A pulsar in a binary with a compact object in the mass gap between neutron stars and black holes.

Some compact objects observed in gravitational wave events have masses in the gap between known neutron stars (NSs) and black holes (BHs). The nature of these mass gap objects is unknown, as is the formation of their host binary systems. We report pulsar timing observations made with the Karoo Array Telescope (MeerKAT) of PSR J0514-4002E, an eccentric binary millisecond pulsar in the globular cluster NGC 1851. We found a total binary mass of 3.887 ± 0.004 solar masses (M⊙), and multiwavelength observations show that the pulsar's binary companion is also a compact object. The companion's mass (2.09 to 2.71 M⊙, 95% confidence interval) is in the mass gap, indicating either a very massive NS or a low-mass BH. We propose that the companion formed in a merger between two earlier NSs.

A highly magnetized environment in a pulsar binary system.

Spider pulsars are millisecond pulsars in short-period (≲12-h) orbits with low-mass (~0.01-0.4 M⊙) companion stars. The pulsars ablate plasma from the companion star, causing time delays and eclipses of the radio emission from the pulsar. The magnetic field of the companion has been proposed to strongly influence both the evolution of the binary system1 and the eclipse properties of the pulsar emission2. Changes in the rotation measure (RM) have been seen in a spider system, implying that there is an increase in the magnetic field near the eclipse3. Here we report a diverse range of evidence for a highly magnetized environment in the spider system PSR B1744 - 24A4, located in the globular cluster Terzan 5. We observe semi-regular profile changes to the circular polarization, V, when the pulsar emission passes close to the companion. This suggests that there is Faraday conversion where the radio wave tracks a reversal in the parallel magnetic field and constrains the companion magnetic field, B (> 10 G). We also see irregular, fast changes in the RM at random orbital phases, implying that the magnetic strength of the stellar wind, B, is greater than 10 mG. There are similarities between the unusual polarization behaviour of PSR B1744 - 24A and some repeating fast radio bursts (FRBs)5-7. Together with the possible binary-produced long-term periodicity of two active repeating FRBs8,9, and the discovery of a nearby FRB in a globular cluster10, where pulsar binaries are common, these similarities suggest that a proportion of FRBs have binary companions.

Sub-second periodicity in a fast radio burst.

Fast radio bursts (FRBs) are millisecond-duration flashes of radio waves that are visible at distances of billions of light years1. The nature of their progenitors and their emission mechanism remain open astrophysical questions2. Here we report the detection of the multicomponent FRB 20191221A and the identification of a periodic separation of 216.8(1) ms between its components, with a significance of 6.5σ. The long (roughly 3 s) duration and nine or more components forming the pulse profile make this source an outlier in the FRB population. Such short periodicity provides strong evidence for a neutron-star origin of the event. Moreover, our detection favours emission arising from the neutron-star magnetosphere3,4, as opposed to emission regions located further away from the star, as predicted by some models5.

Neuroethics Inside and Out: A Comparative Survey of Neural Device Industry Representatives and the General Public on Ethical Issues and Principles in Neurotechnology.

Neurotechnologies are rapidly being developed with the aim of alleviating suffering caused by disease and assisting individuals with various disabilities. As the capabilities and applications of neural devices advance, potential ethical challenges related to agency, identity, privacy, equality, normality and justice have been noted. We sought to explore attitudes toward these ethical challenges in two important, but understudied groups of stakeholders-members of the neural device industry and members of the general public. Survey responses from 66 industry professionals and 1088 members of the general public who do not work with neural devices were collected. After controlling for demographic differences between the groups (industry vs. general public; age, gender, racial/ethnic background), we found a large degree of consistency between the groups in their attitudes toward the ethical topic areas and the need for guiding ethical principles, but also some differences related to privacy, consent, and confidence in the neural device industry to incorporate ethical concerns into the design process. These data have implications for industry professionals tasked with designing and disseminating new neural devices, end-users of their products, and stakeholders at each step in between who must navigate the rapidly-growing landscape of advances in neurotechnology.

Searching for Gravitational Waves from Cosmological Phase Transitions with the NANOGrav 12.5-Year Dataset.

