2,112 research outputs found
Academic Consequences of Legal Handgun Carrying on College Campuses
Many states have discussed allowing concealed handguns on college campuses, known colloquially as campus carry. It is crucial to gauge whether allowing campus carry affects more than just crime rates. Previous research indicated overwhelmingly negative attitudes towards allowing campus carry. The purpose of the current study was to determine whether knowledge of someone carrying a concealed handgun in class would affect studentsâ ability to perform well on an exam. Across two studies, evidence and theoretical rationale suggested that knowledge of someone carrying a concealed handgun in class negatively impacted learning, although non-significantly. Individuals who were told that others (i.e., the professor and/or fellow students) were carrying a concealed handgun did worse on a post-lecture exam than those who are not led to this belief, but this finding was not significant. This work should be important to legislators and the general public because of the social and academic consequences of allowing campus carry
The Implicit Relational Assessment Procedure (IRAP) as a response-time and event-related potentials methodology for testing natural verbal relations: A preliminary study
The current article reports the first attempt to test the Implicit Relational Assessment Procedure (IRAP), as a group-based measure of natural verbal relations, using both response-latency and event-related potentials as dependent variables. On each trial of the IRAP, participants were presented with 1 of 2 attribute stimuli (âPleasantâ or âUnpleasantâ), a positive (e.g., âLoveâ) or negative (e.g., âMurderâ) target stimulus, and 2 relational terms, âSimilarâ and âOpposite,â as response options. Participants were required to respond as quickly and accurately as possible across blocks of trials, with half of the blocks requiring responses that were deemed consistent (e.g., PleasantâLoveâSimilar), and the other half inconsistent (e.g., PleasantâLoveâOpposite), with natural verbal relations. Shorter mean latencies were predicted for consistent than for inconsistent blocks. Two separate experiments supported this prediction. Event-related potentials, gathered during the second experiment, also proved to be sensitive to the IRAP, yielding more negative waveforms for inconsistent relative to consistent blocks of trials. A theoretical interpretation of the IRAP effect is offered, and important directions for future research are highlighted
Competing charge, spin, and superconducting orders in underdoped YBa2Cu3Oy
To explore the doping dependence of the recently discovered charge density
wave (CDW) order in YBa2Cu3Oy, we present a bulk-sensitive high-energy x-ray
study for several oxygen concentrations, including strongly underdoped
YBa2Cu3O6.44. Combined with previous data around the so-called 1/8 doping, we
show that bulk CDW order exists at least for hole concentrations (p) in the
CuO2 planes of 0.078 <~ p <~ 0.132. This implies that CDW order exists in close
vicinity to the quantum critical point for spin density wave (SDW) order. In
contrast to the pseudogap temperature T*, the onset temperature of CDW order
decreases with underdoping to T_CDW ~ 90K in YBa2Cu3O6.44. Together with a
weakened order parameter this suggests a competition between CDW and SDW
orders. In addition, the CDW order in YBa2Cu3O6.44 shows the same type of
competition with superconductivity as a function of temperature and magnetic
field as samples closer to p = 1/8. At low p the CDW incommensurability
continues the previously reported linear increasing trend with underdoping. In
the entire doping range the in-plane correlation length of the CDW order in
b-axis direction depends only very weakly on the hole concentration, and
appears independent of the type and correlation length of the oxygen-chain
order. The onset temperature of the CDW order is remarkably close to a
temperature T^\dagger that marks the maximum of 1/(T_1T) in planar 63^Cu
NQR/NMR experiments, potentially indicating a response of the spin dynamics to
the formation of the CDW. Our discussion of these findings includes a detailed
comparison to the charge stripe order in La2-xBaxCuO4.Comment: 11 pages, 5 figure
The nature of the charge density waves in under-doped YBaCuO revealed by X-ray measurements of the ionic displacements
All underdoped high-temperature cuprate superconductors appear to exhibit
charge density wave (CDW) order, but both the underlying symmetry breaking and
the origin of the CDW remain unclear. We use X-ray diffraction to determine the
microscopic structure of the CDW in an archetypical cuprate
YBaCuO at its superconducting transition temperature Tc ~ 60
K. We find that the CDWs present in this material break the mirror symmetry of
the CuO2 bilayers. The ionic displacements in a CDW have two components: one
perpendicular to the CuO planes, and another parallel to these planes,
which is out of phase with the first. The largest displacements are those of
the planar oxygen atoms and are perpendicular to the CuO planes. Our
results allow many electronic properties of the underdoped cuprates to be
understood. For instance, the CDW will lead to local variations in the doping
(or electronic structure) giving an explicit explanation of the appearance of
density-wave states with broken symmetry in scanning tunnelling microscopy
(STM) and soft X-ray measurements
Recommended from our members
Indoor Air Quality at Home-An Economic Analysis.
