4,307 research outputs found
Narrative, identity, and recovery from serious mental illness: A life history of a runner
In recent years, researchers have investigated the psychological effects of exercise for people with mental health problems, often by focusing on how exercise may alleviate symptoms of mental illness. In this article I take a different tack to explore the ways in which exercise contributed a sense of meaning, purpose, and identity to the life of one individual named Ben, a runner diagnosed with schizophrenia. Drawing on life history data, I conducted an analysis of narrative to explore the narrative types that underlie Ben's stories of mental illness and exercise. For Ben, serious mental illness profoundly disrupted a pre-existing athletic identity removing agency, continuity, and coherence from his life story. By returning to exercise several years later, Ben reclaimed his athletic identity and reinstated some degree of narrative agency, continuity, and coherence. While the relationships between narrative, identity, and mental health are undoubtedly complex, Ben's story suggests that exercise can contribute to recovery by being a personally meaningful activity which reinforces identity and sense of self
A sodium fluoride sensitive mutant of Aspergillus nidulans
Fluoride is a widely spread naturally occurring substance in many foods and is used extensively for industrial purposes. The addition of fluoride to drinking water has been assumed to be safe. However, a number of studies have indicated that sodium fluoride is both genotoxic and cytotoxic to mammalian cells (Tsutsui et al. 1984 Mut. Res. 139:193-198). There is conflicting evidence suggesting that NaF is not genotoxic (Kram et al. 1978 Mut. Res. 57:51-55; Martin et al. 1979 Mut. Res. 66:159-167; Li et al. 1987 Mut. Res. 192:191-202) and can suppress the activity of polyfunctional alkylating agents (Obe and Slacik-Erben 1973 Mut. Res. 18:369-371)
Local Charge Excesses in Metallic Alloys: a Local Field Coherent Potential Approximation Theory
Electronic structure calculations performed on very large supercells have
shown that the local charge excesses in metallic alloys are related through
simple linear relations to the local electrostatic field resulting from
distribution of charges in the whole crystal.
By including local external fields in the single site Coherent Potential
Approximation theory, we develop a novel theoretical scheme in which the local
charge excesses for random alloys can be obtained as the responses to local
external fields. Our model maintains all the computational advantages of a
single site theory but allows for full charge relaxation at the impurity sites.
Through applications to CuPd and CuZn alloys, we find that, as a general rule,
non linear charge rearrangements occur at the impurity site as a consequence of
the complex phenomena related with the electronic screening of the external
potential. This nothwithstanding, we observe that linear relations hold between
charge excesses and external potentials, in quantitative agreement with the
mentioned supercell calculations, and well beyond the limits of linearity for
any other site property.Comment: 11 pages, 1 table, 7 figure
Virtual-crystal approximation that works: Locating a composition phase boundary in Pb(Zr_{1-x}Ti_3)O_3
We present a new method for modeling disordered solid solutions, based on the
virtual crystal approximation (VCA). The VCA is a tractable way of studying
configurationally disordered systems; traditionally, the potentials which
represent atoms of two or more elements are averaged into a composite atomic
potential. We have overcome significant shortcomings of the standard VCA by
developing a potential which yields averaged atomic properties. We perform the
VCA on a ferroelectric oxide, determining the energy differences between the
high-temperature rhombohedral, low-temperature rhombohedral and tetragonal
phases of Pb(Zr_{1-x}Ti_x)O_3 at x=0.5 and comparing these results to
superlattice calculations and experiment. We then use our new method to
determine the preferred structural phase at x=0.4. We find that the
low-temperature rhombohedral phase becomes the ground state at x=0.4, in
agreement with experimental findings.Comment: 5 pages, no figure
Banishing AdS ghosts with a UV cutoff
A recent attempt to make sense of scalars in AdS with "Neumann boundary
conditions" outside of the usual BF-window
led to pathologies including (depending on the precise context) either IR
divergences or the appearance of ghosts. Here we argue that such ghosts may be
banished by imposing a UV cutoff. It is also possible to achieve this goal in
certain UV completions. An example is the above AdS theory with a radial cutoff
supplemented by particular boundary conditions on the cutoff surface. In this
case we explicitly identify a region of parameter space for which the theory is
ghost free. At low energies, this theory may be interpreted as the standard
dual CFT (defined with "Dirichlet" boundary conditions) interacting with an
extra scalar via an irrelevant interaction. We also discuss the relationship to
recent works on holographic fermi surfaces and quantum criticality.Comment: 20 pages, 9 figure
Screened Coulomb interactions in metallic alloys: I. Universal screening in the atomic sphere approximation
We have used the locally self-consistent Green's function (LSGF) method in
supercell calculations to establish the distribution of the net charges
assigned to the atomic spheres of the alloy components in metallic alloys with
different compositions and degrees of order. This allows us to determine the
Madelung potential energy of a random alloy in the single-site mean field
approximation which makes the conventional single-site density-functional-
theory coherent potential approximation (SS-DFT-CPA) method practically
identical to the supercell LSGF method with a single-site local interaction
zone that yields an exact solution of the DFT problem. We demonstrate that the
basic mechanism which governs the charge distribution is the screening of the
net charges of the alloy components that makes the direct Coulomb interactions
short-ranged. In the atomic sphere approximation, this screening appears to be
almost independent of the alloy composition, lattice spacing, and crystal
structure. A formalism which allows a consistent treatment of the screened
Coulomb interactions within the single-site mean-filed approximation is
outlined. We also derive the contribution of the screened Coulomb interactions
to the S2 formalism and the generalized perturbation method.Comment: 28 pages, 8 figure
Achieving equity through 'gender autonomy': the challenges for VET policy and practice
This paper is based on research carried out in an EU Fifth Framework project on 'Gender and Qualification'. The research partners from five European countries investigated the impact of gender segregation in European labour markets on vocational education and training, with particular regard to competences and qualifications. The research explored the part played by gender in the vocational education and training experiences of (i) young adults entering specific occupations in child care, electrical engineering and food preparation/service (ii) adults changing occupations
The Molecule-Rich Tail of the Peculiar Galaxy NGC 2782 (Arp 215)
We present the first detection of a large quantity of molecular gas in the
extended tail of an interacting galaxy. Using the NRAO 12m telescope, we have
detected CO (1 - 0) at five locations in the eastern tail of the peculiar
starburst galaxy NGC 2782. The CO velocities and narrow (FWHM = 50 km/s) line
widths in these positions agree with those seen in HI, confirming that the
molecular gas is indeed associated with the tail rather than the main disk. As
noted previously, the gas in this tail has an apparent `counter-rotation'
compared to gas in the core of the galaxy, probably because the tails do not
lie in the same plane as the disk. Assuming the standard Galactic conversion
N(H2)/I(CO) factor, these observations indicate a total molecular gas mass of 6
X 10**8 M(sun) in this tail. This may be an underestimate of the total H2 mass
if the gas is metal-poor. This molecular gas mass, and the implied H2/HI mass
ratio of 0.6, are higher than that found in many dwarf irregular galaxies.
Comparison with an available H-alpha map of this galaxy, however, shows that
the rate of star formation in this feature is extremely low relative to the
available molecular gas, compared to L(H-alpha)/M(H2) values for both spiral
and irregular galaxies. Thus the timescale for depletion of the gas in this
feature is very long.Comment: 19 pages, 6 figures, Latex. To appear in the Astronomical Journa
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