1,507 research outputs found
Tax Advantages of Foundations and Exempt Organizations
Businessmen these days are playing an ever increasing role in the creation and support of non-profit philanthropic foundations. Their purpose is a dual one; to save taxes and to immortalize a family name, and they are as old as the pyramids. We know of about 20,000 foundations existing in England, but the large broad-purpose foundations were created in the United States. The greatest expansion in this area is attributable to the family and corporate foundations. The corporation tax of 52% and the individual income tax of up to 91% are so severe that high-bracket taxpayers can give to charity at a small cost
Liability of Fiduciary for Decedent\u27s Unpaid Federal Taxes and That of Transferee for Federal Taxes
Duality Symmetric String and M-Theory
We review recent developments in duality symmetric string theory. We begin
with the world sheet doubled formalism which describes strings in an extended
space time with extra coordinates conjugate to winding modes. This formalism is
T-duality symmetric and can accommodate non-geometric T-fold backgrounds which
are beyond the scope of Riemannian geometry. Vanishing of the conformal anomaly
of this theory can be interpreted as a set of spacetime equations for the
background fields. These equations follow from an action principle that has
been dubbed Double Field Theory (DFT). We review the aspects of generalised
geometry relevant for DFT. We outline recent extensions of DFT and explain how,
by relaxing the so-called strong constraint with a Scherk Schwarz ansatz, one
can obtain backgrounds that simultaneously depend on both the regular and
T-dual coordinates. This provides a purely geometric higher dimensional origin
to gauged supergravities that arise from non-geometric compactification. We
then turn to M-theory and describe recent progress in formulating an E_{n(n)}
U-duality covariant description of the dynamics. We describe how spacetime may
be extended to accommodate coordinates conjugate to brane wrapping modes and
the construction of generalised metrics in this extend space that unite the
bosonic fields of supergravity into a single object. We review the action
principles for these theories and their novel gauge symmetries. We also
describe how a Scherk Schwarz reduction can be applied in the M-theory context
and the resulting relationship to the embedding tensor formulation of maximal
gauged supergravities.Comment: Review article. 122 pages. V2 Published Version in Physics Report
The gauge structure of generalised diffeomorphisms
We investigate the generalised diffeomorphisms in M-theory, which are gauge
transformations unifying diffeomorphisms and tensor gauge transformations.
After giving an En(n)-covariant description of the gauge transformations and
their commutators, we show that the gauge algebra is infinitely reducible,
i.e., the tower of ghosts for ghosts is infinite. The Jacobiator of generalised
diffeomorphisms gives such a reducibility transformation. We give a concrete
description of the ghost structure, and demonstrate that the infinite sums give
the correct (regularised) number of degrees of freedom. The ghost towers belong
to the sequences of rep- resentations previously observed appearing in tensor
hierarchies and Borcherds algebras. All calculations rely on the section
condition, which we reformulate as a linear condition on the cotangent
directions. The analysis holds for n < 8. At n = 8, where the dual gravity
field becomes relevant, the natural guess for the gauge parameter and its
reducibility still yields the correct counting of gauge parameters.Comment: 24 pp., plain tex, 1 figure. v2: minor changes, including a few added
ref
Membranes with a boundary
We investigate the recently developed theory of multiple membranes. In
particular, we consider open membranes, i.e. the theory defined on a membrane
world volume with a boundary. We first restrict our attention to the gauge
sector of the theory. We obtain a boundary action from the Chern-Simons terms.
Secondly, we consider the addition of certain boundary terms to various
Chern-Simons theories coupled to matter. These terms ensure the full bulk plus
boundary action has the correct amount of supersymmetry. For the ABJM model,
this construction motivates the inclusion of a boundary quartic scalar
potential. The boundary dynamics obtained from our modified theory produce
Basu-Harvey type equations describing membranes ending on a fivebrane. The
ultimate goal of this work is to throw light on the theory of fivebranes using
the theory of open membranes.Comment: 48 pages, Latex, v2 references adde
Prognostic utility of coronary computed tomographic angiography
AbstractCoronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a noninvasive method that enables accurate detection and exclusion of anatomically obstructive coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. There are numerous potential advantages of CCTA beyond simply luminal stenosis assessment including quantification of atherosclerotic plaque volume as well as assessment of plaque composition, extent, location and distribution. In recent years, an array of studies has evaluated the prognostic utility of CCTA findings of CAD for the prediction of major adverse cardiac events, all-cause death and plaque instability. This prognostic information enhances risk stratification and, if properly acted upon, may improve medical therapy and/or behavioral changes that may enhance event-free survival. The goal of the present article is to summarize the current status of the prognostic utility of CCTA findings of CAD
New Imaging Protocols for New Single Photon Emission CT Technologies
Nuclear cardiology practitioners have several new technologies available with which to perform myocardial perfusion single photon emission CT (MPS). These include dedicated small-footprint cardiac scanners, new stationary or semi-stationary three-dimensional detectors, and advanced software algorithms for optimal image reconstruction. These new technologies have been employed to reduce imaging time and radiation exposure. They require less technologist and camera time and offer improved patient comfort. They have potential for the overall cost reduction of MPS and at the same time for improved accuracy by increased resolution, or accurate attenuation correction. Furthermore, these new technologies offer potential for new protocols such as simultaneous dual isotope, new combinations of isotopes, stress only MPS, or dynamic first-pass imaging. In addition, new imaging technologies in coronary CT angiography (CCTA) allow novel hybrid stress only MPS/CCTA protocols with reduced radiation burden. Additional developments further improving efficiency and diagnostic accuracy of MPS are on the horizon
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