5,433 research outputs found
Gender Politics and Secure Services For Women: Reflections on a study of staff understandings of challenging behaviour.
This paper discusses the findings of a Q methodological study that investigated the complexity of professional understandings of (attitudes towards) residents in a secure unit for women with learning disabilities and challenging behaviours. Particular attention is afforded to the critical debate regarding women in psychiatric and secure care, including the significant contribution made to this literature by feminist perspectives. A multiprofessional group of staff (n = 38) participated in the study and nine distinct accounts of women's challenging behaviour are described. Despite a considerable amount of recent policy concern with the position of women in psychiatric services, the findings of this research suggest that many front line staff are reluctant to highlight gender in their explanations of women's behaviour. This supports the assertion by Williams et al. (2001), who were involved in the National Gender Training Initiative (NGTI), that most critical theorizing about women's mental health has had minimal impact at the level of individuals’ understandings of these important issues. This state of affairs suggests a powerful case for the expansion of staff training as provided in the NGTI, which makes gender central to understanding and emphasizes feminist perspectives
The Local Environments of Core-Collapse SNe within Host Galaxies
We present constraints on core-collapse supernova progenitors through
observations of their environments within host galaxies. This is achieved
through 2 routes. Firstly, we investigate the spatial correlation of supernovae
with host galaxy star formation using pixel statistics. We find that the main
supernova types form a sequence of increasing association to star formation.
The most logical interpretation is that this implies an increasing progenitor
mass sequence going from the supernova type Ia arising from the lowest mass,
through the type II, type Ib, and the supernova type Ic arising from the
highest mass progenitors. We find the surprising result that the supernova type
IIn show a lower association to star formation than type IIPs, implying lower
mass progenitors. Secondly, we use host HII region spectroscopy to investigate
differences in environment metallicity between different core-collapse types.
We find that supernovae of types Ibc arise in slightly higher metallicity
environments than type II events. However, this difference is not significant,
implying that progenitor metallicity does not play a dominant role in deciding
supernova type.Comment: to appear in Proceedings of IAU 279 "Death of Massive Stars:
Supernovae and Gamma-ray Bursts
In situ imaging of vortices in Bose-Einstein condensates
Laboratory observations of vortex dynamics in Bose-Einstein condensates
(BECs) are essential for determination of many aspects of superfluid dynamics
in these systems. We present a novel application of dark-field imaging that
enables \texttt{\it in situ} detection of two-dimensional vortex distributions
in single-component BECs, a step towards real-time measurements of complex
two-dimensional vortex dynamics within a single BEC. By rotating a Rb
BEC in a magnetic trap, we generate a triangular lattice of vortex cores in the
BEC, with core diameters on the order of 400 nm and cores separated by
approximately 9 m. We have experimentally confirmed that the positions of
the vortex cores can be determined without the need for ballistic expansion of
the BEC.Comment: 5 pages, 4 figure
Visual preference for social stimuli in individuals with autism or neurodevelopmental disorders : an eye-tracking study
Background
Recent research has identified differences in relative attention to competing social versus non-social video stimuli in individuals with autism spectrum disorder (ASD). Whether attentional allocation is influenced by the potential threat of stimuli has yet to be investigated. This is manipulated in the current study by the extent to which the stimuli are moving towards or moving past the viewer. Furthermore, little is known about whether such differences exist across other neurodevelopmental disorders. This study aims to determine if adolescents with ASD demonstrate differences in attentional allocation to competing pairs of social and non-social video stimuli, where the actor or object either moves towards or moves past the viewer, in comparison to individuals without ASD, and to determine if individuals with three genetic syndromes associated with differing social phenotypes demonstrate differences in attentional allocation to the same stimuli.
Methods
In study 1, adolescents with ASD and control participants were presented with social and non-social video stimuli in two formats (moving towards or moving past the viewer) whilst their eye movements were recorded. This paradigm was then employed with groups of individuals with fragile X, Cornelia de Lange, and Rubinstein-Taybi syndromes who were matched with one another on chronological age, global adaptive behaviour, and verbal adaptive behaviour (study 2).
