4,288 research outputs found
High Time for Conservation: Adding the Environment to the Debate on Marijuana Liberalization
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
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
Dirhenium complexes supported on silica for the production of highly active single-site heterogeneous catalysts: characterisation of the active sites
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Information needs after stroke: What to include and how to structure it on a website. A qualitative study using focus groups and card sorting
Background: Use of the Internet to obtain health and other information is increasing. Previous studies have identified the specific information needs of people with stroke but not in relation to the Internet. People with aphasia (PwA) may face barriers in accessing the Internet: Navigating websites requires an ability to categorise information and this ability is often impaired in PwA. The website categorisation preferences of people with stroke and with aphasia have not yet been reported.
Aims: This study aimed: (a) to determine what information people who have had a stroke would like to see on a website about living with stroke; (b) to determine the most effective means of structuring information on the website so that it is accessible to people with stroke; and c) to identify any differences between people with and without aphasia in terms of preferences for structuring information on the website.
Methods & Procedures: Participants were recruited from a hospital's Stroke Database. Focus groups were used to elicit what information participants wanted on a website about living with stroke. The themes raised were depicted on 133 cards. To determine the most effective way of structuring information on the website, and whether there were any differences in preferences between PwA and PwoA, participants used a modified closed card-sorting technique to sort the cards under website categories.
Outcomes & Results: A total of 48 people were invited, and 12 (25%) agreed to take part. We ran three focus groups: one with PwA (n = 5) and two with people without aphasia (PwoA) (n = 3, n = 4). Participants wanted more information about stroke causes and effects (particularly emotional issues), roles of local agencies, and returning to previous activities (driving, going out). All participants completed the card-sorting exercise. Few cards (6%) were categorised identically by everyone. Cards relating to local agencies and groups were not consistently categorised together. Cards relating to emotions were segregated. The categorisation preferences for PwA were more fragmented than those for PwoA: 60% of PwA agreed on the categorisation of 51% of the cards, whereas 60% of PwoA agreed on the categorisation of 76% of the cards.
Conclusions: Information needs covered all stages of the stroke journey. The card sorting was accessible to everyone, and provided evidence of structuring preferences and of some of the categorisation difficulties faced by PwA. More research is needed on what an accessible website looks like for PwA
Production of Scalar Higgs Bosons Associated with Boson at the CERN LHC in the MSSM
We investigate the associated production of a scalar Higgs boson ( or
) with boson in the minimal supersymmetric extension of the standard
model (MSSM) at the CERN Large Hadron Collider (LHC), including the
contributions from 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 associated with , we
find that in most of the parameter regions, the contributions from initial
and are at a level of one percent of the total cross section
and therefore almost insignificant. For the production of associated with
, the contributions from channel can be much larger than those
from light quark initial states. Especially for large , the
increment can reach about one order of magnitude. Thus, when considering the
associated production of and at the LHC, the contributions from
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
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
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
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
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
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