Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure

A meta-ethnography of the facilitators and barriers to successful implementation of patient complaints processes in health-care settings

Objective: To synthesize experiences of the patient complaints process for patients and health-care professionals to identify facilitators and barriers in the successful implementation of patient complaints processes. This will assist the development of cultural change programmes, enabling complaints managers to incorporate stakeholder perspectives into future care. Design: Systematic literature search and meta-ethnography, comprising reciprocal syntheses of “patient” and “professional” qualitative studies, combined to form a “line-of-argument” embodying both perspectives. Data sources: MEDLINE, CINAHL and PsycINFO (database inception to April 2015) were searched to identify international literature in primary and secondary health-care settings, involving qualitative data collection and analysis. Further studies were identified from hand-searching relevant journals, contacting authors, article reference lists and Google Scholar. Results: A total of 13 papers, reporting 9 studies from the United Kingdom, Sweden, Australia and New Zealand, were included in the synthesis. Facilitators and barriers to the successful implementation of patient complaints processes were identified across the perspectives of both patients and health-care professionals. Patients sought to individualize the complaints process by targeting specific professionals who engaged in practices that undermined the identity of patients. In contrast, professionals obscured their own individualism through maintaining a collective identity and withholding personal judgement in relation to patient complaints. Conclusions: Complainants recognized health-care professionals as bearers of individual accountability for unsatisfactory care, in opposition to the stance of collective responsibility endorsed by professionals. Implementation of patient complaints processes must reconcile the need for individualized resolution, whilst striving to improve the future provision of health care through a collaborative approach between patients and professionals.</p

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy. Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388. Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16, p<0·0001). Interpretation: Among patients with recent cerebral ischaemia, intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding. Triple antiplatelet therapy should not be used in routine clinical practice

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy.Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388.Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16,

RF measurement of wire complex permeability

The complex permeability of thin round wires is measured with a coaxial system at half-wavelength resonance, using surface impedance and low-loss transmission line concepts. A steel wire is measured over the band 300 MHz-3 GHz. The results compare well to measurements made early in the last century.Articl

Apparently simple low frequency measurements: An EMC view

This paper demonstrates the need for care with some EMI problems present in even simple low-frequency (<1 MHz) measurements. Two experiments on cable crosstalk, found in the IEEE EMC Educational Manual, are used. Predictions are made from field theory, and compared to results from a series of measurement setups. Although the setups appear similar, it is found that unwanted coupling between the experiment and the measurement equipment influences the results.Articl

Radiation to transmission lines with varying load and ground conditions

A transmission line above both an ideal and a lossy ground is illuminated by a plane wave, while its terminations are varied. An intention of this study, for EMI purposes, is to explore the minimisation of power induced in the loads, both by simulation and measurement. The simulations are performed in the time domain and the frequency domain, while measurements are made in the frequency domain with a network analyser. Great care is needed for the measurement procedures.Conference Pape

Strategy for intention to treat analysis in randomised trials with missing outcome data.

Loss to follow-up is often hard to avoid in randomised trials. This article suggests a framework for intention to treat analysis that depends on making plausible assumptions about the missing data and including all participants in sensitivity analyse