"One of the half dozen most important books ever written about the American Revolution."--New York Times Book Review"During the nearly two decades since its publication, this book has set the pace, ...furnished benchmarks, and afforded targets for many subsequent studies. If ever a work of history merited the appellation 'modern classic,' this is surely one."--William and Mary Quarterly"A brilliant and sweeping interpretation of political culture in the Revolutionary generation."--New England Quarterly"This is an admirable, thoughtful, and penetrating study of one of the most important chapters in American history."--Wesley Frank Craven
We present the first fully self-consistent three dimensional model of a neutron star's magnetic field, generated by electric currents in the star's crust via the Hall effect. We find that the ...global-scale field converges to a dipolar Hall-attractor state, as seen in recent axisymmetric models, but that small-scale features in the magnetic field survive even on much longer time scales. These small-scale features propagate toward the dipole equator, where the crustal electric currents organize themselves into a strong equatorial jet. By calculating the distribution of magnetic stresses in the crust, we predict that neutron stars with fields stronger than 10^{14} G can still be subject to starquakes more than 10^{5} yr after their formation.
Mobile health, or 'mHealth', is the application of mobile devices, their components and related technologies to healthcare. It is already improving patients' access to treatment and advice. Now, in ...combination with internet-connected diagnostic devices, it offers novel ways to diagnose, track and control infectious diseases and to improve the efficiency of the health system. Here we examine the promise of these technologies and discuss the challenges in realizing their potential to increase patients' access to testing, aid in their treatment and improve the capability of public health authorities to monitor outbreaks, implement response strategies and assess the impact of interventions across the world.
Repeated exposure to social stress can precipitate the development of psychosocial disorders including depression and comorbid cardiovascular disease. While a major component of social stress often ...encompasses physical interactions, purely psychological stressors (i.e. witnessing a traumatic event) also fall under the scope of social stress. The current study determined whether the acute stress response and susceptibility to stress-related consequences differed based on whether the stressor consisted of physical versus purely psychological social stress. Using a modified resident-intruder paradigm, male rats were either directly exposed to repeated social defeat stress (intruder) or witnessed a male rat being defeated. Cardiovascular parameters, behavioral anhedonia, and inflammatory cytokines in plasma and the stress-sensitive locus coeruleus were compared between intruder, witness, and control rats. Surprisingly intruders and witnesses exhibited nearly identical increases in mean arterial pressure and heart rate during acute and repeated stress exposures, yet only intruders exhibited stress-induced arrhythmias. Furthermore, re-exposure to the stress environment in the absence of the resident produced robust pressor and tachycardic responses in both stress conditions indicating the robust and enduring nature of social stress. In contrast, the long-term consequences of these stressors were distinct. Intruders were characterized by enhanced inflammatory sensitivity in plasma, while witnesses were characterized by the emergence of depressive-like anhedonia, transient increases in systolic blood pressure and plasma levels of tissue inhibitor of metalloproteinase. The current study highlights that while the acute cardiovascular responses to stress were identical between intruders and witnesses, these stressors produced distinct differences in the enduring consequences to stress, suggesting that witness stress may be more likely to produce long-term cardiovascular dysfunction and comorbid behavioral anhedonia while exposure to physical stressors may bias the system towards sensitivity to inflammatory disorders.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star’s outer crust is ...orders of magnitude larger than the dipole component inferred from spin-down measurements. This presents a serious challenge to theories of magnetic field generation in a proto-neutron star. Here, we present detailed modeling of the evolution of the magnetic field in the crust of a neutron star through 3D simulations. We find that, in the plausible scenario of equipartition of energy between global-scale poloidal and toroidal magnetic components, magnetic instabilities transfer energy to nonaxisymmetric, kilometer-sized magnetic features, in which the local field strength can greatly exceed that of the global-scale field. These intense small-scale magnetic features can induce high-energy bursts through local crust yielding, and the localized enhancement of Ohmic heating can power the star’s persistent emission. Thus, the observed diversity in magnetar behavior can be explained with mixed poloidal–toroidal fields of comparable energies.
Objective
It is likely that cognitive deficits are vulnerability markers for developing schizophrenia, as these deficits are already well‐established findings in first‐episode psychosis. Studies ...at‐risk adolescents and young adults are likely to provide information about cognitive deficits that predate the onset of the illness.
Method
We conducted meta‐analyses of studies comparing familial‐high risk (FHR) or ultra‐high risk (UHR; n = 2113) and healthy controls (n = 1748) in youth studies in which the mean age was between 15 and 29.
Results
Compared with controls, high risk subjects were impaired in each domain in both UHR (d = 0.34–0.71) and FHR (d = 0.24–0.81). Heterogeneity of effect sizes across studies was modest, increasing confidence to the findings of the current meta‐analysis (I2 = 0–0.18%). In both risk paradigms, co‐occurrence of genetic risk with attenuated symptoms was associated with more severe cognitive dysfunction. In UHR, later transition to psychosis was associated with more severe cognitive deficits in all domains (d = 0.31–0.49) except sustained attention. However, cognitive impairment has a limited capacity to predict the outcome of high‐risk patients.
Conclusion
Cognitive deficits are already evident in adolescents and young adults who have familial or clinical risk for psychosis. Longitudinal developmental studies are important to reveal timing and trajectory of emergence of such deficits.
