2,646 research outputs found
Looking for Stars and Finding the Moon: Effects of Lunar Gamma-ray Emission on Fermi LAT Light Curves
We are conducting a search for new gamma-ray binaries by making high
signal-to-noise light curves of all cataloged Fermi LAT sources and searching
for periodic variability using appropriately weighted power spectra. The light
curves are created using a variant of aperture photometry where photons are
weighted by the probability that they came from the source of interest. From
this analysis we find that the light curves of a number of sources near the
ecliptic plane are contaminated by gamma-ray emission from the Moon. This shows
itself as modulation on the Moon's sidereal period in the power spectra. We
demonstrate that this contamination can be removed by excluding times when the
Moon was too close to a source. We advocate that this data screening should
generally be used when analyzing LAT data from a source located close to the
path of the Moon.Comment: 2012 Fermi Symposium proceedings - eConf C12102
Type IIA embeddings of minimal gauged supergravity via Non-Abelian T-duality
In this note, we construct explicit Type IIA uplifts of minimal gauged
supergravity, by T-dualising known Type IIB uplifts on ,
and along their isometries. When the gauge field is set
to zero, our uplifts recover precisely the known non-Abelian T-duals of the
solutions. As an application, we obtain new supersymmetric
solutions in Type IIA, where is a weighted projective space. Existing
holographic results of T-dualised AdS solutions suggest that our solutions
capture features of SCFTs with supersymmetry.Comment: 41 pages, 1 figur
A new family of S-folds in type IIB string theory
We construct infinite new classes of solutions of
type IIB string theory which have non-trivial monodromy
along the direction. The solutions are supersymmetric and holographically
dual, generically, to SCFTs in . The solutions are first
constructed as solutions in gauged
supergravity and then uplifted to . The solutions all arise as limiting
cases of Janus solutions of , SYM theory which are
supported both by a different value of the coupling constant on either side of
the interface, as well as by fermion and boson mass deformations. As special
cases, the construction recovers three known S-fold constructions, which
preserve and 4 supersymmetry, as well as a recently
constructed solution (not
S-folded). We also present some novel "one-sided Janus" solutions that are
non-singular.Comment: 54 pages, 13 figure
Changes in racial and gender inequality since 1970
The decades following 1970 to the present were an important period because they marked an era in which measures such as Affirmative Action were introduced to improve opportunities for American minorities and women. Ironically, this also was a period when income inequality dramatically increased in the United States. We analyze Census data from 1970 to 2009 to assess whether inequality in the earnings received by women and minorities has changed in this period. We find a complicated set of results. Racial inequalities persist though to a lesser extent than they did four decades earlier. Asian workers in particular have seen improvements and a lessening of inequality relative to White workers. Gender inequality also persists, though more in some groups than others. Overall, the results of this study underscore the persistence of racial and gender inequality in the United States
Optical Polarization and Spectral Variability in the M87 Jet
During the last decade, M87's jet has been the site of an extraordinary
variability event, with one knot (HST-1) increasing by over a factor 100 in
brightness. Variability was also seen on timescales of months in the nuclear
flux. Here we discuss the optical-UV polarization and spectral variability of
these components, which show vastly different behavior. HST-1 shows a highly
significant correlation between flux and polarization, with P increasing from
at minimum to >40% at maximum, while the orientation of its electric
vector stayed constant. HST-1's optical-UV spectrum is very hard
(, ), and displays "hard lags"
during epochs 2004.9-2005.5, including the peak of the flare, with soft lags at
later epochs. We interpret the behavior of HST-1 as enhanced particle
acceleration in a shock, with cooling from both particle aging and the
relaxation of the compression. We set 2 upper limits of
parsecs and 1.02 on the size and advance speed of the flaring region. The
slight deviation of the electric vector orientation from the jet PA, makes it
likely that on smaller scales the flaring region has either a double or twisted
structure. By contrast, the nucleus displays much more rapid variability, with
a highly variable electric vector orientation and 'looping' in the
plane. The nucleus has a much steeper spectrum () but
does not show UV-optical spectral variability. Its behavior can be interpreted
as either a helical distortion to a steady jet or a shock propagating through a
helical jet.Comment: 14 pages, 7 figures, ApJ, in pres
Higgs Messengers
We explore the consequences of the Higgs fields acting as messengers of
supersymmetry breaking. The hidden-sector paradigm in the gauge mediation
framework is relaxed by allowing two types of gauge-invariant, renormalizable
operators that are typically discarded: direct coupling between the Higgses and
supersymmetry breaking singlets, and Higgs-messenger mixing terms. The most
important phenomenological consequence is a flavor-dependent shift in sfermion
masses. This is from a one-loop contribution, which we compute for a general
set of weak doublet messengers. We also study a couple of explicit models in
detail, finding that precision electroweak constraints can be satisfied with a
spectrum significantly different from that of gauge mediation.Comment: 20 pages, 5 figure
CRISPR Knockout of the HuR Gene Causes a Xenograft Lethal Phenotype.
Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related deaths in the United States, whereas colorectal cancer is the third most common cancer. The RNA-binding protein HuR (ELAVL1) supports a pro-oncogenic network in gastrointestinal (GI) cancer cells through enhanced HuR expression. Using a publically available database, HuR expression levels were determined to be increased in primary PDA and colorectal cancer tumor cohorts as compared with normal pancreas and colon tissues, respectively. CRISPR/Cas9 technology was successfully used to delete the HuR gene in both PDA (MIA PaCa-2 and Hs 766T) and colorectal cancer (HCT116) cell lines. HuR deficiency has a mild phenotype
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