172 research outputs found
Asteroseismic Modeling of 1,153 Kepler Red Giant Branch Stars: Improved Stellar Parameters with Gravity-Mode Period Spacings and Luminosity Constraints
This paper reports estimated stellar parameters of 1,153 Kepler red giant
branch stars determined with asteroseismic modeling. We use radial-mode
oscillation frequencies, gravity-mode period spacings, Gaia luminosities, and
spectroscopic data to characterize these stars. Compared with previous studies,
we find that the two additional observed constraints, i.e., the gravity-mode
period spacing and luminosity, significantly improve the precision of
fundamental stellar parameters. The typical uncertainties are 2.9% for the
mass, 11% for the age, 1.0% for the radius, 0.0039 dex for the surface gravity,
and 0.5\% for the helium core mass, making this the best-characterized large
sample of red-giant stars available to date. With better characterizations for
these red giants, we recalibrate the seismic scaling relations and study the
surface term on the red-giant branch. We confirm that the surface term depends
on the surface gravity and effective temperature, but there is no significant
correlation with metallicity.Comment: Accepted by Ap
Asteroseismic Modeling of 1153 Kepler Red Giant Branch Stars:Improved Stellar Parameters with Gravity-mode Period Spacings and Luminosity Constraints
Reaching the last mile: best practices in leveraging the power of ICTs to communicate climate services to farmers at scale
This report reviews key ICTs for Development (ICT4D) Programs, Innovations and
Information Exchange Platforms which are experimented within South Asia to
explore the use and scale-ability of these innovative approaches to other parts of
Africa and the developing world. Learning from the pioneering experiences of pilot
projects across India and Africa in ICT development, we assess the potential ICTs
offer to not only communicate climate information and related advisory services but
also to build capacity and increase the resilience of rural smallholders. It is our hope
that such South-South learning can pave the way for improved cross-regional
experience sharing to tackle common challenges in reaching ‘the last mile’ with
salient rural extension services, including climate information services
Locally constrained curvature flows and geometric inequalities in hyperbolic space
In this paper, we first study the locally constrained curvature flow of
hypersurfaces in hyperbolic space, which was introduced by Brendle, Guan and Li
[7]. This flow preserves the th quermassintegral and decreases th
quermassintegral, so the convergence of the flow yields sharp
Alexandrov-Fenchel type inequalities in hyperbolic space. Some special cases
have been studied in [7]. In the first part of this paper, we show that
h-convexity of the hypersurface is preserved along the flow and then the smooth
convergence of the flow for h-convex hypersurfaces follows. We then apply this
result to establish some new sharp geometric inequalities comparing the
integral of th Gauss-Bonnet curvature of a smooth h-convex hypersurface to
its th quermassintegral (for ), and comparing the
weighted integral of th mean curvature to its th quermassintegral (for
). In particular, we give an affirmative answer to a
conjecture proposed by Ge, Wang and Wu in 2015.
In the second part of this paper, we introduce a new locally constrained
curvature flow using the shifted principal curvatures. This is natural in the
context of h-convexity. We prove the smooth convergence to a geodesic sphere of
the flow for h-convex hypersurfaces, and provide a new proof of the geometric
inequalities proved by Andrews, Chen and the third author of this paper in
2018. We also prove a family of new sharp inequalities involving the weighted
integral of th shifted mean curvature for h-convex hypersurfaces, which as
application implies a higher order analogue of Brendle, Hung and Wang's [8]
inequality.Comment: 38 pages, accepted version for Mathematische Annalen, add Corollary
1.10 to describe the application of the new locally constrained flow (1.11
Sustainable Afterglow Room-Temperature Phosphorescence Emission Materials Generated Using Natural Phenolics
Reason out Your Layout: Evoking the Layout Master from Large Language Models for Text-to-Image Synthesis
Recent advancements in text-to-image (T2I) generative models have shown
remarkable capabilities in producing diverse and imaginative visuals based on
text prompts. Despite the advancement, these diffusion models sometimes
struggle to translate the semantic content from the text into images entirely.
While conditioning on the layout has shown to be effective in improving the
compositional ability of T2I diffusion models, they typically require manual
layout input. In this work, we introduce a novel approach to improving T2I
diffusion models using Large Language Models (LLMs) as layout generators. Our
method leverages the Chain-of-Thought prompting of LLMs to interpret text and
generate spatially reasonable object layouts. The generated layout is then used
to enhance the generated images' composition and spatial accuracy. Moreover, we
propose an efficient adapter based on a cross-attention mechanism, which
explicitly integrates the layout information into the stable diffusion models.
Our experiments demonstrate significant improvements in image quality and
layout accuracy, showcasing the potential of LLMs in augmenting generative
image models.Comment: preprin
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Transcription factor-pathway co-expression analysis reveals cooperation between SP1 and ESR1 on dysregulating cell cycle arrest in non-hyperdiploid multiple myeloma
Multiple myeloma is a hematological cancer of plasma B-cells and remains incurable. Two major subtypes of myeloma, hyperdiploid (HMM) and non-hyperdiploid myeloma (NHMM), have distinct chromosomal alterations and different survival outcomes. Transcription factors (TrFs) have been implicated in myeloma oncogenesis but their dysregulation in myeloma subtypes are less studied. Here we develop a TrF-pathway co-expression analysis to identify altered co-expression between two sample types. We apply the method to the two myeloma subtypes and the cell cycle arrest pathway, which is significantly differentially expressed between the two subtypes. We find that TrFs MYC, NF-κB and HOXA9 have significantly lower co-expression with cell cycle arrest in HMM, co-occurring with their over-activation in HMM. In contrast, TrFs ESR1, SP1 and E2F1 have significantly lower co-expression with cell cycle arrest in NHMM. SP1 ChIP targets are enriched by cell cycle arrest genes. These results motivate a cooperation model of ESR1 and SP1 in regulating cell cycle arrest, and a hypothesis that their over-activation in NHMM disrupts proper regulation of cell cycle arrest. Co-targeting ESR1 and SP1 shows a synergistic effect on inhibiting myeloma proliferation in NHMM cell lines. Therefore, studying TrF-pathway co-expression dysregulation in human cancers facilitates forming novel hypotheses towards clinical utility
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