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The migration of mid-ocean ridges is driven by asymmetric plate motions on either ridge flank transmitted from far-field subduction forces. Within this model, the geometry and location of mid-ocean ridges are independent of lower-mantle dynamics. However, this fails to recognise the attraction between mid-ocean ridges and mantle plumes. Using numerical models of mantle convection, we show that plumes with high buoyancy flux (> 6000 kg/s) can capture mid-ocean ridges within a 1000 km radius and anchor them in place. If the plume buoyancy flux wanes below 1000 kg/s the ridge may be released, potentially resulting in rapid migration rates that trigger a major plate reorganisation. Plume-ridge interactions are commonly preserved as conjugate large igneous provinces (LIPs), which form on each flank of a mid-ocean ridge as new crust is created. The decoupling of ridges from plumes are demarcated by a switch from conjugate LIPs, formed by a plume beneath a spreading ridge, to trails of intraplate hotspot volcanoes signifying the plume and ridge have separated. We demonstrate that the waning buoyancy flux of the Kerguelen plume, inferred from the geochemistry of eruption products, resulted in its decoupling with the SE Indian Ridge spurring rapid northward migration of the Australian plate. Our modelling predicts that following plume-ridge decoupling, the waning plume can tilt 15° within the upper mantle towards the migrating ridge, providing an explanation for diffuse volcanism and low eruption volumes along the Kerguelen Archipelago. Our results have significant implications for other plume-ridge interactions globally such as the Iceland, Tristan, and Easter plumes, and the generation of intraplate hotspot volcanoes proximal to mid-ocean ridges.

On behalf of the journal, AGU, and the scientific community, the editors of Geophysical Research Letters would like to sincerely thank those who reviewed manuscripts for us in 2021. The hours reading and commenting on manuscripts not only improve the manuscripts, but also increase the scientific rigor of future research in the field. With the advent of AGU's data policy, many reviewers have also helped immensely to evaluate the accessibility and availability of data, and many have provided insightful comments that helped to improve the data presentation and quality. We greatly appreciate the assistance of the reviewers in advancing open science, which is a key objective of AGU's data policy. We particularly appreciate the timely reviews in light of the demands imposed by the rapid review process at Geophysical Research Letters. The COVID pandemic continued to impose additional stresses on the review process, as many reviewers had to juggle increased family commitments, hours of online meetings, remote work and instruction, lack of physical access to library resources, and other hardships, to maintain the quality and timeliness of their reviews. We received 4,832 submissions in 2021 and 5,232 reviewers contributed to their evaluation by providing 8,874 reviews in total. Although we witnessed an increase in the number of submissions, the average number of days to complete a review increased only slightly! That says a lot about the diligence of our reviewers. We deeply appreciate their contributions in these challenging times.

Deep mantle plumes are buoyant upwellings rising from the Earth’s core-mantle boundary to its surface, and describing most hotspot chains. Mechanisms to explain dual chains of hotspot volcanoes for the Hawaiian-Emperor and Yellowstone chains fail to explain the geochemical similarity and large distances between contemporaneous volcanoes of the Tasmantid and Lord Howe chains in the SW Pacific. Using numerical models of mantle convection, we demonstrate how slab-plume interaction can lead to sustained plume branching over a period of >40 million years to produce parallel volcanic chains that track plate motion. We propose a three-part model: first, slabs stagnate in the upper mantle, explaining fast upper mantle P-wave velocity anomalies; second, deflection of a plume conduit by a stagnating slab splits it into two branches 650-900 km apart, aligning to the orientation of the trench axis; third, plume branches heat the stagnating slab causing partial melting and release of volatiles which percolate to the surface forming two contemporaneous volcanic chains with slab-influenced EM1 signatures. Our results highlight the critical role of long-lived subduction on the evolution and behaviour of intraplate volcanism.

The March–April 2007 Piton de la Fournaise basaltic eruption was the most significant eruption on La Réunion Island in historical times. On 2 April, a fissure opened on the southeastern flank of the volcano. Vigorous fountains fed lavas that rapidly reached the coast. Three days later, on the 5–6 April, major caldera collapse occurred at the summit, affecting the floor and walls of Dolomieu caldera. Monitoring records, primarily webcam images, have been analysed and integrated with geophysical data to reconstruct the chronology of events at the summit during caldera collapse. Those events included progressive subsidence of the former caldera floor, landslides, explosions, lava emissions and steam fumaroles, and lasted until 19 April though diminished greatly in frequency after 7 April. For two days after the main caldera collapse on 5 April, subsidence increments, intracaldera lava emission and explosions were closely associated in time and in location. Abundant steam and wet talus on the caldera walls imply that the shallow hydrothermal system and/or groundwater were exposed by subsidence. The presence of juvenile components in ash deposited at the summit during caldera collapse and the close link between intracaldera lavas and explosions suggest that many explosions were phreatomagmatic. Although caldera collapse was related to magma withdrawal from beneath the summit via the flank vent activity, numerous intracaldera lava emissions indicated that magma was nevertheless present at the summit during caldera collapse. We infer that the lava emissions were fed by an intrusion emplaced at the end of March into the eastern summit region and that the intrusion was being actively recharged during caldera collapse. Caldera collapse involved a complex combination of magma withdrawal and magma replenishment at separate summit reservoirs.

