Identifying the Host Galaxy of Gravitational Wave Signals

One of the goals of the current LIGO-GEO-Virgo science run is to identify transient gravitational wave (GW) signals in near real time to allow follow-up electromagnetic (EM) observations. An EM counterpart could increase the confidence of the GW detection and provide insight into the nature of the source. Current GW-EM campaigns target potential host galaxies based on overlap with the GW sky error box. We propose a new statistic to identify the most likely host galaxy, ranking galaxies based on their position, distance, and luminosity. We test our statistic with Monte Carlo simulations of GWs produced by coalescing binaries of neutron stars (NS) and black holes (BH), one of the most promising sources for ground-based GW detectors. Considering signals accessible to current detectors, we find that when imaging a single galaxy, our statistic correctly identifies the true host ~20% to ~50% of the time, depending on the masses of the binary components. With five narrow-field images the probability of imaging the true host increases to ~50% to ~80%. When collectively imaging groups of galaxies using large field-of-view telescopes, the probability improves to ~30% to ~60% for a single image and to ~70% to ~90% for five images. For the advanced generation of detectors (c. 2015+), and considering binaries within 100 Mpc (the reach of the galaxy catalogue used), the probability is ~40% for one narrow-field image, ~75% for five narrow-field images, ~65% for one wide-field image, and ~95% for five wide-field images, irrespective of binary type.Comment: 5 pages, 2 figure

Does nonstationary noise in LIGO and Virgo affect the estimation of H0?

Gravitational-wave observations of binary neutron star mergers and their electromagnetic counterparts provide an independent measurement of the Hubble constant, $H_0$, through the standard-sirens approach. Current methods of determining $H_0$, such as measurements from the early universe and the local distance ladder, are in tension with one another. If gravitational waves are to break this tension a thorough understanding of systematic uncertainty for gravitational-wave observations is required. To accurately estimate the properties of gravitational-wave signals measured by LIGO and Virgo, we need to understand the characteristics of the detectors noise. Non-gaussian transients in the detector data and rapid changes in the instrument, known as non-stationary noise, can both add a systematic uncertainty to inferred results. We investigate how non-stationary noise affects the estimation of the luminosity distance of the source, and therefore of $H_0$. Using a population of 200 simulated binary neutron star signals, we show that non-stationary noise can bias the estimation of the luminosity distance by up to 2.4\%. However, only $\sim$15\% of binary neutron star signals would be affected around their merger time with non-stationary noise at a similar level to that seen in the first half of LIGO-Virgo's third observing run. Comparing the expected bias to other systematic uncertainties, we argue that non-stationary noise in the current generation of detectors will not be a limiting factor in resolving the tension on $H_0$ using standard sirens. Although, evaluating non-stationarity in gravitational-wave data will be crucial to obtain accurate estimates of $H_0$.Comment: 10 pages, 5 figures, 1 tabl

Blip glitches in Advanced LIGO data

Blip glitches are short noise transients present in data from ground-based gravitational-wave observatories. These glitches resemble the gravitational-wave signature of massive binary black hole mergers. Hence, the sensitivity of transient gravitational-wave searches to such high-mass systems and other potential short duration sources is degraded by the presence of blip glitches. The origin and rate of occurrence of this type of glitch have been largely unknown. In this paper we explore the population of blip glitches in Advanced LIGO during its first and second observing runs. On average, we find that Advanced LIGO data contains approximately two blip glitches per hour of data. We identify four subsets of blip glitches correlated with detector auxiliary or environmental sensor channels, however the physical causes of the majority of blips remain unclear

Electromagnetic counterparts of gravitational-wave signals

Laura Nuttall and Christopher Berry review the potential of multimessenger astronomy with gravitational-wave observations

Transgenic sorghum with altered kafirin synthesis : kafirin solubility, polymerization, and protein digestion