Results
Adolescents with ASD demonstrated reduced looking-time to social versus non-social videos only when stimuli were moving towards them. Individuals in the three genetic syndrome groups showed similar looking-time but differences in fixation latency for social stimuli moving towards them. Across both studies, we observed within- and between-group differences in attention to social stimuli that were moving towards versus moving past the viewer.
Conclusions
Taken together, these results provide strong evidence to suggest differential visual attention to competing social versus non-social video stimuli in populations with clinically relevant, genetically mediated differences in socio-behavioural phenotypes
Serendipitous discovery of a strong-lensed galaxy in integral field spectroscopy from MUSE
2MASX J04035024-0239275 is a bright red elliptical galaxy at redshift 0.0661
that presents two extended sources at 2\arcsec~to the north-east and
1\arcsec~to the south-west. The sizes and surface brightnesses of the two blue
sources are consistent with a gravitationally-lensed background galaxy. In this
paper we present MUSE observations of this galaxy from the All-weather MUse
Supernova Integral-field Nearby Galaxies (AMUSING) survey, and report the
discovery of a background lensed galaxy at redshift 0.1915, together with other
15 background galaxies at redshifts ranging from 0.09 to 0.9, that are not
multiply imaged. We have extracted aperture spectra of the lens and all the
sources and fit the stellar continuum with STARLIGHT to estimate their stellar
and emission line properties. A trace of past merger and active nucleus
activity is found in the lensing galaxy, while the background lensed galaxy is
found to be star-forming. Modeling the lensing potential with a singular
isothermal ellipsoid, we find an Einstein radius of 1\farcs450\farcs04,
which corresponds to 1.9 kpc at the redshift of the lens and it is much smaller
than its effective radius ( 9\arcsec). Comparing the Einstein
mass and the STARLIGHT stellar mass within the same aperture yields a dark
matter fraction of \% within the Einstein radius. The advent of
large surveys such as the Large Synoptic Survey Telescope (LSST) will discover
a number of strong-lensed systems, and here we demonstrate how wide-field
integral field spectroscopy offers an excellent approach to study them and to
precisely model lensing effects.Comment: 12 pages, 12 Figures, 4 Tables. Accepted in MNRA
Type Ibc supernovae in disturbed galaxies: evidence for a top-heavy IMF
We compare the radial locations of 178 core-collapse supernovae to the R-band
and H alpha light distributions of their host galaxies. When the galaxies are
split into `disturbed' and `undisturbed' categories, a striking difference
emerges. The disturbed galaxies have a central excess of core-collapse
supernovae, and this excess is almost completely dominated by supernovae of
types Ib, Ic and Ib/c, whereas type II supernovae dominate in all other
environments. The difference cannot easily be explained by metallicity or
extinction effects, and thus we propose that this is direct evidence for a
stellar initial mass function that is strongly weighted towards high mass
stars, specifically in the central regions of disturbed galaxies.Comment: 22 pages, 5 figures, accepted for publication in Ap
Atomistic Simulations of Novel Nanoscale Semiconductor Devices: Resistance Switches and Two-dimensional Transistors
As transistors get smaller, we are achieving record levels of memory density. However, there is a limit to how small transistors can be made before their functionality breaks down. Thus alternatives to traditional transistor technology are needed. The two such technologies we examined are: resistance switching devices, which reversibly grow metal filaments through a dielectric, and two-dimensional transistors, which are capable of breaking through the scalability limit of traditional transistors. In order to design resistance switching devices which create filaments with some level of consistency, the dynamics of the filament formation need to be explored. Herein we model this process using molecular dynamics (MD) simulations under the influence of external electric fields. We examined a configuration using an atomically sharp microscope tip as the active electrode and polyethylene-oxide and silica as the dielectrics. We observed localized filament formation propagating from the tip. Due to their size, two-dimensional transistors cannot be doped by traditional means. One method of doping is to use electrostatic energy from free ions in an electrolyte solution on the surface of a material. To examine the levels of doping in the system, we investigate the diffusion of free ions in a polyethylene-oxide electrolyte as a function of electric field and ion concentration. We expect our simulations of resistance switches and 2D transistors to guide fabrication of future devices by providing a better understanding of the effect initial parameters have on the evolution of the system