Background: People with respiratory conditions are susceptible to health problems caused by exposure to indoor air pollutants. An economic framework was developed to inform a guideline developed by National Institute for Health and Care Excellence (NICE) to estimate the required level of efficacy necessary for an intervention to be cost-saving in dwellings across England. Methods: An economic modelling framework was built to estimate the incremental costs pre- and post-implementation of interventions designed to reduce exposure to indoor air pollution within dwellings of varying building-related risk factors and profiles. The intervention cost was varied simultaneously with the relative reduction in symptomatic cases of each health condition to estimate the point at which an intervention may become cost-saving. Four health conditions were considered. Results: People living in dwellings with either an extreme risk profile or usable floor area <90m2 have the greatest capacity to benefit and save National Health Service (NHS) costs from interventions at any given level of effectiveness and upfront cost. Conclusions: At any effectiveness level, the threshold for the upfront intervention cost to remain cost-saving is equivalent across the different home characteristics. The flexible model can be used to guide decision-making under a range of scenarios
Cost-Effectiveness Analysis of Antimicrobial Prescribing in the Treatment of Clostridioides Difficile Infection in England
BackgroundAn economic model was developed with guidance from the National Institute for Health and Care Excellence (NICE) âManaging Common Infectionsâ (MCI) Committee to evaluate the cost effectiveness of different antibiotic treatment sequences for treating Clostridioides difficile infection (CDI) in England.MethodsThe model consisted of a 90-day decision tree followed by a lifetime cohort Markov model. Efficacy data were taken from a network meta-analysis and published literature, while cost, utility and mortality data were taken from published literature. A treatment sequence was defined as a first-line intervention or a different second-line intervention, and used constant third- and fourth-line interventions. The possible first- and second-line interventions were vancomycin, metronidazole, teicoplanin and fidaxomicin (standard and extended regimens). Total costs and quality-adjusted life-years (QALYs) were calculated and were used to run a fully incremental cost-effectiveness analysis. Threshold analysis was conducted around pricing.ResultsSequences including teicoplanin, fidaxomicin (extended regimen) and second-line metronidazole were excluded based on recommendations from the committee. The final pairwise comparison was between first-line vancomycin and second-line fidaxomicin (VAN-FID), and the reverse (FID-VAN). The incremental cost-effectiveness ratio for FID-VAN compared with VAN-FID was ÂŁ156,000 per QALY gained, and FID-VAN had a 0.2% likelihood of being cost effective at a ÂŁ20,000 threshold.ConclusionFirst-line vancomycin and second-line fidaxomicin was the most cost-effective treatment sequence at the NICE threshold for treating CDI in England. The main limitation of this study was that the initial cure and recurrence rates of each intervention were applied constantly across each line of treatment and each round of recurrence
Spin density wave induced disordering of the vortex lattice in superconducting LaSrCuO
We use small angle neutron scattering to study the superconducting vortex
lattice in LaSrCuO as a function of doping and magnetic field.
We show that near optimally doping the vortex lattice coordination and the
superconducting coherence length are controlled by a van-Hove singularity
crossing the Fermi level near the Brillouin zone boundary. The vortex lattice
properties change dramatically as a spin-density-wave instability is approached
upon underdoping. The Bragg glass paradigm provides a good description of this
regime and suggests that SDW order acts as a novel source of disorder on the
vortex lattice.Comment: Accepted in Phys. Rev.
Motivated Markets: Instruments and Ideologies of Clean Energy in the United Kingdom
This article examines efforts to reconcile capitalist and ecological values, focusing in particular on the instruments and ideologies that pervade the United Kingdom's developing renewable energy sector. In keeping with neoliberal models of economic knowledge and practice, renewable energy instruments target the motivations of individuals by using incentive programs to reach environmental policy goals. The argument focuses especially on the way newly implemented market devices shape and represent the motivations of energy producers, suppliers, and traders. The centerpiece of the U.K. government's initiative is the creation of an artificial market in renewability, bought and sold as a virtual commodity. Although the realities of economic motivation complicate the practical implementation of the renewable market, these are represented as isolated and self-interested âexchangesâ by market devices, providing policymakers and their critics with partial yet authoritative accounts of renewable policy, premised on narrow and contested assumptions about economic motivation and action
Spatially inhomogeneous competition between superconductivity and the charge density wave in YBa2Cu3O6.67
The charge density wave in the high-temperature superconductor YBa2Cu3O7âx (YBCO) has two different ordering tendencies differentiated by their c-axis correlations. These correspond to ferro- (F-CDW) and antiferro- (AF-CDW) couplings between CDWs in neighbouring CuO2 bilayers. This discovery has prompted several fundamental questions: how does superconductivity adjust to two competing orders and are either of these orders responsible for the electronic reconstruction? Here we use x-ray diffraction to study YBa2Cu3O6.67 as a function of magnetic field and temperature. We show that regions with F-CDW correlations suppress superconductivity more strongly than those with AF-CDW correlations. This implies that an inhomogeneous superconducting state exists, in which some regions show a fragile form of superconductivity. By comparison of F-CDW and AF-CDW correlation lengths, it is concluded that F-CDW ordering is sufficiently long-range to modify the electronic structure. Our study thus suggests that F-CDW correlations impact both the superconducting and normal state properties of YBCO
- âŠ