3,949 research outputs found
HOX genes in ovarian cancer
The HOX genes are a family of homeodomain-containing transcription factors that determine cellular identity during development. Here we review a number of recent studies showing that HOX genes are strongly expressed in ovarian cancer, and that in some cases the expression of specific HOX genes is sufficient to confer a particular identity and phenotype upon cancer cells. We also review the recent advances in elucidating the different functions of HOX genes in ovarian cancer. A literature search was performed using the search terms HOX genes (including specific HOX genes), ovarian cancer and oncogenesis. Articles were accessed through searches performed in ISI Web of Knowledge, PubMed and ScienceDirect. Taken together, these studies have shown that HOX genes play a role in the oncogenesis of ovarian cancer and function in the inhibition of apoptosis, DNA repair and enhanced cell motility. The function of HOX genes in ovarian cancer oncogenesis supports their potential role as prognostic and diagnostic markers, and as therapeutic targets in this disease
Meson Decay Constants from Isospin Mass Splittings in the Quark Model
Decay constants of and mesons are estimated within the framework of a
heavy-quark approach using measured isospin mass splittings in the , ,
and states to isolate the electromagnetic hyperfine interaction between
quarks. The values MeV and MeV are
obtained. Only experimental errors are given; possible theoretical ambiguities,
and suggestions for reducing them, are noted.Comment: 7 pages, LaTeX, EFI-92-3
Developmental contexts and features of elite academy football players: Coach and player perspectives
Player profiling can reap many benefits; through reflective coach-athlete dialogue that produces a profile the athlete has a raised awareness of their own development, while the coach has an opportunity to understand the athlete's viewpoint. In this study, we explored how coaches and players perceived the development features of an elite academy footballer and the contexts in which these features are revealed, in order to develop a player profile to be used for mentoring players. Using a Delphi polling technique, coaches and players experienced a number of 'rounds' of expressing their opinions regarding player development contexts and features, ultimately reduced into a consensus. Players and coaches had differing priorities on the key contexts of player development. These contexts, when they reflect the consensus between players and coaches were heavily dominated by ability within the game and training. Personal, social, school, and lifestyle contexts featured less prominently. Although 'discipline' was frequently mentioned as an important player development feature, coaches and players disagreed on the importance of 'training'
Quasar Selection Based on Photometric Variability
We develop a method for separating quasars from other variable point sources
using SDSS Stripe 82 light curve data for ~10,000 variable objects. To
statistically describe quasar variability, we use a damped random walk model
parametrized by a damping time scale, tau, and an asymptotic amplitude
(structure function), SF_inf. With the aid of an SDSS spectroscopically
confirmed quasar sample, we demonstrate that variability selection in typical
extragalactic fields with low stellar density can deliver complete samples with
reasonable purity (or efficiency, E). Compared to a selection method based
solely on the slope of the structure function, the inclusion of the tau
information boosts E from 60% to 75% while maintaining a highly complete sample
(98%) even in the absence of color information. For a completeness of C=90%, E
is boosted from 80% to 85%. Conversely, C improves from 90% to 97% while
maintaining E=80% when imposing a lower limit on tau. With the aid of color
selection, the purity can be further boosted to 96%, with C= 93%. Hence,
selection methods based on variability will play an important role in the
selection of quasars with data provided by upcoming large sky surveys, such as
Pan-STARRS and the Large Synoptic Survey Telescope (LSST). For a typical
(simulated) LSST cadence over 10 years and a photometric accuracy of 0.03 mag
(achieved at i~22), C is expected to be 88% for a simple sample selection
criterion of tau>100 days. In summary, given an adequate survey cadence,
photometric variability provides an even better method than color selection for
separating quasars from stars.Comment: (v2) 50 pages, accepted to Ap
Measurement of the Induced Proton Polarization P_n in the 12C(e,e'\vec{p}) Reaction
The first measurements of the induced proton polarization, P_n, for the 12C
(e,e'\vec{p}) reaction are reported. The experiment was performed at quasifree
kinematics for energy and momentum transfer (\omega,q) \approx (294 MeV, 756
MeV/c) and sampled a recoil momentum range of 0-250 MeV/c. The induced
polarization arises from final-state interactions and for these kinematics is
dominated by the real part of the spin-orbit optical potential. The