We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.

Universality of free fall from the orbital motion of a pulsar in a stellar triple system.

Einstein's theory of gravity-the general theory of relativity1-is based on the universality of free fall, which specifies that all objects accelerate identically in an external gravitational field. In contrast to almost all alternative theories of gravity2, the strong equivalence principle of general relativity requires universality of free fall to apply even to bodies with strong self-gravity. Direct tests of this principle using Solar System bodies3,4 are limited by the weak self-gravity of the bodies, and tests using pulsar-white-dwarf binaries5,6 have been limited by the weak gravitational pull of the Milky Way. PSR J0337+1715 is a hierarchical system of three stars (a stellar triple system) in which a binary consisting of a millisecond radio pulsar and a white dwarf in a 1.6-day orbit is itself in a 327-day orbit with another white dwarf. This system permits a test that compares how the gravitational pull of the outer white dwarf affects the pulsar, which has strong self-gravity, and the inner white dwarf. Here we report that the accelerations of the pulsar and its nearby white-dwarf companion differ fractionally by no more than 2.6 × 10-6. For a rough comparison, our limit on the strong-field Nordtvedt parameter, which measures violation of the universality of free fall, is a factor of ten smaller than that obtained from (weak-field) Solar System tests3,4 and a factor of almost a thousand smaller than that obtained from other strong-field tests5,6.

A massive pulsar in a compact relativistic binary.

Many physically motivated extensions to general relativity (GR) predict substantial deviations in the properties of spacetime surrounding massive neutron stars. We report the measurement of a 2.01 ± 0.04 solar mass (M⊙) pulsar in a 2.46-hour orbit with a 0.172 ± 0.003 M⊙ white dwarf. The high pulsar mass and the compact orbit make this system a sensitive laboratory of a previously untested strong-field gravity regime. Thus far, the observed orbital decay agrees with GR, supporting its validity even for the extreme conditions present in the system. The resulting constraints on deviations support the use of GR-based templates for ground-based gravitational wave detectors. Additionally, the system strengthens recent constraints on the properties of dense matter and provides insight to binary stellar astrophysics and pulsar recycling.

Pelvic floor consequences of cesarean delivery on maternal request in women with a single birth: a cost-effectiveness analysis.

BACKGROUND: The potential benefit in preventing pelvic floor disorders (PFDs) is a frequently cited reason for requesting or performing cesarean delivery on maternal request (CDMR). However, for primigravid women without medical/obstetric indications, the lifetime cost-effectiveness of CDMR remains unknown, particularly with regard to lifelong pelvic floor consequences. Our objective was to assess the cost-effectiveness of CDMR in comparison to trial of labor (TOL) for primigravid women without medical/obstetric indications with a single childbirth over their lifetime, while explicitly accounting for the management of PFD throughout the lifetime. METHODS: We used Monte Carlo simulation of a decision model containing 249 chance events and 101 parameters depicting lifelong maternal and neonatal outcomes in the following domains: actual mode of delivery, emergency hysterectomy, transient maternal morbidity and mortality, perinatal morbidity and mortality, and the lifelong management of PFDs. Parameter estimates were obtained from published literature. The analysis was conducted from a societal perspective. All costs and quality-adjusted life-years (QALYs) were discounted to the present value at childbirth. RESULTS: The estimated mean cost and QALYs were $14,259 (95% confidence interval [CI] $8,964-$24,002) and 58.21 (95% CI 57.43-58.67) for CDMR and $13,283 (95% CI $7,861-$23,829) and 57.87 (95% CI 56.97-58.46) for TOL over the combined lifetime of the mother and the child. Parameters related to PFDs play an important role in determining cost and quality of life. CONCLUSIONS: When a woman without medical/obstetric indications has only one childbirth in her lifetime, cost-effectiveness analysis does not reveal a clearly preferable mode of delivery.

Cost of racial disparity in preterm birth: evidence from Michigan.

