The Location of Young Pulsar PSR J0837-2454: Galactic Halo or Local Supernova Remnant?

We present the discovery and timing of the young (age ∼28.6 kyr) pulsar PSR J0837-2454. Based on its high latitude (b = 9°8) and dispersion measure (DM = 143 pc cm-3), the pulsar appears to be at a z-height of >1 kpc above the Galactic plane, but near the edge of our Galaxy. This is many times the observed scale height of the canonical pulsar population, which suggests this pulsar may have been born far out of the plane. If accurate, the young age and high z-height imply that this is the first pulsar known to be born from a runaway O/B star. In follow-up imaging with the Australia Telescope Compact Array (ATCA), we detect the pulsar with a flux density S1400 = 0.18 ± 0.05 mJy. We do not detect an obvious supernova remnant around the pulsar in our ATCA data, but we detect a colocated, low-surface-brightness region of ∼1°5 extent in archival Galactic and Extragalactic All-sky MWA Survey data. We also detect colocated Hα emission from the Southern Hα Sky Survey Atlas. Distance estimates based on these two detections come out to ∼0.9 kpc and ∼0.2 kpc, respectively, both of which are much smaller than the distance predicted by the NE2001 model (6.3 kpc) and YMW model (>25 kpc) and place the pulsar much closer to the plane of the Galaxy. If the pulsar/remnant association holds, this result also highlights the inherent difficulty in the classification of transients as "Galactic" (pulsar) or "extragalactic" (fast radio burst) toward the Galactic anticenter based solely on the modeled Galactic electron contribution to a detection

Antenatal dexamethasone for early preterm birth in low-resource countries

BACKGROUND: The safety and efficacy of antenatal glucocorticoids in women in low-resource countries who are at risk for preterm birth are uncertain. METHODS: We conducted a multicountry, randomized trial involving pregnant women between 26 weeks 0 days and 33 weeks 6 days of gestation who were at risk for preterm birth. The participants were assigned to intramuscular dexamethasone or identical placebo. The primary outcomes were neonatal death alone, stillbirth or neonatal death, and possible maternal bacterial infection; neonatal death alone and stillbirth or neonatal death were evaluated with superiority analyses, and possible maternal bacterial infection was evaluated with a noninferiority analysis with the use of a prespecified margin of 1.25 on the relative scale. RESULTS: A total of 2852 women (and their 3070 fetuses) from 29 secondary- and tertiary-level hospitals across Bangladesh, India, Kenya, Nigeria, and Pakistan underwent randomization. The trial was stopped for benefit at the second interim analysis. Neonatal death occurred in 278 of 1417 infants (19.6%) in the dexamethasone group and in 331 of 1406 infants (23.5%) in the placebo group (relative risk, 0.84; 95% confidence interval [CI], 0.72 to 0.97; P=0.03). Stillbirth or neonatal death occurred in 393 of 1532 fetuses and infants (25.7%) and in 444 of 1519 fetuses and infants (29.2%), respectively (relative risk, 0.88; 95% CI, 0.78 to 0.99; P=0.04); the incidence of possible maternal bacterial infection was 4.8% and 6.3%, respectively (relative risk, 0.76; 95% CI, 0.56 to 1.03). There was no significant between-group difference in the incidence of adverse events. CONCLUSIONS: Among women in low-resource countries who were at risk for early preterm birth, the use of dexamethasone resulted in significantly lower risks of neonatal death alone and stillbirth or neonatal death than the use of placebo, without an increase in the incidence of possible maternal bacterial infection.Fil: Oladapo, Olufemi T.. Organizacion Mundial de la Salud; ArgentinaFil: Vogel, Joshua P.. Organizacion Mundial de la Salud; ArgentinaFil: Piaggio, Gilda. Organizacion Mundial de la Salud; ArgentinaFil: Nguyen, My-Huong. Organizacion Mundial de la Salud; ArgentinaFil: Althabe, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Metin Gülmezoglu, A.. Organizacion Mundial de la Salud; ArgentinaFil: Bahl, Rajiv. Organizacion Mundial de la Salud; ArgentinaFil: Rao, Suman P.N.. Organizacion Mundial de la Salud; ArgentinaFil: de Costa, Ayesha. Organizacion Mundial de la Salud; ArgentinaFil: Gupta, Shuchita. Organizacion Mundial de la Salud; ArgentinaFil: Shahidullah, Mohammod. No especifíca;Fil: Chowdhury, Saleha B.. No especifíca;Fil: Ara, Gulshan. No especifíca;Fil: Akter, Shaheen. No especifíca;Fil: Akhter, Nasreen. No especifíca;Fil: Dey, Probhat R.. No especifíca;Fil: Abdus Sabur, M.. No especifíca;Fil: Azad, Mohammad T.. No especifíca;Fil: Choudhury, Shahana F.. No especifíca;Fil: Matin, M.A.. No especifíca;Fil: Goudar, Shivaprasad S.. No especifíca;Fil: Dhaded, Sangappa M.. No especifíca;Fil: Metgud, Mrityunjay C.. No especifíca;Fil: Pujar, Yeshita V.. No especifíca;Fil: Somannavar, Manjunath S.. No especifíca;Fil: Vernekar, Sunil S.. No especifíca;Fil: Herekar, Veena R.. No especifíca;Fil: Bidri, Shailaja R.. No especifíca;Fil: Mathapati, Sangamesh S.. No especifíca;Fil: Patil, Preeti G.. No especifíca;Fil: Patil, Mallanagouda M.. No especifíca;Fil: Gudadinni, Muttappa R.. No especifíca;Fil: Bijapure, Hidaytullah R.. No especifíca;Fil: Mallapur, Ashalata A.. No especifíca;Fil: Katageri, Geetanjali M.. No especifíca;Fil: Chikkamath, Sumangala B.. No especifíca;Fil: Yelamali, Bhuvaneshwari C.. No especifíca;Fil: Pol, Ramesh R.. No especifíca;Fil: Misra, Sujata S.. No especifíca;Fil: Das, Leena. No especifíca

