4,288 research outputs found

    High Time for Conservation: Adding the Environment to the Debate on Marijuana Liberalization

    Get PDF
    The liberalization of marijuana policies, including the legalization of medical and recreational marijuana, is sweeping the United States and other countries. Marijuana cultivation can have significant negative collateral effects on the environment that are often unknown or overlooked. Focusing on the state of California, where by some estimates 60% -- 70% of the marijuana consumed in the United States is grown, we argue that (a) the environmental harm caused by marijuana cultivation merits a direct policy response, (b) current approaches to governing the environmental effects are inadequate, and (c) neglecting discussion of the environmental impacts of cultivation when shaping future marijuana use and possession policies represents a missed opportunity to reduce, regulate, and mitigate environmental harm

    XMM-Newton monitoring of X-ray variability in the quasar PKS 0558-504

    Get PDF
    We present the temporal analysis of X-ray observations of the radio-loud Narrow-Line Seyfert 1 galaxy (NLS1) PKS 0558-504 obtained during the XMM-Newton Calibration and Performance Verification (Cal/PV) phase. The long term light curve is characterized by persistent variability with a clear tendency for the X-ray continuum to harden when the count rate increases. Another strong correlation on long time scales has been found between the variability in the hard band and the total flux. On shorter time scales the most relevant result is the presence of smooth modulations, with characteristic time of ~ 2 hours observed in each individual observation. The short term spectral variability turns out to be rather complex but can be described by a well defined pattern in the hardness ratio-count rate plane.Comment: 6 pages, 7 figures, accepted for publication in A&A special issue on first results from XM

    Production of Scalar Higgs Bosons Associated with Z0Z^0 Boson at the CERN LHC in the MSSM

    Full text link
    We investigate the associated production of a scalar Higgs boson (h0h^0 or H0H^0) with Z0Z^0 boson in the minimal supersymmetric extension of the standard model (MSSM) at the CERN Large Hadron Collider (LHC), including the contributions from bbˉb\bar{b} annihilation at the tree level and gluon fusion via quark and squark loops. We quantitatively analyze the total cross sections in the mSUGRA scenario. For the production of h0h^0 associated with Z0Z^0, we find that in most of the parameter regions, the contributions from initial bbˉb\bar{b} and gggg are at a level of one percent of the total cross section and therefore almost insignificant. For the production of H0H^0 associated with Z0Z^0, the contributions from bbˉb\bar{b} channel can be much larger than those from light quark initial states. Especially for large tanβ\tan\beta, the increment can reach about one order of magnitude. Thus, when considering the associated production of H0H^0 and Z0Z^0 at the LHC, the contributions from bbˉb\bar{b} annihilation should be taken into account seriously.Comment: 19 pages, 8 figures, RevTeX4; one reference added, minor changes, conclusion unchanged; Journal-ref adde

    Virological rebound in human immunodeficiency virus-infected patients with or without residual viraemia: results from an extended follow-up

    Get PDF
    AbstractHuman immunodeficiency virus (HIV) -infected patients with HIV RNA loads of < 50 copies/mL were followed-up for a median (interquartile range) of 30.8 (11.7–32.9) months to study the effect of residual viraemia (RV) on virological rebound (VR). At baseline, 446 (60.3%) patients had undetectable HIV RNA (group A) and 293 (39.7%) had RV (1–49 HIV RNA copies/mL, group B) by kinetic PCR. VR occurred in 4 (0.9%) patients in group A and in 12 (4.1%) patients in group B (p 0.007). Time to VR was shorter among patients of group B (Log-rank test: p 0.003). However, the proportion of VR was extremely low also among patients with RV

    First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell {\Lambda}-Hypernuclei

    Get PDF
    Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Lambda-Hypernuclei (A = 5-16) have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Gamma_2N/Gamma_p, are obtained from single proton spectra, Gamma_2N/Gamma_p = 0.50 +/- 0.24, and from neutron and proton coincidence spectra, Gamma_2N/Gamma_p = 0.36 +/- 0.14stat +0.05sys -0.04sys , in full agreement with previously published ones. With these values, a method is developed to extract the one-proton induced decay width in units of the free Lambda decay width, Gamma_p/Gamma_Lambda, without resorting to Intra Nuclear Cascade models but by exploiting only experimental data, under the assumption of a linear dependence on A of the Final State Interaction contribution. This is the first systematic determination ever done and it agrees within the errors with recent theoretical calculations.Comment: 16 pages, 3 figures, 2 table

    The Agile Alert System For Gamma-Ray Transients

    Full text link
    In recent years, a new generation of space missions offered great opportunities of discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) onboard the AGILE space mission. The AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many gamma-ray transients of galactic and extragalactic origins. This work presents the AGILE innovative approach to fast gamma-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe: (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for gamma-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, e-mails, and push notifications of an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in gamma-ray astrophysics.Comment: 34 pages, 9 figures, 5 table

    Efficacy and tolerability of switching to a dual therapy with darunavir/ritonavir plus raltegravir in HIV-infected patients with HIV-1 RNA <= 50 cp/mL

    Get PDF
    Background: Nucleos(t)ide reverse transcriptase inhibitors (NRTI) toxicity may represent a threat for long-term success of combined antiretroviral therapy. Some studies have suggested a possible improvement of NRTI-related toxicity after switching to NRTI-sparing regimens. Objectives: We aimed to explore the efficacy and tolerability of switching to darunavir/ritonavir (DRV/r) plus raltegravir (RAL) while having a viral load (VL) ≤50 copies/mL in the clinical setting. Study design: Treatment-experienced HIV 1-infected patients enrolled in the ICONA Foundation Study cohort were included if they switched their current regimen to DRV/r + RAL with a HIV-RNA ≤50 copies/mL. Different definitions of virological failure (VF) and treatment failure (TF) were employed. Kaplan–Meier curves and Cox regression models were performed to estimate time to event probability. Results: We included 72 HIV-infected patients, 22 (31%) of these were female, 31 (43%) men who have sex with men (MSM) amd 15 (21%) had hepatitis co-infections. Median age was 44 (IQR: 35-50) years amd CD4 count was 389 (IQR 283-606) cells/mmc. Median follow-up time for TF was 24 (IQR 9–31) months. Twenty-five discontinuations occurred (60% simplifications); only 2 (8%) were toxicity-driven (lipid elevations). The probability of VF (confirmed VL >50 copies/mL) was estimated at 7% [95% confidence interval (CI) 1–13%] by 12 and 9% (95% CI 2–16%) by 24 months. When considering TF, we found a probability of stop/intensification/single VL > 200 copies/mL of 13% (95% CI 1–17%) and 22% (95% CI 11–33%) by 12 and 24 months. Female gender (adjusted relative hazard, ARH = 0.10; 95% CI 0.01–0.74; p = 0.024) and older age (AHR = 0.50 per 10 years older; 95% CI 0.25–0.99; p = 0.045) were associated with a lower risk of TF. A previous PI failure was strongly associated with TF (AHR = 52.6, 95% CI 3.6–779; p = 0.004). Conclusions: DRV/r + RAL is a valuable NRTI-sparing option, especially in female and older patients, with a relatively low risk of VF and good tolerability after 2 years since start in an ART-experienced population. However, previous PI-failure should be a limiting factor for this strategy
    corecore