This study examined the economic costs associated with racial disparity in preterm birth and preterm fetal death in Michigan. Linked 2003 Michigan vital statistics and hospital discharge data were used for data analysis. Thirteen percent of the singleton births among non-Hispanic Blacks were before 37 completed weeks of gestation, compared with only 7.7% among non-Hispanic Whites (risk ratio = 1.66, 95% confidence interval: 1.59-1.72; p<.0001). One thousand one hundred and eighty four (1,184) non-Hispanic Black, singleton preterm births and preterm fetal deaths would have been avoided in 2003 had their preterm birth rate been the same as Michigan non-Hispanic Whites. Economic costs associated with these excess Black preterm births and preterm fetal deaths amounted to $329 million (range: $148 million-$598 million) across their lifespan over and above the costs if they were born at term, including costs associated with the initial hospitalization, productivity loss due to perinatal death, and major developmental disabilities. Hence, racial disparity in preterm birth and preterm fetal death has substantial cost implications for society. Improving pregnancy outcomes for African American women and reducing the disparity between Blacks and Whites should continue to be a focus of future research and interventions.

A radio pulsar/x-ray binary link.

Radio pulsars with millisecond spin periods are thought to have been spun up by the transfer of matter and angular momentum from a low-mass companion star during an x-ray-emitting phase. The spin periods of the neutron stars in several such low-mass x-ray binary (LMXB) systems have been shown to be in the millisecond regime, but no radio pulsations have been detected. Here we report on detection and follow-up observations of a nearby radio millisecond pulsar (MSP) in a circular binary orbit with an optically identified companion star. Optical observations indicate that an accretion disk was present in this system within the past decade. Our optical data show no evidence that one exists today, suggesting that the radio MSP has turned on after a recent LMXB phase.

Malpractice burden, rural location, and discontinuation of obstetric care: a study of obstetric providers in Michigan.

CONTEXT: It has long been a concern that professional liability problems disproportionately affect the delivery of obstetrical services to women living in rural areas. Michigan, a state with a large number of rural communities, is considered to be at risk for a medical liability crisis. PURPOSE: This study examined whether higher malpractice burden on obstetric providers was associated with an increased likelihood of discontinuing obstetric care and whether there were rural-urban differences in the relationship. METHODS: Data on 500 obstetrician-gynecologists and family physicians who had provided obstetric care at some point in their career (either currently or previously) were obtained from a statewide survey in Michigan. Statistical tests and multivariate regression analyses were performed to examine the interrelationship among malpractice burden, rural location, and discontinuation of obstetric care. FINDINGS: After adjusting for other factors that might influence a physician's decision about whether to stop obstetric care, our results showed no significant impact of malpractice burden on physicians' likelihood to discontinue obstetric care. Rural-urban location of the practice did not modify the nature of this relationship. However, family physicians in rural Michigan had a nearly 4-fold higher likelihood of withdrawing obstetric care when compared with urban family physicians. CONCLUSIONS: The higher likelihood of rural family physicians to discontinue obstetric care should be carefully weighed in future interventions to preserve obstetric care supply. More research is needed to better understand the practice environment of rural family physicians and the reasons for their withdrawal from obstetric care.

The impact of malpractice burden on Michigan obstetrician-gynecologists' career satisfaction.

BACKGROUND: Medical services for pregnancy and childbirth are inherently risky and unpredictable. In many states, obstetrician-gynecologists (OB-GYNS) who attend the majority of childbirths in the United States and provide the most clinically complex obstetric procedures are struggling with increasing malpractice insurance premiums and litigation risk. Despite its significant implications for patient care, the potential impact of malpractice burden on OB-GYN physicians' career satisfaction has not been rigorously tested in previous research. METHODS: Drawing on data from a statewide survey of obstetric providers in Michigan, this paper examined the association between medical liability burden and OB-GYNs' career satisfaction. Malpractice insurance premiums and malpractice claims experience were used as 2 objective measures for medical liability burden. Descriptive statistics were calculated and multivariable logistic regressions estimated for data analysis. RESULTS: Although most respondents reported satisfaction with their overall career in medicine, 43.7% had become less satisfied over the last 5 years and 34.0% would not recommend obstetrics/gynecology to students seeking career advice. Multivariable regression analysis showed that compared to coverage through an employer, paying > or =$50,000/year for liability insurance premium was associated with lower career satisfaction among OB-GYNs (odds ratio, 0.35; 95% confidence interval, 0.13-0.93). We found no significant impact of malpractice claims experience, including both recent malpractice claims (during the last 5 years [2001--2006]) and earlier malpractice claims (>5 years ago), on overall career satisfaction. CONCLUSIONS: The findings of this study suggest that high malpractice premiums negatively affect OB-GYN physicians' career satisfaction. The impact of the current medical liability climate on quality of care for pregnant women warrants further investigation.

