Finding non-eclipsing binaries through pulsational phase modulation

We present a method for finding binaries among pulsating stars that were observed by the Kepler Mission. We use entire four-year light curves to accurately mea- sure the frequencies of the strongest pulsation modes, then track the pulsation phases at those frequencies in 10-d segments. This produces a series of time-delay measurements in which binarity is apparent as a periodic modulation whose amplitude gives the projected light travel time across the orbit. Fourier analysis of this time-delay curve provides the pa- rameters of the orbit, including the period, eccentricity, angle of ascending node and time of periastron passage. Differentiating the time-delay curve yields the full radial-velocity curve directly from the Kepler photometry, without the need for spectroscopy. We show examples with delta Scuti stars having large numbers of pulsation modes, including one system in which both components of the binary are pulsating. The method is straightfor- ward to automate, thus radial velocity curves can be derived for hundreds of non-eclipsing binary stars from Kepler photometry alone. This contribution is based largely upon the work by Murphy et al. [1], describing the phase-modulation method in detail

Two-Pion Exchange Nucleon-Nucleon Potential: Model Independent Features

A chiral pion-nucleon amplitude supplemented by the HJS subthreshold coefficients is used to calculate the the long range part of the two-pion exchange nucleon-nucleon potential. In our expressions the HJS coefficients factor out, allowing a clear identification of the origin of the various contributions. A discussion of the configuration space behaviour of the loop integrals that determine the potential is presented, with emphasis on cancellations associated with chiral symmetry. The profile function for the scalar-isoscalar component of the potential is produced and shown to disagree with those of several semi-phenomenological potentials.Comment: 16 pages, 9 embedded figures, Latex 2.09, Revtex.sty, epsf.st

Quality of life with conservative care compared with assisted peritoneal dialysis and haemodialysis

Background. There is little information about quality of life (QoL) for patients with end-stage kidney disease (ESKD) choosing conservative kidney management (CKM). The Frail and Elderly Patients on Dialysis (FEPOD) study demonstrated that frailty was associated with poorer QoL outcomes with little difference between dialysis modalities [assisted peritoneal dialysis (aPD) or haemodialysis (HD)]. We therefore extended the FEPOD study to include CKM patients with estimated glomerular filtration rate ⌉10 mL/min/1.73m2 (i.e. individuals with ESKD otherwise likely to be managed with dialysis). Methods. CKM patients were propensity matched to HD and aPD patients by age, gender, ethnicity, diabetes status and index of deprivation. QoL outcomes measured were Short Form-12 (SF12), Hospital Anxiety and Depression Scale depression score, symptom score, Illness Intrusiveness Rating Scale (IIRS) and Renal Treatment Satisfaction Questionnaire. Frailty was assessed using the Clinical Frailty Scale. Generalized linear modelling was used to assess the impact of treatment modality on QoL outcomes, adjusting for baseline characteristics. Results. In total, 84 (28 CKM, 28 HD and 28 PD) patients were included. Median age for the cohort was 82 (79-88) years. Compared with CKM, aPD was associated with higher SF12 physical component score (PCS) [Exp B (95% confidence interval)=1.20 (1.00-1.45), P<0.05] and lower symptom score [Exp B=0.62 (0.43-0.90), P=0.01]; depression score was lower in HD compared with CKM [Exp B=0.70 (0.52-0.92), P=0.01]. Worsening frailty was associated with higher depression scores [Exp B=2.59 (1.45-4.62), P<0.01], IIRS [Exp B=1.20 (1.12-1.28), P<0.01] and lower SF12 PCS [Exp B=0.87 (0.83-0.93), P<0.01]. Conclusion. Treatment by dialysis, both with aPD and HD, improved some QoL measures. Overall, aPD was equal to or slightly better than the other modalities in this elderly population. However, as in the primary FEPOD study, frailty was associated with worse QoL measures irrespective of CKD modality. These findings highlight the need for an individualized approach to the management of ESKD in older people.Peer reviewedFinal Published versio

