Explore the vast range of titles available.

We present the successful recovery of common-envelope ejection efficiency assumed in a simulated population of double white dwarf (DWD) binaries like those which may be observed by the future Laser Interferometer Space Antenna (LISA) mission. We simulate the formation of DWD binaries by using the COSMIC population synthesis code to sample binary formation conditions such as initial mass function, metallicity of star formation, initial orbital period, and initial eccentricity. These binaries are placed in the m12i synthetic Milky Way–like galaxy, and their signal-to-noise ratio (SNR) for the LISA instrument is estimated, considering a Galactic gravitational-wave foreground informed by the population. Through the use of Fisher estimates, we construct a likelihood function for the measurement error of the LISA-bright DWD binaries (≥20 SNR, fGW ≥ 5 mHz), in their gravitational-wave frequency (fGW) and chirp mass. By repeating this process for different assumptions of the common-envelope ejection efficiency, we apply Bayesian hierarchical inference to find the best match to an injected astrophysical assumption for a fiducial population model. We conclude that the impact of common-envelope ejection efficiency on the mass-transfer processes involved in DWD formation may be statistically relevant in the future observed LISA population, and that constraints on binary formation may be found by comparing simulated populations to a future observed population.

We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ∼ 10−5 − 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of propagation of gravitational waves; the binding energy and gravitational-wave radiation of binaries, and therefore the time evolution of binary inspirals; the strength and shape of the waves emitted from binary mergers and ringdowns; the true nature of astrophysical black holes; and much more. The strength of this science alone calls for the swift implementation of a space-based detector; the remarkable richness of astrophysics, astronomy, and cosmology in the low-frequency gravitational-wave band make the case even stronger.

We identify 240 short-period (P ≲ 10 days) binary systems in Transiting Exoplanet Survey Satellite data, 180 of which are heartbeat binaries. The sample is mostly a mix of A- and B-type stars and primarily includes eclipsing systems, where over 30% of the sources with primary and secondary eclipses show a secular change in their intereclipse timings and relative eclipse depths over a multiyear timescale, likely due to orbital precession. The orbital parameters of the population are estimated by fitting a heartbeat model to their phase curves and Gaia magnitudes, where the model accounts for ellipsoidal variability, Doppler beaming, reflection effects, and eclipses. We construct the sample’s period–eccentricity distribution and find an eccentricity cutoff (where e → 0) at a period of 1.7 days. Additionally, we measure the periastron advance rate for 12 of the precessing sources and find that they all exhibit prograde apsidal precession, which is as high as 9° yr−1 for one of the systems. Using the inferred stellar parameters, we estimate the general relativistic precession rate of the argument of periastron for the population and expect over 30 systems to show a precession in excess of 0.3° yr−1.

Management of the athlete with postconcussion syndrome (PCS) is challenging because of the nonspecificity of PCS symptoms. Ongoing symptoms reflect prolonged concussion pathophysiology or conditions such as migraine headaches, depression or anxiety, chronic pain, cervical injury, visual dysfunction, vestibular dysfunction, or some combination of these. In this paper, we focus on the physiological signs of concussion to help narrow the differential diagnosis of PCS in athletes. The physiological effects of exercise on concussion are especially important for athletes. Some athletes with PCS have exercise intolerance that may result from altered control of cerebral blood flow. Systematic evaluation of exercise tolerance combined with a physical examination of the neurologic, visual, cervical, and vestibular systems can in many cases identify one or more treatable postconcussion disorders.

ObjectiveThe Concussion in Sport Group guidelines recommend a multifaceted approach to help clinicians make return to sport decisions. The purpose of this study was to identify the most common multifaceted measures used to define clinical recovery from sport-related concussion in young athletes (high school and/or college level) and to summarise existing knowledge of criteria used to make return to sport decisions.DesignSystematic review.Data sourcesThe PubMed (MEDLINE), SPORTDiscus and Embase electronic databases were searched from 1 January 2000 to 1 March 2017 by three independent reviewers.Eligibility criteriaInclusion criteria: elementary, high school and college age groups, and a specific definition of clinical recovery that required two or more measures. Exclusion criteria: review articles, articles using the same sample population, case studies, non-English language and those that used one measure only or did not specify the recovery measures used.Study qualityStudy quality was assessed using the Downs and Black Criteria.ResultsOf 2023 publications, 43 met inclusion criteria. Included articles reported the following measures of recovery: somatic symptom resolution or return to baseline (100%), cognitive recovery or return to baseline (86%), no exacerbation of symptoms on physical exertion (49%), normalisation of balance (30%), normal special physical examination (12%), successful return to school (5%), no exacerbation of symptoms with cognitive exertion (2%) and normalisation of cerebral blood flow (2%). Follow-up to validate the return to sport decision was reported in eight (19%) articles. Most studies were case–control or cohort (level of evidence 4) and had significant risk of bias.ConclusionAll studies of sport-related concussion use symptom reports to define recovery. A minority of studies used multiple measures of outcome or had clearly defined recovery criteria, the most common being a combination of a self-reported symptom checklist and a computerised neurocognitive test. Future studies ideally should define recovery a priori using objective physiological measures in addition to symptom reports.

