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In Kawahara et al. (2018) and Masuda et al. (2019), we reported the discovery of four self-lensing binaries consisting of F/G-type stars and (most likely) white dwarfs whose masses range from 0.2 to 0.6 solar masses. Here we present their updated system parameters based on new radial velocity data from the Tillinghast Reflector Echelle Spectrograph at the Fred Lawrence Whipple Observatory, and the Gaia parallaxes and spectroscopic parameters of the primary stars. We also briefly discuss the astrophysical implications of these findings.
We employ Pan-STARRS photometry, Gaia trigonometric parallaxes, modern stellar evolution and atmosphere models, and our Bayesian fitting approach to determine cooling and total ages for 159,238 white dwarfs. In many cases we are able to derive precise ages (better than 5%) for individual white dwarfs. These results are meant for broad use within the white dwarf and stellar astrophysics communities and we plan to make available on-line the posterior distributions for cooling age, total age, initial stellar mass, and other parameters.
We used a survey to characterize contemporary infection prevention and antibiotic stewardship program practices across 64 healthcare facilities, and we compared these findings to those of a similar 2013 survey. Notable findings include decreased frequency of active surveillance for methicillin-resistant Staphylococcus aureus, frequent active surveillance for carbapenem-resistant Enterobacteriaceae, and increased support for antibiotic stewardship programs.
We present low-frequency spectral energy distributions of 60 known radio pulsars observed with the Murchison Widefield Array telescope. We searched the GaLactic and Extragalactic All-sky Murchison Widefield Array survey images for 200-MHz continuum radio emission at the position of all pulsars in the Australia Telescope National Facility (ATNF) pulsar catalogue. For the 60 confirmed detections, we have measured flux densities in 20 × 8 MHz bands between 72 and 231 MHz. We compare our results to existing measurements and show that the Murchison Widefield Array flux densities are in good agreement.
The Omani basement is located spatially distant from the dominantly juvenile Arabian–Nubian Shield (ANS) to its west, and its relationship to the amalgamation of those arc terranes has yet to be properly constrained. The Jebel Ja'alan (NE Oman) basement inlier provides an excellent opportunity to better understand the Neoproterozoic tectonic geography of Oman and its relationship to the ANS. To understand the origin of this basement inlier, we present new radiogenic isotopic data from igneous bodies in Jebel Ja'alan. U–Pb and 40Ar/39Ar geochronological data are used to constrain the timing of magmatism and metamorphism in the jebel. Positive εHf and εNd values indicate a juvenile origin for the igneous lithologies. Phase equilibria modelling is used to constrain the metamorphic conditions recorded by basement. Pressure–temperature (P–T) pseudosections show that basement schists followed a clockwise P–T path, reaching peak metamorphic conditions of c. 650–700°C at 4–7.5 kbar, corresponding to a thermal gradient of c. 90–160°C/kbar. From the calculated thermal gradient, in conjunction with collected trace-element data, we interpret that the Jebel Ja'alan basement formed in an arc environment. Geochronological data indicate that this juvenile arc formed during Tonian time and is older than basement further west in Oman. We argue that the difference in timing is related to westwards arc accretion and migration, which implies that the Omani basement represents its own tectonic domain separate to the ANS and may be the leading edge of the Neoproterozoic accretionary margin of India.
Critical to the development of improved HIV elimination efforts is a greater understanding of how social networks and their dynamics are related to HIV risk and prevention. In this paper, we examine network stability of confidant and sexual networks among young black men who have sex with men (YBMSM). We use data from uConnect (2013–2016), a population-based, longitudinal cohort study. We use an innovative approach to measure both sexual and confidant network stability at three time points, and examine the relationship between each type of stability and HIV risk and prevention behaviors. This approach is consistent with a co-evolutionary perspective in which behavior is not only affected by static properties of an individual's network, but may also be associated with changes in the topology of his or her egocentric network. Our results indicate that although confidant and sexual network stability are moderately correlated, their dynamics are distinct with different predictors and differing associations with behavior. Both types of stability are associated with lower rates of risk behaviors, and both are reduced among those who have spent time in jail. Public health awareness and engagement with both types of networks may provide new opportunities for HIV prevention interventions.
