readers) “could return to their common home of language” (p. 12)

    Analyses of Aliphatic Aldehydes and Ketones in Carbonaceous Chondrites

    Get PDF
    Aliphatic aldehydes and ketones are essential building blocks for the synthesis of more complex organic compounds. In spite of their potentially key role as precursors of astrobiologically-important molecules, such as amino acids and carboxylic acids, this family of compounds has scarcely been evaluated in carbonaceous chondrites. The paucity of such analyses likely derives from the low concentration of aldehydes and ketones in the meteorites, and from the currently used chromatographic methodologies that have not been optimized for meteorite analysis. In this work, we report the development of a novel analytical method to quantify the molecular distribution and compound-specific isotopic analysis of 29 aliphatic aldehydes and ketones. Using this method, we have investigated the molecular distribution and 13C-isotopic composition of aldehydes and ketones in ten carbonaceous chondrites from the CI, CM, CR and CV groups. The total concentration of carbonyl compounds ranged from 130 to 1000 nmolg-1 of meteorite, with formaldehyde, acetaldehyde, and acetone being the most abundant species in all investigated samples. The 13C-isotopic values ranged from 67 to +64 and we did not observe clear relationships between 13C-content and molecular weight. Accurately measuring the relative abundances, determining the molecular distribution, and isotopic composition of chondritic organic compounds is central in assessing both their formation chemistry and synthetic relationships

    Molecular Distribution, 13C-Isotope, and Enantiomeric Compositions of Carbonaceous Chondrite Monocarboxylic Acids

    Get PDF
    The watersoluble organic compounds in carbonaceous chondrite meteorites constitute a record of the synthetic reactions occurring at the birth of the solar system and those taking place during parent body alteration and may have been important for the later origins and development of life on Earth. In this present work, we have developed a novel methodology for the simultaneous analysis of the molecular distribution, compoundspecific 13C, and enantiomeric compositions of aliphatic monocarboxylic acids (MCA) extracted from the hotwater extracts of 16 carbonaceous chondrites from CM, CR, CO, CV, and CK groups. We observed high concentrations of meteoritic MCAs, with total carbon weight percentages which in some cases approached those of carbonates and insoluble organic matter. Moreover, we found that the concentration of MCAs in CR chondrites is higher than in the other meteorite groups, with acetic acid exhibiting the highest concentration in all samples. The abundance of MCAs decreased with increasing molecular weight and with increasing aqueous and/or thermal alteration experienced by the meteorite sample. The 13C isotopic values of MCAs ranged from 52 to +27, and aside from an inverse relationship between 13C value and carbon straightchain length for C3C6 MCAs in Murchison, the 13Cisotopic values did not correlate with the number of carbon atoms per molecule. We also observed racemic compositions of 2methylbutanoic acid in CM and CR chondrites. We used this novel analytical protocol and collective data to shed new light on the prebiotic origins of chondritic MCAs

    Pathways to Meteoritic Glycine and Methylamine

    Get PDF
    Glycine and methylamine are meteoritic water-soluble organic compounds that provide insights into the processes that occurred before, during, and after the formation of the Solar System. Both glycine and methylamine and many of their potential synthetic precursors have been studied in astrophysical environments via observations, laboratory experiments, and modeling. Despite these studies, the synthetic mechanisms for their formation leading to their occurrence in meteorites remain poorly understood. Typical 13C-isotopic values (13C) of meteoritic glycine and methylamine are 13C-enriched relative to their terrestrial counterparts; thus, analyses of their stable carbon isotopic compositions (13C/12C) may be used not only to assess terrestrial contamination in meteorites but also to provide information about their synthetic routes inside the parent body. Here, we examine potential synthetic routes of glycine and methylamine from a common set of precursors present in carbonaceous chondrite meteorites, using data from laboratory analyses of the well-studied CM2 Murchison meteorite. Several synthetic mechanisms for the origins of glycine and methylamine found in carbonaceous chondrites may be possible, and the prevalence of these mechanisms will largely depend on (a) the molecular abundance of the precursor molecules and (b) the levels of processing (aqueous and thermal) that occurred inside the parent body. In this work, we also aim to contextualize the current knowledge about gas-phase reactions and irradiated ice grain chemistry for the synthesis of these species through parent body processes. Our evaluation of various mechanisms for the origins of meteoritic glycine and methylamine from simple species shows what work is still needed to evaluate both the abundances and isotopic compositions of simpler precursor molecules from carbonaceous chondrites as well as the effects of parent body processes on those abundances and isotopic compositions. The analyses presented here combined with the indicated measurements will aid a better interpretation of quantitative analysis of reaction rates, molecular stability, and distribution of organic products from laboratory simulations of interstellar ices, astronomical observations, and theoretical modeling

    Lei-Shi Li: a giant in international nephrology

    Get PDF

    The prisoner's right to vote and civic responsibility: Reaffirming the social contract?

    Get PDF
    Copyright © 2009 NAPOThis article considers the issue of the prisoner’s right to vote in the light of recent developments in law and policy. It critically reviews the purported justifications for disenfranchisement and argues that re-enfranchisement should be pursued on the grounds of both principle and policy
    • …
    corecore