A full understanding of LISA's science capability will require accurate models of incident waveform signals and the instrumental response. While Fisher matrix analysis is useful for some estimates, a full Bayesian treatment is needed for important cases at the limit of LISA's capability. We will apply fast analysis algorithms enabling accurate treatment with EOB waveforms and the full-featured LISA response to study the significance of higher spherical harmonics and mergers in LISA analysis.

The Spratly Islands have represented a potential political and military flashpoint in the South China Sea for years, involving as they do various claims by China, the Philippines, Vietnam, Malaysia, and Taiwan. This edited volume examines the issues involved in light of confidence- building measures that new high-resolution satellite imagery can offer to this, and other, regions. Baker, Wiencek, and their contributors assess the potential role for cooperative monitoring in mitigating the risk of conflict arising from multinational disputes over the Spratly Islands. They analyze how this new generation of civilian and commercial observation satellites can be used to reduce the changes of armed conflict breaking out by providing transparency that will detect and identify politically significant activities occurring at disputed islands and reefs among the Spratlys. Of particular interest to policy makers, scholars, and other researchers involved with military issues in Asia and international security concerns.

Background The objective of this study was to investigate factors associated with substance use disorder identification and follow-up rates among samples of members of a private health insurance plan. Methods In an observational study, samples of claims data for 2017 for Commercial and Medicare members from a private health insurer were accessed and analyzed using descriptive statistics, decision tree analysis, and linear regression models. Results Commercial and Medicare members differed in age. Medicare members had higher rates of inclusion in a measure of substance use disorder than Commercial members, lower rates of initial short term follow-up, more opioid prescriptions from primary care provides, fewer prescriptions for opioid treatment, and higher rates of selected comorbid conditions. Mental health diagnoses and substance use disorder co-occurred frequently and to a greater extent in the Medicare sample. Among commercial members, there were primarily alcohol problems that increased with age, while opioid problems at about 10% peaked in the mid-twenties. More males were included among all substance types. The overall rate for an initial short term follow-up visit indicating initiation of treatment was 30%. There were large differences in the follow-up rates across settings with a very low rate (4.6% for alcohol and 6.9% for opioid) in primary care settings. Conclusions These results suggest that increased attention in primary care to young adult males and to older adults, may help to reduce substance use disorder rates, especially alcohol use disorders.

This unique book demonstrates the current status, and future potential, of millimetre wavelength (MMW) spectrometry as a means of quantitative analysis of gaseous mixtures. After outlining the spectroscopic theory required, the authors then go on to discuss the components of an MMW cavity spectrometer, concentrating on compact, automatic, low-cost instruments. Other topics covered include solid state MMW sources with both cryogenically cooled and room temperature detectors. Post-detector signal processing, smoothing, filtering and spectral profile fitting are also discussed. The book concludes with a look at the future of the technique, in areas such as millimetre wave-over-fibre technology. Quantitative Millimetre Wavelength Spectrometry will be welcomed by practitioners in both industry and academia.

Background Youth ice hockey injury rates and mechanisms have been described by various classification systems. Intentional versus unintentional contact was used to classify mechanisms of injuries. All injuries (n=247) in one youth hockey programme over a 5-year period were recorded and included in the analysis. Purpose To evaluate youth ice hockey injuries and compare programmes that allow body checking versus programmes that do not allow body checking. A primary goal was to determine whether programmes that allow body checking have increased injury rates from intentional body contact. Another goal was to describe the rates of injury across ages, levels of competitive play and during games versus practices. Methods Rates of injury were compared for three levels of competition (house, select and representative) for approximately 3000 boys aged 4–18 years over a 5-year period. This represents 13 292 player years. Data were collected prospectively in this cohort study. All injuries were reported prospectively by a designated team official and verified by a physician. The log injury rate (per 1000 player hours) was modelled via Poisson regression with log player hours used as an offset. Rate ratio was used to explain the covariate-adjusted injury rate for each of three groups (all injuries, intentional injuries, unintentional injuries). Results Unintentional contacts accounted for 66.0% of overall injuries (95% CI 60.0 to 72.0), compared with 34.0% from intentional contacts (p<0.001;Z=5.25). Serious injuries (fractures, dislocations, concussions) resulted more often from unintentional collisions (p=0.04). Players in more competitive leagues that allow body checking had a greater incidence of total injuries than less competitive leagues. Conclusions Most injuries in the youth hockey programme studied were the result of unintentional contact, and were generally more severe. These findings were not expected given previously published research.