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Finite temperature micromagnetic simulations are used to probe stochastic domain wall pinning behaviours in magnetic nanowire devices. By exploring field-induced propagation both below and above the Walker breakdown field it is shown that all experimentally observed phenomena can be comprehensively explained by the influence of thermal perturbations on the domain walls’ magnetisation dynamics. Nanowires with finite edge roughness are also investigated and these demonstrate how this additional form of disorder couples with thermal perturbations to significantly enhance stochasticity. Cumulatively, these results indicate that stochastic pinning is an intrinsic feature of DW behaviour at finite temperatures and would not be suppressed even in hypothetical systems where initial DW states and experimental parameters were perfectly defined.

The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of quantum chromodynamics. However, as these equations cannot be solved directly, nuclear interactions are described using simplified models, which are well constrained at typical inter-nucleon distances 1 – 5 but not at shorter distances. This limits our ability to describe high-density nuclear matter such as that in the cores of neutron stars 6 . Here we use high-energy electron scattering measurements that isolate nucleon pairs in short-distance, high-momentum configurations 7 – 9 , accessing a kinematical regime that has not been previously explored by experiments, corresponding to relative momenta between the pair above 400 megaelectronvolts per c ( c , speed of light in vacuum). As the relative momentum between two nucleons increases and their separation thereby decreases, we observe a transition from a spin-dependent tensor force to a predominantly spin-independent scalar force. These results demonstrate the usefulness of using such measurements to study the nuclear interaction at short distances and also support the use of point-like nucleon models with two- and three-body effective interactions to describe nuclear systems up to densities several times higher than the central density of the nucleus. High-energy electron scattering that can isolate pairs of nucleons in high-momentum configurations reveals a transition to spin-independent scalar forces at small separation distances, supporting the use of point-like nucleon models to describe dense nuclear systems.

In-materia reservoir computing (RC) leverages the intrinsic physical responses of functional materials to perform complex computational tasks. Magnetic metamaterials are exciting candidates for RC due to their huge state space, nonlinear emergent dynamics, and non-volatile memory. However, to be suitable for a broad range of tasks, the material system is required to exhibit a broad range of properties, and isolating these behaviours experimentally can often prove difficult. By using an electrically accessible device consisting of an array of interconnected magnetic nanorings- a system shown to exhibit complex emergent dynamics- here we show how reconfiguring the reservoir architecture allows exploitation of different aspects the system’s dynamical behaviours. This is evidenced through state-of-the-art performance in diverse benchmark tasks with very different computational requirements, highlighting the additional computational configurability that can be obtained by altering the input/output architecture around the material system. Magnetic metamaterials are excellent candidates for in-materia reservoir computing (RC), though typical implementations are under a single reservoir architecture. The authors exploit the dynamic properties of interconnected magnetic nanorings to realize reconfigurable reservoir architectures to perform a diverse set of tasks with the same device.

Finite temperature micromagnetic simulations were used to investigate the magnetisation structure, propagation dynamics and stochastic pinning of domain walls in rare earth-doped Ni 80 Fe 20 nanowires. We first show how the increase of the Gilbert damping, caused by the inclusion rare-earth dopants such as holmium, acts to suppress Walker breakdown phenomena. This allows domain walls to maintain consistent magnetisation structures during propagation. We then employ finite temperature simulations to probe how this affects the stochastic pinning of domain walls at notch-shaped artificial defect sites. Our results indicate that the addition of even a few percent of holmium allows domain walls to pin with consistent and well-defined magnetisation configurations, thus suppressing dynamically-induced stochastic pinning/depinning phenomena. Together, these results demonstrate a powerful, materials science-based solution to the problems of stochastic domain wall pinning in soft ferromagnetic nanowires.

Understanding dynamically-induced stochastic switching effects in soft ferromagnetic nanowires is a critical challenge for realising spintronic devices with deterministic switching behaviour. Here, we present a micromagnetic simulation protocol for qualitatively predicting dynamic stochastic domain wall (DW) pinning/depinning at artificial defect sites in Ni 80 Fe 20 nanowires, and demonstrate its abilities by correlating its predictions with the results of focused magneto-optic Kerr effect measurements. We analyse DW pinning configurations in both thin nanowires (t = 10 nm) and thick nanowires (t = 40 nm) with both single (asymmetric) and double (symmetric) notches, showing how our approach provides understanding of the complex DW-defect interactions at the heart of stochastic pinning behaviours. Key results explained by our model include the total suppression of stochastic pinning at single notches in thick nanowires and the intrinsic stochasticity of pinning at double notches, despite their apparent insensitivity to DW chirality.

