Tensor interaction constraints from beta decay recoil spin asymmetry of trapped atoms

We have measured the angular distribution of recoiling daughter nuclei emitted from the Gamow-Teller $\beta$ decay of spin-polarized $^{80}$Rb. The asymmetry of this distribution vanishes to lowest order in the Standard Model (SM) in pure Gamow-Teller decays, producing an observable very sensitive to new interactions. We measure the non-SM contribution to the asymmetry to be $A_{T}$= 0.015 $\pm$ 0.029 (stat) $\pm$ 0.019 (syst), consistent with the SM prediction. We constrain higher-order SM corrections using the measured momentum dependence of the asymmetry, and their remaining uncertainty dominates the systematic error. Future progress in determining the weak magnetism term theoretically or experimentally would reduce the final errors. We describe the resulting constraints on fundamental 4-Fermi tensor interactions.Comment: 11 pages, 13 figures; v2 published in Phys. Rev. C, with referee clarifications and figures improved for black-and-whit

Carbon dioxide generation and drawdown during active orogenesis of siliciclastic rocks in the Southern Alps, New Zealand

C.D.M. was supported by NERC CASE PhD studentship award NE/G524160/1 (GNS Science, NZ, CASE partner). D.A.H.T. acknowledges support from research grants NE/H012842/1 and NE/J022128/1 and a Royal Society Wolfson Research Merit Award (WM130051). S.C.C. was funded under GNS Science's “Impacts of Global Plate Tectonics in and around New Zealand Programme” (PGST Contract CO5X0203). J.C.A. was supported by NSF OCE1334758. We also thank Matthew Cooper, Andy Milton, Darryl Green and Lora Wingate for laboratory assistance. We thank Mike Bickle for editorial advice and comments, and reviews from two anonymous reviewers that improved this manuscript.Peer reviewedPublisher PD

Getting shot of elves: healing, witchcraft and fairies in the Scottish witchcraft trials

This paper re-examines the evidence of the Scottish witchcraft trials for beliefs associated by scholars with "elf-shot." Some supposed evidence for elf-shot is dismissed, but other material illuminates the interplay between illness, healing and fairy-lore in early modern Scotland, and the relationship of these beliefs to witchcraft itself

Inequalities in the prevalence of major depressive disorder in Brazilian slum populations : a cross-sectional analysis

The mental health of slum residents is under-researched globally, and depression is a significant source of worldwide morbidity. Brazil's large slum-dwelling population is often considered part of a general urban-poor demographic. This study aims to identify the prevalence and distribution of depression in Brazil and compare mental health inequalities between slum and non-slum populations. Data were obtained from Brazil's 2019 National Health Survey. Slum residence was defined based on the UN-Habitat definition for slums and estimated from survey responses. Doctor-diagnosed depression, Patient Health Questionnaire (PHQ-9)-screened depression and presence of undiagnosed depression (PHQ-9-screened depression in the absence of a doctor's diagnosis) were analysed as primary outcomes, alongside depressive symptom severity as a secondary outcome. Prevalence estimates for all outcomes were calculated. Multivariable logistic regression models were used to investigate the association of socioeconomic characteristics, including slum residence, with primary outcomes. Depressive symptom severity was analysed using generalised ordinal logistic regression. Nationally, the prevalence of doctor diagnosed, PHQ-9 screened and undiagnosed depression were 9.9% (95% confidence interval (CI): 9.5-10.3), 10.8% (95% CI: 10.4-11.2) and 6.9% (95% CI: 6.6-7.2), respectively. Slum residents exhibited lower levels of doctor-diagnosed depression than non-slum urban residents (8.6%; 95% CI: 7.9-9.3 v. 10.7%; 95% CI: 10.2-11.2), while reporting similar levels of PHQ-9-screened depression (11.3%; 95% CI: 10.4-12.1 v. 11.3%; 95% CI: 10.8-11.8). In adjusted regression models, slum residence was associated with a lower likelihood of doctor diagnosed (adjusted odds ratio (adjusted OR): 0.87; 95% CI: 0.77-0.97) and PHQ-9-screened depression (adjusted OR: 0.87; 95% CI: 0.78-0.97). Slum residents showed a greater likelihood of reporting less severe depressive symptoms. There were significant ethnic/racial disparities in the likelihood of reporting doctor-diagnosed depression. Black individuals were less likely to report doctor-diagnosed depression (adjusted OR: 0.66; 95% CI: 0.57-0.75) than white individuals. A similar pattern was observed in Mixed Black (adjusted OR: 0.72; 95% CI: 0.66-0.79) and other (adjusted OR: 0.63; 95% CI: 0.45-0.88) ethnic/racial groups. Slum residents self-reporting a diagnosis of one or more chronic non-communicable diseases had greater odds of exhibiting all three primary depression outcomes. Substantial inequalities characterise the distribution of depression in Brazil including in slum settings. People living in slums may have lower diagnosed rates of depression than non-slum urban residents. Understanding the mechanisms behind the discrepancy in depression diagnosis between slum and non-slum populations is important to inform health policy in Brazil, including in addressing potential gaps in access to mental healthcare

Wide-Angle Seismic Imaging of Two Modes of Crustal Accretion in Mature Atlantic Ocean Crust