The anticipated release of EnlistTM cotton, corn, and soybean cultivars likely will increase the use of 2,4-D, raising concerns over potential injury to susceptible cotton. An experiment was conducted at 12 locations over 2013 and 2014 to determine the impact of 2,4-D at rates simulating drift (2 g ae ha−1) and tank contamination (40 g ae ha−1) on cotton during six different growth stages. Growth stages at application included four leaf (4-lf), nine leaf (9-lf), first bloom (FB), FB + 2 wk, FB + 4 wk, and FB + 6 wk. Locations were grouped according to percent yield loss compared to the nontreated check (NTC), with group I having the least yield loss and group III having the most. Epinasty from 2,4-D was more pronounced with applications during vegetative growth stages. Importantly, yield loss did not correlate with visual symptomology, but more closely followed effects on boll number. The contamination rate at 9-lf, FB, or FB + 2 wk had the greatest effect across locations, reducing the number of bolls per plant when compared to the NTC, with no effect when applied at FB + 4 wk or later. A reduction of boll number was not detectable with the drift rate except in group III when applied at the FB stage. Yield was influenced by 2,4-D rate and stage of cotton growth. Over all locations, loss in yield of greater than 20% occurred at 5 of 12 locations when the drift rate was applied between 4-lf and FB + 2 wk (highest impact at FB). For the contamination rate, yield loss was observed at all 12 locations; averaged over these locations yield loss ranged from 7 to 66% across all growth stages. Results suggest the greatest yield impact from 2,4-D occurs between 9-lf and FB + 2 wk, and the level of impact is influenced by 2,4-D rate, crop growth stage, and environmental conditions.
Students in an introductory undergraduate Astrobiology course were given a pre/post-test based on the Drake Equation in an attempt to measure changes in their perceptions regarding the prevalence of life in the Galaxy after taking the course. The results indicated that, after taking the course, the students were considerably more optimistic, by a 2 to 1 margin or more, about the prospect of habitable planets, the origin of life, and the evolution of intelligence in other planetary systems. The results suggest that, while it may not be the explicit goal of an astrobiology course to change student beliefs about the abundance or rarity of extraterrestrial life, such changes in opinion can and do occur.
The relationship between childhood adversity (CA) and psychotic disorder is well documented. As the adequacy of the current categorical diagnosis of psychosis is being increasingly questioned, we explored independent associations between different types of CA and specific psychotic symptom dimensions in a well-characterized sample of first-episode psychosis (FEP) patients.
This study involved 236 FEP cases aged 18–65 years who presented for the first time to psychiatric services in South London, UK. Psychopathology was assessed with the Positive and Negative Syndrome Scale and confirmatory factor analysis was used to evaluate the statistical fit of the Wallwork/Fortgang five-factor model of psychosis. CA prior to 17 years of age (physical abuse, sexual abuse, parental separation, parental death, and being taken into care) was retrospectively assessed using the Childhood Experience of Care and Abuse Questionnaire.
Childhood sexual abuse [β = 0.96, 95% confidence interval (CI) 0.40–1.52], childhood physical abuse (β = 0.48, 95% CI 0.03–0.93) and parental separation (β = 0.60, 95% CI 0.10–1.11) showed significant associations with the positive dimension; while being taken into care was associated with the excited dimension (β = 0.36, 95% CI 0.08–0.65), independent of the other types of CA. No significant associations were found between parental death and any of the symptom dimensions.
A degree of specificity was found in the relationships between different types of CA and psychosis symptom dimensions in adulthood, suggesting that distinct pathways may be involved in the CA–psychosis association. These potentially different routes to developing psychosis merit further empirical and theoretical exploration.
We investigated longitudinal relations among gaze following and face scanning in infancy and later language development. At 12 months, infants watched videos of a woman describing an object while their passive viewing was measured with an eye-tracker. We examined the relation between infants' face scanning behavior and their tendency to follow the speaker's attentional shift to the object she was describing. We also collected language outcome measures on the same infants at 18 and 24 months. Attention to the mouth and gaze following at 12 months both predicted later productive vocabulary. The results are discussed in terms of social engagement, which may account for both attentional distribution and language onset. We argue that an infant's inherent interest in engaging with others (in addition to creating more opportunities for communication) leads infants to attend to the most relevant information in a social scene and that this information facilitates language learning.
We present the results of an approximately 6 100 deg2 104–196 MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the MWACS. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 h < RA < 8.5 h, − 58° < Dec < −14°over three frequency bands centred on 119, 150 and 180 MHz, with image resolutions of 6–3 arcmin. The catalogue has 3 arcmin angular resolution and a typical noise level of 40 mJy beam− 1, with reduced sensitivity near the field boundaries and bright sources. We describe the data reduction strategy, based upon mosaicked snapshots, flux density calibration, and source-finding method. We present a catalogue of flux density and spectral index measurements for 14 110 sources, extracted from the mosaic, 1 247 of which are sub-components of complexes of sources.
Consumers’ willingness to pay for postharvest-processed (PHP) raw oysters—oysters without health risks—is studied in experimental auction markets. The experimental design decomposes the effects of taste, objective risk information, and information on four PHP technologies on consumer valuations. Results show that relatively uninformed consumers are willing to pay equivalent amounts for PHP and traditional raw oysters. However, after a blind taste test, consumers are willing to pay a significant premium for traditional raw oysters, and the premium persists after objective information on risk and processing technologies is provided. The results are robust across PHP technologies.