3,927 research outputs found
Vitamin D3 receptor is highly expressed in Hodgkin's lymphoma
Background: Hodkin s lymphoma is one of the most frequent lymphoma in western world. Despite an overall good prognosis some patients suffer relapsing tumors which are difficult to cure. Over a long period Vitamin D has been shown to be a potential treatment for cancer. Vitamin D acts via the vitamin D receptor, a nuclear receptor, acting as an inducible transcription factor. We aimed to investigate the expression of vitamin D receptor as potential therapeutic target structure in Hodgkin s lymphoma as well as in non Hodgkin s lymphoma.
Methods: We used a panel of 193 formalin fixed tissues of lymphoma cases consisting of 55 cases of Hodgkin s lymphoma and 138 cases on several non Hodgkin s lymphoma entities.
Results: Vitamin D receptor is strongly expressed in Hodgkin s lymphoma, regardless of the subentity with an overall positivity of 80% of all Hodgkin lymphoma cases. In contrast, only about 17% of the analyzed non Hodgkin s lymphoma of B-cell origin showed positivity for vitamin D receptor. Predominant nuclear localization of vitamin D receptor in Hodgkin s lymphoma suggests activated status of the vitamin D receptor.
Conclusions: From this study, we conclude that vitamin D receptor plays a potentially important role in pathogenesis of Hodgkin s lymphoma but not in non Hodgkin s lymphoma. Further investigations of mutational status and functional studies may shed some light in functional relevance of vitamin D receptor signaling in Hodgkin s lymphoma
CHEOPS performance for exomoons: The detectability of exomoons by using optimal decision algorithm
Many attempts have already been made for detecting exomoons around transiting
exoplanets but the first confirmed discovery is still pending. The experience
that have been gathered so far allow us to better optimize future space
telescopes for this challenge, already during the development phase. In this
paper we focus on the forthcoming CHaraterising ExOPlanet Satellite
(CHEOPS),describing an optimized decision algorithm with step-by-step
evaluation, and calculating the number of required transits for an exomoon
detection for various planet-moon configurations that can be observable by
CHEOPS. We explore the most efficient way for such an observation which
minimizes the cost in observing time. Our study is based on PTV observations
(photocentric transit timing variation, Szab\'o et al. 2006) in simulated
CHEOPS data, but the recipe does not depend on the actual detection method, and
it can be substituted with e.g. the photodynamical method for later
applications. Using the current state-of-the-art level simulation of CHEOPS
data we analyzed transit observation sets for different star-planet-moon
configurations and performed a bootstrap analysis to determine their detection
statistics. We have found that the detection limit is around an Earth-sized
moon. In the case of favorable spatial configurations, systems with at least
such a large moon and with at least Neptune-sized planet, 80\% detection chance
requires at least 5-6 transit observations on average. There is also non-zero
chance in the case of smaller moons, but the detection statistics deteriorates
rapidly, while the necessary transit measurements increase fast. (abridged)Comment: 32 pages, 14 figures, accepted for publication in PAS
Effects of a giant impact on Uranus
The effects of a giant impact on Uranus with respect to the axis tilt of Uranus and its satellites are discussed. The simulations of possible giant impacts were carried out using Cray supercomputers. The technique used is called smooth particle hydrodynamics (SPH). In this technique, the material in the proto-Uranus planet and in the impactor is divided into a large number of particles which can overlap one another so that local averages over these particles determine density and pressure in the problem, and the particles themselves have their own temperatures and internal energies. During the course of the simulation, these particles move around under the influence of the forces acting on them: gravity and pressure gradients. The results of model simulations are presented
Spectropolarimetry of C-class flare footpoints
We investigate the decay phase of a C-class flare in full-Stokes imaging
spectropolarimetry with quasi-simultaneous measurements in the photosphere
(6302.5 A line) and in the chromosphere (8542 A line) with the IBIS instrument.
We analyze data from two fields-of-view, each spanning about 40" \times 80" and
targeting the two footpoints of the flare. A region of interest is identified
from V/I images: a patch of opposite polarity in the smaller sunspot's
penumbra. We find unusual flows in this patch at photospheric levels: a Doppler
shift of -4 km/s, but also a possible radial inflow into the sunspot of 4 km/s.