We present a high‐resolution 2‐D P‐wave velocity model from a 225‐km‐long active seismic profile, collected over ~60–75 Ma central Atlantic crust. The profile crosses five ridge segments separated by a transform and three nontransform offsets. All ridge discontinuities share similar primary characteristics, independent of the offset. We identify two types of crustal segment. The first displays a classic two‐layer velocity structure with a high gradient Layer 2 (~0.9 s$^{−1}$) above a lower gradient Layer 3 (0.2 s$^{−1}$). Here, PmP coincides with the 7.5 km s$^{−1}$ contour, and velocity increases to >7.8 km s$^{−1}$ within 1 km below. We interpret these segments as magmatically robust, with PmP representing a petrological boundary between crust and mantle. The second has a reduced contrast in velocity gradient between the upper and lower crust and PmP shallower than the 7.5 km s$^{−1}$ contour. We interpret these segments as tectonically dominated, with PmP representing a serpentinized (alteration) front. While velocity‐depth profiles fit within previous envelopes for slow‐spreading crust, our results suggest that such generalizations give a misleading impression of uniformity. We estimate that the two crustal styles are present in equal proportions on the floor of the Atlantic. Within two tectonically dominated segments, we make the first wide‐angle seismic identifications of buried oceanic core complexes in mature (>20 Ma) Atlantic Ocean crust. They have a ~20‐km‐wide “domal” morphology with shallow basement and increased upper crustal velocities. We interpret their midcrustal seismic velocity inversions as alteration and rock‐type assemblage contrasts across crustal‐scale detachment faults

Controlling Noncollinear Ferromagnetism in van der Waals Metal–Organic Magnets

Van der Waals (vdW) magnets both allow exploration of fundamental 2D physics and offer a route toward exploiting magnetism in next generation information technology, but vdW magnets with complex, noncollinear spin textures are currently rare. We report here the syntheses, crystal structures, magnetic properties and magnetic ground states of four bulk vdW metal–organic magnets (MOMs): FeCl2(pym), FeCl2(btd), NiCl2(pym), and NiCl2(btd), pym = pyrimidine and btd = 2,1,3-benzothiadiazole. Using a combination of neutron diffraction and bulk magnetometry we show that these materials are noncollinear magnets. Although only NiCl2(btd) has a ferromagnetic ground state, we demonstrate that low-field hysteretic metamagnetic transitions produce states with net magnetization in zero-field and high coercivities for FeCl2(pym) and NiCl2(pym). By combining our bulk magnetic data with diffuse scattering analysis and broken-symmetry density-functional calculations, we probe the magnetic superexchange interactions, which when combined with symmetry analysis allow us to suggest design principles for future noncollinear vdW MOMs. These materials, if delaminated, would prove an interesting new family of 2D magnets

Spin-state dependent pressure responsiveness of Fe(<scp>ii</scp>)-based triazolate metal–organic frameworks

Fe(II)-containing Metal–Organic Frameworks (MOFs) that exhibit temperature-induced spin-crossover (SCO) are candidate materials in the field of sensing, barocalorics, and data storage. Their responsiveness towards pressure is therefore of practical importance and is related to their longevity and processibility. The impact of Fe(II) spin-state on the pressure responsiveness of MOFs is yet unexplored. Here we report the synthesis of two new Fe(II)-based MOFs, i.e. Fe(cta)2 ((cta)− = 1,4,5,6-tetrahydrocyclopenta[d][1,2,3]triazolate) and Fe(mta)2 ((mta)− = methyl[1,2,3]triazolate), which are both in high-spin at room temperature. Together with the isostructural MOF Fe(ta)2 ((ta)− = [1,2,3]triazolate), which is in its low-spin state at room temperature, we apply these as model systems to show how spin-state controls their mechanical properties. As a proxy, we use their bulk modulus, which was obtained via high-pressure powder X-ray diffraction experiments. We find that an interplay of spin-state, steric effects, void fraction, and absence of available distortion modes dictates their pressure-induced structural distortions. Our results show for the first time the role of spin-state on the pressure-induced structural deformations in MOFs and bring us a step closer to estimating the effect of pressure as a stimulus on MOFs a priori

Sensing the Spin State of Room-Temperature Switchable Cyanometallate Frameworks with Nitrogen-Vacancy Centers in Nanodiamonds

Room-temperature magnetically switchable materials play a vital role in current and upcoming quantum technologies, such as spintronics, molecular switches, and data storage devices. The increasing miniaturization of device architectures produces a need to develop analytical tools capable of precisely probing spin information at the single-particle level. In this work, we demonstrate a methodology using negatively charged nitrogen vacancies (NV–) in fluorescent nanodiamond (FND) particles to probe the magnetic switching of a spin crossover (SCO) metal–organic framework (MOF), [Fe(1,6-naphthyridine)2(Ag(CN)2)2] material (1), and a single-molecule photomagnet [X(18-crown-6)(H2O)3]Fe(CN)6·2H2O, where X = Eu and Dy (materials 2a and 2b, respectively), in response to heat, light, and electron beam exposure. We employ correlative light–electron microscopy using transmission electron microscopy (TEM) finder grids to accurately image and sense spin–spin interacting particles down to the single-particle level. We used surface-sensitive optically detected magnetic resonance (ODMR) and magnetic modulation (MM) of FND photoluminescence (PL) to sense spins to a distance of ca. 10–30 nm. We show that ODMR and MM sensing was not sensitive to the temperature-induced SCO of FeII in 1 as formation of paramagnetic FeIII through surface oxidation (detected by X-ray photoelectron spectroscopy) on heating obscured the signal of bulk SCO switching. We found that proximal FNDs could effectively sense the chemical transformations induced by the 200 keV electron beam in 1, namely, AgI → Ag0 and FeII → FeIII. However, transformations induced by the electron beam are irreversible as they substantially disrupt the structure of MOF particles. Finally, we demonstrate NV– sensing of reversible photomagnetic switching, FeIII + (18-crown-6) ⇆ FeII + (18-crown-6)+ •, triggered in 2a and 2b by 405 nm light. The photoredox process of 2a and 2b proved to be the best candidate for room-temperature single-particle magnetic switching utilizing FNDs as a sensor, which could have applications into next-generation quantum technologies