6,431 research outputs found

### Euclidean Supersymmetry, Twisting and Topological Sigma Models

We discuss two dimensional N-extended supersymmetry in Euclidean signature
and its R-symmetry. For N=2, the R-symmetry is SO(2)\times SO(1,1), so that
only an A-twist is possible. To formulate a B-twist, or to construct Euclidean
N=2 models with H-flux so that the target geometry is generalised Kahler, it is
necessary to work with a complexification of the sigma models. These issues are
related to the obstructions to the existence of non-trivial twisted chiral
superfields in Euclidean superspace.Comment: 8 page

### New Gauged N=8, D=4 Supergravities

New gaugings of four dimensional N=8 supergravity are constructed, including
one which has a Minkowski space vacuum that preserves N=2 supersymmetry and in
which the gauge group is broken to $SU(3)xU(1)^2$. Previous gaugings used the
form of the ungauged action which is invariant under a rigid $SL(8,R)$ symmetry
and promoted a 28-dimensional subgroup ($SO(8),SO(p,8-p)$ or the
non-semi-simple contraction $CSO(p,q,8-p-q)$) to a local gauge group. Here, a
dual form of the ungauged action is used which is invariant under $SU^*(8)$
instead of $SL(8,R)$ and new theories are obtained by gauging 28-dimensional
subgroups of $SU^*(8)$. The gauge groups are non-semi-simple and are different
real forms of the $CSO(2p,8-2p)$ groups, denoted $CSO^*(2p,8-2p)$, and the new
theories have a rigid SU(2) symmetry. The five dimensional gauged N=8
supergravities are dimensionally reduced to D=4. The $D=5,SO(p,6-p)$ gauge
theories reduce, after a duality transformation, to the $D=4,CSO(p,6-p,2)$
gauging while the $SO^*(6)$ gauge theory reduces to the $D=4, CSO^*(6,2)$ gauge
theory. The new theories are related to the old ones via an analytic
continuation. The non-semi-simple gaugings can be dualised to forms with
different gauge groups.Comment: 33 pages. Reference adde

### D=6, N=2, F(4)-Supergravity with supersymmetric de Sitter Background

We show that there exists a supersymmetric de Sitter background for the D=6,
N=2, F(4) supergravity preserving the compact R-symmetry and gauging with
respect to the conventional Anti de Sitter version of the theory. We construct
the gauged matter coupled F(4) de Sitter supergravity explicitly and show that
it contains ghosts in the vector sector.Comment: 19 pages, Late

### Behavioural and cognitive sex/gender differences in autism spectrum condition and typically developing males and females

Studies assessing sex/gender differences in autism spectrum conditions often fail to include typically developing control groups. It is, therefore, unclear whether observed sex/gender differences reflect those found in the general population or are particular to autism spectrum conditions. A systematic search identified articles comparing behavioural and cognitive characteristics in males and females with and without an autism spectrum condition diagnosis. A total of 13 studies were included in meta-analyses of sex/gender differences in core autism spectrum condition symptoms (social/communication impairments and restricted/repetitive behaviours and interests) and intelligence quotient. A total of 20 studies were included in a qualitative review of sex/gender differences in additional autism spectrum condition symptoms. For core traits and intelligence quotient, sex/gender differences were comparable in autism spectrum conditions and typical samples. Some additional autism spectrum condition symptoms displayed different patterns of sex/gender differences in autism spectrum conditions and typically developing groups, including measures of executive function, empathising and systemising traits, internalising and externalising problems and play behaviours. Individuals with autism spectrum conditions display typical sex/gender differences in core autism spectrum condition traits, suggesting that diagnostic criteria based on these symptoms should take into account typical sex/gender differences. However, awareness of associated autism spectrum condition symptoms should include the possibility of different male and female phenotypes, to ensure those who do not fit the ‘typical’ autism spectrum condition presentation are not missed

### Patient safety and estimation of renal function in patients prescribed new oral anticoagulants for stroke prevention in atrial fibrillation

