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Magnetic structure, excitations, and field-induced transitions in the honeycomb lattice compound Er2Si2O7
Get PDFWe investigate the magnetic properties of the monoclinic D-type
Er2Si2O7 with a distorted honeycomb lattice using powder and single-crystal neutron scattering techniques, as well as single-crystal magnetization measurements. The powder neutron diffraction shows that below the ordering temperature, TN=1.85K, the compound forms a
q=0 antiferromagnetic structure with four sublattices. For H∥a, magnetization measurements reveal a narrow but clearly visible plateau at one-third of the magnetization saturation value. The plateau's stabilization is accompanied by a significant increase of the magnetic unit cell, as the magnetic peaks with fractional indices are observed in single-crystal neutron diffraction experiments. At low temperatures, the inelastic neutron scattering measurements reveal the presence of low-energy, almost dispersionless excitations. Their spectrum is sensitive to the applied field, it significantly softens on the magnetization plateau, and demonstrates the behavior expected for a noncollinear Ising antiferromagnet away from the plateau
Performative state capacity and climate (in) action
Get PDFClimate action requires significant public- and private sector investment to achieve meaningful reductions in carbon emissions. This paper documents that large-scale austerity, coupled with barriers to flows of data and a lack of (digital) skills in (local) government, may have been a significant barrier to delivering climate action in the form of retrofitting. Decomposing heterogeneity in estimated treatment effects of a large-scale energy efficiency savings program that was rolled out through a regression discontinuity design in the early 2010s, we find that both the extent of austerity-induced local budget cuts and poor digital connectivity – may be responsible for up to 30% fewer retrofit installations that counterfactually would have taken place had it not been for austerit
Slender phoretic loops and knots
No full textWe present an asymptotic theory for solving the dynamics of slender autophoretic loops and knots. Our formulation is valid for nonintersecting three-dimensional center lines, with arbitrary chemical patterning and varying (circular) cross-sectional radius, allowing a broad class of slender active loops and knots to be studied. The theory is amenable to closed-form solutions in simpler cases, allowing us to analytically derive the swimming speed of chemically patterned tori, and the pumping strength (stresslet) of a uniformly active slender torus. Using simple numerical solutions of our asymptotic equations, we then elucidate the behavior of many exotic active particle geometries, such as a bumpy uniformly active torus that spins and a Janus trefoil knot, which rotates as it swims forwards
Comparing the prevalence of psychiatric disorders in cohorts of children born extremely preterm in 1995 and 2006 : the EPICure studies
Get PDFObjective:
This study aimed to identify the prevalence of psychiatric disorders in 2 population-based cohorts of children born extremely preterm (EP) 11 years apart to ascertain whether psychiatric outcomes have changed over time following improved survival of EP children.
Method:
In the EPICure2 study, 200 children born EP (22-26 weeks’ gestation) in England in 2006 were assessed at 11 years of age alongside 143 term-born children. Children were assessed using the Developmental and Wellbeing Assessment (DAWBA). DSM-IV diagnoses were assigned by clinical psychiatrists for 145 EP and 98 term-born children. Outcomes were compared between a subsample of children from the EPICure2 cohort (2006, n = 76) and the earlier-born EPICure (1995, n = 161) cohort born at 22 to 25 weeks’ gestation in England.
Results:
EP children in EPICure2 were significantly more likely than term-born children to have any psychiatric disorder (39.3% vs 3.1%; adjusted odds ratio [OR] = 15.1, 95% CI = 4.4-51.1), emotional disorders (14.6% vs 2.0%; OR = 7.3, 95% CI = 1.6-32.7), conduct disorders (6.3% vs 0.0%, p = .01), attention-deficit/hyperactivity disorder (ADHD, 21.9% vs 2.6%; OR = 7.2; 95% CI = 1.5-33.6), and autism spectrum disorder (ASD, 18.9%; vs 0.0%, p < .001). There was no significant difference in the rates of any psychiatric disorder between EP children in the EPICure2 and EPICure cohorts.
