627 research outputs found
Representations of the -algebra and the loop representation in -dimensions
We consider the phase-space of Yang-Mills on a cylindrical space-time () and the associated algebra of gauge-invariant functions, the
-variables. We solve the Mandelstam identities both classically and
quantum-mechanically by considering the -variables as functions of the
eigenvalues of the holonomy and their associated momenta. It is shown that
there are two inequivalent representations of the quantum -algebra. Then we
compare this reduced phase space approach to Dirac quantization and find it to
give essentially equivalent results. We proceed to define a loop representation
in each of these two cases. One of these loop representations (for ) is
more or less equivalent to the usual loop representation.Comment: 15 pages, LaTeX, 1 postscript figure included, uses epsf.sty,
G\"oteborg ITP 93-3
Loop Correlators and Theta States in 2D Yang-Mills Theory
Explicit computations of the partition function and correlation functions of
Wilson and Polyakov loop operators in theta-sectors of two dimensional
Yang-Mills theory on the line cylinder and torus are presented. Several
observations about the correspondence of two dimensional Yang-Mills theory with
unitary matrix quantum mechanics are presented. The incorporation of the
theta-angle which characterizes the states of two dimensional adjoint QCD is
discussed.Comment: 30 pages, Latex, no figure
Magnetic moment interaction in the anyon superconductor
Magnetic moment interaction is shown to play a defining role in the magnetic
properties of anyon superconductors. The necessary condition for the existence
of the Meissner effect is found.Comment: 4 pages, Revtex, to appear in Phys. Rev. B, corrected typo
Antiferromagnetic S=1/2 Heisenberg Chain and the Two-flavor Massless Schwinger Model
An antiferromagnetic S=1/2 Heisenberg chain is mapped to the two-flavor
massless Schwinger model at \theta=\pi. The electromagnetic coupling constant
and velocity of light in the Schwinger model are determined in terms of the
Heisenberg coupling and lattice spacing in the spin chain system.Comment: 3 pages. LaTex2
Evidence Map of Prevention and Treatment Interventions for Depression in Young People
Introduction. Depression in adolescents and young people is associated with reduced social, occupational, and interpersonal functioning, increases in suicide and self-harm behaviours, and problematic substance use. Age-appropriate, evidence-based treatments are required to provide optimal care. Methods. “Evidence mapping” methodology was used to quantify the nature and distribution of the extant high-quality research into the prevention and treatment of depression in young people across psychological, medical, and other treatment domains. Results. Prevention research is dominated by cognitive-behavioral- (CBT-) based interventions. Treatment studies predominantly consist of CBT and SSRI medication trials, with few trials of other psychological interventions or complementary/alternative treatments. Quality studies on relapse prevention and treatment for persistent depression are distinctly lacking. Conclusions. This map demonstrates opportunities for future research to address the numerous evidence gaps for interventions to prevent or treat depression in young people, which are of interest to clinical researchers, policy makers, and funding bodies
Evidence Map of Prevention and Treatment Interventions for Depression in Young People
Introduction. Depression in adolescents and young people is associated with reduced social, occupational, and interpersonal functioning, increases in suicide and self-harm behaviours, and problematic substance use. Age-appropriate, evidence-based treatments are required to provide optimal care. Methods. “Evidence mapping” methodology was used to quantify the nature and distribution of the extant high-quality research into the prevention and treatment of depression in young people across psychological, medical, and other treatment domains. Results. Prevention research is dominated by cognitive-behavioral- (CBT-) based interventions. Treatment studies predominantly consist of CBT and SSRI medication trials, with few trials of other psychological interventions or complementary/alternative treatments. Quality studies on relapse prevention and treatment for persistent depression are distinctly lacking. Conclusions. This map demonstrates opportunities for future research to address the numerous evidence gaps for interventions to prevent or treat depression in young people, which are of interest to clinical researchers, policy makers, and funding bodies
Is there a gap between recommended and ‘real world’ practice in the management of depression in young people? : a medical file audit of practice
Background:
Literature has shown that dissemination of guidelines alone is insufficient to ensure that guideline recommendations are incorporated into every day clinical practice.
Methods:
We aimed to investigate the gaps between guideline recommendations and clinical practice in the management of young people with depression by undertaking an audit of medical files in a catchment area public mental health service for 15 to 25 year olds in Melbourne, Australia.
Results:
The results showed that the assessment and recording of depression severity to ensure appropriate treatment planning was not systematic nor consistent; that the majority of young people (74.5%) were prescribed an antidepressant before an adequate trial of psychotherapy was undertaken and that less than 50% were monitored for depression symptom improvement and antidepressant treatment emergent suicide related behaviours (35% and 30% respectively). Encouragingly 92% of first line prescriptions for those aged 18 years or under who were previously antidepressant-naïve was for fluoxetine as recommended.
Conclusions:
This research has highlighted the need for targeted strategies to ensure effective implementation. These strategies might include practice system tools that allow for systematic monitoring of depression symptoms and adverse side effects, particularly suicide related behaviours. Additionally, youth specific psychotherapy that incorporates the most effective components for this age group, delivered in a youth friendly way would likely aid effective implementation of guideline recommendations for engagement in an adequate trial of psychotherapy before medication is initiated
The experience of young people receiving cognitive behavioural therapy for major depression : A qualitative study
Aim
Major depressive disorder (MDD) has far reaching impacts for young people, their families and society. Cognitive behavioural therapy (CBT) is one of the first-line treatments for young people experiencing MDD; however, there is limited research examining how young people with MDD experience CBT. The aim of this study was to explore their experience and their views of this intervention.
Methods
We employed a qualitative research design, with semi-structured interviews and thematic analysis. Eight participants aged between 17 and 24 years who received CBT for MDD in a randomized controlled trial were recruited.
Results
Five themes were identified: the importance of relationship with clinician; the range of useful components within CBT; the ability for CBT to accommodate different techniques and presenting issues; the importance of checking in with clients during the process of therapy; and the impacts of MDD on therapy.
Conclusions
The findings highlight the importance of clinicians having a youth friendly and collaborative approach that allows a modular delivery of a range of CBT techniques to suit the client's presenting issue and formulation. There is a need to continually check how young people are responding to interventions, and to be aware of potential cognitive deficits and adjust therapy accordingly. This is a small study that provides insight into how young people with MDD experience CBT and avenues to explore for tailoring provision of CBT to enhance the therapeutic experience for this population
Chiral Symmetry Breaking on the Lattice: a Study of the Strongly Coupled Lattice Schwinger Model
We revisit the strong coupling limit of the Schwinger model on the lattice
using staggered fermions and the hamiltonian approach to lattice gauge
theories. Although staggered fermions have no continuous chiral symmetry, they
posses a discrete axial invari ance which forbids fermion mass and which must
be broken in order for the lattice Schwinger model to exhibit the features of
the spectrum of the continuum theory. We show that this discrete symmetry is
indeed broken spontaneously in the strong coupling li mit. Expanding around a
gauge invariant ground state and carefully considering the normal ordering of
the charge operator, we derive an improved strong coupling expansion and
compute the masses of the low lying bosonic excitations as well as the chiral
co ndensate of the model. We find very good agreement between our lattice
calculations and known continuum values for these quantities already in the
fourth order of strong coupling perturbation theory. We also find the exact
ground state of the antiferromag netic Ising spin chain with long range Coulomb
interaction, which determines the nature of the ground state in the strong
coupling limit.Comment: 24 pages, Latex, no figure
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