4,032 research outputs found
The silver lining in Trump’s Paris pullout: a chance for the EU and China to take the leadership mantle
Donald Trump’s decision to pull the United States out of the Paris Climate Agreement produced a strong reaction from European leaders. Charles F. Parker argues the decision may provide an opportunity for the EU to strengthen its climate change leadership by forging an alliance with China. He suggests that there were several silver linings to the US withdrawal, but the EU will have to translate its rhetoric into concrete action if it is to reclaim leadership over the issue
Assessing the EU’s global climate change leadership: From Copenhagen to the Paris agreement
The EU has attempted to take a leading role in climate negotiations, but how effective has it been in shaping agreements? Charles F. Parker and Christer Karlsson present survey evidence from eight climate summits leading up to the Paris agreement in 2015. They highlight that although the EU’s perception of itself as a world leader was not shared to the same extent outside of the EU, it was still perceived to be one of the key leaders alongside China and the US
Geochemical constraints on basalt petrogenesis in the Strait of Sicily Rift Zone (Italy): Insights into the importance of short lengthscale mantle heterogeneity
Igneous activity from the late Miocene to historic time (most recently 1891 CE) in the Strait of Sicily has created
two volcanic islands (Pantelleria and Linosa) and several seamounts. These volcanoes are dominated by transitional
(ol + hy-normative) to alkaline (ne-normative) basaltic lavas and scoriae; volcanic felsic rocks (peralkaline
trachyte-rhyolite) crop out only on Pantelleria. Although most likely erupted through continental crust,
basalts demonstrate no evidence of crustal contamination and are geochemically similar to oceanic island basalts
(OIB). Despite their isotopic similarities, there are considerable compositional differences with respect to major
and trace element geochemistry both between and within the two islands that are due to short-length scale
mantle heterogeneity beneath the region as well as variability in partial melting and magma storage conditions.
Published geophysical surveys suggest that lithospheric thickness beneath both islands is ~60 km; this is consistent
with the results of our geochemical modelling (59\u201360 km), which also suggest mantle potential temperatures
between 1415 and 1435 \ub0C, similar to those documented in other continental passive rifts. Trace
element and isotopic data reveal that the asthenosphere beneath the Strait of Sicily is heterogenous at both interisland
(100s of km) and intra-island (10s of km) scales. Although there is some compositional overlap between
the two major synthems at Linosa, in general the older magmas (Arena Bianca, 700 ka) formed as a result of
~5% partial melting of a depleted MORB mantle (DMM) source enriched with a relatively small amount of
recycled MORB material, whereas the younger magmas (Monte Bandiera, 530 ka) formed as a result of ~2%
partial melting of a similar mantle source. Pantelleria magmas formed from a higher degree (~6%) of partial
melting of a DMM source with a relatively greater amount of recycled MORB material and possibly other
components. Geochemical modelling also suggests the older magmas on Linosa differentiated at a much shallower
level (~8 km) than the younger magmas (~25 km, at or below the base of the crust) prior to eruption.
Magmas stored in higher-level reservoirs were effectively homogenized and preserve a narrower compositional
range than magmas sourced from depth. Data for the seamounts are scarce and compromised by significant
seawater alteration; thus, these volcanic centers cannot be modelled but based on comparative geochemistry
with the islands are likely the result of even smaller (< 2%) degrees of partial melting beneath thicker
(> 60 km) lithosphere. Despite the geophysical similarities between the two islands in terms of lithospheric
thickness and crustal thinning, melt productivity has been greater at Pantelleria, producing a much larger island
and sustaining felsic magmatism, which we hypothesize may ultimately be entirely due to the local occurrence of
much more fusible mantle
The reaction of formic acid with RaneyTM copper
The interaction of formic acid with RaneyTM Cu proves to be complex. Rather than the expected generation of a monolayer of bidentate formate, we find the formation of a Cu(II) compound. This process occurs by direct reaction of copper and formic acid; in contrast, previous methods are by solution reaction. This is a rare example of formic acid acting as an oxidant rather than, as more commonly found, a reductant. The combination of diffraction, spectroscopic and computational methods has allowed this unexpected process to be characterized
Criminal Justice and Suicide Outcomes with Indiana's Risk-Based Gun Seizure Law
This article examines the application and effectiveness of a 2006 Indiana law designed to prevent gun violence by authorizing police officers to separate firearms from persons who present imminent or future risk of injury to self or others, or display a propensity for violent or emotionally unstable conduct. A court hearing is held to determine ongoing risk in these cases; a judge decides whether to return the seized firearms or retain them for up to five years. The study examines the frequency of criminal arrest as well as suicide outcomes for 395 gun-removal actions in Indiana. Fourteen individuals (3.5%) died from suicide, seven (1.8%) using a firearm. The study population's annualized suicide rate was about 31 times higher than that of the general adult population in Indiana, demonstrating that the law is being applied to a population genuinely at high risk. By extrapolating information on the case fatality rate for different methods of suicide, we calculated that one life was saved for every 10 gun-removal actions, similar to results of a previous study in Connecticut. Perspectives from key stakeholders are also presented along with implications for gun policy reform and implementation
The Turbulent Magnetic Prandtl Number of MHD Turbulence in Disks
