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Magnetars are young, magnetically powered neutron stars that possess the strongest magnetic fields in the Universe. Fast radio bursts (FRBs) are extremely intense millisecond-long radio pulses of primarily extragalactic origin, and a leading attribution for their genesis focuses on magnetars. A hallmark signature of magnetars is their emission of bright, hard X-ray bursts of sub-second duration. On 27 April 2020, the Galactic magnetar SGR J1935+2154 emitted hundreds of X-ray bursts within a few hours. One of these temporally coincided with an FRB, the first known detection of an FRB from the Milky Way. Here, we present spectral and temporal analyses of 24 X-ray bursts emitted 13 hours prior to the FRB and seen simultaneously with the Neutron Star Interior Composition Explorer (NICER) mission of the National Aeronautics and Space Administration and with the Fermi Gamma-ray Burst Monitor (GBM) mission in their combined energy range of 0.2 keV to 30 MeV. These broadband spectra permit direct comparison with the spectrum of the FRB-associated X-ray burst (FRB-X). We demonstrate that all 24 NICER and GBM bursts are very similar temporally to the FRB-X, but strikingly different spectrally. The singularity of the FRB-X burst is perhaps indicative of an uncommon locale for its origin. We suggest that this event originated in quasi-polar open or closed magnetic field lines that extend to high altitudes.

Aims Optometrists are becoming increasingly involved in the co-management of glaucoma patients as the burden on the Hospital Eye Service continues to escalate. The aim of this study was to assess the agreement between specially trained optometrists and glaucoma-specialist consultant ophthalmologists in their management of glaucoma patients. Methods Four optometrists examined 23–25 patients each and the clinical findings, up to the point of dilation, were documented in the hospital records. The optometrist, and one of two consultant ophthalmologists, then independently examined and documented the optic-disc appearance before recording their decisions regarding the stability and management of the patient on a specially designed proforma. Percentage agreement was calculated together with kappa or weighted kappa statistics, where appropriate. Results Agreement between consultants and optometrists in evaluating glaucoma stability was 68.5% (kappa ( κ )=0.42–0.50) for visual fields, 64.5% (weighted κ =0.17–0.31) for optic discs, and 84.5% (weighted κ =0.55–0.60) for intraocular pressures. Agreement regarding medical management was 96.5% ( κ =0.73–0.81) and for other glaucoma management decisions, including timing of follow-up, referral to a consultant ophthalmologist, and discharge, was 72% (weighted κ =0.65). This agreement increased to 90% following a retrospective independent then consensus review between the two consultants and when qualified agreements were included. Of the 47 glaucoma and non-glaucoma queries generated during the study, 42 resulted in a change of management. Conclusion Confirming the ability of optometrists to make appropriate decisions regarding the stability and management of glaucoma patients is essential if their involvement is to continue to develop to meet the demand of an aging population.

The large number of ${\\it\\gamma}$ -ray pulsars discovered by the Fermi Gamma-Ray Space Telescope since its launch in 2008 dwarfs the handful that were previously known. The variety of observed light curves makes possible a tomography of both the ensemble-averaged field structure and the high-energy emission regions of a pulsar magnetosphere. Fitting the ${\\it\\gamma}$ -ray pulsar light curves with model magnetospheres and emission models has revealed that most of the high-energy emission, and the particles acceleration, takes place near or beyond the light cylinder, near the current sheet. As pulsar magnetosphere models become more sophisticated, it is possible to probe magnetic field structure and emission that are self-consistently determined. Light curve modelling will continue to be a powerful tool for constraining the pulsar magnetosphere physics.

Magnetars are a special subset of the isolated neutron star family, with X-ray and radio emission mainly powered by the decay of their immense magnetic fields. Many attributes of magnetars remain poorly understood: spin-down glitches or the sudden reductions in the star’s angular momentum, radio bursts reminiscent of extragalactic fast radio bursts (FRBs) and transient pulsed radio emission lasting months to years. Here we unveil the detection of a large spin-down glitch event (fractional change in spin frequency ∣Δν/ν∣=5.8−1.6+2.6×10−6) from the magnetar SGR 1935+2154 on 5 October 2020 (±1 day). We find no change to the source-persistent surface thermal or magnetospheric X-ray behaviour, nor is there evidence of strong X-ray bursting activity. Yet, in the subsequent days, the magnetar emitted three FRB-like radio bursts followed by a month-long episode of pulsed radio emission. Given the rarity of spin-down glitches and radio signals from magnetars, their approximate synchronicity suggests an association, providing pivotal clues to their origin and triggering mechanisms with ramifications to the broader magnetar and FRB populations. We postulate that impulsive crustal plasma shedding close to the magnetic pole generates a wind that combs out magnetic field lines, rapidly reducing the star’s angular momentum while temporarily altering the magnetospheric field geometry to permit the pair creation needed to precipitate radio emission.An abrupt slow-down in a magnetar’s rotation rate (a ‘glitch’) may be related to the subsequent emission of three radio bursts (resembling fast radio bursts) and a month-long episode of pulsed radio emission.

Non-thermal quiescent X-ray emission extending between 10 keV and around 150 keV has been seen in about 10 magnetars by RXTE, INTEGRAL, Suzaku, NuSTAR and Fermi-GBM. For inner magnetospheric models of such hard X-ray signals, inverse Compton scattering is anticipated to be the most efficient process for generating the continuum radiation, because the scattering cross section is resonant at the cyclotron frequency. We present hard X-ray upscattering spectra for uncooled monoenergetic relativistic electrons injected in inner regions of pulsar magnetospheres. These model spectra are integrated over bundles of closed field lines and obtained for different observing perspectives. The spectral turnover energies are critically dependent on the observer viewing angles and electron Lorentz factor. We find that electrons with energies less than around 15 MeV will emit most of their radiation below 250 keV, consistent with the turnovers inferred in magnetar hard X-ray tails. Electrons of higher energy still emit most of the radiation below around 1 MeV, except for quasi-equatorial emission locales for select pulse phases. Our spectral computations use a new state-of-the-art, spin-dependent formalism for the QED Compton scattering cross section in strong magnetic fields.