Current results and future prospects from PSR J1757-1854, a highly-relativistic double neutron star binary

Pulsars, rapidly-rotating highly-magnetised neutron stars, can serve as useful laboratories for probing aspects of fundamental physics. Binary pulsars, especially those in tight binary systems with massive, compact companions, are useful in testing different theories of gravity, the current paradigm being General Relativity (GR). Additionally, binary pulsars can also be utilised to explore other areas of fundamental physics, such as the behaviour of matter at ultra-high densities and the neutron star moment of inertia. A standout example is PSR J1757-1854, a 21.5-ms pulsar in a highly-eccentric (e=0.61), 4.4-hr orbit around a neutron star companion. This pulsar exhibits some of the most extreme relativistic parameters ever observed in a binary pulsar, reaching a maximum line-of-sight acceleration of close to 700 m/s/s and displaying among the strongest relativistic effects due to gravitational wave damping. To date, five post-Keplerian parameters have been measured in PSR J1757-1854, allowing for three independent tests of gravity to be conducted (of which GR passes all three) and for the component neutron star masses to be separated. The extreme properties of this system (particularly its high eccentricity) are expected to allow for future measurements of Lense-Thirring precession effects (allow for a measurement of the neutron star moment of inertia) and the relativistic deformation of the orbit, both of which remain almost completely unexplored by other binary systems. Although first discovered by the Parkes Radio Telescope in 2016 as part of the High Time Resolution Universe Southern Galactic Plane survey, it is ongoing observations with the Green Bank Telescope (GBT) which have provided the backbone of PSR J1757-1854’s continuing study. The large-bandwidth, high-precision observations afforded by the GBT played a fundamental role in delivering the science derived from the pulsar so far, and will be critical in allowing it to reach its full scientific potential going forward. In this talk I will provide a progress report on the ongoing timing of the system, including a review of the latest mass measurements and gravity tests, with an emphasis towards the future science which this pulsar will make possible

RAPIDIRON Trial Follow-Up Study - the RAPIDIRON-KIDS Study: Protocol of a Prospective Observational Follow-Up Study