The magnetic Prandtl number Pr_M is the ratio of viscosity to resistivity. In
astrophysical disks the diffusion of angular momentum (viscosity) and magnetic
fields (resistivity) are controlled by turbulence. Phenomenological models of
the evolution of large scale poloidal magnetic fields in disks suggest that the
turbulent magnetic Prandtl number Pr_{M,T} controls the rate of escape of
vertical field from the disk; for Pr_{M,T} leq R/H vertical field diffuses
outward before it can be advected inward by accretion. Here we measure field
diffusion and angular momentum transport due to MHD turbulence in a shearing
box, and thus Pr_{M,T}, by studying the evolution of a sinusoidal perturbation
in the magnetic field that is injected into a turbulent background. We show
that the perturbation is always stable, decays approximately exponentially, has
decay rate proportional to k^2, and that the implied Pr_{M,T} ~ 1.Comment: 15pages, 1 figure, accepted by Ap
Applied Plasma Research
Contains reports on two research projects.National Science Foundation (Grant GK-28282X1)National Science Foundation (Grant GK-33843)U. S. Army - Research Office - Durham (Contract DAHC04-72-C-0044
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The study design and rationale of the randomized controlled trial: translating COPD guidelines into primary care practice
Background: Chronic obstructive pulmonary disease (COPD) is a progressive, debilitating disease associated with significant clinical burden and is estimated to affect 15 million individuals in the US. Although a large number of individuals are diagnosed with COPD, many individuals still remain undiagnosed due to the slow progression of the disorder and lack of recognition of early symptoms. Not only is there under-diagnosis but there is also evidence of sub-optimal evidence-based treatment of those who have COPD. Despite the development of international COPD guidelines, many primary care physicians who care for the majority of patients with COPD are not translating this evidence into effective clinical practice. Method/Design This paper describes the design and rationale for a randomized, cluster design trial (RCT) aimed at translating the COPD evidence-based guidelines into clinical care in primary care practices. During Phase 1, a needs assessment evaluated barriers and facilitators to implementation of COPD guidelines into clinical practice through focus groups of primary care patients and providers. Using formative evaluation and feedback from focus groups, three tools were developed. These include a computerized patient activation tool (an interactive iPad with wireless data transfer to the spirometer); a web-based COPD guideline tool to be used by primary care providers as a decision support tool; and a COPD patient education toolkit to be used by the practice team. During phase II, an RCT will be performed with one year of intervention within 30 primary care practices. The effectiveness of the materials developed in Phase I are being tested in Phase II regarding physician performance of COPD guideline implementation and the improvement in the clinically relevant outcomes (appropriate diagnosis and management of COPD) compared to usual care. We will also examine the use of a patient activation tool - ‘MyLungAge’ - to prompt patients at risk for or who have COPD to request spirometry confirmation and to request support for smoking cessation if a smoker. Discussion Using a multi-modal intervention of patient activation and a technology-supported health care provider team, we are testing the effectiveness of this intervention in activating patients and improving physician performance around COPD guideline implementation. Trial registration ClinicalTrials.gov, NCT0123756
Adsorption of formate species on Cu(h,k,l) low index surfaces
We report a density functional theory study on the relative stability of formate species on Cu(h,k,l) low index surfaces using a range of exchange-correlation functionals. We find that these functionals predict similar geometries for the formate molecule adsorbed on the Cu surface. A comparison of the calculated vibrational transition energies of a perpendicular configuration of formate on Cu surface shows an excellent agreement with the experimental spectrum obtained from inelastic neutron spectroscopy. From the calculations on adsorption energy we find that formate is most stable on the Cu(110) surface as compared to Cu(111) and Cu(100) surfaces. Bader analysis shows that this feature could be related to the higher charge transfer from the Cu(110) surface and optimum charge density at the interfacial region due to bidirectional electron transfer between the formate and the Cu surface. Analysis of the partial density of states finds that in the –5.5 eV to –4.0 eV region, hybridization between O p and the non-axial Cu dyz and dxz orbitals takes place on the Cu(110) surface, which is energetically more favourable than on the other surfaces
NuSTAR reveals the hidden nature of SS433
SS433 is the only Galactic binary system known to accrete at highly
super-critical rates, analogous to tidal disruption events, and needed to
explain the mass of some high redshift quasars. Probing the inner regions of
SS433 in the X-rays is crucial to understanding this system, and super-critical
accretion in general, but has not yet been possible due to obscuration. NuSTAR
observed SS433 in the hard X-ray band across multiple phases of its
super-orbital precession period. Spectral-timing tools have allowed us to
confirm that the hard X-ray emission from the inner regions is scattered
towards us by the walls of the wind-cone. By comparing to numerical models, we
determine an intrinsic X-ray luminosity of >= 3x10^37 erg/s and that, if viewed
face on, the apparent luminosity would be > 1x10^39 erg/s, confirming its
long-suspected nature as an ultraluminous X-ray source (ULX). A lag due to
absorption by Fe XXV/XXVI in outflowing material travelling at least 0.14-0.29c
matches absorption lines seen in ULXs and - in future - will allow us to map a
super-critical outflow for the first time.Comment: 24 pages, 8 figures, submitted for publicatio
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