distorted-wave impulse approximation provides good agreement with data for the
1p_{3/2} shell. The data for the continuum suggest that both the 1s_{1/2} shell
and underlying l > 1 configurations contribute.Comment: 5 pages LaTeX, 2 postscript figures, accepted by Physical Reveiw
Letter
A Description of Quasar Variability Measured Using Repeated SDSS and POSS Imaging
We provide a quantitative description and statistical interpretation of the
optical continuum variability of quasars. The Sloan Digital Sky Survey (SDSS)
has obtained repeated imaging in five UV-to-IR photometric bands for 33,881
spectroscopically confirmed quasars. About 10,000 quasars have an average of 60
observations in each band obtained over a decade along Stripe 82 (S82), whereas
the remaining ~25,000 have 2-3 observations due to scan overlaps. The observed
time lags span the range from a day to almost 10 years, and constrain quasar
variability at rest-frame time lags of up to 4 years, and at rest-frame
wavelengths from 1000A to 6000A. We publicly release a user-friendly catalog of
quasars from the SDSS Data Release 7 that have been observed at least twice in
SDSS or once in both SDSS and the Palomar Observatory Sky Survey, and we use it
to analyze the ensemble properties of quasar variability. Based on a damped
random walk (DRW) model defined by a characteristic time scale and an
asymptotic variability amplitude that scale with the luminosity, black hole
mass, and rest wavelength for individual quasars calibrated in S82, we can
fully explain the ensemble variability statistics of the non-S82 quasars such
as the exponential distribution of large magnitude changes. All available data
are consistent with the DRW model as a viable description of the optical
continuum variability of quasars on time scales of ~5-2000 days in the rest
frame. We use these models to predict the incidence of quasar contamination in
transient surveys such as those from PTF and LSST.Comment: 33 pages, 19 figures, replaced with accepted version. Catalog is
available at http://www.astro.washington.edu/users/ivezic/macleod/qso_dr7
Don't Blink: Constraining the Circumstellar Environment of the Interacting Type Ia Supernova 2015cp
Despite their cosmological utility, the progenitors of Type Ia supernovae
(SNe Ia) are still unknown, with many efforts focused on whether accretion from
a nondegenerate companion can grow a carbon-oxygen white dwarf to near the
Chandrasekhar mass. The association of SNe Ia resembling SN 1991T ("91T-like")
with circumstellar interaction may be evidence for this "single-degenerate"
channel. However, the observed circumstellar medium (CSM) in these interacting
systems is unlike a stellar wind -- of particular interest, it is sometimes
detached from the stellar surface, residing at . A
Hubble Space Telescope (HST) program to discover detached CSM around 91T-like
SNe Ia successfully discovered interaction nearly two years after explosion in
SN 2015cp (Graham et al., 2018). In this work, we present radio and X-ray
follow-up observations of SN 2015cp and analyze them in the framework of
Harris, Nugent, & Kasen (2016) to limit the properties of a constant-density
CSM shell in this system. Assuming the HST detection was shortly after the
shock crossed the CSM, we constrain the total CSM mass in this system to be . This limit is comparable to the CSM mass of supernova
PTF11kx, but does not rule out lower masses predicted for recurrent novae. From
lessons learned modeling PTF11kx and SN 2015cp, we suggest a strategy for
future observations of these events to increase the sample of known interacting
SNe Ia.Comment: 13 pages, 5 figures, published in The Astrophysical Journa
Bovine Tuberculosis in Free-Ranging Carnivores from Michigan
During a survey of carnivores and omnivores for bovine tuberculosis conducted in Michigan (USA) since 1996, Mycobacterium bovis was cultured from lymph nodes pooled from six coyotes (Canis latrans) (four adult female, two adult male), two adult male raccoons (Procyon lotor), one adult male red fox (Vulpes vulpes), and one 1.5-yr-old male black bear (Ursus americanus). One adult, male bobcat (Felis rufus) with histologic lesions suggestive of tuberculosis was negative on culture but positive for organisms belonging to the Mycobacterium tuberculosis complex when tested by polymerase chain reaction. All the tuberculous animals were taken from three adjoining counties where M. bovis is known to be endemic in the free-ranging white-tailed deer (Odocoileus virginianus) population. There were two coyotes, one raccoon, one red fox, and one bobcat infected in Alpena county. Montmorency County had two coyotes and one raccoon with M. bovis. Two coyotes and a bear were infected from Alcona County. These free-ranging carnivores/omnivores probably became infected with M. bovis through consumption of tuberculous deer. Other species included in the survey were opossum (Didelphis virginiana), gray fox (Urocyon cinereoargenteus), and badger (Taxidea taxus); these were negative for M. bovis
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