(Sub)millimetre interferometric imaging of a sample of COSMOS/AzTEC submillimetre galaxies. II. The spatial extent of the radio-emitting regions

Radio emission at centimetre wavelengths from highly star-forming galaxies, like submillimetre galaxies (SMGs), is dominated by synchrotron radiation arising from supernova activity. Hence, radio continuum imaging has the potential to determine the spatial extent of star formation in these types of galaxies. Using deep, high-resolution (1σ = 2.3 μJy beam-1; 0.75 arcsec) centimetre radio-continuum observations taken by the Karl G. Jansky Very Large Array (VLA)-COSMOS 3 GHz Large Project, we studied the radio-emitting sizes of a flux-limited sample of SMGs in the COSMOS field. The target SMGs were originally discovered in a 1.1 mm continuum survey carried out with the AzTEC bolometer, and followed up with higher resolution interferometric (sub)millimetre continuum observations. Of the 39 SMGs studied here, 3 GHz emission was detected towards 18 of them (~46 ± 11%) with signal-to-noise ratios in the range of S/N = 4.2-37.4. Towards four SMGs (AzTEC2, 5, 8, and 11), we detected two separate 3 GHz sources with projected separations of ~1''&dotbelow;5-6''&dotbelow;6, but they might be physically related in only one or two cases (AzTEC2 and 11). Using two-dimensional elliptical Gaussian fits, we derived a median deconvolved major axis FWHM size of 0''&dotbelow;54±0''&dotbelow;11 for our 18 SMGs detected at 3 GHz. For the 15 SMGs with known redshift we derived a median linear major axis FWHM of 4.2 ± 0.9 kpc. No clear correlation was found between the radio-emitting size and the 3 GHz or submm flux density, or the redshift of the SMG. However, there is a hint of larger radio sizes at z ~ 2.5-5 compared to lower redshifts. The sizes we derived are consistent with previous SMG sizes measured at 1.4 GHz and in mid-J CO emission, but significantly larger than those seen in the (sub)mm continuum emission (typically probing the rest-frame far-infrared with median FWHM sizes of only ~1.5-2.5 kpc). One possible scenario is that SMGs have i) an extended gas component with a low dust temperature, which can be traced by low- to mid-J CO line emission and radio continuum emission; and ii) a warmer, compact starburst region giving rise to the high-excitation line emission of CO, which could dominate the dust continuum size measurements. Because of the rapid cooling of cosmic-ray electrons in dense starburst galaxies (~104-105 yr), the more extended synchrotron radio-emitting size being a result of cosmic-ray diffusion seems unlikely. Instead, if SMGs are driven by galaxy mergers - a process where the galactic magnetic fields can be pulled out to larger spatial scales - the radio synchrotron emission might arise from more extended magnetised interstellar medium around the starburst region

An ASKAP Search for a Radio Counterpart to the First High-significance Neutron Star-Black Hole Merger LIGO/Virgo S190814bv

We present results from a search for a radio transient associated with the LIGO/Virgo source S190814bv, a likely neutron star-black hole (NSBH) merger, with the Australian Square Kilometre Array Pathfinder. We imaged a 30 deg2 field at ΔT = 2, 9, and 33 days post-merger at a frequency of 944 MHz, comparing them to reference images from the Rapid ASKAP Continuum Survey observed 110 days prior to the event. Each epoch of our observations covers 89% of the LIGO/Virgo localization region. We conducted an untargeted search for radio transients in this field, resulting in 21 candidates. For one of these, AT2019osy, we performed multiwavelength follow-up and ultimately ruled out the association with S190814bv. All other candidates are likely unrelated variables, but we cannot conclusively rule them out. We discuss our results in the context of model predictions for radio emission from NSBH mergers and place constrains on the circum-merger density and inclination angle of the merger. This survey is simultaneously the first large-scale radio follow-up of an NSBH merger, and the most sensitive widefield radio transients search to-date

SkyMapper Southern Survey: First Data Release (DR1)