The part-per-million measurement of the positive muon lifetime and determination of the Fermi constant by the MuLan experiment at the Paul Scherrer Institute is reviewed. The experiment used an innovative, time-structured, surface muon beam and a near-4\piπ, finely-segmented, plastic scintillator positron detector. Two in-vacuum muon stopping targets were used: a ferromagnetic foil with a large internal magnetic field, and a quartz crystal in a moderate external magnetic field. The experiment acquired a dataset of 1.6 \times 10^{12}1.6×1012 positive muon decays and obtained a muon lifetime \tau_{\mu} = 2\, 196\, 980.3(2.2)τμ=2196980.3(2.2)~ps (1.0~ppm) and Fermi constant G_F = 1.166\, 378\, 7(6) \times 10^{-5}F=1.1663787(6)×10−5 GeV^{-2}−2 (0.5~ppm). The thirty-fold improvement in \tau_{\mu}τμ has proven valuable for precision measurements in nuclear muon capture and the commensurate improvement in G_FF has proven valuable for precision tests of the standard model.

The Program for All-Inclusive Care for the Elderly (PACE) is a Medicare/Medicaid Managed Care benefit for frail older adults age 55 years or older who, although certified by the state as long-term care (LTC) eligible, choose to live independently in the community. PACE features comprehensive medical and social services coordinated by an interdisciplinary team whose goal is to promote independence. Cheyenne Regional Medical Center has served as Wyoming’s only PACE site since 2007. However, an effort to reduce Medicaid expenditures resulted in elimination of funding and closure of the program by the state. The purpose of this study was to examine the impacts of PACE closure on transition to LTC, concomitant Medicaid expenditures, as well as impacts on participant well-being. Results showed, as expected, that nursing home placement exceeded that projected, thereby increasing Medicaid expenditures in Wyoming. Additional impacts on participant well-being and advocacy benefits of GWEP partnership are discussed.

The study compared the effects of a professional development course delivered in an online and a face-to-face format. The effects examined included changes in teachers’ pedagogical beliefs, instructional practices, and understanding of teaching number-sense and related mathematical concepts. The study randomly assigned participants to either the online or the face-to-face format and employed the same instructors, reading materials, and instructional activities for both formats of the course. Both formats of the course were also delivered over the same eight-week period and required participants to invest approximately the same amount of time each week engaging in learning activities. Both formats of the course showed significant impacts on teachers’ mathematical understanding, pedagogical beliefs, and instructional practices. Consistent with prior research on online versus face-to-face instruction, the positive outcomes were comparable across both formats. Interestingly, teachers who participated in the online course reported that they were more willing to take courses in the future online than did teachers in the face-to-face condition. Further research is needed to determine whether this finding is limited to self-selectedteachers, the specifics of this course, or other factors that limit generalizability.

Education has become the tipping point that separates those who thrive from those who struggle just to survive. This chapter synthesizes many of the powerful and previously unexamined psychological consequences of educational attainment, illustrating that education influences behavior by shaping one’s experience of self. Although most people have both an independent and an interdependent self, people inhabiting college-educated contexts tend to prioritize their independent selves. Those inhabiting high school-educated contexts—and thus with fewer resources and less power and status—tend to emphasize their interdependent selves. From music preferences, to friendship, to responses to natural disasters, these different selves organize how people think, feel, and behave in their world. However, these differences are not inherent or fixed. They are the highly malleable products of the different interactions, institutions, and ideas that characterize high school–educated and college-educated contexts.

