The view of AGN-host alignment via reflection spectroscopy

The fuelling of active galactic nuclei (AGN) - via material propagated through the galactic disc or via minor mergers - is expected to leave an imprint on the alignment of the sub-pc disc relative to the host galaxy's stellar disc. Determining the inclination of the inner disc usually relies on the launching angle of the jet; here instead we use the inclination derived from reflection fits to a sample of AGN. We determine the distorting effect of unmodeled Fe XXV/XXVI features and, via extensive simulations, determine the difference in disc inclination resulting from the use of relxill compared to reflionx. We compare inner disc inclinations to those for the host galaxy stellar disc derived from the Hubble formula and, via Monte-Carlo simulations, find a strong lack of a correlation (at >> 5-sigma) implying either widespread feeding via mergers if we assume the sample to be homogeneous, or that radiative disc warps are distorting our view of the emission. However, we find that by removing a small (~1/5) subset of AGN, the remaining sample is consistent with random sampling of an underlying 1:1 correlation (at the 3-sigma level). A heterogenous sample would likely imply that our view is not dominated by radiative disc warps but instead by different feeding mechanisms with the majority consistent with coplanar accretion (although this may be the result of selection bias), whilst a smaller but not insignificant fraction may have been fuelled by minor mergers in the recent history of the host galaxy.Comment: 10 pages, 5 figures, accepted to MNRA

Antenatal corticosteroids for fetal lung maturation: an overview of Cochrane reviews

This is the protocol for a review and there is no abstract. The objectives are as follows: The objective is to summarise the available evidence from Cochrane systematic reviews for the effectiveness and safety of antenatal corticosteroid therapy to improve infant outcomes

Parameter estimation on gravitational waves from neutron-star binaries with spinning components

Inspiraling binary neutron stars are expected to be one of the most significant sources of gravitational-wave signals for the new generation of advanced ground-based detectors. We investigate how well we could hope to measure properties of these binaries using the Advanced LIGO detectors, which began operation in September 2015. We study an astrophysically motivated population of sources (binary components with masses $1.2~\mathrm{M}_\odot$--$1.6~\mathrm{M}_\odot$ and spins of less than $0.05$) using the full LIGO analysis pipeline. While this simulated population covers the observed range of potential binary neutron-star sources, we do not exclude the possibility of sources with parameters outside these ranges; given the existing uncertainty in distributions of mass and spin, it is critical that analyses account for the full range of possible mass and spin configurations. We find that conservative prior assumptions on neutron-star mass and spin lead to average fractional uncertainties in component masses of $\sim 16\%$, with little constraint on spins (the median $90\%$ upper limit on the spin of the more massive component is $\sim 0.7$). Stronger prior constraints on neutron-star spins can further constrain mass estimates, but only marginally. However, we find that the sky position and luminosity distance for these sources are not influenced by the inclusion of spin; therefore, if LIGO detects a low-spin population of BNS sources, less computationally expensive results calculated neglecting spin will be sufficient for guiding electromagnetic follow-up.Comment: 10 pages, 9 figure