Neutron stars are not only of astrophysical interest, but are also of great interest to nuclear physicists because their attributes can be used to determine the properties of the dense matter in ...their cores. One of the most informative approaches for determining the equation of state (EoS) of this dense matter is to measure both a star's equatorial circumferential radius Re and its gravitational mass M. Here we report estimates of the mass and radius of the isolated 205.53 Hz millisecond pulsar PSR J0030+0451 obtained using a Bayesian inference approach to analyze its energy-dependent thermal X-ray waveform, which was observed using the Neutron Star Interior Composition Explorer (NICER). This approach is thought to be less subject to systematic errors than other approaches for estimating neutron star radii. We explored a variety of emission patterns on the stellar surface. Our best-fit model has three oval, uniform-temperature emitting spots and provides an excellent description of the pulse waveform observed using NICER. The radius and mass estimates given by this model are km and (68%). The independent analysis reported in the companion paper by Riley et al. explores different emitting spot models, but finds spot shapes and locations and estimates of Re and M that are consistent with those found in this work. We show that our measurements of Re and M for PSR J0030+0451 improve the astrophysical constraints on the EoS of cold, catalyzed matter above nuclear saturation density.
Background
Recent literature on the effect of induction of labour (compared with expectant management) has provided conflicting results. Reviews of observational studies generally report an increase ...in the rate of caesarean section, whereas reviews of post‐dates and term prelabour rupture of membrane (PROM trials suggest either no difference or a reduction in risk.
Objective
To evaluate with a systematic review and meta‐analysis of randomised controlled trials (RCTs) whether or not the induction of labour increases the risk of caesarean section in women with intact membranes.
Search strategy
Literature search using electronic databases: MEDLINE, EMBASE, and the Cochrane Database of Clinical Trials.
Selection criteria
RCTs comparing a policy of induction of labour with expectant management in women with intact membranes.
Data collection and analysis
A total of 37 trials were identified and reviewed. Quantitative analyses with fixed‐ and random‐effects models were performed with revman 5.1.
Main results
Of the 37 RCTs, 27 were trials of uncomplicated pregnancies at 37–42 weeks of gestation. The remaining ten evaluated induction versus expectant management in pregnancies with suspected macrosomia (two), diabetes in pregnancy (one), oligohydramnios (one), twins (two), intrauterine growth restriction (IUGR) (two), mild pregnancy‐induced hypertension (PIH) (one), and women with a high‐risk score for caesarean section (one). Meta‐analysis of 31 trials determined that a policy of induction was associated with a reduction in the risk of caesarean section compared with expectant management (OR 0.83, 95% CI 0.76–0.92).
Author's Conclusions
Induction of labour in women with intact membranes reduces the risk of caesarean section. Review of the trials suggests that this effect may arise from non‐treatment effects, and that additional trials are needed.
Neutron stars harbor extremely strong magnetic fields within their solid outer crust. The topology of this field strongly influences the surface temperature distribution and, hence, the star's ...observational properties. In this work, we present the first realistic simulations of the coupled crustal magnetothermal evolution of isolated neutron stars in three dimensions accounting for neutrino emission, obtained with the pseudo-spectral code parody. We investigate both the secular evolution, especially in connection with the onset of instabilities during the Hall phase, and the short-term evolution following episodes of localized energy injection. Simulations show that a resistive tearing instability develops in about a Hall time if the initial toroidal field exceeds G. This leads to crustal failures because of the huge magnetic stresses coupled with the local temperature enhancement produced by dissipation. Localized heat deposition in the crust results in the appearance of hot spots on the star surface, which can exhibit a variety of patterns. Because the transport properties are strongly influenced by the magnetic field, the hot regions tend to drift away and get deformed following the magnetic field lines while cooling. The shapes obtained with our simulations are reminiscent of those recently derived from NICER X-ray observations of the millisecond pulsar PSR J0030+0451.
Risk of recurrent stillbirth: a cohort study Wood, SL; Tang, S
BJOG : an international journal of obstetrics and gynaecology,
October 2021, Letnik:
128, Številka:
11
Journal Article
Recenzirano
Objectives
To evaluate the recurrence risk of stillbirth.
Design
Retrospective cohort study.
Setting and population
All births 1992–2017, Alberta, Canada.
Methods
Retrospective cohort study.
Main ...outcome measures
Stillbirth was defined as the death in utero of a fetus with gestational age ≥20 weeks or weighing ≥500 g. Stillbirths were further subdivided into those occurring before labour and those in labour.
Results
We identified 744 897 births from 308 478 women. Of these, 3698 women experienced a stillbirth and, of these, 97.7%, experienced only one. For women with a small‐for‐gestational‐ age stillbirth in the first birth, their risk of a subsequent antepartum stillbirth was increased substantially: 4.09%, relative risk (RR) 10.39, 95% CI 5.81–18.59. For women with a first birth appropriate‐for‐gestational‐age stillbirth with no risk factors such as pregnancy induced hypertension, the risk with pre‐existing diabetes mellitus or hypertension was also increased but to a much lesser degree (RR 2.46, 95% CI 1.23–4.91). For women who had experienced a first birth intrapartum stillbirth, the risk of another intrapartum stillbirth was very high (3.59%, RR 36.50, 95% CI 20.17–66.05). Most of these births also occurred prior to 24 weeks’ gestation: 83% (10/12).
Conclusions
The risk of recurrent antepartum stillbirth is low. The increase in risk in instances where the antepartum stillbirth was not growth‐restricted is not clinically meaningful. Given the very low risk in any given gestational week, fetal surveillance is unlikely to be effective and may lead to unnecessary interventions. Intrapartum stillbirth has a very high recurrence risk but may not be preventable.
Tweetable
Stillbirth recurrence is rare.
Tweetable
Stillbirth recurrence is rare.
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