Recent studies have demonstrated that skyrmionic states can be the ground state in thin-film FeGe disk nanostructures in the absence of a stabilising applied magnetic field. In this work, we advance this understanding by investigating to what extent this stabilisation of skyrmionic structures through confinement exists in geometries that do not match the cylindrical symmetry of the skyrmion -- such as as squares and triangles. Using simulation, we show that skyrmionic states can form the ground state for a range of system sizes in both triangular and square-shaped FeGe nanostructures of $10\,\text{nm}$ thickness in the absence of an applied field. We further provide data to assist in the experimental verification of our prediction; to imitate an experiment where the system is saturated with a strong applied field before the field is removed, we compute the time evolution and show the final equilibrium configuration of magnetization fields, starting from a uniform alignment., Comment: 7 pages, 7 figures

Confined nanogeometries have proved interesting research arenas in magnetism in recent years, with bit-patterned media being one prospective method for increasing storage densities of future hard drives [1].

Female patients receiving immunosuppressive therapy may be at increased risk for human papillomavirus (HPV) infection and cervical neoplasia.We administered the 3-dose HPV vaccine Gardasil to 37 females aged 9 to 26 years with inflammatory bowel disease (IBD) prescribed immunosuppressive therapy (prospective cohort). Geometric mean titers (GMT) in milli-Merck (mMu/mL) units were determined before dose 1 and 1 month after dose 3 by competitive Luminex immunoassay (cLIA) and qualitatively compared with healthy females of similar age from Merck's database. Side effects and adverse events were evaluated. Concurrently, in 15 similar patients with inflammatory bowel disease previously vaccinated by their primary care provider, we assessed antibody titers by competitive Luminex immunoassay and total immunoglobulin G LIA after dose 3 of vaccine (range, 0.5-27 months).Mean age of prospective patients was 15 years with 51% on anti-tumor necrosis factor therapy and 49% on immunomodulators: 33 of 37 completed all 3 doses. Seropositivity after dose 3 was 100% for types 6, 11 and 16 and 96% for type 18. Geometric mean titers for HPV-6, HPV-11, HPV-16 and HPV-18 was 1080, 1682, 3975 and 858, respectively and did not qualitatively differ from healthy females. No serious adverse events were attributable to the vaccine. In the previously vaccinated cohort, seropositivity was 100% for types 6, 11, and 16, and 40% for type 18 by competitive Luminex immunoassay (93% for HPV-18 by immunoglobulin G LIA). Titers decreased with time since dose 3.In this small study of patients with inflammatory bowel disease prescribed immunosuppressive therapy, Gardasil was immunogenic and there were no clinically significant vaccine-associated adverse events.

The potential for application of magnetic skyrmions in high density storage devices provides a strong drive to investigate and exploit their stability and manipulability. Through a three-dimensional micromagnetic hysteresis study, we investigate the question of existence of skyrmions in cylindrical nanostructures of variable thickness. We quantify the applied field and thickness dependence of skyrmion states, and show that these states can be accessed through relevant practical hysteresis loop measurement protocols. As skyrmionic states have yet to be observed experimentally in confined helimagnetic geometries, our work opens prospects for developing viable hysteresis process-based methodologies to access and observe skyrmionic states., 4 pages, 2 figures

Using finite element micromagnetic simulations, we study how resonant magnetisation dynamics in thin magnetic discs with perpendicular anisotropy are influenced by magnetostatic coupling to a magnetic nanoparticle. We identify resonant modes within the disc using direct magnetic eigenmode calculations and study how their frequencies and profiles are changed by the nanoparticle's stray magnetic field. We demonstrate that particles can generate shifts in the resonant frequency of the disc's fundamental mode which exceed resonance linewidths in recently studied spin torque oscillator devices. Importantly, it is shown that the simulated shifts can be maintained over large field ranges (here up to 1T). This is because the resonant dynamics (the basis of nanoparticle detection here) respond directly to the nanoparticle stray field, i.e. detection does not rely on nanoparticle-induced changes to the magnetic ground state of the disk. A consequence of this is that in the case of small disc-particle separations, sensitivities to the particle are highly mode- and particle-position-dependent, with frequency shifts being maximised when the intense stray field localised directly beneath the particle can act on a large proportion of the disc's spins that are undergoing high amplitude precession., 9 pages, 9 figures. Updated version from 31.7.2016 includes minor changes in introduction and sections III.C and III.D (additional information linking the results to real-world bio-sensing devices)

We demonstrate that chiral skyrmionic magnetization configurations can be found as the minimum energy state in B20 thin film materials with easy-plane magnetocrystalline anisotropy with an applied magnetic field perpendicular to the film plane. Our observations contradict results from prior analytical work, but are compatible with recent experimental investigations. The size of the observed skyrmions increases with the easy-plane magnetocrystalline anisotropy. We use a full micromagnetic model including demagnetization and a three-dimensional geometry to find local energy minimum (metastable) magnetization configurations using numerical damped time integration. We explore the phase space of the system and start simulations from a variety of initial magnetization configurations to present a systematic overview of anisotropy and magnetic field parameters for which skyrmions are metastable and global energy minimum (stable) states., 5 pages, 3 figures

