1,748 research outputs found

    Greening the invisible hand : how environmental non-governmental organizations (NGOs) succeed and fall in technology change

    Get PDF
    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2003.Includes bibliographical references (p. 473-491).This dissertation examines how national environmental non-governmental organizations (NGOs) in Sweden and the United States (US) tried to diffuse cleaner production technologies in the pulp and paper industry from 1980-1998. The environmental organizations were: Greenpeace Sweden, Swedish Society for Nature Conservation, Environmental Defense, Greenpeace USA, and Natural Resources Defense Council. The technologies they tried to diffuse reduced dioxins and other organochlorines from mills that bleach pulp for making white paper products. Totally chlorine-free (TCF) bleaching emerged as the cleanest bleaching technology in commercial use: it eliminated organochlorine water pollution. The Swedish environmental organizations, with help from Greenpeace Germany, were more successful at diffusing TCF bleaching. The success in Sweden emerged because the environmental organizations created market demand for TCF paper: they formed collaborative relations with major buyers of bleached paper, proved that TCF paper was a technically viable alternative, and connected environmentally-minded consumers with like-minded manufacturers. Supporting their success were: a longer history of market campaigns to transform paper bleaching, the lack of opposition to TCF paper in Germany (a major consumer of Swedish bleached pulp), and massive seal and fish die-offs in 1988. The failure in the US occurred because the environmental organizations did not create market demand: they disagreed on environmental goals, they did not succeed in forming collaborative alliances with major purchasers in favor of TCF paper, and they could not overcome a sophisticated counter-campaign from environmental laggards in the American pulp and paper industry.(cont.) This dissertation proposes that success in the face of strident industry opposition entails changing organizing strategy: national environmental groups need to engage in sectoral organizing. In sectoral organizing environmental groups work to create a more environmentally sustainable busies sector, rather than addressing a single problem within that sector. Sectoral organizing creates opportunities for achieving challenging goals by collaborating with consumers across multiple environmental problems, addressing the low hanging fruit first, then moving to more complex problems. By creating trust, credibility, and legitimacy with consumers, environmental organizations are more likely to succeed in the face of opposition from environmental laggards.by Mark S. Rossi.Ph.D

    Counter-propagating entangled photons from a waveguide with periodic nonlinearity

    Full text link
    The conditions required for spontaneous parametric down-conversion in a waveguide with periodic nonlinearity in the presence of an unguided pump field are established. Control of the periodic nonlinearity and the physical properties of the waveguide permits the quasi-phase matching equations that describe counter-propagating guided signal and idler beams to be satisfied. We compare the tuning curves and spectral properties of such counter-propagating beams to those for co-propagating beams under typical experimental conditions. We find that the counter-propagating beams exhibit narrow bandwidth permitting the generation of quantum states that possess discrete-frequency entanglement. Such states may be useful for experiments in quantum optics and technologies that benefit from frequency entanglement.Comment: submitted to Phys. Rev.

    Shade and Drought Stress-Induced Changes in Phenolic Content of Wild Oat (Avena fatua L.) Seeds

    Get PDF
    Plants develop under a wide range of maternal environments, depending on the time of emergence, prevailing competition from other plants, and presence or absence of other biotic or abiotic stress factors. Stress factors, such as light limitation and drought, during plant development typically reduces the reproductive allocation to seeds, resulting in fewer and often smaller seeds. Such stress factors may also influence seed quality traits associated with persistence in the soil, such as seed dormancy and chemical defense. For this research, we hypothesized that light limitation and drought during wild oat (Avena fatua L.) seed development would result in reduced allocation to seed phenolics and other aliphatic organic acids previously identified in the seeds of this species. Wild oat isolines (M73 and SH430) were grown in the greenhouse under cyclic drought conditions (2005 only) or two levels of shade (50 and 70%; 2005 and 2006) achieved with standard black shade cloth. The soluble and cellular bound chemical constituents were identified and quantified using gas chromatography - mass spectrometry. The shade and drought stress treatments often significantly affected the mass of the caryopsis and hull seed fractions, as well as the phenolic content of these seed fractions, depending upon isoline, seed fraction, phenolic fraction, and specific phenolics analyzed. Phenolic content of the hull was reduced by the stress environments by up to 48%, whereas there was some evidence of an increase in the soluble phenolic content of the caryopsis in response to the stress environments. Ferulic and p-coumaric acids were the most abundant phenolic acids in both soluble and bound fractions, and bound phenolics comprised generally 95% or more of total phenolics. There was no discernable evidence that the aliphatic organic content was affected by the stress environments. Our results indicate that plant stress during seed development can reduce both the physical and chemical defense in seeds, which may result in seeds that are less persistent in the soil seed bank and potentially less of a weed management concern