OBJECTIVE: In clinical trials of dabigatran and rivaroxaban for stroke prevention in atrial fibrillation (AF), drug eligibility and dosing were determined using the Cockcroft-Gault equation to estimate creatine clearance as a measure of renal function. This cross-sectional study aimed to compare whether using estimated glomerular filtration rate (eGFR) by the widely available and widely used Modified Diet in Renal Disease (MDRD) equation would alter prescribing or dosing of the renally excreted new oral anticoagulants. PARTICIPANTS: Of 4712 patients with known AF within a general practitioner-registered population of 930 079 in east London, data were available enabling renal function to be calculated by both Cockcroft-Gault and MDRD methods in 4120 (87.4%). RESULTS: Of 4120 patients, 2706 were <80 years and 1414 were ≥80 years of age. Among those ≥80 years, 14.9% were ineligible for dabigatran according to Cockcroft-Gault equation but would have been judged eligible applying MDRD method. For those <80 years, 0.8% would have been incorrectly judged eligible for dabigatran and 5.3% would have received too high a dose. For rivaroxaban, 0.3% would have been incorrectly judged eligible for treatment and 13.5% would have received too high a dose. CONCLUSIONS: Were the MDRD-derived eGFR to be used instead of Cockcroft-Gault in prescribing these new agents, many elderly patients with AF would either incorrectly become eligible for them or would receive too high a dose. Safety has not been established using the MDRD equation, a concern since the risk of major bleeding would be increased in patients with unsuspected renal impairment. Given the potentially widespread use of these agents, particularly in primary care, regulatory authorities and drug companies should alert UK doctors of the need to use the Cockcroft-Gault formula to calculate eligibility for and dosing of the new oral anticoagulants in elderly patients with AF and not rely on the MDRD-derived eGFR

### ALMA Science Verification Data: Millimeter Continuum Polarimetry of the Bright Radio Quasar 3C 286

We present full-polarization observations of the compact, steep-spectrum
radio quasar 3C~286 made with the ALMA at 1.3~mm. These are the first
full-polarization ALMA observations, which were obtained in the framework of
Science Verification. A bright core and a south-west component are detected in
the total intensity image, similar to previous centimeter images. Polarized
emission is also detected toward both components. The fractional polarization
of the core is about 17\%, this is higher than the fractional polarization at
centimeter wavelengths, suggesting that the magnetic field is even more ordered
in the millimeter radio core than it is further downstream in the jet. The
observed polarization position angle (or EVPA) in the core is
$\sim$\,$39^{\circ}$, which confirms the trend that the EVPA slowly increases
from centimeter to millimeter wavelengths. With the aid of multi-frequency VLBI
observations, we argue that this EVPA change is associated with the
frequency-dependent core position. We also report a serendipitous detection of
a sub-mJy source in the field of view, which is likely to be a submillimeter
galaxy.Comment: 10 pages, 9 figures, Accepted for publication in the Ap

### T-duality in the weakly curved background

We consider the closed string propagating in the weakly curved background
which consists of constant metric and Kalb-Ramond field with infinitesimally
small coordinate dependent part. We propose the procedure for constructing the
T-dual theory, performing T-duality transformations along coordinates on which
the Kalb-Ramond field depends. The obtained theory is defined in the
non-geometric double space, described by the Lagrange multiplier $y_\mu$ and
its $T$-dual $\tilde{y}_\mu$. We apply the proposed T-duality procedure to the
T-dual theory and obtain the initial one. We discuss the standard relations
between T-dual theories that the equations of motion and momenta modes of one
theory are the Bianchi identities and the winding modes of the other

### Super Weyl invariance: BPS equations from heterotic worldsheets

It is well-known that the beta functions on a string worldsheet correspond to
the target space equations of motion, e.g. the Einstein equations. We show that
the BPS equations, i.e. the conditions of vanishing supersymmetry variations of
the space-time fermions, can be directly derived from the worldsheet. To this
end we consider the RNS-formulation of the heterotic string with (2,0)
supersymmetry, which describes a complex torsion target space that supports a
holomorphic vector bundle. After a detailed account of its quantization and
renormalization, we establish that the cancellation of the Weyl anomaly
combined with (2,0) finiteness implies the heterotic BPS conditions: At the one
loop level the geometry is required to be conformally balanced and the gauge
background has to satisfy the Hermitean Yang-Mills equations.Comment: 1+31 pages LaTeX, 5 figures; final version, discussion relation Weyl
invariance and (2,0) finiteness extended, typos correcte

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