Relativistic spin precession in the double pulsar.

The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly relativistic orbit that displays a roughly 30-second eclipse when pulsar A passes behind pulsar B. Describing this eclipse of pulsar A as due to absorption occurring in the magnetosphere of pulsar B, we successfully used a simple geometric model to characterize the observed changing eclipse morphology and to measure the relativistic precession of pulsar B's spin axis around the total orbital angular momentum. This provides a test of general relativity and alternative theories of gravity in the strong-field regime. Our measured relativistic spin precession rate of 4.77 degrees (-0 degrees .65)(+0 degrees .66) per year (68% confidence level) is consistent with that predicted by general relativity within an uncertainty of 13%.

An eccentric binary millisecond pulsar in the galactic plane.

Binary pulsar systems are superb probes of stellar and binary evolution and the physics of extreme environments. In a survey with the Arecibo telescope, we have found PSR J1903+0327, a radio pulsar with a rotational period of 2.15 milliseconds in a highly eccentric (e = 0.44) 95-day orbit around a solar mass (M(middle dot in circle)) companion. Infrared observations identify a possible main-sequence companion star. Conventional binary stellar evolution models predict neither large orbital eccentricities nor main-sequence companions around millisecond pulsars. Alternative formation scenarios involve recycling a neutron star in a globular cluster, then ejecting it into the Galactic disk, or membership in a hierarchical triple system. A relativistic analysis of timing observations of the pulsar finds its mass to be 1.74 +/- 0.04 M solar symbol, an unusually high value.

Malpractice liability burden in midwifery: a survey of Michigan certified nurse-midwives.

A statewide survey was conducted among 282 nurse-midwives in Michigan to examine the extent of their current medical liability burden. Two hundred ten responses were received for an adjusted response rate of 76.9%. Data from 145 certified nurse-midwives (CNMs) who were currently engaged in clinical practice in Michigan were used for this analysis. Sixty-nine percent of CNMs reported that liability concerns had a negative impact on their clinical decision making. Most CNMs (88.1%) acquired malpractice insurance coverage through an employer, whereas 4.9% were practicing "bare" due to difficulty in obtaining coverage. Thirty-five percent of the respondents had been named in a malpractice claim at least once in their career, and 15.5% had at least one malpractice payment of $30,000 or more made on their behalf. CNMs who purchased malpractice insurance coverage themselves or were going bare were significantly less likely to include obstetrics in their practice than their counterparts covered through an employer (70.6% versus 87.2%; P = .04). These findings among Michigan CNMs call for further investigation into the consequences of the current malpractice situation surrounding nurse-midwifery practice and its influence on obstetric care, particularly among women from disadvantaged populations.

The effects of medical liability on obstetric care supply in Michigan.

OBJECTIVE: The objective of the study was to examine Michigan obstetric providers' provision of obstetric care and the impact of malpractice concerns on their practice decisions. STUDY DESIGN: Data were obtained from 899 Michigan obstetrician-gynecologists, family physicians, and nurse-midwives via a statewide survey. Statistical tests were conducted to examine differences in obstetric care provision and the influence of various factors across specialties. RESULTS: Among providers currently practicing obstetrics, 18.3%, 18.7%, and 11.9% of obstetrician-gynecologists, family physicians, and nurse-midwives, respectively, planned to discontinue delivering babies in the next 5 years, and 35.5%, 24.5%, and 12.6%, respectively, planned to reduce their provision of high-risk obstetric care. "Risk of malpractice litigation" was 1 of the most cited factors affecting providers' decision to include obstetrics in their practice. CONCLUSION: Litigation risk appears to be an important factor influencing Michigan obstetric providers' decisions about provision of care. Its implications for obstetric care supply and patients' access to care warrants further research.

