Fermi Surface as the Driving Mechanism for Helical Antiferromagnetic Ordering in Gd-Y Alloys

The first direct experimental evidence for the Fermi surface (FS) driving the helical antiferromagnetic ordering in a gadolinium-yttrium alloy is reported. The presence of a FS sheet capable of nesting is revealed, and the nesting vector associated with the sheet is found to be in excellent agreement with the periodicity of the helical ordering.Comment: 4 pages, 4 figure

The martyrdom effect : when pain and effort increase prosocial contributions

Most theories of motivation and behavior (and lay intuitions alike) consider pain and effort to be deterrents. In contrast to this widely held view, we provide evidence that the prospect of enduring pain and exerting effort for a prosocial cause can promote contributions to the cause. Specifically, we show that willingness to contribute to a charitable or collective cause increases when the contribution process is expected to be painful and effortful rather than easy and enjoyable. Across five experiments, we document this “martyrdom effect,” show that the observed patterns defy standard economic and psychological accounts, and identify a mediator and moderator of the effect. Experiment 1 showed that people are willing to donate more to charity when they anticipate having to suffer to raise money. Experiment 2 extended these findings to a non-charity laboratory context that involved real money and actual pain. Experiment 3 demonstrated that the martyrdom effect is not the result of an attribute substitution strategy (whereby people use the amount of pain and effort involved in fundraising to determine donation worthiness). Experiment 4 showed that perceptions of meaningfulness partially mediate the martyrdom effect. Finally, Experiment 5 demonstrated that the nature of the prosocial cause moderates the martyrdom effect: the effect is strongest for causes associated with human suffering. We propose that anticipated pain and effort lead people to ascribe greater meaning to their contributions and to the experience of contributing, thereby motivating higher prosocial contributions. We conclude by considering some implications of this puzzling phenomenon. Copyright © 2011 John Wiley & Sons, Ltd

3D Coronal Density Reconstruction and Retrieving the Magnetic Field Structure during Solar Minimum

Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal phenomena at all scales. We employed STEREO/COR1 data obtained during a deep minimum of solar activity in February 2008 (Carrington rotation CR 2066) to retrieve and analyze the three-dimensional (3D) coronal electron density in the range of heights from 1.5 to 4 Rsun using a tomography method. With this, we qualitatively deduced structures of the coronal magnetic field. The 3D electron density analysis is complemented by the 3D STEREO/EUVI emissivity in the 195 A band obtained by tomography for the same CR. A global 3D MHD model of the solar corona was used to relate the reconstructed 3D density and emissivity to open/closed magnetic field structures. We show that the density maximum locations can serve as an indicator of current sheet position, while the locations of the density gradient maximum can be a reliable indicator of coronal hole boundaries. We find that the magnetic field configuration during CR 2066 has a tendency to become radially open at heliocentric distances greater than 2.5 Rsun. We also find that the potential field model with a fixed source surface (PFSS) is inconsistent with the boundaries between the regions with open and closed magnetic field structures. This indicates that the assumption of the potential nature of the coronal global magnetic field is not satisfied even during the deep solar minimum. Results of our 3D density reconstruction will help to constrain solar coronal field models and test the accuracy of the magnetic field approximations for coronal modeling.Comment: Published in "Solar Physics

Experimental investigation of the initial regime in fingering electrodeposition: dispersion relation and velocity measurements

Recently a fingering morphology, resembling the hydrodynamic Saffman-Taylor instability, was identified in the quasi-two-dimensional electrodeposition of copper. We present here measurements of the dispersion relation of the growing front. The instability is accompanied by gravity-driven convection rolls at the electrodes, which are examined using particle image velocimetry. While at the anode the theory presented by Chazalviel et al. describes the convection roll, the flow field at the cathode is more complicated because of the growing deposit. In particular, the analysis of the orientation of the velocity vectors reveals some lag of the development of the convection roll compared to the finger envelope.Comment: 11 pages, 15 figures, REVTEX 4; reference adde

Does ohmic heating influence the flow field in thin-layer electrodeposition?

