1,173 research outputs found
Neural network classification of eigenmodes in the magnetohydrodynamic spectroscopy code Legolas
JDJ was supported by funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme, Grant agreement No. 833251 PROMINENT ERC-ADG 2018.A neural network is employed to address a non-binary classification problem of plasma instabilities in astrophysical jets, calculated with the Legolas code. The trained models exhibit reliable performance in the identification of the two instability types supported by these jets. We also discuss the generation of artificial data and refinement of predictions in general eigenfunction classification problems.Peer reviewe
The BPHZ renormalised BV master equation and Two-loop Anomalies in Chiral Gravities
Anomalies and BRST invariance are governed, in the context of Lagrangian
Batalin-Vilkovisky quantization, by the master equation, whose classical limit
is . Using Zimmerman's normal products and the BPHZ renormalisation
method, we obtain a corresponding local quantum operator equation, which is
valid to all orders in perturbation theory. The formulation implies a
calculational method for anomalies to all orders that is useful also outside
the BV context and that remains completely within regularised perturbation
theory. It makes no difference in principle whether the anomaly appears at one
loop or at higher loops. The method is illustrated by computing the one- and
two-loop anomalies in chiral gravity.Comment: 44 pages, LaTex. 4 figures, epsf. Discussion in section 4 extended,
assorted small modifications, 3 references added. As it will be published in
NP
Superspace formulation of general massive gauge theories and geometric interpretation of mass-dependent BRST symmetries
A superspace formulation is proposed for the osp(1,2)-covariant Lagrangian
quantization of general massive gauge theories. The superalgebra os0(1,2) is
considered as subalgebra of sl(1,2); the latter may be considered as the
algebra of generators of the conformal group in a superspace with two
anticommuting coordinates. The mass-dependent (anti)BRST symmetries of proper
solutions of the quantum master equations in the osp(1,2)-covariant formalism
are realized in that superspace as invariance under translations combined with
mass-dependent special conformal transformations. The Sp(2) symmetry - in
particular the ghost number conservation - and the "new ghost number"
conservation are realized as invariance under symplectic rotations and
dilatations, respectively. The transformations of the gauge fields - and of the
full set of necessarily required (anti)ghost and auxiliary fields - under the
superalgebra sl(1,2) are determined both for irreducible and first-stage
reducible theories with closed gauge algebra.Comment: 35 pages, AMSTEX, precision of reference
The SU(2) Skyrme model and anomaly
The SU(2) Skyrme model,expanding in the collective coordinates variables,
gives rise to second-class constraints. Recently this system was embedded in a
more general Abelian gauge theory using the BFFT Hamiltonian method. In this
work we quantize this gauge theory computing the Noether current anomaly using
for this two different methods: an operatorial Dirac first class formalism and
the non-local BV quantization coupled with the Fujikawa regularization
procedure.Comment: 6 pages, Revtex. Final version to be published in Physics Letters
Nonsense mutations in alpha-II spectrin in three families with juvenile onset hereditary motor neuropathy
Distal hereditary motor neuropathies are a rare subgroup of inherited peripheral neuropathies hallmarked by a length-dependent axonal degeneration of lower motor neurons without significant involvement of sensory neurons. We identified patients with heterozygous nonsense mutations in the alpha II-spectrin gene, SPTAN1, in three separate dominant hereditary motor neuropathy families via next-generation sequencing. Variable penetrance was noted for these mutations in two of three families, and phenotype severity differs greatly between patients. The mutant mRNA containing nonsense mutations is broken down by nonsense-mediated decay and leads to reduced protein levels in patient cells. Previously, dominant-negative alpha II-spectrin gene mutations were described as causal in a spectrum of epilepsy phenotypes
Integrated Project Support Study Group : findings
The challenges of the LHC project have lead CERN to produce a comprehensive set of project management tools covering engineering data management, project scheduling and costing, event management and document management. Each of these tools represents a significant and world-recognised advance in their respective domains. Reviewing the offering on the eve of LHC commissioning one can identify three major challenges: 1. How to integrate the tools to provide a uniform and integrated full-product lifecycle solution 2. How to evolve the functionality in certain areas to address weaknesses identified with our experience in constructing the LHC and integrate emerging industry best practices 3. How to coherently package the offering not just for future projects in CERN, but moreover in the context of providing a centre of excellence for worldwide collaboration in future HEP projects