Dynamic performance of high frequency floors

This thesis presents an investigation into the dynamic performance of high frequency floors (HFFs) due to walking excitation. The rationale behind the research is the lack of knowledge of the dynamic characteristics of the HFFs and the poor guidance available in estimating the vibration response due to walking excitation. The most recent design guides published for the evaluation of HFF are by the Concrete Centre and the Steel Construction Institute. The design of HFF is based on similar principles used in the design of low frequency floors (LFFs). However, the dynamic characteristics of each floor type are very different, which leads to inaccurate response estimations. The thesis is split into three main sections: the classic source, path, receiver layout. The source, within the scope of this work, is excitation due to walking. HFFs are defined at which resonance will not occur from walking, and are designed for environments that require low levels of vibration. Traditionally, a floor's response to walking was analysed using the harmonic amplitudes of the footfall force. As resonance does not occur, this approach is no longer valid, and a number of different methods were developed, namely the 'kf method', Arup's 'effective impulse', and a polynomial method presented in a European Commission (EC) report. It was shown that each method has a number of flaws and characteristics for a new, improved, footfall model are defined. A new footfall model is created based on a cubic spline fit of 'key points' of the footfall force. The new model included intra-subject variability (i.e. natural variation between each pace rate). The new model was shown to be more accurate than current models recommended in the relevant guidance. Due to the inclusion of variation in the model, the spline force was also valid for LFFs and is therefore the first accurate universal force model. Assessment of the path consisted evaluating current deign methods for HFFs. It was found that for a transient response of floor (i.e. not resonant) a large number of modes contribute to the response. As such, the only simplified guidance suitable for analysis was the guide published by the Concrete Centre. The Concrete Centre guide was then compared with finite element analysis (FEA) and was found to give inaccurate response estimates due to poor estimates of modal mass and mode shapes. HFFs are often large structures containing many floor bays. These multi-bay structures have interesting characteristics, unique to this style of floor. A large parametric study considering the effects of the number of bays within the structure, the size of the floor bay and the stiffness of columns had on the characteristics of the floor. It was found that mode groupings of closely spaced modes exist due to the large number of bays. It was also found the column stiffness affects the modal mass of the floor. Due to the complexities of the large multi-bay floors, a number of methods were investigated to make the analysis process more efficient. A method of modal participation was developed to assess the importance of the large number of modes. The degree of modelling detail that was required in the model was investigated, and it was found that away from areas of interest the structure could be modelled very crudely. Wave propagation analysis was conducted on the floors using the spectral element method (SEM) applied to a grillage model of the floor. It was shown that the SEM had advantages over conventional FEA, including more efficient analysis and the use of semi-infinite elements. Assessment of the receiver consisted of an evaluation of the current generic vibration criteria for sensitive occupancies. The vibration criteria were assessed under a number of different types of responses. It was shown that if a criteria for a sensitive machine was developed using one type of excitation (e.g. pure-tone sine) it could not be compared with the response of another type of excitation (e.g. broadband random). Overall, it was shown that all aspects regarding response estimation of HFFs require further research. The work presented in this thesis adds to the current knowledge surrounding HFFs

Thrombolysis ImPlementation in Stroke (TIPS): evaluating the effectiveness of a strategy to increase the adoption of best evidence practice – protocol for a cluster randomised controlled trial in acute stroke care

BACKGROUND Stroke is a leading cause of death and disability internationally. One of the three effective interventions in the acute phase of stroke care is thrombolytic therapy with tissue plasminogen activator (tPA), if given within 4.5 hours of onset to appropriate cases of ischaemic stroke. OBJECTIVES To test the effectiveness of a multi-component multidisciplinary collaborative approach compared to usual care as a strategy for increasing thrombolysis rates for all stroke patients at intervention hospitals, while maintaining accepted benchmarks for low rates of intracranial haemorrhage and high rates of functional outcomes for both groups at three months. METHODS AND DESIGN A cluster randomised controlled trial of 20 hospitals across 3 Australian states with 2 groups: multi- component multidisciplinary collaborative intervention as the experimental group and usual care as the control group. The intervention is based on behavioural theory and analysis of the steps, roles and barriers relating to rapid assessment for thrombolysis eligibility; it involves a comprehensive range of strategies addressing individual-level and system-level change at each site. The primary outcome is the difference in tPA rates between the two groups post-intervention. The secondary outcome is the proportion of tPA treated patients in both groups with good functional outcomes (modified Rankin Score (mRS <2) and the proportion with intracranial haemorrhage (mRS ≥2), compared to international benchmarks. DISCUSSION TIPS will trial a comprehensive, multi-component and multidisciplinary collaborative approach to improving thrombolysis rates at multiple sites. The trial has the potential to identify methods for optimal care which can be implemented for stroke patients during the acute phase. Study findings will include barriers and solutions to effective thrombolysis implementation and trial outcomes will be published whether significant or not. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry: ACTRN12613000939796

HANS ARP: SCULPTOR AND POET

HANS ARP: SCULPTOR AND POE

EO-1 Data Quality and Sensor Stability with Changing Orbital Precession at the End of a 16 Year Mission

