Probing the interface magnetism in the FeMn/NiFe exchange bias system using magnetic second harmonic generation

Second harmonic generation magneto-optic Kerr effect (SHMOKE) experiments, sensitive to buried interfaces, were performed on a polycrystalline NiFe/FeMn bilayer in which areas with different exchange bias fields were prepared using 5 KeV He ion irradiation. Both reversible and irreversible uncompensated spins are found in the antiferromagnetic layer close to the interface with the ferromagnetic layer. The SHMOKE hysteresis loop shows the same exchange bias field as obtained from standard magnetometry. We demonstrate that the exchange bias effect is controlled by pinned uncompensated spins in the antiferromagnetic layer.Comment: submitted to Phys. Rev. Let

Yearbook of Medical Informatics

Objectives: To introduce the 2023 International Medical Informatics Association (IMIA) Yearbook by the editors. Methods: The editorial provides an introduction and overview to the 2023 IMIA Yearbook where the special topic is "Informatics for One Health". The special topic, survey papers and some best papers are discussed. The section changes in the Yearbook editorial committee are also described. Results: IMIA Yearbook 2023 provides many perspectives on a relatively new topic called "One Digital Health". The subject is vast, and includes the use of digital technologies to promote the well-being of people and animals, but also of the environment in which they evolve. Many sections produced new work in the topic including One Health and all sections included the latest themes in many specialties in medical informatics. Conclusions: The theme of "Informatics for One Health" is relatively new but the editors of the IMIA Yearbook have presented excellent and thought-provoking work for biomedical informatics in 2023

Mapping data elements to terminological resources for integrating biomedical data sources

BACKGROUND: Data integration is a crucial task in the biomedical domain and integrating data sources is one approach to integrating data. Data elements (DEs) in particular play an important role in data integration. We combine schema- and instance-based approaches to mapping DEs to terminological resources in order to facilitate data sources integration. METHODS: We extracted DEs from eleven disparate biomedical sources. We compared these DEs to concepts and/or terms in biomedical controlled vocabularies and to reference DEs. We also exploited DE values to disambiguate underspecified DEs and to identify additional mappings. RESULTS: 82.5% of the 474 DEs studied are mapped to entries of a terminological resource and 74.7% of the whole set can be associated with reference DEs. Only 6.6% of the DEs had values that could be semantically typed. CONCLUSION: Our study suggests that the integration of biomedical sources can be achieved automatically with limited precision and largely facilitated by mapping DEs to terminological resources

Yearb Med Inform

OBJECTIVES: To introduce the 2022 International Medical Informatics Association (IMIA) Yearbook by the editors. METHODS: The editorial provides an introduction and overview to the 2022 IMIA Yearbook whose special topic is "Inclusive Digital Health: Addressing Equity, Literacy, and Bias for Resilient Health Systems". The special topic, survey papers, section editor synopses and some best papers are discussed. The sections' changes in the Yearbook Editorial Committee are also described. RESULTS: As shown in the previous edition, health informatics in the context of a global pandemic has led to the development of ways to collect, standardize, disseminate and reuse data worldwide. The Corona Virus Disease 2019 (COVID-19) pandemic has demonstrated the need for timely, reliable, open, and globally available information to support decision making. It has also highlighted the need to address social inequities and disparities in access to care across communities. This edition of the Yearbook acknowledges the fact that much work has been done to study health equity in recent years in the various fields of health informatics research. CONCLUSION: There is a strong desire to better consider disparities between populations to avoid biases being induced in Artificial Intelligence algorithms in particular. Telemedicine and m-health must be more inclusive for people with disabilities or living in isolated geographical areas

Magnetic reversal in ion-irradiated FePt thin films

International audiencePrevious work on ion irradiation control of FePt thin films magnetic anisotropy is extended to ultrathin films (2-10nm). The effects of 30keV He ion irradiation on the magnetic properties are explored as a function of ion fluence and film thickness. Depending on their growth conditions, the thinnest films exhibit different magnetic properties. Although this affects their final magnetic behaviour, we show that after irradiation at 300 @BULLET C the easy magnetization axis may rotate entirely from inplane to out-of-plane at very low fluences, e.g. 2×10 13 He + /cm 2 on 5 nm thick film. This demonstrates the extreme sensitivity of the magnetic anisotropy to ion-induced local L1 0 ordering. Under these conditions, ultrathin films may exhibit perfectly square hysteresis loops with 100% remnant magnetization and low coercivity

Aging dynamics of non-linear elastic interfaces: the Kardar-Parisi-Zhang equation

In this work, the out-of-equilibrium dynamics of the Kardar-Parisi-Zhang equation in (1+1) dimensions is studied by means of numerical simulations, focussing on the two-times evolution of an interface in the absence of any disordered environment. This work shows that even in this simple case, a rich aging behavior develops. A multiplicative aging scenario for the two-times roughness of the system is observed, characterized by the same growth exponent as in the stationary regime. The analysis permits the identification of the relevant growing correlation length, accounting for the important scaling variables in the system. The distribution function of the two-times roughness is also computed and described in terms of a generalized scaling relation. These results give good insight into the glassy dynamics of the important case of a non-linear elastic line in a disordered medium.Comment: 14 pages, 6 figure