Dose-effect relations in time-limited combined psycho-pharmacological treatment for depression
BACKGROUND: A limited number of psychotherapy sessions in combination with medication is preferable to pharmacotherapy only in the treatment of ambulatory patients with major depression. Whether there is a relation between the number of sessions and the efficacy of the treatment is uncertain. METHOD: Randomized clinical trial comparing two treatment conditions in outpatients with major depression. All patients studied had a baseline score of at least 14 points on the 17-item Hamilton Depression Rating Scale. The two conditions consist of 8-session or 16-session Short Psychodynamic Supportive Psychotherapy, both in combination with pharmacotherapy. Efficacy was assessed using the 17-item HDRS, the CGI of Severity and of Improvement, the depression subscale of the SCL-90 and the Quality of Life Depression Scale. RESULTS: The rate of change would seem to indicate that eight sessions are preferable for both moderately and severely depressed patients, although the results converged again at the end. Furthermore, in terms of satisfaction with the number of sessions and drop-out percentages during treatment, no differences were found between the conditions. CONCLUSION: In the light of the outcome analysis (faster remission after fewer sessions), a short version of the psychotherapy treatment in a combined course of treatment seems to be justifie
Multisystem proteinopathy due to a homozygous p.Arg159His VCP mutation : a tale of the unexpected
ObjectiveTo assess the clinical, radiologic, myopathologic, and proteomic findings in a patient manifesting a multisystem proteinopathy due to a homozygous valosin-containing protein gene (VCP) mutation previously reported to be pathogenic in the heterozygous state.MethodsWe studied a 36-year-old male index patient and his father, both presenting with progressive limb-girdle weakness. Muscle involvement was assessed by MRI and muscle biopsies. We performed whole-exome sequencing and Sanger sequencing for segregation analysis of the identified p.Arg159His VCP mutation. To dissect biological disease signatures, we applied state-of-the-art quantitative proteomics on muscle tissue of the index case, his father, 3 additional patients with VCP-related myopathy, and 3 control individuals.ResultsThe index patient, homozygous for the known p.Arg159His mutation in VCP, manifested a typical VCP-related myopathy phenotype, although with a markedly high creatine kinase value and a relatively early disease onset, and Paget disease of bone. The father exhibited a myopathy phenotype and discrete parkinsonism, and multiple deceased family members on the maternal side of the pedigree displayed a dementia, parkinsonism, or myopathy phenotype. Bioinformatic analysis of quantitative proteomic data revealed the degenerative nature of the disease, with evidence suggesting selective failure of muscle regeneration and stress granule dyshomeostasis.ConclusionWe report a patient showing a multisystem proteinopathy due to a homozygous VCP mutation. The patient manifests a severe phenotype, yet fundamental disease characteristics are preserved. Proteomic findings provide further insights into VCP-related pathomechanisms
Global Anomalies in the Batalin Vilkovisky Quantization
The Batalin Vilkovisky (BV) quantization provides a general procedure for
calculating anomalies associated to gauge symmetries. Recent results show that
even higher loop order contributions can be calculated by introducing an
appropriate regularization-renormalization scheme. However, in its standard
form, the BV quantization is not sensible to quantum violations of the
classical conservation of Noether currents, the so called global anomalies. We
show here that the BV field antifield method can be extended in such a way that
the Ward identities involving divergencies of global Abelian currents can be
calculated from the generating functional, a result that would not be obtained
by just associating constant ghosts to global symmetries. This extension,
consisting of trivially gauging the global Abelian symmetries, poses no extra
obstruction to the solution of the master equation, as it happens in the case
of gauge anomalies. We illustrate the procedure with the axial model and also
calculating the Adler Bell Jackiw anomaly.Comment: We emphasized the fact that our procedure only works for the case of
Abelian global anomalies. Section 3 was rewritten and some references were
added. 12 pages, LATEX. Revised version that will appear in Phys. Rev.
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