The Earth Observing One (EO-1) satellite has completed 16 years of Earth observations in early 2017. What started as a technology mission to test various new advancements turned into a science and application mission that extended many years beyond the satellites planned life expectancy. EO-1s primary instruments are spectral imagers: Hyperion, the only civilian full spectrum spectrometer (430-2400 nm) in orbit; and the Advanced Land Imager (ALI), the prototype for Landsat-8s pushbroom imaging technology. Both Hyperion and ALI instruments have continued to perform well, but in February 2011 the satellite ran out of the fuel necessary to maintain orbit, which initiated a change in precession rate that led to increasingly earlier equatorial crossing times during its last five years. The change from EO-1s original orbit, when it was formation flying with Landsat-7 at a 10:01am equatorial overpass time, to earlier overpass times results in image acquisitions with increasing solar zenith angles (SZAs). In this study, we take several approaches to characterize data quality as SZAs increased. Our results show that for both EO-1 sensors, atmospherically corrected reflectance products are within 5 to 10 of mean pre-drift products. No marked trend in decreasing quality in ALI or Hyperion is apparent through 2016, and these data remain a high quality resource through the end of the mission

Thrombolysis ImPlementation in Stroke (TIPS): evaluating the effectiveness of a strategy to increase the adoption of best evidence practice – protocol for a cluster randomised controlled trial in acute stroke care

BACKGROUND: Stroke is a leading cause of death and disability internationally. One of the three effective interventions in the acute phase of stroke care is thrombolytic therapy with tissue plasminogen activator (tPA), if given within 4.5 hours of onset to appropriate cases of ischaemic stroke. OBJECTIVES: To test the effectiveness of a multi-component multidisciplinary collaborative approach compared to usual care as a strategy for increasing thrombolysis rates for all stroke patients at intervention hospitals, while maintaining accepted benchmarks for low rates of intracranial haemorrhage and high rates of functional outcomes for both groups at three months. METHODS AND DESIGN: A cluster randomised controlled trial of 20 hospitals across 3 Australian states with 2 groups: multi- component multidisciplinary collaborative intervention as the experimental group and usual care as the control group. The intervention is based on behavioural theory and analysis of the steps, roles and barriers relating to rapid assessment for thrombolysis eligibility; it involves a comprehensive range of strategies addressing individual-level and system-level change at each site. The primary outcome is the difference in tPA rates between the two groups post-intervention. The secondary outcome is the proportion of tPA treated patients in both groups with good functional outcomes (modified Rankin Score (mRS <2) and the proportion with intracranial haemorrhage (mRS ≥2), compared to international benchmarks. DISCUSSION: TIPS will trial a comprehensive, multi-component and multidisciplinary collaborative approach to improving thrombolysis rates at multiple sites. The trial has the potential to identify methods for optimal care which can be implemented for stroke patients during the acute phase. Study findings will include barriers and solutions to effective thrombolysis implementation and trial outcomes will be published whether significant or not. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN1261300093979

Trophic rewilding presents regionally specific opportunities for mitigating climate change

Large-bodied mammalian herbivores can influence processes that exacerbate or mitigate climate change. Herbivore impacts are, in turn, influenced by predators that place top-down forcing on prey species within a given body size range. Here, we explore how the functional composition of terrestrial large herbivore and carnivore guilds vary between three mammal distribution scenarios: Present-Natural, Current-Day, and Extant-Native Trophic (ENT) Rewilding. Considering the effects of herbivore species weakly influenced by top-down forcing, we quantify the relative influence keystone large herbivore guilds have on methane emissions, woody vegetation expansion, fire dynamics, large-seed dispersal, and nitrogen and phosphorous transport potential. We find strong regional differences in the number of herbivores under weak top-down regulation between our three scenarios with important implications for how they will influence climate change relevant processes. Under the Present-Natural non-ruminant, megaherbivore, browsers were a particularly important guild across much of the world. Megaherbivore extinction and range contraction and the arrival of livestock means large, ruminant, grazers have become more dominant. ENT Rewilding can restore the Afrotropics and Indo-Malay to the Present-Natural benchmark, but causes top-down forcing of the largest herbivores to become common place elsewhere. ENT Rewilding will reduce methane emissions, but does not maximise Natural Climate Solution potential