268 research outputs found
Superembeddings, Non-Linear Supersymmetry and 5-branes
We examine general properties of superembeddings, i.e., embeddings of
supermanifolds into supermanifolds. The connection between an embedding
procedure and the method of non-linearly realised supersymmetry is clarified,
and we demonstrate how the latter arises as a special case of the former. As an
illustration, the super-5-brane in 7 dimensions, containing a self-dual 3-form
world-volume field strength, is formulated in both languages, and provides an
example of a model where the embedding condition does not suffice to put the
theory on-shell.Comment: plain tex, 28 p
Optical properties of nanowires based on a blend of poly (9,9-dioctylfluorene) [PFO] and poly(9,9-dioctyl fluorene-alt-benzothiadiazole) [F8BT]
Near-field and far-field optical microscopy are used to study the optical properties of nanowires based on a blend of 95% poly (9,9-dioctylfluorene) [PFO] doped with 5% poly (9,9-dioctylfluorene-alt-benzothiadiazole) [F8BT]. Single nanowires were imaged and optical investigations revealed that they act as nanoscale optical waveguides. Investigation using polarization-resolved far-field PL spectroscopy revealed emission from the nanowires was strongly anisotropic having preferred axial polarization. This suggests that a significant number of the polymer chains are oriented along the nanowire axis
The Self-Dual String and Anomalies in the M5-brane
We study the anomalies of a charge self-dual string solution in the
Coulomb branch of M5-branes. Cancellation of these anomalies allows us to
determine the anomaly of the zero-modes on the self-dual string and their
scaling with and . The dimensional reduction of the five-brane
anomalous couplings then lead to certain anomalous couplings for D-branes.Comment: 13 pages, Harvmac, refs adde
Assessment of Dapagliflozin Effectiveness as Add-on Therapy for the Treatment of Type 2 Diabetes Mellitus in a Qatari Population
The effectiveness of dapagliflozin in the management of type-2 diabetes mellitus (T2-DM) is an essential issue for establishing a basis for prescribing dapagliflozin. This study aimed to assess the effectiveness of dapagliflozin in combination with other hypoglycemic agents (OHAs) in reducing glycated hemoglobin (HbA1c) and fasting blood glucose (FBG) at 3, 6, 9 and 12 months. This retrospective observational study included all patients who visited the endocrine clinics at Hamad Medical Corporation (HMC) and were treated with dapagliflozin. Demographics and laboratory data were obtained retrospectively from computerized patient medical profiles (eMR-viewer). The main outcome measures were the differences in HbA1c and FBG from baseline at different months. Eighty-one Qatari patients were found to have received dapagliflozin during the study period; 72% of them (n = 58) were males, with a mean age of 57.0 ± 9.0 years and a mean baseline HbA1c of 9.0 ± 1.4%. Administration of dapagliflozin as an add-on therapy was found to decrease HbA1c significantly by 0.8 percentage point after 6 months (P = 0.006) and by 1.5 percentage point after 12 months (P = 0.062). FBG was significantly reduced at 6 months and 9 months (P = 0.001 and P = 0.03, respectively). Dapagliflozin effectively reduced the HbA1c level and FBG when used in combination with other OHAs or insulin within 6 to 12 months. © 2019, The Author(s).Ethical approval. This study was approved by the Institutional Review Board at the Medical Research Center of Hamad Medical Corporation.
The authors would like to thank the Hamad Medical Corporation for proving the research funding. This work was supported by the Medical Research Center of Hamad Medical Corporation [grant number 15292/15].Scopu
Dirac equation for the supermembrane in a background with fluxes from a component description of the D=11 supergravity-supermembrane interacting system
We present a simple derivation of the 'Dirac' equation for the supermembrane
fermionic field in a D=11 supergravity background with fluxes by using a
complete but gauge-fixed description of the supergravity-supermembrane
interacting system previously developed. We also discuss the contributions
linear in the supermembrane fermions -the Goldstone fields for the local
supersymmetry spontaneously broken by the superbrane- to the field equations of
the supergravity-supermembrane interacting system. The approach could also be
applied to more complicated dynamical systems such as those involving the
M5-brane and the D=10 Dirichlet branes.Comment: 1+22 pages, JHEP style. v2: cosmetic changes and references added to
conform to the JHEP published versio
Propofol and Kearns-Sayre Syndrome: An idiographic approach
With the focus on an idiographic approach whereby the observations incorporated the various dimensions of individual functioning âtop-downâ to âbottom-upâ, this case report describes the successful management of a 14-year-old girl with Kearns-Sayre syndrome and Dyggve-Melchior-Clausen disease requiring a transvenous permanent pacemaker implantation for complete heart block. The patient presented to a tertiary care centre in Muscat, Oman, in 2023 seeking consultation. The current idiographic approach appears to have a heuristic value for 2 interrelated reasons. Firstly, it is unlikely that even tertiary care units can accrue such rare presentations and scrutinise them under nomothetic approach. Secondly, by employing the idiographic approach that is capable of examining each case in-depth, the aspiration for good health and well-being may come to the forefront. To the best of the authorsâ knowledge this is the first published idiographic report in anaesthesia care.
