55 research outputs found
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
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Safety and efficacy of whole-body chlorhexidine gluconate cleansing with or without emollient in hospitalised neonates (NeoCHG): a multicentre, randomised, open-label, factorial pilot trial.
BACKGROUND: Healthcare-associated infections account for substantial neonatal in-hospital mortality. Chlorhexidine gluconate (CHG) whole body skin application could reduce sepsis by lowering bacterial colonisation density, although safety and optimal application regimen is unclear. Emollients, including sunflower oil, may independently improve skin condition, thereby reducing sepsis. We aimed to inform which concentration and frequency of CHG, with or without emollient, would best balance safety and the surrogate marker of efficacy of reduction in bacterial colonisation, to be taken forward in a future pragmatic trial evaluating clinical outcomes of sepsis and mortality. METHODS: In this multicentre, randomised, open-label, factorial pilot trial, neonates in two hospital sites (South Africa, Bangladesh) aged 1-6 days with gestational age ā„ 28 weeks and birthweight 1000-1999 g were randomly assigned in a factorial design stratified by site to three different concentrations of CHG (0.5%, 1%, and 2%), with or without emollient (sunflower oil) applied on working days vs alternate working days. A control arm received neither product. Caregivers were unblinded although laboratory staff were blinded to randomisation Co-primary outcomes were safety (change in neonatal skin condition score incorporating dryness, erythema, and skin breakdown) and efficacy in reducing bacterial colonisation density (change in total skin bacterial log10Ā CFU from randomisation to day-3 and day-8). The trial is registered at the ISRCTN registry, ISRCTNĀ 69836999. FINDINGS: Between Apr 12 2021 and Jan 18 2022, 208 infants were randomised and 198 were included in the final analysis. Skin condition scores were low with mean 0.1 (sdĀ =Ā 0.3; NĀ =Ā 208) at baseline, 0.1 (sdĀ =Ā 0.3; NĀ =Ā 199) at day 3 and 0.1 (sdĀ =Ā 0.3; NĀ =Ā 189) at day 8, with no evidence of differences between concentration (1% CHG vs 0.5% estimateĀ =Ā -0.3, 95% CIĀ = (-1.2, 0.6), pĀ =Ā 0.55. 2% CHG vs 0.5% CHG estimateĀ =Ā 0.5 (-0.4, 1.4), pĀ =Ā 0.30), increasing frequency (estimateĀ =Ā -0.4; 95% CIĀ = (-1.1, 0.4), pĀ =Ā 0.33), emollient (estimateĀ =Ā -0.5, (-1.2, 0.3), pĀ =Ā 0.23) or with control (estimateĀ =Ā -0.9, (-2.3, 0.4), pĀ =Ā 0.18). Mean log10Ā CFU was 4.9 (sdĀ =Ā 3.0; NĀ =Ā 208) at baseline, 6.3 (sdĀ =Ā 3.1; NĀ =Ā 198) at day 3 and 8.4 (sdĀ =Ā 2.6; NĀ =Ā 183) with no evidence of differences between concentration (1% CHG vs 0.5% estimateĀ =Ā -0.4; 95% CIĀ = (-1.1, 0.23); pĀ =Ā 0.23. 2% CHG vs 0.5% CHG estimateĀ =Ā 0.0 (-0.6, 0.6), pĀ =Ā 0.96), with increasing frequency (estimateĀ =Ā -0.4; 95% CIĀ = (-0.9, 0.2); pĀ =Ā 0.17), with emollient (estimateĀ =Ā 0.4, 95% CIĀ = (-0.2, 0.9); pĀ =Ā 0.18) or with control (estimateĀ =Ā -0.2, 95% CIĀ = (-1.3, 0.9); pĀ =Ā 0.73). By day-8, overall 158/183 (86%) of neonates were colonised with Enterobacterales, and 72/183 (39%) and 69/183 (9%) with Klebsiella spp resistant to third-generation cephalosporin and carbapenems, respectively. There were no CHG-related SAEs, emollient-related SAEs, grade 3 or 4 skin scores or grade 3 or 4 hypothermias. INTERPRETATION: In this pilot trial of CHG with or without sunflower oil, no safety issues were identified, and further trials examining clinical outcomes are warranted. The relatively late start application of emollient, at a mean of 3.8 days of life, may have reduced the impact of the intervention although no subgroup effects were detected. There was no clear evidence in favour of a specific concentration of chlorhexidine, and there was rapid colonisation with Enterobacterales with frequent antimicrobial resistance, regardless of skin application regimen. FUNDING: The MRC Joint Applied Global Health award, the Global Antibiotic Research and Development Partnership (GARDP), MRC Clinical Trials Unit core funding (UKRI) and St. George's, University of London