Conclusion:
EP children remain at increased risk for psychiatric disorders at 11 years of age compared with term-born peers. Increased survival has not translated into improved psychiatric outcomes. Health care professionals need to be aware of this ongoing risk when caring for children born preterm
Amalia Holst
No full textAmalia Holst’s trailblazing book On the Vocation of Woman to Higher Intellectual Education (1802) dropped a bomb on the German speaking states—a bomb that failed to detonate. In one of the first works of philosophy in German published under a woman’s name, Holst declares that it is time a member of the female sex spoke out about the plight of women in Germany. Despite her bold attempt to ignite a new movement of women’s education, her book was harshly reviewed by male critics and thrust into obscurity. This Element presents the first comprehensive study of Holst’s writings, unearthing their striking contribution to philosophy’s growing awareness of the social conditions of human freedom. The force of her argument, and the difficulties she encountered, reveal the ambiguous character of the German Enlightenment and prompt us to reconsider what can be salvaged from it
Quantitative modelling of type Ia supernovae spectral time series : constraining the explosion physics
No full textMultiple explosion mechanisms have been proposed to explain type Ia supernovae (SNe Ia). Empirical modelling tools have also been developed that allow for fast, customised modelling of individual SNe and direct comparisons between observations and explosion model predictions. Such tools have provided useful insights, but the subjective nature with which empirical modelling is performed makes it difficult to obtain robust constraints on the explosion physics or expand studies to large populations of objects. Machine learning accelerated tools have therefore begun to gain traction. In this paper, we present riddler, a framework for automated fitting of SNe Ia spectral sequences up to shortly after maximum light. We train a series of neural networks on realistic ejecta profiles predicted by the W7 and N100 explosion models to emulate full radiative transfer simulations and apply nested sampling to determine the best-fitting model parameters for multiple spectra of a given SN simultaneously. We show that riddler is able to accurately recover the parameters of input spectra and use it to fit observations of two well-studied SNe Ia. We also investigate the impact of different weighting schemes when performing quantitative spectral fitting and show that best-fitting models and parameters are highly dependent on the assumed weighting schemes and priors. As spectroscopic samples of SNe Ia continue to grow, automated spectral fitting tools such as riddler will become increasingly important to maximise the physical constraints that can be gained in a quantitative and consistent manner
Risky decisions from personal and observed experience
No full textPeople often learn about risks from other people. In the current study, we investigated the impact of social learning on risky decisions from experience by incorporating direct observational learning. Participants were placed in pairs – one participant observed the other participant sampling from different options, and then both made decisions based on this personal/observed experience. Participants tended to underweight rare outcomes less when learning from observed experience, particularly with high-value rare outcomes. This difference was not reliably significant, however, suggesting a subtle effect. The study discusses potential contributing factors such as active hypothesis testing, psychological distance, social environment, competitiveness, and goal alignment to explain the results. Overall, the findings contribute to understanding the dynamics of social learning in risky decision-making
A mesh reinforced pressure-sensitive adhesive for a linerless label design
Get PDFA concept for an on-demand linerless pressure sensitive adhesive (PSA) label is shown. Containment of a PSA has been achieved by entrapment within a scaffolding 3D hard mesh structure. The label sticks upon instant application of heat and pressure, which softens and deforms the mesh allowing for PSA release. The design eliminates the need for a release liner and release coating in labels offering a more sustainable product. Herein, the mesh-reinforced PSA system was made by film formation of a binary polymer latex mixture consisting of ‘hard’ (high glass transition temperature, Tg,hard) polystyrene particles and a ‘soft’ (low glass transition temperature Tg,soft) poly(n-butyl acrylate)-based PSA latex of similar particle diameter, onto a model polyethylene terephthalate (PET) facestock. The system was annealed above Tg,hard to fuse the polystyrene colloids, creating a 3D interconnected open cellular network. The porous scaffold was shown by scanning electron microscopy, X-ray computed tomography, and confocal microscopy. The linerless PSA label is in a dormant, ‘non-stick’ state at room temperature l storage conditions. Adhesion is activated on demand with heat (T > Tg,hard) and light pressure. The adhesive behavior of the linerless PSA labels was probed using peel, shear strength and tack, its performance being promising
Probing the role of surface termination in the adsorption of azupyrene on copper
Get PDFThe role of the inorganic substrate termination, within the organic–inorganic interface, has been well studied for systems that contain strong localised bonding. However, how varying the substrate termination affects coordination to delocalised electronic states, like that found in aromatic molecules, is an open question. Azupyrene, a non-alternant polycyclic aromatic hydrocarbon, is known to bind strongly to metal surfaces through its delocalised π orbitals, thus yielding an ideal probe into delocalised surface-adsorbate interactions. Normal incidence X-ray standing wave (NIXSW) measurements and density functional theory calculations are reported for the adsorption of azupyrene on the (111), (110) and (100) surface facets of copper to investigate the dependence of the adsorption structure on the substrate termination. Structural models based on hybrid density functional theory calculations with non-local many-body dispersion yield excellent agreement with the experimental NIXSW results. No statistically significant difference in the azupyrene adsorption height was observed between the (111) and (100) surfaces. On the Cu(110) surface, the molecule was found to adsorb 0.06 ± 0.04 Å closer to the substrate than on the other surface facets. The most energetically favoured adsorption site on each surface, as determined by DFT, is subtly different, but in each case involved a configuration where the aromatic rings were centred above a hollow site, consistent with previous reports for the adsorption of small aromatic molecules on metal surfaces
The rainbow saturation number is linear
Get PDFGiven a graph H , we say that an edge-colored graph G is H -rainbow saturated if it does not contain a rainbow copy of H, but the addition of any nonedge in any color creates a rainbow copy of H. The rainbow saturation number rsat (n,H) is the minimum number of edges among all
H-rainbow saturated edge-colored graphs on n vertices. We prove that for any nonempty graph H, the rainbow saturation number is linear in n, thus proving a conjecture of Girão, Lewis, and Popielarz. In addition, we give an improved upper bound on the rainbow saturation number of the complete graph, disproving a second conjecture of Girão, Lewis, and Popielarz