In confined helimagnetic nanostructures, skyrmionic states in the form of incomplete and isolated skyrmion states can emerge as the ground state in absence of both external magnetic field and magnetocrystalline anisotropy. In this work, we study the dynamic properties (resonance frequencies and corresponding eigenmodes) of skyrmionic states in thin film FeGe disk samples. We employ two different methods in finite-element based micromagnetic simulation: eigenvalue and ringdown method. The eigenvalue method allows us to identify all resonance frequencies and corresponding eigenmodes that can exist in the simulated system. However, using a particular experimentally feasible excitation can excite only a limited set of eigenmodes. Because of that, we perform ringdown simulations that resemble the experimental setup using both in-plane and out-of-plane excitations. In addition, we report the nonlinear dependence of resonance frequencies on the external magnetic bias field and disk sample diameter and discuss the possible reversal mode of skyrmionic states. We compare the power spectral densities of incomplete skyrmion and isolated skyrmion states and observe several key differences that can contribute to the experimental identification of the state present in the sample. We measure the FeGe Gilbert damping, and using its value we determine what eigenmodes can be expected to be observed in experiments. Finally, we show that neglecting the demagnetisation energy contribution or ignoring the magnetisation variation in the out-of-film direction - although not changing the eigenmode's magnetisation dynamics significantly - changes their resonance frequencies substantially. Apart from contributing to the understanding of skyrmionic states physics, this systematic work can be used as a guide for the experimental identification of skyrmionic states in confined helimagnetic nanostructures., Comment: manuscript: 17 pages, 9 figures; supplementary information: 10 pages, 8 figures

Genotypic variation in signal transducer and activator of transcription 3 (STAT3) increases risk for inflammatory bowel disease (IBD), and STAT3-dependent inflammatory networks are induced in the colon in these patients. We hypothesized that STAT3 "A" risk allele carriage would be associated with increased cellular STAT3 activation and colon leukocyte recruitment.Colonic expression of genes regulating STAT3 signaling and leukocyte recruitment and function was measured in pediatric patients with Crohn disease (CD) stratified by STAT3 genotype. The frequency of colonic pSTAT3* and CXCR2* neutrophils was determined using immunohistochemistry. STAT3 tyrosine phosphorylation (pSTAT3) was measured in circulating leukocytes by flow cytometry, and mechanisms regulating STAT3 activation were tested in IBD Epstein-Barr virus (EBV)-transformed lymphocytes (EBL).Colonic expression of interleukin 6 (IL-6), the STAT3 target gene SOCS3, the neutrophil chemoattractants IL-8, CXCL1, and CXCL3, and the neutrophil products S100A8, S100A9, and S100A12 were increased in patients carrying the STAT3 "A" risk allele. The frequency of neutrophils expressing the cognate receptor for IL-8, CXCR2, was increased in colonic biopsies from patients carrying the risk allele, and the frequency of pSTAT3* or CXCR2* neutrophils correlated with histologic severity. The frequency of CD4 lymphocytes and granulocytes expressing pSTAT3 was increased in patients carrying the STAT3 "A" risk allele. EBLs from patients carrying the STAT3 "A" risk allele exhibited increased basal and IL-6-stimulated STAT3 tyrosine phosphorylation, increased transcription of STAT3 and SOCS3 after IL-6 stimulation, and increased membrane localization of the IL-6 receptor, GP130, and Janus-associated kinase 2.The STAT3 "A" risk allele is associated with increased cellular STAT3 activation and upregulation of pathways that promote recruitment of CXCR2* neutrophils to the gut.

Growth hormone (GH) may reduce symptoms and improve growth in Crohn disease (CD). The effect on mucosal inflammation is not known. We hypothesized that GH would improve both clinical and mucosal disease activity and stimulate linear growth in pediatric CD.Twenty patients ages 7 to 18 receiving corticosteroids (CTX) for active CD were randomized to begin GH, 0.075 mg x kg(-1) x day(-1) (group A), or continue CTX alone (group B). Clinical and endoscopic disease activities were assessed after 12 weeks. Group B began GH at 12 weeks, and clinical disease activity was assessed at 24 weeks. Subjects who experienced a clinical response after 12 weeks of GH therapy continued treatment for an additional 52 weeks, and linear growth was assessed.Sixty-five percent of patients receiving GH achieved clinical remission, compared with 20% treated with CTX alone (P = 0.03). Although endoscopic disease activity trended toward an improvement at week 12 in group A, this did not differ between the groups. Sixty-one percent of week 12 GH responders maintained their clinical response through week 64. Mean (95th confidence interval) height z score on GH increased from -1.1 (-1.6, -0.6) to -0.4 (-1, 0.2), P = 0.004 during this 52-week extension phase. GH was well tolerated with no unexpected safety signals.The addition of GH to CTX therapy did not induce a reduction in mucosal inflammation, relative to CTX alone. However, GH was safe and effective as an adjunct to CTX for treatment of clinical disease activity and growth failure in pediatric CD.