Robot-assisted laparoscopic myomectomy versus abdominal myomectomy: a comparison of short-term surgical outcomes and immediate costs.

STUDY OBJECTIVE: To compare surgical outcomes of myomectomy by robot-assisted laparoscopy with those performed by traditional laparotomy and to analyze the financial impact of these 2 approaches. DESIGN: Retrospective case-matched analysis (Canadian Task Force classification III). SETTING: University teaching hospital. PATIENTS: A total of 58 patients with symptomatic leiomyomata. INTERVENTION: Myomectomy by robot-assisted laparoscopy or traditional laparotomy was administered. MEASUREMENTS AND MAIN RESULTS: An equal number of case-matched patients based on age, body mass index, and myoma weight were analyzed in each group. Among these 3 variables, there were no statistically significant differences between the robotic and laparotomy groups. Mean age was 36.59 +/- 4.93 years (95% CI 34.71-38.46 years) versus 34.86 +/- 4.41 years (95% CI 33.18-36.54 years), mean body mass index was 25.22 +/- 3.85 kg/m(2) (90% central range [CR] 20.30-31.20 kg/m2) versus 28.3 +/- 6.95 kg/m2 (90% CR 21.50-42.80 kg/m2), and mean myoma weight was 227.86 +/- 247.54 g (90% CR 11.60-680.00 g) versus 223.76 +/- 228.28 g (90% CR 11.50-660.00 g), respectively. Patients with robot-assisted laparoscopic myomectomy had decreased estimated blood loss (mean 195.69 +/- 228.55 mL [90% CR 50.00-700.00 mL] vs mean 364.66 +/- 473.28 mL [90% CR 75.00-1550.00 mL]) and length of stay (mean 1.48 +/- 0.95 days [90% CR 1.00-3.00 days] vs mean 3.62 +/- 1.50 days [90% CR 3.00-8.00 days]) when compared with the laparotomy group. Both of these differences were statistically significant at p <.05. Operative times were significantly longer in the robotic group: mean 231.38 +/- 85.10 minutes (95% CI 199.01-263.75 minutes) versus mean 154.41 +/- 43.14 minutes (95% CI 138.00-170.82 minutes, p <.05) in the laparotomy group. Complication rates were higher in the laparotomy group. Professional charges (mean $5946.48 +/- $1447.17 [90% CR $4034.46-$8937.00] vs mean $4664.48 +/- $642.11 [90% CR $3944.36-$6010.90, p <.0002]) and hospital charges (mean $30084.20 +/- $6689.29 [90% CR $22939.81-$45588.22] vs mean $13400.62 +/- $7747.26 [90% CR $8703.20-$26771.22, p <.0001]) were statistically higher for the robotic group. Although professional reimbursement was not significantly different between groups (mean $2263.02 +/- $1354.97 [90% CR $0.00- $4831.08] versus mean $1841.99 +/- $827.51 [90% CR $0.00-$3376.97, p = .2831]), mean hospital reimbursement rates for the robotic group were significantly higher: $13181.39 +/- $10752.00 (90% CR $1081.76-$37396.03) versus $7015.24 +/- $3467.97 (90% CR $2492.48-$10394.83, p = .0372). CONCLUSION: As a new technology, it is not unexpected that a robotic approach to myomectomy costs more than a traditional laparotomy. On the other hand, decreased estimated blood loss, complication rates, and length of stay with the robotic approach in the end may prove to have a significant societal benefit that will outweigh upfront financial impact.

Emergency contraception provision: a survey of Michigan physicians from five medical specialties.

