558 research outputs found

    International Investment Agreements, Human Rights, and Environmental Justice: The Texaco/Chevron Case From the Ecuadorian Amazon

    Get PDF
    The Texaco/Chevron lawsuit, which started in November 1993 and is still being litigated in 2020, is a prominent example ofthe process of judicialization of environmental conflict. The Ecuadorian plaintiffs claim that the oil company’s operations generated ruinous impacts on the environment and on the development prospects and health of nearby individuals and communities. The tortuous and lengthy judiciary process was further hindered by an arbitration process, an Investor–State Dispute Settlement mechanism nested in the Ecuador—United States Bilateral Investment Treaty. The significance of the case goes beyond the specifics of Ecuador and provides further arguments fuelling the protracted legitimacy crisis experienced by International Investment Agreements. The current praxis of Investor–State Dispute Settlement mechanisms is generating an asymmetrical system, protectingthe interest of investors, and intruding intothe space of human and environmental rights. These issues are resonating with social movements, activist scholars and policy makers who are reacting to the vulnerabilities engendered by International Investment Agreements thro

    The dark side of curvature

    Get PDF
    Geometrical tests such as the combination of the Hubble parameter H(z) and the angular diameter distance d_A(z) can, in principle, break the degeneracy between the dark energy equation of state parameter w(z), and the spatial curvature Omega_k in a direct, model-independent way. In practice, constraints on these quantities achievable from realistic experiments, such as those to be provided by Baryon Acoustic Oscillation (BAO) galaxy surveys in combination with CMB data, can resolve the cosmic confusion between the dark energy equation of state parameter and curvature only statistically and within a parameterized model for w(z). Combining measurements of both H(z) and d_A(z) up to sufficiently high redshifts around z = 2 and employing a parameterization of the redshift evolution of the dark energy equation of state are the keys to resolve the w(z)-Omega_k degeneracy.Comment: 18 pages, 9 figures. Minor changes, matches version accepted in JCA

    Mass hierarchy, 2-3 mixing and CP-phase with Huge Atmospheric Neutrino Detectors

    Full text link
    We explore the physics potential of multi-megaton scale ice or water Cherenkov detectors with low (∌1\sim 1 GeV) threshold. Using some proposed characteristics of the PINGU detector setup we compute the distributions of events versus neutrino energy EÎœE_\nu and zenith angle Ξz\theta_z, and study their dependence on yet unknown neutrino parameters. The (EΜ−Ξz)(E_\nu - \theta_z) regions are identified where the distributions have the highest sensitivity to the neutrino mass hierarchy, to the deviation of the 2-3 mixing from the maximal one and to the CP-phase. We evaluate significance of the measurements of the neutrino parameters and explore dependence of this significance on the accuracy of reconstruction of the neutrino energy and direction. The effect of degeneracy of the parameters on the sensitivities is also discussed. We estimate the characteristics of future detectors (energy and angle resolution, volume, etc.) required for establishing the neutrino mass hierarchy with high confidence level. We find that the hierarchy can be identified at 3σ3\sigma -- 10σ10\sigma level (depending on the reconstruction accuracies) after 5 years of PINGU operation.Comment: 39 pages, 21 figures. Description of Fig.3 correcte

    Space-time inhomogeneity, anisotropy and gravitational collapse

    Full text link
    We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite mass and size on an inhomogeneous space-time background. The collapse is found to proceed without formation of an even horizon to singularity when the collapsing configuration radiates all its mass energy. The impact of inhomogeneity on various parameters of the collapsing stellar configuration is examined in some specific space-time backgrounds.Comment: To appear in Gen. Relativ. Gra

    Precision on leptonic mixing parameters at future neutrino oscillation experiments

    Get PDF
    We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta_{13} and the CP phase, delta, assuming that theta_{13} is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effect, the comparison of the physics reach of different experiments on the basis of the CP discovery potential, as usually done, can be misleading. We have compared various proposed super-beam, beta-beam and neutrino factory setups on the basis of the relative precision of theta_{13} and the error on delta. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on theta_{13} below 3% and an error on delta of < 7^{\circ} at 1 sigma (1 d.o.f.) can be obtained at a neutrino factory.Comment: Minor changes, matches version accepted in JHEP. 30 pages, 9 figure

    Mass hierarchy discrimination with atmospheric neutrinos in large volume ice/water Cherenkov detectors