Such patches seem to be common during flares, but only high-resolution
observations allowed us to see the inflow, which may be related to future
flares observed in this region. Chromospheric images show variable overlying
emission and flows and unusual Stokes profiles. We also investigate the
irregular penumbra, whose formation may be blocked by the opposite polarity
patch and flux emergence. The 40 min temporal evolution depicts the larger of
the flare ribbons becoming fainter and changing its shape. Measurable
photospheric magnetic fields remain constant and we do not detect flare energy
transport down from the chromosphere. We find no clear indications of impact
polarization in the 8542 A line. We cannot exclude the possibility of impact
polarization, because weaker signals may be buried in the prominent Zeeman
signatures or it may have been present earlier during the flare.Comment: accepted by ApJ, 12 pages, 13 figure
Human-Aligned Calibration for AI-Assisted Decision Making
Whenever a binary classifier is used to provide decision support, it
typically provides both a label prediction and a confidence value. Then, the
decision maker is supposed to use the confidence value to calibrate how much to
trust the prediction. In this context, it has been often argued that the
confidence value should correspond to a well calibrated estimate of the
probability that the predicted label matches the ground truth label. However,
multiple lines of empirical evidence suggest that decision makers have
difficulties at developing a good sense on when to trust a prediction using
these confidence values. In this paper, our goal is first to understand why and
then investigate how to construct more useful confidence values. We first argue
that, for a broad class of utility functions, there exist data distributions
for which a rational decision maker is, in general, unlikely to discover the
optimal decision policy using the above confidence values -- an optimal
decision maker would need to sometimes place more (less) trust on predictions
with lower (higher) confidence values. However, we then show that, if the
confidence values satisfy a natural alignment property with respect to the
decision maker's confidence on her own predictions, there always exists an
optimal decision policy under which the level of trust the decision maker would
need to place on predictions is monotone on the confidence values, facilitating
its discoverability. Further, we show that multicalibration with respect to the
decision maker's confidence on her own predictions is a sufficient condition
for alignment. Experiments on four different AI-assisted decision making tasks
where a classifier provides decision support to real human experts validate our
theoretical results and suggest that alignment may lead to better decisions
Temporal Correlation of Hard X-rays and Meter/Decimeter Radio Structures in Solar Flares
We investigate the relative timing between hard X-ray (HXR) peaks and
structures in metric and decimetric radio emissions of solar flares using data
from the RHESSI and Phoenix-2 instruments. The radio events under consideration
are predominantly classified as type III bursts, decimetric pulsations and
patches. The RHESSI data are demodulated using special techniques appropriate
for a Phoenix-2 temporal resolution of 0.1s. The absolute timing accuracy of
the two instruments is found to be about 170 ms, and much better on the
average. It is found that type III radio groups often coincide with enhanced
HXR emission, but only a relatively small fraction ( 20%) of the groups
show close correlation on time scales 1s. If structures correlate, the HXRs
precede the type III emissions in a majority of cases, and by 0.690.19 s
on the average. Reversed drift type III bursts are also delayed, but
high-frequency and harmonic emission is retarded less. The decimetric
pulsations and patches (DCIM) have a larger scatter of delays, but do not have
a statistically significant sign or an average different from zero. The time
delay does not show a center-to-limb variation excluding simple propagation
effects. The delay by scattering near the source region is suggested to be the
most efficient process on the average for delaying type III radio emission
Vitamin D3receptor is highly expressed in Hodgkinâs lymphoma
BACKGROUND: Hodgkin lymphoma (HL) is one of the most frequent lymphoma in the western world. Despite a good overall prognosis, some patients suffer relapsing tumors which are difficult to cure. Over a long period Vitamin D has been shown to be a potential treatment for cancer. Vitamin D acts via the vitamin D receptor, a nuclear receptor, acting as an inducible transcription factor. We aimed to investigate the expression of vitamin D receptor as a possible diagnostic marker and potential therapeutic target in HL as well as in B-cell derived non-Hodgkin lymphoma (B-NHL). METHODS: We used a panel of 193 formalin fixed tissues of lymphoma cases consisting of 55 cases of HL and 138 cases on several B-NHL entities. RESULTS: Vitamin D receptor is strongly expressed in tumor cells of HL, regardless of the sub entity with an overall positivity of 80% of all HL cases. In contrast, only about 17% of the analyzed origin-NHL showed positivity for vitamin D receptor. The detection of nuclear localization of vitamin D receptor in the tumor cells of HL suggests activated status of the vitamin D receptor. CONCLUSIONS: Our study suggests VDR as a specific marker for tumor cells of HL, but not of B-NHL subtypes. Further, the observed nuclear localization suggests an activated receptor status in tumor cells of HL. Further investigations of mutational status and functional studies may shed some light in functional relevance of vitamin D receptor signaling in HL
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