The 1.28 GHz MeerKAT DEEP2 Image
We present the confusion-limited 1.28 GHz MeerKAT DEEP2 image covering one qb Ā» Ā¢ 68 FWHM primarybeam area with Īø = 7 6 FWHM resolution and s = m - n 0.55 0.01 Jy beam 1 rms noise. Its J2000 center position
Ī± = 04h 13m 26 4, Ī“ = ā80Ā° 00ā² 00ā³ was selected to minimize artifacts caused by bright sources. We introduce
the new 64-element MeerKAT array and describe commissioning observations to measure the primary-beam
attenuation pattern, estimate telescope pointing errors, and pinpoint (u, v) coordinate errors caused by offsets in
frequency or time. We constructed a 1.4 GHz differential source count by combining a power-law count fit to the
DEEP2 confusion P(D) distribution from 0.25 to 10 Ī¼Jy with counts of individual DEEP2 sources between 10 Ī¼Jy
and 2.5 mJy. Most sources fainter than S ā¼ 100 Ī¼Jy are distant star-forming galaxies (SFGs) obeying the far-IR/
radio correlation, and sources stronger than 0.25 Ī¼Jy account for ā¼93% of the radio background produced by
SFGs. For the first time, the DEEP2 source count has reached the depth needed to reveal the majority of the star
formation history of the universe. A pure luminosity evolution of the 1.4 GHz local luminosity function consistent
with the Madau & Dickinson model for the evolution of SFGs based on UV and infrared data underpredicts our
1.4 GHz source count in the range -5 log Jy 4 [ ( )] S
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 100 larger than during its dormant state. The X-ray flux one month after reactivation was at least 800 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
The MeerKAT Galaxy Cluster Legacy Survey: I. Survey overview and highlights
Please abstract in the article.The South African Radio Astronomy Observatory (SARAO), the National Research Foundation (NRF), the National Radio Astronomy Observatory, US National Science Foundation, the South African Research Chairs Initiative of the DSI/NRF, the SARAO HCD programme, the South African Research Chairs Initiative of the Department of Science and Innovation.http://www.aanda.orghj2022Physic
Obstruction-strangulation of post-traumatic diaphragmatic hernia : delayed diagnosis and fatal outcome : a report of 9 cases
ArticleThe original publication is avialable at Schulman, A., Fataar, S. & Alheit, B. 1985. Obstruction-strangulation of post-traumatic diaphragmatic hernia: delayed diagnosis and fatal outcome: a report of 9 cases. SAMJ, 68:39-44, http://www.samj.org.zaThe radiological and clinical features of 9 cases of obstructed post-traumatic diaphragmatic hernia are reviewed. In none of these patients was the diagnosis of a diaphragmatic hernia considered before radiography, all cases being clinically diagnosed as 'acute abdomen', most frequently pancreatitis or perforated peptic ulcer. Even after radiographs had shown opacity at the left base in all 9 cases, together with a distended proximal bowel in 6, the correct diagnosis was made in only 4. Through lack of correct radiological diagnosis, there was a delay of at least 1 day between admission and operation in 6 patients, and 3 of the 4 deaths occurred in this group. Obstruction-strangulation of diaphragmatic hernia should be considered as a possible cause of 'acute abdomen' in the presence of a left basal abnormality, especially in patients from areas with a high incidence of assault. confirmatory contrast studies should be done only if they can be done immediately and quickly. Pregnancy can cause hernias to become obstructed and strangulated, but this can be averted by obtaining a history of previous trauma early in the pregnancy.Publishers' versio
Ambiguous accommodation: Cape muslims and post-apartheid politics
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