Type II supernova spectral diversity, II: spectroscopic and photometric correlations
We present an analysis of observed trends and correlations between a large range of spectral and photometric parameters of more than 100 type II supernovae (SNe II), during the photospheric phase. We define a common epoch for all SNe of 50 days post-explosion, where the majority of the sample is likely to be under similar physical conditions. Several correlation matrices are produced to search for interesting trends between more than 30 distinct light-curve and spectral properties that characterize the diversity of SNe II. Overall, SNe with higher expansion velocities are brighter, have more rapidly declining light curves, shorter plateau durations, and higher 56Ni masses. Using a larger sample than previous studies, we argue that "Pd" - the plateau duration from the transition of the initial to "plateau" decline rates to the end of the "plateau" - is a better indicator of the hydrogen envelope mass than the traditionally used optically thick phase duration (OPTd: explosion epoch to end of plateau). This argument is supported by the fact that Pd also correlates with s 3, the light-curve decline rate at late times: lower Pd values correlate with larger s 3 decline rates. Large s 3 decline rates are likely related to lower envelope masses, which enables gamma-ray escape. We also find a significant anticorrelation between Pd and s 2 (the plateau decline rate), confirming the long standing hypothesis that faster declining SNe II (SNe IIL) are the result of explosions with lower hydrogen envelope masses and therefore have shorter Pd values.Fil: Gutiérrez, Claudia P.. Universidad de Chile; Chile. University of Southampton; Reino Unido. European Southern Observatory Santiago; Chile. Millennium Institute Of Astrophysics; ChileFil: Anderson, Joseph P.. European Southern Observatory Santiago; ChileFil: Hamuy, Mario. Millennium Institute Of Astrophysics; Chile. Universidad de Chile; ChileFil: González Gaitan, Santiago. Universidad de Chile; Chile. Universidade de Lisboa; Portugal. Millennium Institute Of Astrophysics; ChileFil: Galbany, Lluis. University of Pittsburgh at Johnstown; Estados Unidos. University of Pittsburgh; Estados UnidosFil: Dessart, Luc. Universidad de Chile; ChileFil: Stritzinger, Maximilian D.. University Aarhus; DinamarcaFil: Phillips, Mark M.. Las Campanas Observatory; ChileFil: Morrell, Nidia. Las Campanas Observatory; ChileFil: Folatelli, Gaston. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin
Creation of a trajectory framework that could be sustainable for a continuous exploration of Mars and its moons
As humanity looks to the Cislunar region in recent space flight operations, the question remains: where will technology advance next? Mars is of particular interest with both the public and private sector aiming to get humans on the planet in the coming decades. Investigating stable trajectories in the Mars-Phobos-Deimos system for telecommunications and observation is the next step in developing future mission plans. Innovations in orbital mechanics must be considered, neither the Two Body Problem (2BP) nor the Circular Restricted Three Body Problem (CR3BP) are sufficient to effectively model satellite motion. Instead, in similar fashion to the patched-conics solution of transfers between the influence of celestial bodies, a patched CR3BP-2BP-CR3BP method of propagating the orbits is proposed. To begin, assumptions about Deimos and Phobos will be made—co-planar orbits and spherical symmetry to name a few. Once the problem has been successfully modeled, each assumption will be undone methodically to increase modeling accuracy. Impulsive maneuvers will be considered, as well as low, continuous thrust maneuvers. The aim of this project is to develop a robust, sustainable trajectory framework that can be used in future missions
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