Transgenic sorghum (TG) lines with altered kafirin synthesis, particularly suppression of γ-kafirin synthesis, and improved protein quality have been developed. The proportion of kafirin extracted with 60% tert-butyl alcohol alone was greatly increased in the TG lines. However, the total amount of kafirin remained unchanged. Further, in the TG lines, the kafirin was much less polymerized by disulfide bonding. There was also evidence of compensatory synthesis of other kafirin proteins. Cooked protein digestibility was increased in the TG form, even after removal of interfering starch. The TG protein bodies were intermediate in appearance between the normal type and the invaginated high digestibility mutants. Hence, the increased protein digestibility of these TG lines is probably related to their lower levels of disulfide-bonded kafirin polymerization, allowing better access of proteases. This work appears to confirm that disulfide bond formation in kafirin is responsible for the reduced protein digestibility of cooked sorghum.This project was funded through the Bill and Melinda Gates Grand Challenges 9, Africa Biofortified Sorghum (Project) under a sub-grant from the Africa Harvest Biotechnology Foundation International. L.S.d.S. received financial support from the South African National Research Foundation and the Tshwane University of Technology Faculty of Science Research and Innovation Committee.http://pubs.acs.org/JAF

Effectiveness of nurse‐led group CBT for hot flushes and night sweats in women with breast cancer: results of the MENOS4 randomised controlled trial

Objective Troublesome hot flushes and night sweats (HFNS) are experienced by many women after treatment for breast cancer, impacting significantly on sleep and quality of life. Cognitive behavioural therapy (CBT) is known to be effective for the alleviation of HFNS. However, it is not known if it can effectively be delivered by specialist nurses. We investigated whether group CBT delivered by breast care nurses (BCNs) can reduce the impact of HFNS.MethodsWe recruited women with primary breast cancer following primary treatment with seven or more HFNS/week (including 4/10 or above on the HFNS problem rating scale), from six UK hospitals to an open, randomised, phase 3 effectiveness trial. Participants were randomised to Group CBT or usual care (UC). The primary endpoint was HFNS problem rating at 26 weeks post randomisation. Secondary outcomes included sleep, depression, anxiety and quality of life. ResultsBetween 2017-2018, 130 participants were recruited (CBT:63, control:67). We found a 46% (6.9 to 3.7) reduction in the mean HFNS problem rating score from randomisation to 26 weeks in the CBT arm and a 15% (6.5 to 5.5) reduction in the UC arm (adjusted mean difference -1.96, CI -3.68 to -0.23, p=0.039). Secondary outcomes, including frequency of HFNS, sleep, anxiety and depression all improved significantly.ConclusionOur results suggest that specialist nurses can be trained to deliver CBT effectively to alleviate troublesome menopausal hot flushes in women following breast cancer in the NHS setting

Improving the sensitivity of Advanced LIGO using noise subtraction

This paper presents an adaptable, parallelizable method for subtracting linearly coupled noise from Advanced LIGO data. We explain the features developed to ensure that the process is robust enough to handle the variability present in Advanced LIGO data. In this work, we target subtraction of noise due to beam jitter, detector calibration lines, and mains power lines. We demonstrate noise subtraction over the entirety of the second observing run, resulting in increases in sensitivity comparable to those reported in previous targeted efforts. Over the course of the second observing run, we see a 30% increase in Advanced LIGO sensitivity to gravitational waves from a broad range of compact binary systems. We expect the use of this method to result in a higher rate of detected gravitational-wave signals in Advanced LIGO data

Factors influencing clinicians', health visitors' and social workers' professional judgements, decision‐making and multidisciplinary collaboration when safeguarding children with burn injuries: a qualitative study

Burns are a common injury to young children, sometimes related to neglect or physical abuse. Emergency department (ED) clinicians, health visitors and social workers must work collaboratively when safeguarding children with burns; however, little is known about the factors influencing their professional judgements, decision‐making and multidisciplinary collaboration. Objective was to explore factors affecting ED clinicians', health visitors' and social workers' professional judgements and decision‐making when children present to the ED with burns, and experiences of multidisciplinary collaboration, to identify areas for improvement. This was a qualitative semi‐structured interview study using purposive and snowball sampling to recruit participants. Data were analysed using ‘codebook’ thematic analysis. Four themes were identified: ‘perceived roles and responsibilities when safeguarding children with burn injuries’, ‘factors influencing judgment of risk and decision‐making’, ‘information sharing’ and ‘barriers and facilitators to successful multidisciplinary collaboration’. There is limited understanding between the groups about each other's roles. Each agency is dependent on one another to understand the full picture; however, information sharing is lacking in detail and context and hindered by organisational and resource constraints. Formal opportunities for multiagency team working such as strategy meetings can be facilitators of more successful collaborations. Professionals may benefit from multiagency training to improve understanding of one another's roles. Greater detail and context are needed when notifying health visitors of burn injuries in children or making a referral to children's services