Keywords: Intravenous Anaesthetics; Artificial Pacemaker; Kearns-Sayre Syndrome; Propofol; Idiographic Approach; Case Report; Oman
Efficient out-coupling and beaming of Tamm optical states via surface plasmon polariton excitation
We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed
Density functional theory for the crystallization of two-dimensional dipolar colloidal alloys
Two-dimensional mixtures of dipolar colloidal particles with different dipole moments exhibit extremely rich self-assembly behaviour and are relevant to a wide range of experimental systems, including charged and super-paramagnetic colloids at liquid interfaces. However, there is a gap in our understanding of the crystallization of these systems because existing theories such as integral equation theory and lattice sum methods can only be used to study the high temperature fluid phase and the zero-temperature crystal phase, respectively. In this paper we bridge this gap by developing a density functional theory (DFT), valid at intermediate temperatures, in order to study the crystallization of one and two-component dipolar colloidal monolayers. The theory employs a series expansion of the excess Helmholtz free energy functional, truncated at second order in the density, and taking as input highly accurate bulk fluid direct correlation functions from simulation. Although truncating the free energy at second order means that we cannot determine the freezing point accurately, our approach allows us to calculate \emph{ab initio} both the density profiles of the different species and the symmetry of the final crystal structures. Our DFT predicts hexagonal crystal structures for one-component systems, and a variety of superlattice structures for two-component systems, including those with hexagonal and square symmetry, in excellent agreement with known results for these systems. The theory also provides new insights into the structure of two-component systems in the intermediate temperature regime where the small particles remain molten but the large particles are frozen on a regular lattice
On the equivalence of bound state solutions
In this paper we show the equivalence of various (non-threshold) bound state
solutions of branes, or equivalently branes in background potentials, in ten-
and eleven-dimensional supergravity. We compare solutions obtained in two very
different ways. One method uses a zero mode analysis to make an Ansatz which
makes it possible to solve the full non-linear supergravity equations. The
other method utilises T-duality techniques to turn on the fields on the brane.
To be specific, in eleven dimensions we show the equivalence for the (M2,M5)
bound state, or equivalently an M5-brane in a C_3 field, where we also consider
the (MW,M2,M2',M5) solution, which can be obtained from the (M2,M5) bound state
by a boost. In ten dimensions we show the equivalence for the ((F,D1),D3) bound
state as well as the bound states of (p,q) 5-branes with lower dimensional
branes in type IIB, corresponding to D3-branes in B_2 and C_2 fields and (p,q)
5-branes in B_2, C_2 and C_4 fields. We also comment on the recently proposed
V-duality related to infinitesimally boosted solutions.Comment: 19 pages, LaTe
Time-Dependent Warping, Fluxes, and NCYM
We describe the supergravity solutions dual to D6-branes with both
time-dependent and time-independent B-fields. These backgrounds generalize the
Taub-NUT metric in two key ways: they have asymmetric warp factors and
background fluxes. In the time-dependent case, the warping takes a novel form.
Kaluza-Klein reduction in these backgrounds is unusual, and we explore some of
the new features. In particular, we describe how a localized gauge-field
emerges with an analogue of the open string metric and coupling. We also
describe a gravitational analogue of the Seiberg-Witten map. This provides a
framework in supergravity both for studying non-commutative gauge theories, and
for constructing novel warped backgrounds.Comment: 32 pages, LaTeX, references adde
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