1,671 research outputs found
ANALYSIS OF THE PROTEOMIC PROFILE AND COMPOSITION IN PROSTATE CANCER PATIENTS
Prostate cancer is a significant public health concern among American men. The current screening method for prostate cancer relies on elevated levels of prostate-specific antigen (PSA), which can be unreliable. Alternatively, a protein fingerprint identifies a characteristic set of proteins indicative of disease. Previous research in this laboratory group has identified a baseline protein fingerprint for prostate cancer. Here, an analysis is performed to identify how the protein fingerprint changes in composition throughout disease progression through inspection of the proteomic composition of human serum and review of the current scientific literature to investigate why these proteins might be dysregulated with respect to the metabolic activity of malignant cells. It was found that different disease states (metastasis, positive biopsy, negative biopsy, and healthy control) had distinctly different sets of upregulated and downregulated proteins. These dysregulated proteins had varying levels of relevance to physiological mechanisms involved in the progression of prostate cancer, with some proteins having a clearly defined role in cancer development while other proteins had unclear roles and appeared to have primarily diagnostic value at this time, elucidating areas for potential further research. Together these results provide a better understanding of the metabolic progression and consequences of prostate cancer, potentially contributing to earlier, more accurate diagnosis in the future
ELLIPTIC MONOPOLES AND (4,0)-SUPERSYMMETRIC SIGMA MODELS WITH TORSION
We explicitly construct the metric and torsion couplings of two-dimensional
(4,0)-super\-sym\-metric sigma models with target space a four-manifold that
are invariant under a symmetry generated by a tri-holomorphic Killing
vector field that leaves in addition the torsion invariant. We show that the
metric couplings arise from magnetic monopoles on the three-sphere which is the
space of orbits of the group action generated by the tri-holomorphic Killing
vector field on the sigma model target manifold. We also examine the global
structure of a subclass of these metrics that are in addition -invariant
and find that the only non-singular one, for models with non-zero torsion, is
that of WZW model.Comment: 12 pages, phyzz
Remarks on Non-Abelian Duality
A class of two-dimensional globally scale-invariant, but not conformally
invariant, theories is obtained. These systems are identified in the process of
discussing global and local scaling properties of models related by duality
transformations, based on non-semisimple isometry groups. The construction of
the dual partner of a given model is followed through; non-local as well as
local versions of the former are discussed.Comment: 33 pages, CERN-TH.7414/94, RI-9-94, WIS-7-9
Black-Hole-Wave Duality in String Theory
Extreme 4-dimensional dilaton black holes embedded into 10-dimensional
geometry are shown to be dual to the gravitational waves in string theory. The
corresponding gravitational waves are the generalization of pp-fronted waves,
called supersymmetric string waves. They are given by Brinkmann metric and the
two-form field, without a dilaton. The non-diagonal part of the metric of the
dual partner of the wave together with the two-form field correspond to the
vector field in 4-dimensional geometry of the charged extreme black holes.Comment: 12 pages, LaTeX, preprint UG-3/94, SU-ITP-94-11, QMW-PH-94-1
Complexified sigma model and duality
We show that the equations of motion associated with a complexified
sigma-model action do not admit manifest dual SO(n,n) symmetry. In the process
we discover new type of numbers which we called `complexoids' in order to
emphasize their close relation with both complex numbers and matroids. It turns
out that the complexoids allow to consider the analogue of the complexified
sigma-model action but with (1+1)-worldsheet metric, instead of
Euclidean-worldsheet metric. Our observations can be useful for further
developments of complexified quantum mechanics.Comment: 15 pages, Latex, improved versio
Michelson Interferometry with the Keck I Telescope
We report the first use of Michelson interferometry on the Keck I telescope
for diffraction-limited imaging in the near infrared JHK and L bands. By using
an aperture mask located close to the f/25 secondary, the 10 m Keck primary
mirror was transformed into a separate-element, multiple aperture
interferometer. This has allowed diffraction-limited imaging of a large number
of bright astrophysical targets, including the geometrically complex dust
envelopes around a number of evolved stars. The successful restoration of these
images, with dynamic ranges in excess of 200:1, highlights the significant
capabilities of sparse aperture imaging as compared with more conventional
filled-pupil speckle imaging for the class of bright targets considered here.
In particular the enhancement of the signal-to-noise ratio of the Fourier data,
precipitated by the reduction in atmospheric noise, allows high fidelity
imaging of complex sources with small numbers of short-exposure images relative
to speckle. Multi-epoch measurements confirm the reliability of this imaging
technique and our whole dataset provides a powerful demonstration of the
capabilities of aperture masking methods when utilized with the current
generation of large-aperture telescopes. The relationship between these new
results and recent advances in interferometry and adaptive optics is briefly
discussed.Comment: Accepted into Publications of the Astronomical Society of the
Pacific. To appear in vol. 112. Paper contains 10 pages, 8 figure
Type 0 T-Duality and the Tachyon Coupling
We consider the T-duality relations between Type 0A and 0B theories, and show
that this constraints the possible couplings of the tachyon to the RR-fields.
Due to the `doubling' of the RR sector in Type 0 theories, we are able to
introduce a democratic formulation for the Type 0 effective actions, in which
there is no Chern-Simons term in the effective action. Finally we discuss how
to embed Type II solutions into Type 0 theories.Comment: some misprints corrected and a reference adde
On the fermionic T-duality of the AdS_4 \times CP^3 sigma-model
In this note we consider a fermionic T-duality of the coset realization of
the type IIA sigma-model on AdS_4 \times CP^3 with respect to the three flat
directions in AdS_4, six of the fermionic coordinates and three of the CP^3
directions. We show that the Buscher procedure fails as it leads to a singular
transformation and discuss the result and its implications.Comment: LaTeX2e, 9 pages, no figures, JHEP style; v2: minor clarifications;
v3: typos fixed, matches the published versio
An Equivalence Between Momentum and Charge in String Theory
It is shown that for a translationally invariant solution to string theory,
spacetime duality interchanges the momentum in the symmetry direction and the
axion charge per unit length. As one application, we show explicitly that
charged black strings are equivalent to boosted (uncharged) black strings. The
extremal black strings (which correspond to the field outside of a fundamental
macroscopic string) are equivalent to plane fronted waves describing strings
moving at the speed of light.Comment: 10 page
Integration of the atmospheric fluctuations in a dual-field optical interferometer: the short exposure regime
Spatial phase-referencing in dual-field optical interferometry is
reconsidered. Our analysis is based on the 2-sample variance of the
differential phase between target and reference star. We show that averaging
over time of the atmospheric effects depends on this 2-sample phase variance
(Allan variance) rather than on the true variance. The proper expression for
fringe smearing beyond the isoplanatic angle is derived. With simulations of
atmospheric effects, based on a Paranal turbulence model, we show how the
performances of a dual-field optical interferometer can be evaluated in a
diagram 'separation angle' versus 'magnitude of faint object'. In this diagram,
a domain with short exposure is found to be most useful for interferometry,
with about the same magnitude limits in the H and K bands. With star counts
from a Galaxy model, we evaluate the sky coverage for differential astrometry
and detection of exoplanets, i.e. likelihood of faint reference stars in the
vicinity of a bright target. With the 2mass survey, we evaluate sky coverage
for phase-referencing, i.e. avaibility of a bright enough star for main delay
tracking in the vicinity of any target direction.Comment: 9 pages, 8 figures, accepted for publication in A&
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