The study investigated whether online professional development courses with different levels of support have different impacts on teacher outcomes. Variations of an online course for middle school algebra teachers were created for four experimental conditions. One was a highly supported condition, with a math education instructor, an online facilitator, and asynchronous peer interactions among participants available as participants worked through the course together. Another was a self-paced condition, in which none of the supports were available. The other two conditions provided intermediate levels of support. All conditions showed significant impact on teachers’ mathematical understanding, pedagogical beliefs, and instructional practices. Surprisingly, the positive outcomes were comparable across all four conditions. Further research is needed to determine whether this finding is limited to self-selected teachers, the specifics of this online course, or other factors that limit generalizability. (Keywords: Online professional development, distance learning, e-learning, online facilitation, self-paced learning)

Clinical studies have demonstrated a link between the eosinophil-selective chemokines, eotaxins (eotaxin-1/CCL11 and eotaxin-2/CCL24), eosinophils, and the inflammatory bowel diseases, Crohn’s disease and ulcerative colitis (UC). However, the cellular source and individual contribution of the eotaxins to colonic eosinophilic accumulation in inflammatory bowel diseases remain unclear. In this study we demonstrate, by gene array and quantitative PCR, elevated levels of eotaxin-1 mRNA in the rectosigmoid colon of pediatric UC patients. We show that elevated levels of eotaxin-1 mRNA positively correlated with rectosigmoid eosinophil numbers. Further, colonic eosinophils appeared to be degranulating, and the levels positively correlated with disease severity. Using the dextran sodium sulfate (DSS)-induced intestinal epithelial injury model, we show that DSS treatment of mice strongly induced colonic eotaxin-1 and eotaxin-2 expression and eosinophil levels. Analysis of eosinophil-deficient mice defined an effector role for eosinophils in disease pathology. DSS treatment of eotaxin-2−/− and eotaxin-1/2−/− mice demonstrated that eosinophil recruitment was dependent on eotaxin-1. In situ and immunofluorescence analysis-identified eotaxin-1 expression was restricted to intestinal F4/80+CD11b+ macrophages in DSS-induced epithelial injury and to CD68+ intestinal macrophages and the basolateral compartment of intestinal epithelial cells in pediatric UC. These data demonstrate that intestinal macrophage and epithelial cell-derived eotaxin-1 plays a critical role in the regulation of eosinophil recruitment in colonic eosinophilic disease such as pediatric UC and provides a basis for targeting the eosinophil/eotaxin-1 axis in UC.

Student enrollment in K–12 online learning programs showed a tenfold expansion in the years between 2002 and 2005. Despite increased implementation to fulfill critical local needs, there is very little evidence-based research available to inform education leaders’ decisions relating to these initiatives. To address the important question of whether online learning can be as effective as traditional face-to-face learning, this research presents the findings from a quasi-experimental design implemented to examine the effect of the Louisiana Algebra I Online initiative on student outcomes. The findings presented suggest that the Louisiana Algebra I Online model is a viable online model for providing effective Algebra I instruction.

Magnetic skyrmions have the potential to provide solutions for low-power, high-density data storage and processing. One of the major challenges in developing skyrmion-based devices is the skyrmions' magnetic stability in confined helimagnetic nanostructures. Through a systematic study of equilibrium states, using a full three-dimensional micromagnetic model including demagnetisation effects, we demonstrate that skyrmionic textures are the lowest energy states in helimagnetic thin film nanostructures at zero external magnetic field and in absence of magnetocrystalline anisotropy. We also report the regions of metastability for non-ground state equilibrium configurations. We show that bistable skyrmionic textures undergo hysteretic behaviour between two energetically equivalent skyrmionic states with different core orientation, even in absence of both magnetocrystalline and demagnetisation-based shape anisotropies, suggesting the existence of Dzyaloshinskii-Moriya-based shape anisotropy. Finally, we show that the skyrmionic texture core reversal dynamics is facilitated by the Bloch point occurrence and propagation., Comment: manuscript: 14 pages, 7 figures; supplementary information: 8 pages, 7 figures