2,186 research outputs found
A Tale of Two Narrow-Line Regions: Ionization, Kinematics, and Spectral Energy Distributions for a Local Pair of Merging Obscured Active Galaxies
We explore the gas ionization and kinematics, as well as the optical--IR
spectral energy distributions for UGC 11185, a nearby pair of merging galaxies
hosting obscured active galactic nuclei (AGNs), also known as SDSS
J181611.72+423941.6 and J181609.37+423923.0 (J1816NE and J1816SW, ). Due to the wide separation between these interacting galaxies ( kpc), observations of these objects provide a rare glimpse of the
concurrent growth of supermassive black holes at an early merger stage. We use
BPT line diagnostics to show that the full extent of the narrow line emission
in both galaxies is photoionized by an AGN and confirm the existence of a
10-kpc-scale ionization cone in J1816NE, while in J1816SW the AGN narrow-line
region is much more compact (1--2 kpc) and relatively undisturbed. Our
observations also reveal the presence of ionized gas that nearly spans the
entire distance between the galaxies which is likely in a merger-induced tidal
stream. In addition, we carry out a spectral analysis of the X-ray emission
using data from {\em XMM-Newton}. These galaxies represent a useful pair to
explore how the [\ion{O}{3}] luminosity of an AGN is dependent on the size of
the region used to explore the extended emission. Given the growing evidence
for AGN "flickering" over short timescales, we speculate that the appearances
and impact of these AGNs may change multiple times over the course of the
galaxy merger, which is especially important given that these objects are
likely the progenitors of the types of systems commonly classified as "dual
AGNs."Comment: 15 pages, 10 figures, accepted by the Astrophysical Journa
An evaluation of the Public Health Responsibility Deal: Informants' experiences and views of the development, implementation and achievements of a pledge-based, public-private partnership to improve population health in England.
: The Coalition Government's Public Health Responsibility Deal (RD) was launched in England in 2011 as a public-private partnership designed to improve public health in the areas of food, alcohol, health at work and physical activity. As part of a larger evaluation, we explored informants' experiences and views about the RD's development, implementation and achievements. : We conducted 44 semi-structured interviews with 50 interviewees, purposively sampled from: RD partners (businesses, public sector and non-governmental organisations); individuals with formal roles in implementing the RD; and non-partners and former partners. Data were analysed thematically: NVivo (10) software was employed to manage the data. : Key motivations underpinning participation were corporate social responsibility and reputational enhancement. Being a partner often involved making pledges related to work already underway or planned before joining the RD, suggesting limited 'added value' from the RD, although some pledge achievements (e.g., food reformulation) were described. Benefits included access to government, while drawbacks included resource implications and the risk of an 'uneven playing field' between partners and non-partners. : To ensure that voluntary agreements like the RD produce gains to public health that would not otherwise have occurred, government needs to: increase participation and compliance through incentives and sanctions, including those affecting organisational reputation; create greater visibility of voluntary agreements; and increase scrutiny and monitoring of partners' pledge activities.<br/
Effect of many-body interactions on the solid-liquid phase-behavior of charge-stabilized colloidal suspensions
The solid-liquid phase-diagram of charge-stabilized colloidal suspensions is
calculated using a technique that combines a continuous Poisson-Boltzmann
description for the microscopic electrolyte ions with a molecular-dynamics
simulation for the macroionic colloidal spheres. While correlations between the
microions are neglected in this approach, many-body interactions between the
colloids are fully included. The solid-liquid transition is determined at a
high colloid volume fraction where many-body interactions are expected to be
strong. With a view to the Derjaguin-Landau-Verwey-Overbeek theory predicting
that colloids interact via Yukawa pair-potentials, we compare our results with
the phase diagram of a simple Yukawa liquid. Good agreement is found at high
salt conditions, while at low ionic strength considerable deviations are
observed. By calculating effective colloid-colloid pair-interactions it is
demonstrated that these differences are due to many-body interactions. We
suggest a density-dependent pair-potential in the form of a truncated Yukawa
potential, and show that it offers a considerably improved description of the
solid-liquid phase-behavior of concentrated colloidal suspensions
Schizotypy and Nicotine, Alcohol, and Cannabis Use in a Non-Psychiatric Sample
Schizotypy is a multidimensional personality construct that is characterized by perceptual abnormalities, social withdrawal, mild suspiciousness, and odd thinking patterns. This study examined the relationship between four dimensions of self-reported schizotypy and substance use involving nicotine, alcohol, and cannabis, in undergraduate students. Results showed that higher levels of disorganized schizotypy, or odd thinking and behavior, were associated with greater indices of use of all three substances. Furthermore, higher cognitive-perceptual schizotypy was selectively associated with cannabis use. Results confirm findings of recent research that has discovered associations among schizotypy and substance use, highlighting links between behavioral traits and use of nicotine, alcohol, and cannabis. This study is one of the first to examine a wide range of schizotypy domains, and to show selective effects of the disorganized domain of schizotypy
High levels of childhood obesity observed among 3- to 7-year-old New Zealand Pacific children is a public health concern.