We present the first data release (DR1) of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction and database schema. The DR1 dataset includes over 66,000 images from the Shallow Survey component, covering an area of 17,200 deg$^2$ in all six SkyMapper passbands $uvgriz$, while the full area covered by any passband exceeds 20,000 deg$^2$. The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18 mag in all bands. We compare our $griz$ point-source photometry with PanSTARRS1 DR1 and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2 arcsec based on comparison with Gaia DR1. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.Comment: 31 pages, 19 figures, 10 tables, PASA, accepte

Keep it simple: three indicators to deal with overfishing

Three simple fisheries indicators are presented: (i) percentage of mature fish in catch, with 100% as target; (ii) percent of specimens with optimum length in catch, with 100% as target; and (iii) percentage of ‘mega-spawners‘ in catch, with 0% as target, and 30–40% as representative of reasonable stock structure if no upper size limit exists. Application of these indicators to stocks of Gadus morhua, Sardinella aurita and Epinephelus aeneus demonstrate their usefulness. It is argued that such simple indicators have the potential to allow more stakeholders such as fishers, fish dealers, supermarket managers, consumers and politicians to participate in fisheries management and eventually hold and reverse the global pattern of convenience overfishing, which is defined here as deliberate overfishing sanctioned by official bodies who find it more convenient to risk eventual collapse of fish stocks than to risk social and political conflicts

A framework for power analysis using a structural equation modelling procedure

BACKGROUND: This paper demonstrates how structural equation modelling (SEM) can be used as a tool to aid in carrying out power analyses. For many complex multivariate designs that are increasingly being employed, power analyses can be difficult to carry out, because the software available lacks sufficient flexibility. Satorra and Saris developed a method for estimating the power of the likelihood ratio test for structural equation models. Whilst the Satorra and Saris approach is familiar to researchers who use the structural equation modelling approach, it is less well known amongst other researchers. The SEM approach can be equivalent to other multivariate statistical tests, and therefore the Satorra and Saris approach to power analysis can be used. METHODS: The covariance matrix, along with a vector of means, relating to the alternative hypothesis is generated. This represents the hypothesised population effects. A model (representing the null hypothesis) is then tested in a structural equation model, using the population parameters as input. An analysis based on the chi-square of this model can provide estimates of the sample size required for different levels of power to reject the null hypothesis. CONCLUSIONS: The SEM based power analysis approach may prove useful for researchers designing research in the health and medical spheres

Genome-wide association study in obsessive-compulsive disorder: results from the OCGAS.

Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by intrusive thoughts and urges and repetitive, intentional behaviors that cause significant distress and impair functioning. The OCD Collaborative Genetics Association Study (OCGAS) is comprised of comprehensively assessed OCD patients with an early age of OCD onset. After application of a stringent quality control protocol, a total of 1065 families (containing 1406 patients with OCD), combined with population-based samples (resulting in a total sample of 5061 individuals), were studied. An integrative analyses pipeline was utilized, involving association testing at single-nucleotide polymorphism (SNP) and gene levels (via a hybrid approach that allowed for combined analyses of the family- and population-based data). The smallest P-value was observed for a marker on chromosome 9 (near PTPRD, P=4.13 × 10(-)(7)). Pre-synaptic PTPRD promotes the differentiation of glutamatergic synapses and interacts with SLITRK3. Together, both proteins selectively regulate the development of inhibitory GABAergic synapses. Although no&nbsp;SNPs were identified as associated with OCD at genome-wide significance level, follow-up analyses of genome-wide association study (GWAS) signals from a previously published OCD study identified significant enrichment (P=0.0176). Secondary analyses of high-confidence interaction partners of DLGAP1 and GRIK2 (both showing evidence for association in our follow-up and the original GWAS study) revealed a trend of association (P=0.075) for a set of genes such as NEUROD6, SV2A, GRIA4, SLC1A2 and PTPRD. Analyses at the gene level revealed association of IQCK and C16orf88 (both P&lt;1 × 10(-)(6), experiment-wide significant), as well as OFCC1 (P=6.29 × 10(-)(5)). The suggestive findings in this study await replication in larger samples