Large Magnetoresistance of Isolated Domain Walls in La2/3Sr1/3MnO3 Nanowires

Generation, manipulation, and sensing of magnetic domain walls are cornerstones in the design of efficient spintronic devices. Half-metals are amenable for this purpose as large low field magnetoresistance signals can be expected from spin accumulation at spin textures. Among half metals, La1−xSrxMnO3 (LSMO) manganites are considered as promising candidates for their robust half-metallic ground state, Curie temperature above room temperature (Tc = 360 K, for x = 1/3), and chemical stability. Yet domain wall magnetoresistance is poorly understood, with large discrepancies in the reported values and conflicting interpretation of experimental data due to the entanglement of various source of magnetoresistance, namely, spin accumulation, anisotropic magnetoresistance, and colossal magnetoresistance. In this work, the domain wall magnetoresistance is measured in LSMO cross-shape nanowires with single-domain walls nucleated across the current path. Magnetoresistance values above 10% are found to be originating at the spin accumulation caused by the mistracking effect of the spin texture of the domain wall by the conduction electrons. Fundamentally, this result shows the importance on non-adiabatic processes at spin textures despite the strong Hund coupling to the localized t2g electrons of the manganite. These large magnetoresistance values are high enough for encoding and reading magnetic bits in future oxide spintronic sensors. © 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.G.O. and D.S.-M. contributed equally to this work. The authors ac-knowledge received funding from the project To2Dox of FlagERA ERA-NET Cofund in Quantum Technologies implemented within the Euro-pean Union’s Horizon 2020 Program. This work was supported by Span-ish AEI through grants, PID2020-118078RB-I00, PID2020-11556RB-100and PID2020-117024GB-C43 and by Regional Government of MadridCAM through SINERGICO project Y2020/NMT-6661 CAIRO-CM. S.R.-G.also gratefully acknowledges the financial support of the Alexander vonHumboldt foundation. Work at CNRS/Thales supported by French ANR-22CE30-0020 "SUPERFAST". J.J.R was supported by the CSIC program forthe Spanish Recovery, Transformation and Resilience Plan funded by the Recovery and Resilience EU Facility EU regulation 2020/2094. The authorsthank the Helmholtz-Zentrum Berlin für Materialien und Energie for theallocation of synchrotron radiation beamtime.Open access funding enabled and organized by Projekt DEAL.Supporting InformationPeer reviewe

Protocol for a partially nested randomised controlled trial to evaluate the effectiveness of the scleroderma patient-centered intervention network COVID-19 home-isolation activities together (SPIN-CHAT) program to reduce anxiety among at-risk scleroderma patients

Objective: Contagious disease outbreaks and related restrictions can lead to negative psychological outcomes, particularly in vulnerable populations at risk due to pre-existing medical conditions. No randomised controlled trials (RCTs) have tested interventions to reduce mental health consequences of contagious disease outbreaks. The primary objective of the Scleroderma Patient-centered Intervention Network COVID-19 Home-isolation Activities Together (SPIN-CHAT) Trial is to evaluate the effect of a videoconference-based program on symptoms of anxiety. Secondary objectives include evaluating effects on symptoms of depression, stress, loneliness, boredom, physical activity, and social interaction.Methods: The SPIN-CHAT Trial is a pragmatic RCT that will be conducted using the SPIN-COVID-19 Cohort, a sub-cohort of the SPIN Cohort. Eligible participants will be SPIN-COVID-19 Cohort participants without a positive COVID-19 test, with at least mild anxiety (PROMIS Anxiety 4a v1.0 T-score >= 55), not working from home, and not receiving current counselling or psychotherapy. We will randomly assign 162 participants to intervention groups of 7 to 10 participants each or waitlist control. We will use a partially nested RCT design to reflect dependence between individuals in training groups but not in the waitlist control. The SPIN-CHAT Program includes activity engagement, education on strategies to support mental health, and mutual participant support. Intervention participants will receive the 4-week (3 sessions per week) SPIN-CHAT Program via video-conference. The primary outcome is PROMIS Anxiety 4a score immediately post-intervention.Ethics and dissemination: The SPIN-CHAT Trial will test whether a brief videoconference-based intervention will improve mental health outcomes among at-risk individuals during contagious disease outbreak

