Spatially resolved ultrafast magnetic dynamics initiated at a complex oxide heterointerface

Static strain in complex oxide heterostructures has been extensively used to engineer electronic and magnetic properties at equilibrium. In the same spirit, deformations of the crystal lattice with light may be used to achieve functional control across heterointerfaces dynamically. Here, by exciting large-amplitude infrared-active vibrations in a LaAlO3 substrate we induce magnetic order melting in a NdNiO3 film across a heterointerface. Femtosecond resonant soft X-ray diffraction is used to determine the spatiotemporal evolution of the magnetic disordering. We observe a magnetic melt front that propagates from the substrate interface into the film, at a speed that suggests electronically driven motion. Light control and ultrafast phase front propagation at heterointerfaces may lead to new opportunities in optomagnetism, for example by driving domain wall motion to transport information across suitably designed devices.

Suicidal ideation and suicide plans or attempts in adults with Asperger's syndrome attending a specialist diagnostic clinic: a clinical cohort study

BACKGROUND

Asperger's syndrome in adulthood is frequently associated with depression, but few studies have explored the lifetime experience of self-reported suicidal ideation and suicide plans or attempts in this clinical group. We aimed to assess this prevalence in a clinical cohort of patients in the UK.

METHOD

In a clinical cohort study, we undertook a retrospective analysis of clinical survey data from adults newly diagnosed with Asperger's syndrome at a specialist diagnostic clinic between Jan 23, 2004, and July 8, 2013, in England. Patients completed a self-report questionnaire before clinical assessment, recording lifetime experience of depression, suicidal ideation, and suicide plans or attempts, along with self-reported measures of autistic traits and empathy. We compared the rate of suicidal ideation in the sample with published rates of suicidal ideation in the general population and other clinical groups. We also assessed associations between depression, autistic traits, empathy, and likelihood of suicidal ideation and suicide plans or attempts.

FINDINGS

374 adults (256 men and 118 women) were diagnosed with Asperger's syndrome in the study period. 243 (66%) of 367 respondents self-reported suicidal ideation, 127 (35%) of 365 respondents self-reported plans or attempts at suicide, and 116 (31%) of 368 respondents self-reported depression. Adults with Asperger's syndrome were significantly more likely to report lifetime experience of suicidal ideation than were individuals from a general UK population sample (odds ratio 9·6 [95% CI 7·6-11·9], p<0·0001), people with one, two, or more medical illnesses (p<0·0001), or people with psychotic illness (p=0·019). Compared with people diagnosed with Asperger's syndrome without depression, people with Asperger's syndrome and depression were more likely to report suicidal ideation (p<0·0001) and suicide plans or attempts (p<0·0001).

INTERPRETATION

Our findings lend support to anecdotal reports of increased rates of suicidal ideation in adults with Asperger's syndrome, and depression as an important potential risk factor for suicidality in adults with this condition. Because adults with Asperger's syndrome often have many risk factors for secondary depression (eg, social isolation or exclusion, and unemployment), our findings emphasise the need for appropriate service planning and support to reduce risk in this clinical group.

FUNDING

The Three Guineas Trust, the Baily Thomas Foundation, the Medical Research Council, NIHR-CLAHRC-EoE, Cambridgeshire and Peterborough NHS Foundation Trust (CPFT), and the Autism Research Trust.

Perceptions of people with multiple sclerosis on the effect and comfort of two different textured insoles: A qualitative study

Background:

People with multiple sclerosis (MS) suffer from progressive impairment of gait and balance. One of the causal factors is reduced plantar sensation. Pilot studies indicate that textured insoles may improve gait and balance by way of enhanced plantar tactile stimulation. However, no studies have reported subjective outcomes, which could provide significant information regarding the acceptance of textured insoles and their effect on psychological wellbeing. This study aimed to report the subjective experience of participants with MS when they wore insoles with two different textures.

Methods:

A within-subjects experimental design was used with two insole textures. Forty six participants were recruited (12 males, 34 females, mean age 49.1 years, SD=6.83). Participants were randomly allocated to one of the two textured insole types, which they wore for 2 weeks. They then took part in individual semi-structured interviews about their experience of wearing the insoles. Their answers were coded using thematic analysis to identify key themes.

Results:

The same themes emerged in both texture groups. Two key themes were identified: insole comfort and efficacy. Individual participants responded to the same texture in different ways; the perception of comfort was highly individual, as was insole acceptability. Perception of efficacy influenced acceptability, with participants more likely to wear the insoles if they thought they were beneficial. In several cases, confidence in mobility increased during insole use.

Conclusions:

Textured insoles have therapeutic potential in an MS population in regard to improving mobility confidence. However, their acceptability is highly individual so generalisations about their efficacy are difficult to make. Their acceptability and efficacy appear to be linked with a perception of benefit. The perception that they are beneficial encourages participants to wear the insoles and they are more likely to experience increased confidence.

Implications:

Textured insoles could provide a simple, inexpensive intervention to help people with MS maintain function and independence, thus enhancing quality of life. However, there is likely to be considerable individual variability regarding subjective outcomes.

Photoproduction of π0 mesons off neutrons in the nucleon resonance region

Precise angular distributions have been measured for the first time for the photoproduction of π0 mesons off neutrons bound in the deuteron. The effects from nuclear Fermi motion have been eliminated by a complete kinematic reconstruction of the final state. The influence of final-state-interaction effects has been estimated by a comparison of the reaction cross section for quasifree protons bound in the deuteron to the results for free protons and then applied as a correction to the quasifree neutron data. The experiment was performed at the tagged photon facility of the Mainz Microtron MAMI with the Crystal Ball and TAPS detector setup for incident photon energies between 0.45 and 1.4 GeV. The results are compared to the predictions from reaction models and partial-wave analyses based on data from other isospin channels. The model predictions show large discrepancies among each other and the present data will provide much tighter constraints. This is demonstrated by the results of a new analysis in the framework of the Bonn-Gatchina coupled-channel analysis which included the present data.

Measurement of the 1H(γ, p)π0 reaction using a novel nucleon spin polarimeter

We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon. The measurement pioneers a novel polarimetry technique, which can be applied to many other nuclear and hadron physics experiments. The commissioning reaction of 1H(γ, p)π0 in the range 0.4<Eγ<1.4  GeV validates the technique and provides essential new data to constrain the excitation spectrum of the nucleon.