    Full text link
    Large mass ice/water Cherenkov experiments, optimized to detect low energy (1-20 GeV) atmospheric neutrinos, have the potential to discriminate between normal and inverted neutrino mass hierarchies. The sensitivity depends on several model and detector parameters, such as the neutrino flux profile and normalization, the Earth density profile, the oscillation parameter uncertainties, and the detector effective mass and resolution. A proper evaluation of the mass hierarchy discrimination power requires a robust statistical approach. In this work, the Toy Monte Carlo, based on an extended unbinned likelihood ratio test statistic, was used. The effect of each model and detector parameter, as well as the required detector exposure, was then studied. While uncertainties on the Earth density and atmospheric neutrino flux profiles were found to have a minor impact on the mass hierarchy discrimination, the flux normalization, as well as some of the oscillation parameter (\Delta m^2_{31}, \theta_{13}, \theta_{23}, and \delta_{CP}) uncertainties and correlations resulted critical. Finally, the minimum required detector exposure, the optimization of the low energy threshold, and the detector resolutions were also investigated.Comment: 23 pages, 16 figure

    Echinoderms have bilateral tendencies

    Get PDF
    Echinoderms take many forms of symmetry. Pentameral symmetry is the major form and the other forms are derived from it. However, the ancestors of echinoderms, which originated from Cambrian period, were believed to be bilaterians. Echinoderm larvae are bilateral during their early development. During embryonic development of starfish and sea urchins, the position and the developmental sequence of each arm are fixed, implying an auxological anterior/posterior axis. Starfish also possess the Hox gene cluster, which controls symmetrical development. Overall, echinoderms are thought to have a bilateral developmental mechanism and process. In this article, we focused on adult starfish behaviors to corroborate its bilateral tendency. We weighed their central disk and each arm to measure the position of the center of gravity. We then studied their turning-over behavior, crawling behavior and fleeing behavior statistically to obtain the center of frequency of each behavior. By joining the center of gravity and each center of frequency, we obtained three behavioral symmetric planes. These behavioral bilateral tendencies might be related to the A/P axis during the embryonic development of the starfish. It is very likely that the adult starfish is, to some extent, bilaterian because it displays some bilateral propensity and has a definite behavioral symmetric plane. The remainder of bilateral symmetry may have benefited echinoderms during their evolution from the Cambrian period to the present

    Mechanisms Underlying the Antiarrhythmic Effect of ARumenamide-787 in Experimental Models of the J Wave Syndromes and Hypothermia

    Get PDF
    BACKGROUND: Brugada (BrS) and early repolarization syndromes (ERS), the so-called J wave syndromes (JWS), are associated with life-threatening ventricular arrhythmias. Pharmacologic approaches to therapy are currently limited. In this study, we examine the effects of ARumenamide-787 (AR-787) to suppress the electrocardiographic and arrhythmic manifestations of JWS and hypothermia. METHODS: We studied the effects of AR-787 on INa and IKr in HEK-293 cells stably expressing the α- and ÎČ1-subunits of the cardiac (NaV1.5) sodium channel and hERG channel, respectively. In addition, we studied its effect on Ito, INa and ICa in dissociated canine ventricular myocytes along with action potentials and ECG from coronary-perfused right (RV) and left (LV) ventricular wedge preparations. The Ito agonist, NS5806 (5-10 ÎŒM), ICa blocker, verapamil (2.5 ÎŒM), and INa blocker, ajmaline (2.5 ÎŒM), were used to mimic the genetic defects associated with JWS and to induce the electrocardiographic and arrhythmic manifestations of JWS (prominent J waves/ST segment elevation, phase 2 reentry and polymorphic VT/VF) in canine ventricular wedge preparations. RESULTS: AR-787 (1, 10 and 50 ÎŒM) exerted pleiotropic effects on cardiac ion channels. The predominant effect was inhibition of the transient outward current (Ito) and enhancement of the sodium channel current (INa), with lesser effects to inhibit IKr and augment calcium channel current (ICa). AR-787 diminished the electrocardiographic J wave and prevented and/or suppressed all arrhythmic activity in canine RV and LV experimental models of BrS, ERS and hypothermia. CONCLUSIONS: Our findings point to AR-787 as promising candidate for the pharmacologic treatment of JWS and hypothermia

    Super-acceleration on the Brane by Energy Flow from the Bulk

    Full text link
    We consider a brane cosmological model with energy exchange between brane and bulk. Parameterizing the energy exchange term by the scale factor and Hubble parameter, we are able to exactly solve the modified Friedmann equation on the brane. In this model, the equation of state for the effective dark energy has a transition behavior changing from wdeeff>−1w_{de}^{eff}>-1 to wdeeff<−1w_{de}^{eff}<-1, while the equation of state for the dark energy on the brane has w>−1w>-1. Fitting data from type Ia supernova, Sloan Digital Sky Survey and Wilkinson Microwave Anisotropy Probe, our universe is predicted now in the state of super-acceleration with wde0eff=−1.21w_{de0}^{eff}=-1.21.Comment: Revtex, 11 pages including 2 figures,v2: tpos fixed, references added, to appear in JCA
    • 

    corecore