    Baseline transtheoretical and dietary behavioral predictors of dietary fat moderation over 12 and 24 months

    Get PDF
    Longitudinal predictors of dietary behavior change are important and in need of study. This secondary data analysis combined primary data across three randomized trials to examine transtheoretical model (TTM) and specific dietary predictors of successful dietary change at 12 and 24 months separately in treatment and control groups (N = 4178). The treatment group received three TTM-tailored print interventions over 12 months between 1995 and 2000. Chi-square and MANOVA analyses were used to examine baseline predictors of dietary outcome at 12 and 24 months. Last, a multivariable logistic regression was conducted with all baseline variables included. Across all analyses in both treatment and control groups, the most robust predictors of successful change were for TTM-tailored treatment group, preparation stage of change, and increased use of dietary behavior variables such as moderating fat intake, substitution of lower fat foods, and increasing intake of healthful foods. These results provide strong evidence for treatment, stage and behavioral dietary severity effects predicting dietary behavior change over time, and for targeting these variables with the strongest relationships to outcome in interventions, such as TTM-tailored dietary interventions

    Baseline Stage, Severity, and Effort Effects Differentiate Stable Smokers from Maintainers and Relapsers

    Get PDF
    This cross-sectional study (N = 4,144) compared three longitudinal dynatypes (Maintainers, Relapsers, and Stable Smokers) of smokers on baseline demographics, stage, addiction severity, and transtheoretical model effort effect variables. There were significant small-to-medium-sized differences between the Stable Smokers and the other two groups on stage, severity, and effort effect variables in both treatment and control groups. There were few significant, very small differences on baseline effort variables between Maintainers and Relapsers in the control, but not the treatment group. The ability to identify Stable Smokers at baseline could permit enhanced tailored treatments that could improve population cessation rates

    Planet Hunters. VI: An Independent Characterization of KOI-351 and Several Long Period Planet Candidates from the Kepler Archival Data

    Get PDF
    We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlapped with Kepler Objects of Interest (KOIs) at the time of submission. We report the discovery of one more addition to the six planet candidate system around KOI-351, making it the only seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven planet candidates orbiting 1\lesssim 1 AU from their host star. A Hill stability test and an orbital integration of the system shows that the system is stable. Furthermore, we significantly add to the population of long period transiting planets; periods range from 124-904 days, eight of them more than one Earth year long. Seven of these 14 candidates reside in their host star's habitable zone.Comment: 27 pages, 6 figures, 5 tables, Accepted to AJ (in press) (updated title from original astro-ph submission

    Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in acute lung injury to reduce pulmonary dysfunction (HARP-2) trial : study protocol for a randomized controlled trial

    Get PDF
    Acute lung injury (ALI) is a common devastating clinical syndrome characterized by life-threatening respiratory failure requiring mechanical ventilation and multiple organ failure. There are in vitro, animal studies and pre-clinical data suggesting that statins may be beneficial in ALI. The Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in Acute lung injury to Reduce Pulmonary dysfunction (HARP-2) trial is a multicenter, prospective, randomized, allocation concealed, double-blind, placebo-controlled clinical trial which aims to test the hypothesis that treatment with simvastatin will improve clinical outcomes in patients with ALI

