46,713 research outputs found
On Topologically Massive Spin-2 Gauge Theories beyond Three Dimensions
We investigate in which sense, at the linearized level, one can extend the 3D
topologically massive gravity theory beyond three dimensions. We show that, for
each k=1,2,3... a free topologically massive gauge theory in 4k-1 dimensions
can be defined describing a massive "spin-2" particle provided one uses a
non-standard representation of the massive "spin-2" state which makes use of a
two-column Young tableau where each column is of height 2k-1. We work out the
case of k=2, i.e. 7D, and show, by canonical analysis, that the model
describes, unitarily, 35 massive "spin-2" degrees of freedom. The issue of
interactions is discussed and compared with the three-dimensional situation.Comment: 14 pages. v2: minor changes - published versio
Massive Three-Dimensional Supergravity From R+R^2 Action in Six Dimensions
We obtain a three-parameter family of massive N=1 supergravities in three
dimensions from the 3-sphere reduction of an off-shell N=(1,0) six-dimensional
Poincare supergravity that includes a curvature squared invariant. The
three-dimensional theory contains an off-shell supergravity multiplet and an
on-shell scalar matter multiplet. We then generalise this in three dimensions
to an eight-parameter family of supergravities. We also find a duality
relationship between the six-dimensional theory and the N=(1,0) six-dimensional
theory obtained through a T^4 reduction of the heterotic string effective
action that includes the higher-order terms associated with the
supersymmetrisation of the anomaly-cancelling \tr(R\wedge R) term.Comment: Latex, 32 Pages, an equation is corrected, a few new equations and a
number of clarifying remarks are adde
Critical and Non-Critical Einstein-Weyl Supergravity
We construct N=1 supersymmetrisations of some recently-proposed theories of
critical gravity, conformal gravity, and extensions of critical gravity in four
dimensions. The total action consists of the sum of three separately off-shell
supersymmetric actions containing Einstein gravity, a cosmological term and the
square of the Weyl tensor. For generic choices of the coefficients for these
terms, the excitations of the resulting theory around an AdS_4 background
describe massive spin-2 and massless spin-2 modes coming from the metric;
massive spin-1 modes coming from a vector field in the theory; and massless and
massive spin-3/2 modes (with two unequal masses) coming from the gravitino.
These assemble into a massless and a massive N=1 spin-2 multiplet. In critical
supergravity, the coefficients are tuned so that the spin-2 mode in the massive
multiplet becomes massless. In the supersymmetrised extensions of critical
gravity, the coefficients are chosen so that the massive modes lie in a
"window" of lowest energies E_0 such that these ghostlike fields can be
truncated by imposing appropriate boundary conditions at infinity, thus leaving
just positive-norm massless supergravity modes.Comment: 29 page
On-shell versus off-shell equivalence in 3D gravity
A given field theory action determines a set of field equations but other actions may yield equivalent field equations; if so they are on-shell equivalent. They may also be off-shell equivalent, being related by the elimination of auxiliary fields or by local field redefinitions, but this is not guaranteed, as we demonstrate by consideration of the linearized limit
of 3D massive gravity models. Failure to appreciate this subtlety has led to incorrect conclusions in recent studies of the ``Minimal Massive Gravity'' model
Analysis of the essential oil from the leaves of Sesamum radiatum, a potential medication for male infertility factor, by gas chromatography - mass spectrometry
Essential oil was extracted from the dried leaves of Sesamum radiatum by hydro-distillation and analyzed by combined gas chromatography-mass spectrometry. n-Hexadecanoic acid was found to be the major constituent and with three other fatty acids namely, 9,12,15-octadecanoic acid-(Z,Z,Z),dodecanoic acid and tetradecanoic acid constitute 40.64% of the oil. Other constituents include heptatriacontanol, estra–1,3,5(10)–trien-17á-ol, 1-(+)–ascorbic acid, 2,6-dihexadecanoate, ethyl isoallocholate, 18,19–secoyohimban–19-oic acid, 16,17,20,21-tetrahydro-16-(hydroxymethyl)-methyl ester, (15á, 16E)-trans-(2,3-diphenylcyclopropyl) methylphenyl sulfoxide, 1,1-[2-methyl-2-(phenylthio)cyclopropylidene]bis-benzene and phenolics. The presence of some of these constituents in the essential oil provides the scientific evidences for the observed cardiovascular and estrogenic activity as well as curative properties of the plant for male infertility factor, constipation, fungal and bacterial infections and bruises
UK Specialists’ and GDPs’ Use of Systemic and Local Antimicrobial Administration in Periodontal Therapy: A Questionnaire Study