On the number of modes of a Gaussian mixture

We consider a problem intimately related to the creation of maxima under Gaussian blurring: the number of modes of a Gaussian mixture in D dimensions. To our knowledge, a general answer to this question is not known. We conjecture that if the components of the mixture have the same covariance matrix (or the same covariance matrix up to a scaling factor), then the number of modes cannot exceed the number of components. We demonstrat

Changes in mental health symptoms from pre-COVID-19 to COVID-19 among participants with systemic sclerosis from four countries: A Scleroderma Patient-centered Intervention Network (SPIN) Cohort study

Introduction: No studies have reported mental health symptom comparisons prior to and during COVID-19 in vulnerable medical populations.Objective: To compare anxiety and depression symptoms among people with a pre-existing medical condition and factors associated with changes.Methods: Pre-COVID-19 Scleroderma Patient-centered Intervention Network Cohort data were linked to COVID-19 data from April 2020. Multiple linear and logistic regression were used to assess factors associated with continuous change and >= 1 minimal clinically important difference (MCID) change for anxiety (PROMIS Anxiety 4a v1.0; MCID = 4.0) and depression (Patient Health Questionnaire-8; MCID = 3.0) symptoms, controlling for pre-COVID-19 levels.Results: Mean anxiety symptoms increased 4.9 points (95% confidence interval [CI] 4.0 to 5.7). Depression symptom change was negligible (0.3 points; 95% CI-0.7 to 0.2). Compared to France (N = 159), adjusted anxiety symptom change scores were significantly higher in the United Kingdom (N = 50; 3.3 points, 95% CI 0.9 to 5.6), United States (N = 128; 2.5 points, 95% CI 0.7 to 4.2), and Canada (N = 98; 1.9 points, 95% CI 0.1 to 3.8). Odds of >= 1 MCID increase were 2.6 for the United Kingdom (95% CI 1.2 to 5.7) but not significant for the United States (1.6, 95% CI 0.9 to 2.9) or Canada (1.4, 95% CI 0.7 to 2.5). Older age and adequate financial resources were associated with less continuous anxiety increase. Employment and shorter time since diagnosis were associated with lower odds of a >= 1 MCID increase.Conclusions: Anxiety symptoms, but not depression symptoms, increased dramatically during COVID-19 among people with a pre-existing medical condition.Pathophysiology and treatment of rheumatic disease

Shortening patient-reported outcome measures through optimal test assembly: application to the Social Appearance Anxiety Scale in the Scleroderma Patient-centered Intervention Network Cohort

OBJECTIVES: The Social Appearance Anxiety Scale (SAAS) is a 16-item measure that assesses social anxiety in situations where appearance is evaluated. The objective was to use optimal test assembly (OTA) methods to develop and validate a short-form SAAS based on objective and reproducible criteria. DESIGN: This study was a cross-sectional analysis of baseline data from adults enrolled in the Scleroderma Patient-centered Intervention Network (SPIN) Cohort. SETTING: Adults in the SPIN Cohort in the present study were enrolled at 28 centres in Canada, the USA and the UK. PARTICIPANTS: The SAAS was administered to 926 adults with scleroderma. PRIMARY AND SECONDARY MEASURES: The SAAS, Brief Fear of Negative Evaluation II (BFNE II), Brief Satisfaction with Appearance Scale (Brief-SWAP), Patient Health Questionnaire-8 (PHQ8) and Social Interaction Anxiety Scale-6 (SIAS-6) were collected, as well as demographic characteristics. RESULTS: OTA methods identified a maximally informative shortened version for each possible form length between 1 and 15 items. The final shortened version was selected based on prespecified criteria for reliability, concurrent validity and statistically equivalent convergent validity with the BFNE II scale. A five-item short version was selected (SAAS-5). The SAAS-5 had a Cronbach's α of 0.95 and had high concurrent validity with the full-length form (r=0.97). The correlation of the SAAS-5 with the BFNE II was 0.66, which was statistically equivalent to that of the full-length form. Furthermore, the correlation of the SAAS-5 with the two subscales of the Brief-SWAP, and the SIAS-6, were statistically equivalent to that of the full-length form. CONCLUSIONS: OTA was an efficient method for shortening the full-length SAAS to create the SAAS-5