In thin-layer electrodeposition the dissipated electrical energy leads to a substantial heating of the ion solution. We measured the resulting temperature field by means of an infrared camera. The properties of the temperature field correspond closely with the development of the concentration field. In particular we find, that the thermal gradients at the electrodes act like a weak additional driving force to the convection rolls driven by concentration gradients.Comment: minor changes: correct estimation of concentration at the anode, added Journal-re

30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being

There is a need to increase people’s engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature

Relative energetics and structural properties of zirconia using a self-consistent tight-binding model

We describe an empirical, self-consistent, orthogonal tight-binding model for zirconia, which allows for the polarizability of the anions at dipole and quadrupole levels and for crystal field splitting of the cation d orbitals. This is achieved by mixing the orbitals of different symmetry on a site with coupling coefficients driven by the Coulomb potentials up to octapole level. The additional forces on atoms due to the self-consistency and polarizabilities are exactly obtained by straightforward electrostatics, by analogy with the Hellmann-Feynman theorem as applied in first-principles calculations. The model correctly orders the zero temperature energies of all zirconia polymorphs. The Zr-O matrix elements of the Hamiltonian, which measure covalency, make a greater contribution than the polarizability to the energy differences between phases. Results for elastic constants of the cubic and tetragonal phases and phonon frequencies of the cubic phase are also presented and compared with some experimental data and first-principles calculations. We suggest that the model will be useful for studying finite temperature effects by means of molecular dynamics.Comment: to be published in Physical Review B (1 march 2000

Identifying Key Factors Associated with Aggression on Acute Inpatient Psychiatric Wards

Aggressive behaviour is a critical issue for modern acute psychiatric services, not just because of the adverse impact it has on patients and staff, but also because it puts a financial strain on service providers. The aim of this study was to assess the relationship of patient violence to other variables: patient characteristics, features of the service and physical environment, patient routines, staff factors, the use of containment methods, and other patient behaviours. A multivariate cross sectional design was utilised. Data were collected for a six month period on 136 acute psychiatric wards in 26 NHS Trusts in England. Multilevel modelling was conducted to ascertain those factors most strongly associated with verbal aggression, aggression toward objects, and physical aggression against others. High levels of aggression were associated with a high proportion of patients formally detained under mental health legislation, high patient turnover, alcohol use by patients, ward doors being locked, and higher staffing numbers (especially qualified nurses). The findings suggest that the imposition of restrictions on patients exacerbates the problem of violence, and that alcohol management strategies may be a productive intervention. Insufficient evidence is available to draw conclusions about the nature of the link between staffing numbers and violence

Effect of private insurance incentive policy reforms on trends in coronary revascularisation procedures in the private and public health sectors in Western Australia: A cohort study

Background: The Australian federal government introduced private health insurance incentive policy reforms in 2000 that increased the uptake of private health insurance in Australia. There is currently a lack of evidence on the effect of the policy reforms on access to cardiovascular interventions in public and private hospitals in Australia. The aim was to investigate whether the increased private health insurance uptake influenced trends in emergency and elective coronary artery revascularisation procedures (CARPs) for private and public patients. Methods: We included 34,423 incident CARPs from Western Australia during 1995-2008 in this study. Rates of emergency and elective CARPs were stratified for publicly and privately funded patients. The average annual percent change (AAPC) in trend was calculated before and after 2000 using joinpoint regression. Results: The rate of emergency CARPs, which were predominantly percutaneous coronary interventions (PCIs) with stenting, increased throughout the study period for both public and private patients (AAPC=12.9%, 95% CI=5.0,22.0 and 14.1%, 95% CI=9.8,18.6, respectively) with no significant difference in trends before and after policy implementation. The rate of elective PCIs with stenting from 2000 onwards remained relatively stable for public patients (AAPC=−6.0, 95% C= −16.9,6.4), but increased by 4.1% on average annually (95% CI=1.8,6.3) for private patients (Pdifference=0.04 between groups). This rate increase for private patients was only seen in people aged over 65 years and people residing in high socioeconomic areas.Conclusions: The private health insurance incentive policy reforms are a likely contributing factor in the shift in 2000 from public to privately-funded elective PCIs with stenting. These reforms as well as the increasing number of private hospitals may have been successful in increasing the availability of publicly-funded beds since 2000