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.

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.

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.

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.

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.

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.

The geometry of the double-pulsar system J0737-3039 from systematic intensity variations.

Two pulsars (PSR J0737-3039A and B) were recently discovered in highly relativistic orbits around one another. The system contains a rapidly rotating pulsar with a spin period of 22.7 ms and a slow companion with a spin period of 2.77 s, referred to here as 'A' and 'B', respectively. A unique property of the system is that the pulsed radio flux from B increases systematically by almost two orders of magnitude during two short portions of its orbit. Here we report a geometrical model of the system that simultaneously explains the intensity variations of B and provides constraints on the spin axis orientation and emission geometry of A. Our model assumes that B's pulsed radio flux increases when illuminated by emission from A. We predict that A's pulse profile will evolve considerably over the next several years owing to geodetic precession until it disappears entirely in 15-20 years.

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.

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.

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.

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.

Childbirth and pelvic floor dysfunction: an epidemiologic approach to the assessment of prevention opportunities at delivery.

Female pelvic floor dysfunction is integral to the woman's role in the reproductive process, largely because of the unique anatomic features that facilitate vaginal birth and also because of the trauma that can occur during that event. Interventions such as primary elective cesarean delivery have been discussed for the primary prevention of pelvic floor dysfunction; however, existing data about potentially causal factors limit our ability to evaluate such strategies critically. Here we consider the conceptual principles of epidemiologic function and the availability of data that are necessary to make informed recommendations about prevention opportunities for pelvic floor dysfunction at delivery. Available epidemiologic data on pelvic floor dysfunction suggest that there may be substantial opportunities for the primary prevention of pelvic organ prolapse at delivery. Although definitive recommendations await further epidemiologic studies of the potential risk and benefits of obstetric practice change, it is hoped that this discussion will provide a novel, quantitative framework for the assessment of pelvic floor dysfunction prevention opportunities.

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.

The impact of medical legal risk on obstetrician-gynecologist supply.

OBJECTIVE: To evaluate the effects of medical legal risk on practice location of obstetrician-gynecologists. METHODS: We used the American College of Obstetricians and Gynecologists (ACOG) Membership Record to determine the number of Fellows and Junior Fellows by state. We obtained state malpractice premiums from the Medical Liability Monitor and state birth rates from the National Center for Health Statistics. The American Medical Association (AMA) "Crisis" and ACOG "Red Alert" designations, as well as state malpractice premium levels, were used to approximate malpractice risk. We examined the changes in state births to obstetrician-gynecologist rates from 1995 to 2003 by using the Student t test and Mann-Whitney tests. Comparisons were made between states of different risk levels. RESULTS: We found no significant difference in the percentage changes in births per Fellow or births per Junior Fellow between AMA "Crisis" and remaining states, nor between ACOG "Red Alert" and Safe states. The percentage changes in births per Fellow were similar in the 10 highest-premium states and the 10 lowest-premium states. The percentage increase in births per Junior Fellow in the 10 highest-premium states was significantly greater than the 10 lowest-premium states (median 28.5% versus 5.0%, P = .03). CONCLUSION: Malpractice premiums appear to influence practice location of new obstetrician-gynecologists. Neither the AMA designation of "Crisis" nor the ACOG designation of "Red Alert" had supply implications in the analysis. More research on the interaction of malpractice rates and obstetrician-gynecologist supply is needed for informed decisions regarding malpractice premium management.

Reduced medicolegal risk by compliance with obstetric clinical pathways: a case--control study.

OBJECTIVE: To estimate whether guideline compliance affected medicolegal risk in obstetrics and whether malpractice claims data can provide useful information on guideline noncompliance by focusing on the claims experience of a large health system delivering approximately 12000 infants annually. METHODS: We retrospectively identified 290 delivery-related (diagnosis-related groups 370-374) malpractice claims and 262 control deliveries at the health system during the period from 1988 to 1998. Clinical pathways for vaginal and cesarean delivery implemented in 1998 were used as a "standard of care." We compared rates of noncompliance with the pathways in the claims and control groups, calculated an odds ratio for increased risk of being sued given departure from the guideline standards, and calculated the elevated risk of litigation introduced by noncompliance. We also compared the frequencies of different types of departures across claims and control groups. RESULTS: Claims closely resembled controls on several descriptive measures (mother's age, location of delivery, type of delivery, and complication rates), but noncompliance with the clinical pathway was significantly more common among claims than controls (43.2% versus 11.7%, P <.001; odds ratio = 5.76, 95% confidence interval 3.59, 9.2). In 81 (79.4%) of the claims involving noncompliance with the pathway, the main allegation in the claim related directly to the departure from the pathway. The excess malpractice risk attributable to noncompliance explained approximately one third (104 of 290) of the claims filed (attributable risk = 82.6%). There were no significant differences in the types of deviation from the guidelines across claims and control groups. CONCLUSION: In addition to reducing clinical variation and improving clinical quality of care, adherence to clinical pathways might protect clinicians and institutions against malpractice litigation. Malpractice data might also be a useful resource in understanding breakdowns in processes of care.

Evaluation of a Grief Group for Women in Residential Substance Abuse Treatment.

Most women in substance abuse treatment have experienced significant losses. This preliminary study examined the effectiveness of a therapy group addressing grief and loss among women enrolled in a gender-specific residential substance abuse treatment program. The intervention group consisted of 24 grief group participants and the comparison group consisted of 31 nonparticipants. Qualitative analysis revealed a pattern: participants identified traumatic loss, moved to emotional loss and abandonment by their own mothers, then focused on their own children. Data obtained at induction and at exit or follow-up were used for quantitative analysis. Length of stay, self-esteem, depression, mood, and parenting attitudes were assessed using standardized instruments. Women who participated in the grief group remained in treatment longer. While both groups were depressed and had low self-esteem at induction, the self-esteem of nonparticipants was significantly lower than that of participants. Both groups improved over time on mood, depression, and parenting. At exit or follow-up, participants had higher self-esteem. Based on these findings, we hypothesized that higher self-esteem at induction made it possible for women to participate in and benefit from the grief group, thus contributing to length of stay. To test this hypothesis we conducted regression analyses which found that, individually, group status (participation) and self-esteem explained 11% of the variance in length of stay. However, since the number of women with available data varied for group status and self-esteem, group status was a significant predictor of length of stay and self-esteem showed only a trend toward significance. These findings support our hypothesis. The women's pattern of disclosure and the hypotheses drawn from the results of this preliminary analysis will be examined further in an evaluation of a series of groups focused on loss and grief.

8 keys to the chief executive suite.

What makes a great CEO? Take a look at some of the critical skills you need to develop if you expect to land the top spot.

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.