Numerical simulations of relativistic plasmas have become more feasible, popular, and crucial for various astrophysical sources with the availability of computational resources. The necessity for high-accuracy particle dynamics is especially highlighted in pulsar modelling due to the extreme associated electromagnetic fields and particle Lorentz factors. Including the radiation-reaction force in the particle dynamics adds even more complexity to the problem, but is crucial for such extreme astrophysical sources. We have also realised the need for such modelling concerning magnetic mirroring and particle injection models proposed for AR Sco, the first white dwarf pulsar. This paper demonstrates the benefits of using higher-order explicit numerical integrators with adaptive time step methods to solve the full particle dynamics with radiation-reaction forces included. We show that for standard test scenarios, namely various combinations of uniform \\(E\\)- and \\(B\\)-fields and a static dipole \\(B\\)-field, the schemes we use are equivalent to and in extreme field cases outperform standard symplectic integrators in accuracy. We show that the higher-order schemes have massive computational time improvements due to the adaptive time steps we implement, especially in non-uniform field scenarios and included radiation reaction where the particle gyro-radius rapidly changes. When balancing accuracy and computational time, we identified the adaptive Dormand-Prince eighth-order scheme to be ideal for our use cases. The schemes we use maintain accuracy and stability in describing the particle dynamics and we indicate how a charged particle enters radiation-reaction equilibrium and conforms to the analytic Aristotelian Electrodynamics expectations.

We present results of a population synthesis study of radio-loud and radio-quiet g-ray pulsars from the Galactic plane and the Gould Belt. The simulation includes the Parkes multibeam pulsar survey, realistic beam geometries for radio and g-ray emission from neutron stars and the new electron density model of Cordes and Lazio. Normalizing to the number of radio pulsars observed by a set of nine radio surveys, the simulation suggests a neutron star birth rate of 1.4 neutron stars per century in the Galactic plane. In addition, the simulation predicts 19 radio-loud and 7 radio-quiet g-ray pulsars from the plane that EGRET should have observed as point sources. Assuming that during the last 5 Myr the Gould Belt produced 100 neutron stars, only 10 of these would be observed as radio pulsars with three radio-loud and four radio-quiet g-ray pulsars observed by EGRET. These results are in general agreement with the recent number of about 25 EGRET error boxes that contain Parkes radio pulsars. Since the Gould Belt pulsars are relatively close by, the selection of EGRET radio-quiet g-ray pulsars strongly favors large impact angles, b, in the viewing geometry where the off-beam emission from curvature radiation provides the g-ray flux. Therefore, the simulated EGRET radio-quiet g-ray pulsars, being young and nearby, most closely reflect the current shape of the Gould Belt suggesting that such sources may significantly contribute to the EGRET unidentified g-ray sources correlated with the Gould Belt.

This paper discusses a study of four communities in Oregon that were divided into two control groups and surveyed according to water contamination problems and how their perceptions of risk affected their use of tap water versus bottled water. Results indicated that risk perception about drinking water appears to be affected by three factors: the consumer's level of awareness of a problem; the presence or absence of drinking water contamination problems; and, the chronicity of the problem. Findings suggest that water contamination problems contribute to increased levels of risk perception with those drinking tap water. Also, long‐term problems that are not easily solved by the water utility may heighten consumers' perception of risk. Higher levels of risk perception may be the driving force behind higher rates of bottled water use in some communities.

The Healthy Families America (HFA) initiative seeks to expand the availability of high-quality, intensive home visitation services and to create communitywide commitments to these services and others that promote a supportive atmosphere for all new parents. This article briefly describes HFA's theoretical framework, its history, and its current status. The HFA Research Network, a partnership among researchers who are engaged in evaluating HFA programs around the country, is also highlighted. Preliminary findings of the research partners suggest that HFA programs may have the most success at improving parent-child interactions, with more limited or mixed success in the areas of health care status and utilization, the prevention of child abuse and neglect, and improved maternal life course outcomes. HFA programs so far have not demonstrated significant improvements in children's development or maternal social support. The authors report variability in both outcomes and attrition rates across subgroups of families in these studies, but there are no consistent patterns to identify who is most likely to stay enrolled in an HFA program or who is most likely to benefit from that enrollment. The authors conclude that these and several other areas require additional research. They further recommend that researchers and practitioners move beyond a singular focus on individualized interventions and work to create a communitywide and national context in which support for all new parents is the norm.

Electromagnetic phenomena occurring in the strong magnetic fields of neutron stars are currently of great interest in high-energy astrophysics. Observations of rotation rate changes and cyclotron lines in pulsars and γ-ray bursts indicate that surface magnetic fields of neutron stars often exceed 10$^{12}$ gauss. In fields this strong, where electrons behave much as if they were in bound atomic states, familiar processes undergo profound changes, and exotic processes become important. Strong magnetic fields affect the physics in several fundamental ways: Energies perpendicular to the field are quantized, transverse momentum is not conserved, and electron-positron spin is important. Neutron stars therefore provide a unique laboratory for the study of physics in extremely high fields that cannot be generated on Earth.