Background and purpose: Macrophages release cytokines that may contribute to pulmonary inflammation in conditions such as chronic obstructive pulmonary disease. Thus, inhibition of macrophage cytokine production may have therapeutic benefit. p38 MAPK may regulate cytokine production, therefore, the effect of two p38 MAPK inhibitors, SB239063 and SD‐282, on the release of TNF‐α, GM‐CSF and IL‐8 from human macrophages was investigated. Experimental approach: Cytokine release was measured by ELISA. Immunoblots and mRNA expression studies were performed to confirm p38 MAPK isoform expression and activity. Macrophages were isolated from lung tissue of current smokers, ex‐smokers and emphysema patients and exposed to lipopolysaccharide. These cells then released cytokines in a concentration‐dependent manner. Key results: SB239063 only inhibited TNF‐α release (EC50 0.3±0.1 μM). Disease status had no effect on the efficacy of SB239063. SD‐282 inhibited both TNF‐α and GM‐CSF release from macrophages (EC50 6.1±1.4 nM and 1.8±0.6 μM respectively) but had no effect on IL‐8 release. In contrast, both inhibitors suppressed cytokine production in monocytes. Conclusions and Implications: The differential effects of p38 MAPK inhibitors between macrophages and monocytes could not be explained by differences in p38 MAPK isoform expression or activity. However, the stability of TNF‐α mRNA was significantly increased in macrophages compared to monocytes. These data suggest a differential involvement for p38 MAPK in macrophage cytokine production compared with monocytes. These effects are not due to lack of p38 activation or p38α expression in macrophages but may reflect differential effects on the stability of cytokine mRNA. British Journal of Pharmacology (2006) 149, 393–404. doi:10.1038/sj.bjp.0706885

Neutrinos exist in one of three types or ‘flavours’—electron, muon and tau neutrinos—and oscillate from one flavour to another when propagating through space. This phenomena is one of the few that cannot be described using the standard model of particle physics (reviewed in ref.  1 ), and so its experimental study can provide new insight into the nature of our Universe (reviewed in ref.  2 ). Neutrinos oscillate as a function of their propagation distance ( L ) divided by their energy ( E ). Therefore, experiments extract oscillation parameters by measuring their energy distribution at different locations. As accelerator-based oscillation experiments cannot directly measure E , the interpretation of these experiments relies heavily on phenomenological models of neutrino–nucleus interactions to infer E . Here we exploit the similarity of electron–nucleus and neutrino–nucleus interactions, and use electron scattering data with known beam energies to test energy reconstruction methods and interaction models. We find that even in simple interactions where no pions are detected, only a small fraction of events reconstruct to the correct incident energy. More importantly, widely used interaction models reproduce the reconstructed energy distribution only qualitatively and the quality of the reproduction varies strongly with beam energy. This shows both the need and the pathway to improve current models to meet the requirements of next-generation, high-precision experiments such as Hyper-Kamiokande (Japan) 3 and DUNE (USA) 4 . Electron scattering measurements are shown to reproduce only qualitatively state-of-the-art lepton–nucleus energy reconstruction models, indicating that improvements to these particle-interaction models are required to ensure the accuracy of future high-precision neutrino oscillation experiments.

Social-psychological interventions have raised the learning and performance of students in rigorous efficacy trials. Yet, after they are distributed “in the wild” for students to self-administer, there has been little research following up on their translational effectiveness. We used cutting-edge educational technology to tailor, scale up, and track a previously-validated Strategic Resource Use intervention among 12,065 college students in 14 STEM and Economics classes. Students who self-administered this “Exam Playbook” benefitted by an average of 2.17 percentage points (i.e., a standardized effect size of 0.18), compared to non-users. This effect size was 1.65 percentage points when controlling for college entrance exam scores and 1.75 [−1.88] for adding [dropping] the Exam Playbook in stratified matching analyses. Average benefits differed in magnitude by the conduciveness of the class climate (including peer norms and incentives), gender, first-generation status, as well as how often and how early they used the intervention. These findings on how, when, and who naturally adopts these resources address a need to improve prediction, translation, and scalability of social-psychological intervention benefits.

We describe Cornell’s near‐infrared camera system PHARO (Palomar High Angular Resolution Observer) built for use with the JPL Palomar Adaptive Optics System on the 5 m Hale telescope. PHARO uses a \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $1024\\times 1024$ \\end{document} HgCdTe HAWAII detector for observations between 1 and 2.5 μm wavelength. An all‐reflecting optical system provides diffraction‐limited images at two scales, 25 and 40 mas pixel−1, plus a pupil imaging mode. PHARO also has a coronagraphic imaging capability and a long‐slit grism spectroscopy mode at resolving power ≈1500. The instrument has been in use with the AO system at Palomar since early 1998.