Construction and evaluation of tests of rate of learning in reading for children in the first grade

Thesis (M.A.)--Boston University, 1942. This item was digitized by the Internet Archive

Assessing the Feasibility of a Parent Life Coaching Intervention to Support Parents and Children Who Have Experienced Domestic Violence and Abuse

This is the final version. Available on open access from Springer Verlag via the DOI in this recordData accessibility: Due to ethical concerns, the research data supporting this publication are not publicly available.Children exposed to domestic violence are at risk for a range of psychosocial difficulties, which may be mitigated by improving their caregiver’s mental health and capacity to parent. Life coaching is a promising behaviour change approach for improving the empowerment, efficacy and well-being of carers who are parenting alone following domestic violence. This study evaluated the feasibility of a novel life coaching programme. Using a pre- post-test design, the Family Vision© (FV) programme was implemented in two community settings. The programme was offered to single mothers with experience of domestic violence. Feasibility data were collected using satisfaction forms, semi-structured interviews and focus groups with parents, facilitators and managers. Mothers’ self-reports about their mental well-being; empowerment and self-efficacy were collected, as well as the quality of their parent-child relationships and children’s psychosocial functioning, using standardised measures at baseline and end of programme. The programme was found to have good acceptability for this population of parents and was considered feasible to deliver in the two community settings where it was piloted. There were indications that women who completed the programme had improved mental well-being, as well as improved empowerment and efficacy by the end of the programme. The FV programme is feasible to implement and could support positive change for single parents with respect to their mental health and capacity to parent effectively. Demonstrated mediators, these effects could also promote children’s health and well-being. Feasibility for a randomised trial and wider scale-up in the community is now required.Economic and Social Research Council (ESRC

Hints of spin-orbit resonances in the binary black hole population

Binary black hole spin measurements from gravitational wave observations can reveal the binary's evolutionary history. In particular, the spin orientations of the component black holes within the orbital plane, $\phi_1$ and $\phi_2$, can be used to identify binaries caught in the so-called spin-orbit resonances. In a companion paper, we demonstrate that $\phi_1$ and $\phi_2$ are best measured near the merger of the two black holes. In this work, we use these spin measurements to provide the first constraints on the full six-dimensional spin distribution of merging binary black holes. In particular, we find that there is a preference for $\Delta \phi = \phi_1 - \phi_2 \sim \pm \pi$ in the population, which can be a signature of spin-orbit resonances. We also find a preference for $\phi_1 \sim -\pi/4$ with respect to the line of separation near merger, which has not been predicted for any astrophysical formation channel. However, the strength of these preferences depends on our prior choices, and we are unable to constrain the widths of the $\phi_1$ and $\Delta \phi$ distributions. Therefore, more observations are necessary to confirm the features we find. Finally, we derive constraints on the distribution of recoil kicks in the population, and use this to estimate the fraction of merger remnants retained by globular and nuclear star clusters. We make our spin and kick population constraints publicly available

The role of team compassion in mitigating the impact of hierarchical bullying

Hierarchical bullying in public healthcare organizations is an entrenched negative behaviour that results in a range of adverse outcomes for staff, including diminished wellbeing. This study integrates social exchange and conservation of resources theories as a lens for formulating hypotheses and employs multilevel statistical modelling to examine whether team-level compassion moderates the impact of hierarchical bullying on wellbeing. Using multilevel statistical modelling, the study analysed cross-sectional data from 632 healthcare workers nested within 48 teams in a single public health district in Australia. The findings indicate that work teams with higher levels of team compassion can mitigate the negative effects of hierarchical bullying on employee wellbeing. The results imply that investing in developing compassion within teams is an effective strategy for mitigating some harmful effects of hierarchical bullying on employee outcomes

Measuring binary black hole orbital-plane spin orientations

Binary black hole spins are among the key observables for gravitational wave astronomy. Among the spin parameters, their orientations within the orbital plane, $\phi_1$, $\phi_2$ and $\Delta \phi=\phi_1-\phi_2$, are critical for understanding the prevalence of the spin-orbit resonances and merger recoils in binary black holes. Unfortunately, these angles are particularly hard to measure using current detectors, LIGO and Virgo. Because the spin directions are not constant for precessing binaries, the traditional approach is to measure the spin components at some reference stage in the waveform evolution, typically the point at which the frequency of the detected signal reaches 20 Hz. However, we find that this is a poor choice for the orbital-plane spin angle measurements. Instead, we propose measuring the spins at a fixed dimensionless time or frequency near the merger. This leads to significantly improved measurements for $\phi_1$ and $\phi_2$ for several gravitational wave events. Furthermore, using numerical relativity injections, we demonstrate that $\Delta \phi$ will also be better measured near the merger for louder signals expected in the future. Finally, we show that numerical relativity surrogate models are key for reliably measuring the orbital-plane spin orientations, even at moderate signal-to-noise ratios like $\sim 30-45$

Modeling the Redshift Evolution of the Normal Galaxy X-ray Luminosity Function

Emission from X-ray binaries (XRBs) is a major component of the total X-ray luminosity of normal galaxies, so X-ray studies of high redshift galaxies allow us to probe the formation and evolution of X-ray binaries on very long timescales. In this paper, we present results from large-scale population synthesis models of binary populations in galaxies from z = 0 to 20. We use as input into our modeling the Millennium II Cosmological Simulation and the updated semi-analytic galaxy catalog by Guo et al. (2011) to self-consistently account for the star formation history (SFH) and metallicity evolution of each galaxy. We run a grid of 192 models, varying all the parameters known from previous studies to affect the evolution of XRBs. We use our models and observationally derived prescriptions for hot gas emission to create theoretical galaxy X-ray luminosity functions (XLFs) for several redshift bins. Models with low CE efficiencies, a 50% twins mass ratio distribution, a steeper IMF exponent, and high stellar wind mass loss rates best match observational results from Tzanavaris & Georgantopoulos (2008), though they significantly underproduce bright early-type and very bright (Lx > 10d41) late-type galaxies. These discrepancies are likely caused by uncertainties in hot gas emission and SFHs, AGN contamination, and a lack of dynamically formed Low-mass XRBs. In our highest likelihood models, we find that hot gas emission dominates the emission for most bright galaxies. We also find that the evolution of the normal galaxy X-ray luminosity density out to z = 4 is driven largely by XRBs in galaxies with X-ray luminosities between 10d40 and 10d41 erg/s.Comment: Accepted into ApJ, 17 pages, 3 tables, 7 figures. Text updated to address referee's comment

Supplement: Going the Distance: Mapping Host Galaxies of LIGO and Virgo Sources in Three Dimensions Using Local Cosmography and Targeted Follow-up

This is a supplement to the Letter of Singer et al. (https://arxiv.org/abs/1603.07333), in which we demonstrated a rapid algorithm for obtaining joint 3D estimates of sky location and luminosity distance from observations of binary neutron star mergers with Advanced LIGO and Virgo. We argued that combining the reconstructed volumes with positions and redshifts of possible host galaxies can provide large-aperture but small field of view instruments with a manageable list of targets to search for optical or infrared emission. In this Supplement, we document the new HEALPix-based file format for 3D localizations of gravitational-wave transients. We include Python sample code to show the reader how to perform simple manipulations of the 3D sky maps and extract ranked lists of likely host galaxies. Finally, we include mathematical details of the rapid volume reconstruction algorithm.Comment: For associated data release, see http://asd.gsfc.nasa.gov/Leo.Singer/going-the-distanc