    Trends in Veno-Arterial Extracorporeal Life Support With and Without an Impella or Intra-Aortic Balloon Pump for Cardiogenic Shock

    Get PDF
    Background: Mechanical circulatory support devices, such as the intra-aortic balloon pump (IABP) and Impella, are often used in patients on veno-arterial extracorporeal life support (VA-ECLS) with cardiogenic shock despite limited supporting clinical trial data. Methods and Results: Hospitalizations for cardiogenic shock from 2016 to 2018 were identified from the National Inpatient Sample. Trends in the use of VA-ECLS with and without an IABP or Impella were assessed semiannually. Multivariable logistic regression and general linear regression evaluated the association of Impella and IABP use with in-hospital outcomes. Overall, 12 035 hospitalizations with cardiogenic shock and VA-ECLS were identified, of which 3115 (26%) also received an IABP and 1880 (16%) an Impella. Use of an Impella with VA-ECLS substantially increased from 10% to 18% over this period (P\u3c0.001), whereas an IABP modestly increased from 25% to 26% (P\u3c0.001). In-hospital mortality decreased 54% to 48% for VA-ECLS only, 61% to 58% for VA-ECLS with an Impella, and 54% to 49% for VA-ECLS with an IABP (P\u3c0.001 each). Most (57%) IABPs or Impellas were placed on the same day as VA-ECLS. After adjustment, there were no differences in in-hospital mortality or length of stay with the addition of an IABP or Impella compared with VA-ECLS alone. Conclusions: From 2016 to 2018 in the United States, use of an Impella and IABP with VA-ECLS significantly increased. More than half of Impellas and IABPs were placed on the same day as VA-ECLS, and the use of a second mechanical circulatory support device did not impact in-hospital mortality. Further studies are needed to decipher the optimal timing and patient selection for this growing practice

    Deriving effective models for multiscale systems via evolutionary GammaGamma-convergence

    Get PDF
    We discuss possible extensions of the recently established theory of evolutionary Gamma convergence for gradient systems to nonlinear dynamical systems obtained by perturbation of a gradient systems. Thus, it is possible to derive effective equations for pattern forming systems with multiple scales. Our applications include homogenization of reaction-diffusion systems, the justification of amplitude equations for Turing instabilities, and the limit from pure diffusion to reaction-diffusion. This is achieved by generalizing the Gamma-limit approaches based on the energy-dissipation principle or the evolutionary variational estimate

    Universal principles in the repair of communication problems

    Get PDF
    There would be little adaptive value in a complex communication system like human language if there were no ways to detect and correct problems. A systematic comparison of conversation in a broad sample of the world’s languages reveals a universal system for the real-time resolution of frequent breakdowns in communication. In a sample of 12 languages of 8 language families of varied typological profiles we find a system of ‘other-initiated repair’, where the recipient of an unclear message can signal trouble and the sender can repair the original message. We find that this system is frequently used (on average about once per 1.4 minutes in any language), and that it has detailed common properties, contrary to assumptions of radical cultural variation. Unrelated languages share the same three functionally distinct types of repair initiator for signalling problems and use them in the same kinds of contexts. People prefer to choose the type that is the most specific possible, a principle that minimizes cost both for the sender being asked to fix the problem and for the dyad as a social unit. Disruption to the conversation is kept to a minimum, with the two-utterance repair sequence being on average no longer that the single utterance which is being fixed. The findings, controlled for historical relationships, situation types and other dependencies, reveal the fundamentally cooperative nature of human communication and offer support for the pragmatic universals hypothesis: while languages may vary in the organization of grammar and meaning, key systems of language use may be largely similar across cultural groups. They also provide a fresh perspective on controversies about the core properties of language, by revealing a common infrastructure for social interaction which may be the universal bedrock upon which linguistic diversity rests
    corecore