BACKGROUND: Anemia is a worldwide problem with iron deficiency being the most common cause. When anemia occurs in pregnancy, it increases the risk of adverse maternal, fetal, and postnatal outcomes. It induces preterm births and low birth weight (LBW) deliveries, long-term neurodevelopmental sequelae, and an increased risk of earlier onset of postnatal iron deficiency. Anemia rates are among the highest in South Asia, and India\u27s National Family Health Survey (NFHS-5) for 2019-2021 indicated that over half of pregnant women, and more than 65% of children, in the country are classified as anemic (Sciences IIfP, National Family Health Survey-5, 2019-21, India Fact Sheet). In 2021, the parent RAPIDIRON Trial (Derman et al., Trials 22:649, 2021) was initiated in two states in India, with the goal of assessing whether a dose of intravenous (IV) iron given to anemic women during early pregnancy results in a greater proportion of participants with normal hemoglobin concentrations in the third trimester and a lower proportion of participants with LBW deliveries compared to oral iron. As a follow-up to the RAPIDIRON Trial, the RAPIDIRON-KIDS Study will follow the offspring of previously randomized mothers to assess, neurobehavioral, hematological, and health outcomes. METHODS: This prospective observational cohort study will follow a subset of participants previously randomized as part of the RAPIDIRON Trial and their newborns. Study visits occur at birth, 6 weeks, 4 months, 12 months, 24 months, and 36 months and include blood sample collection with both maternal and infant participants and specific neurobehavioral assessments conducted with the infants (depending on the study visit). The primary outcomes of interest are (1) infant iron status as indicated by both hemoglobin and ferritin (a) at birth and (b) at 4 months of age and (2) the developmental quotient (DQ) for the cognitive domain of the Bayley Scales of Infant Development Version IV (BSID-IV) at 24 months of age. DISCUSSION: This RAPIDIRON-KIDS Study builds upon its parent RAPIDIRON Trial by following a subset of the previously randomized participants and their offspring through the first 3 years of life to assess neurodevelopmental and neurobehavioral (infants, children), hematological, and health outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT05504863 , Registered on 17 August 2022. Clinical Trials Registry - India CTRI/2022/05/042933 . Registered on 31 May 2022

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Current results and future prospects from PSR J1757-1854, a highly-relativistic double neutron star binary.

Pulsars, rapidly-rotating highly-magnetised neutron stars, can serve as useful laboratories for probing aspects of fundamental physics. Binary pulsars, especially those in tight binary systems with massive, compact companions, are useful in testing different theories of gravity, the current paradigm being General Relativity (GR). Additionally, binary pulsars can also be utilised to explore other areas of fundamental physics, such as the behaviour of matter at ultra-high densities and the neutron star moment of inertia. A standout example is PSR J1757-1854, a 21.5-ms pulsar in a highly-eccentric (e=0.61), 4.4-hr orbit around a neutron star companion. This pulsar exhibits some of the most extreme relativistic parameters ever observed in a binary pulsar, reaching a maximum line-of-sight acceleration of close to 700 m/s/s and displaying among the strongest relativistic effects due to gravitational wave damping. To date, five post-Keplerian parameters have been measured in PSR J1757-1854, allowing for three independent tests of gravity to be conducted (of which GR passes all three) and for the component neutron star masses to be separated. The extreme properties of this system (particularly its high eccentricity) are expected to allow for future measurements of Lense-Thirring precession effects (allow for a measurement of the neutron star moment of inertia) and the relativistic deformation of the orbit, both of which remain almost completely unexplored by other binary systems. Although first discovered by the Parkes Radio Telescope in 2016 as part of the High Time Resolution Universe Southern Galactic Plane survey, it is ongoing observations with the Green Bank Telescope (GBT) which have provided the backbone of PSR J1757-1854’s continuing study. The large-bandwidth, high-precision observations afforded by the GBT played a fundamental role in delivering the science derived from the pulsar so far, and will be critical in allowing it to reach its full scientific potential going forward. In this talk I will provide a progress report on the ongoing timing of the system, including a review of the latest mass measurements and gravity tests, with an emphasis towards the future science which this pulsar will make possible. ..