OBJECTIVE: Despite the controversy over expanding delivery options for emergency contraceptive pills (ECP), little is known about physicians' attitudes toward over-the-counter (OTC) provision of ECP, and prior research on physicians' practices often has focused on a single specialty. This study examined the attitudes and practices regarding advance provision and OTC status of ECP among physicians in five medical specialties likely to encounter patients in need of ECP. METHODS: A mail survey of a random sample of 850 Michigan physicians in family/general medicine, internal medicine, obstetrics/gynecology, pediatrics, and emergency medicine was conducted. Respondents' ECP-related attitudes and practices were assessed, and differences by physician characteristics were examined using chi-square tests and multivariable logistic regression analyses. RESULTS: Two hundred seventy-one physicians responded to the survey (response rate = 32%), with 42% of them favoring OTC provision of ECP and 40% opposing it. Half of respondents never routinely initiated discussions about ECP with their sexually active, female patients, and 77% of respondents did not routinely offer advance prescriptions. After adjusting for other factors, including medical specialty, older physicians ( > or =50 years) were significantly more likely than their younger counterparts to support OTC provision of ECP (OR = 2.9, 95% CI 1.7-4.9) or offer advance prescriptions (OR = 2.5, 95% CI 1.1-5.8). Physicians with a specialty in obstetrics/gynecology were 3.5 times (95% CI 1.3-9.8) as likely as physicians in family/general medicine to offer advance prescriptions for ECP, and female physicians were 2.5 (95% CI 1.05-6.0) times as likely as male physicians to offer advance prescriptions. Graduation from a medical school within the United States and practicing in a private practice were marginally associated with a lower likelihood of supporting OTC status of ECP (OR = 0.5, 95% CI: 0.2-1.0; and OR equals; 0.6, 95% CI 0.3-1.1, respectively). CONCLUSIONS: Certain physician characteristics were significantly associated with their ECP-related attitudes and practices. The majority of physicians surveyed in this study did not offer advance prescriptions for ECP, and few had initiated discussions on ECP with patients, which may pose critical barriers to patients' timely access.

Transient pulsed radio emission from a magnetar.

Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >10(14) G, according to the 'magnetar' model. The radio pulsations that have been observed from more than 1,700 neutron stars with weaker magnetic fields have never been detected from any of the dozen known magnetars. The X-ray pulsar XTE J1810-197 was revealed (in 2003) as the first AXP with transient emission when its luminosity increased 100-fold from the quiescent level; a coincident radio source of unknown origin was detected one year later. Here we show that XTE J1810-197 emits bright, narrow, highly linearly polarized radio pulses, observed at every rotation, thereby establishing that magnetars can be radio pulsars. There is no evidence of radio emission before the 2003 X-ray outburst (unlike ordinary pulsars, which emit radio pulses all the time), and the flux varies from day to day. The flux at all radio frequencies is approximately equal--and at >20 GHz XTE J1810-197 is currently the brightest neutron star known. These observations link magnetars to ordinary radio pulsars, rule out alternative accretion models for AXPs, and provide a new window into the coronae of magnetars.

Insurance coverage and health care use among near-elderly women.

OBJECTIVES: Data on near-elderly (ages 55-64) women's access to and use of health care have been limited. In this study, we sought to examine the status of near-elderly women's health insurance coverage in the United States and how it may influence their use of health care services. METHODS: A nationwide random sample of women aged 55-64 was drawn from the 2002 wave of the Health and Retirement Study. Descriptive statistics were calculated and multivariable regression analyses were performed to quantify the impact of insurance coverage on near-elderly women's use of outpatient services, inpatient services, and prescription medication over a 2-year period. RESULTS: In 2002, 9.4% of near-elderly women in the United States were uninsured and 15.4% had public coverage. Those who had coverage for a particular service were significantly more likely to use that service compared to women without coverage, with odds ratios ranging from 2.0-6.7 for services such as a physician visit, hospital stay, dental visit, and use of prescription medication. Among those who had at least one physician visit, near-elderly women who had some of the cost covered by insurance reported significantly more visits than women without coverage. Likewise, for near-elderly women regularly taking prescription medications, having more extensive coverage significantly increased their likelihood of medication adherence. The frequency of hospitalization was also higher for women who had complete coverage for the cost. CONCLUSIONS: The nature of a near-elderly woman's insurance coverage significantly affects her use of health care services. More attention is needed to improve the health care of near-elderly women with inadequate insurance coverage.