Aim: The aim of the present study was to evaluate the use of antimicrobials, the prescription patterns and the reason(s) for prescribing antimicrobials when treating periodontal disease in selected UK General Dental Practitioner (GDP) and Periodontal Specialists. Materials & Methods: The questionnaire consisted of 21 questions and was sent to 488 Periodontal Specialists and 488 GDPs. Data management and analysis was performed using Microsoft Excel, SPSS® version 22.0 software and frequency distributions, cross tabulation tables and graphs were constructed from the data. Any association between variables was tested at the 5 % level of significance (P≤ 0.05). Results: The questionnaires were completed by the Specialists (38.72%) (n=189) and 23.36% (n=114) of the GDPs. The results indicated that the use of systemic and local antimicrobials followed the current guidelines. Specialists prescribed more systemic antimicrobials than the GDPs, although Specialists limited the use of local antimicrobials. The GDPs reported that decision making was difficult when to use local antimicrobials although recognised that using local antimicrobials were more effective than root surface debridement alone. Other reasons for using antimicrobials were based either on the patient request or patient satisfaction with the treatment. Lower frequency of antimicrobial use was reported in regeneration and implant procedures by both Specialists and GDPs although the Specialists were more inclined to use antibiotics/antimicrobials in these procedures. Conclusions: The results of the study suggested that there was a need for dentists to follow current guidelines when prescribing antibiotics/antimicrobials in order to avoid unnecessary prescriptions, antibiotic resistance and adverse drug reactions
Domain walls and instantons in N=1, d=4 supergravity
We study the supersymmetric sources of (multi-) domain-wall and (multi-)
instanton solutions of generic N=1, d=4 supergravities, that is: the
worldvolume effective actions for said supersymmetric topological defects. The
domain-wall solutions naturally couple to the two 3-forms recently found as
part of the N=1, d=4 tensor hierarchy (i.e. they have two charges in general)
and their tension is the absolute value of the superpotential section L. The
introduction of sources (we study sources with finite and vanishing thickness)
is equivalent to the introduction of local coupling constants and results in
dramatic changes of the solutions. Our results call for a democratic
reformulation of N=1,d=4 supergravity in which coupling constants are,
off-shell, scalar fields. The effective actions for the instantons are always
proportional to the coordinate orthogonal to the twist-free embedding of the
null-geodesic (in the Wick-rotated scalar manifold) describing the instanton.
We show their supersymmetry and find the associated supersymmetric (multi-)
instanton solutions.Comment: 34 pages, 4 figures, references adde
Word-level Symbolic Trajectory Evaluation
Symbolic trajectory evaluation (STE) is a model checking technique that has
been successfully used to verify industrial designs. Existing implementations
of STE, however, reason at the level of bits, allowing signals to take values
in {0, 1, X}. This limits the amount of abstraction that can be achieved, and
presents inherent limitations to scaling. The main contribution of this paper
is to show how much more abstract lattices can be derived automatically from
RTL descriptions, and how a model checker for the general theory of STE
instantiated with such abstract lattices can be implemented in practice. This
gives us the first practical word-level STE engine, called STEWord. Experiments
on a set of designs similar to those used in industry show that STEWord scales
better than word-level BMC and also bit-level STE.Comment: 19 pages, 3 figures, 2 tables, full version of paper in International
Conference on Computer-Aided Verification (CAV) 201
How useful is thrombocytosis in predicting an underlying cancer in primary care? Systematic review protocol
Early diagnosis of cancer is imperative to reduce the cancer burden in the UK and improve cancer survival. Identifying early markers of cancer can help general practitioners to direct patients at the greatest risk of cancer to appropriate investigative services. A raised platelet count, or thrombocytosis, has been linked to malignancy and identified as a marker of poor prognosis in secondary care, but there is little evidence around the importance of this marker in a primary care setting, within a diagnostic context. This review aims to identify and explore the body of evidence concerning the association between thrombocytosis and cancer in primary care. This protocol was produced using guidance from the PRISMA-P statement
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