This cross-sectional, community-based survey was designed to assess attained growth and body composition of 3- to 7-y-old Pacific children (n = 21 boys and 20 girls) living in Dunedin, New Zealand, and to examine nondietary factors associated with the percentage of body fat. Fat mass, lean tissue mass and the percentage of body fat were measured using dual energy X-ray absorptiometry. One trained anthropometrist also measured height, weight, skinfolds (triceps, subscapular) and circumferences (mid-upper arm, chest, waist, calf). Compared with the National Center for Health Statistics and National Health and Examination Surveys I and II reference data, these Pacific children were tall and heavy for their age with high arm-muscle-area-for-height. Median (quartiles) Z-scores for height and BMI-for-age and arm-muscle-area-for-height were 1.33 (0.60, 2.15), 1.20 (0.74, 4.43) and 1.09 (0.63, 1.85), respectively. Their median (quartile) percentage of body fat was 21.8% (15.0, 35.5) of which 38.5% was located in the trunk. The estimated percentage of children classified as obese ranged from 34 to 49% depending on the criterion used. Over 60% of the children had levels of trunk fat above 1 SD of reported age- and sex-specific Z-scores for New Zealand children. The nondietary factors examined (hours of television viewing and hours playing organized sports, as reported by parents) were not associated with variations in the percentage of body fat, after adjusting for age, sex and birth weight. These extremely high levels of obesity and truncal fat among very young New Zealand children will have major public health implications as these children age
Developing implementation research capacity: longitudinal evaluation of the King's College London Implementation Science Masterclass, 2014-2019.
BACKGROUND: Despite an increasing number of training opportunities in implementation science becoming available, the demand for training amongst researchers and practitioners is unmet. To address this training shortfall, we developed the King's College London 'Implementation Science Masterclass' (ISM), an innovative 2-day programme (and currently the largest of its kind in Europe), developed and delivered by an international faculty of implementation experts. METHODS: This paper describes the ISM and provides delegates' quantitative and qualitative evaluations (gathered through a survey at the end of the ISM) and faculty reflections over the period it has been running (2014-2019). RESULTS: Across the 6-year evaluation, a total of 501 delegates have attended the ISM, with numbers increasing yearly from 40 (in 2014) to 147 (in 2019). Delegates represent a diversity of backgrounds and 29 countries from across the world. The overall response rate for the delegate survey was 64.5% (323/501). Annually, the ISM has been rated 'highly' in terms of delegates' overall impression (92%), clear and relevant learning objectives (90% and 94%, respectively), the course duration (85%), pace (86%) and academic level 87%), and the support provided on the day (92%). Seventy-one percent of delegates reported the ISM would have an impact on how they approached their future work. Qualitative feedback revealed key strengths include the opportunities to meet with an international and diverse pool of experts and individuals working in the field, the interactive nature of the workshops and training sessions, and the breadth of topics and contexts covered. CONCLUSIONS: Yearly, the UK ISM has grown, both in size and in its international reach. Rated consistently favourably by delegates, the ISM helps to tackle current training demands from all those interested in learning and building their skills in implementation science. Evaluation of the ISM will continue to be an annual iterative process, reflective of changes in the evidence base and delegates changing needs as the field evolves
J-band variability of M dwarfs in the WFCAM Transit Survey
We present an analysis of the photometric variability of M dwarfs in the Wide Field Camera (WFCAM) Transit Survey. Although periodic light-curve variability in low mass stars is generally dominated by photospheric star spot activity, M dwarf variability in the J band has not been as thoroughly investigated as at visible wavelengths. Spectral type estimates for a sample of over 200 000 objects are made using spectral type-colour relations, and over 9600 dwarfs (J 0.2 mag flaring event from an M4V star in our sample.Peer reviewe
Surface-charge-induced freezing of colloidal suspensions
Using grand-canonical Monte Carlo simulations we investigate the impact of
charged walls on the crystallization properties of charged colloidal
suspensions confined between these walls. The investigations are based on an
effective model focussing on the colloids alone. Our results demonstrate that
the fluid-wall interaction stemming from charged walls has a crucial impact on
the fluid's high-density behavior as compared to the case of uncharged walls.
In particular, based on an analysis of in-plane bond order parameters we find
surface-charge-induced freezing and melting transitions
The Bayesian Spatial Bradley--Terry Model: Urban Deprivation Modeling in Tanzania
Identifying the most deprived regions of any country or city is key if policy
makers are to design successful interventions. However, locating areas with the
greatest need is often surprisingly challenging in developing countries. Due to
the logistical challenges of traditional household surveying, official
statistics can be slow to be updated; estimates that exist can be coarse, a
consequence of prohibitive costs and poor infrastructures; and mass
urbanisation can render manually surveyed figures rapidly out-of-date.
Comparative judgement models, such as the Bradley--Terry model, offer a
promising solution. Leveraging local knowledge, elicited via comparisons of
different areas' affluence, such models can both simplify logistics and
circumvent biases inherent to house-hold surveys. Yet widespread adoption
remains limited, due to the large amount of data existing approaches still
require. We address this via development of a novel Bayesian Spatial
Bradley--Terry model, which substantially decreases the amount of data
comparisons required for effective inference. This model integrates a network
representation of the city or country, along with assumptions of spatial
smoothness that allow deprivation in one area to be informed by neighbouring
areas. We demonstrate the practical effectiveness of this method, through a
novel comparative judgement data set collected in Dar es Salaam, Tanzania.Comment: 23 pages, 7 figures, to be published in the journal of the Royal
Statistical Society: Series
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