48 research outputs found
Potentialities of Hubble parameter and expansion rate function data to alleviate Hubble tension
Taking advantage of Gaussian process (GP), we obtain an improved estimate of
the Hubble constant, km s Mpc, using Hubble
parameter [] from cosmic chronometers (CCH) and expansion rate function
[], extracted from type Ia supernovae, data. This result is higher than
those obtained by directly reconstructing CCH data with GP. In order to
estimate the potential of future CCH data, we simulate two sets of data
and use them to constrain by either using GP reconstruction or fitting
them with data. We find that simulated data alleviate
tension by pushing values higher towards km s Mpc.
We also find that joint + data favor higher values of ,
which is also confirmed by constraining in the flat concordance model and
2-order Taylor expansion of . In summary, we conclude that more and
better-quality CCH data as well as data can provide a new and useful
perspective on resolving tension.Comment: 11 pages, 8 figure
Learning Disentangled Representation with Mutual Information Maximization for Real-Time UAV Tracking
Efficiency has been a critical problem in UAV tracking due to limitations in
computation resources, battery capacity, and unmanned aerial vehicle maximum
load. Although discriminative correlation filters (DCF)-based trackers prevail
in this field for their favorable efficiency, some recently proposed
lightweight deep learning (DL)-based trackers using model compression
demonstrated quite remarkable CPU efficiency as well as precision.
Unfortunately, the model compression methods utilized by these works, though
simple, are still unable to achieve satisfying tracking precision with higher
compression rates. This paper aims to exploit disentangled representation
learning with mutual information maximization (DR-MIM) to further improve
DL-based trackers' precision and efficiency for UAV tracking. The proposed
disentangled representation separates the feature into an identity-related and
an identity-unrelated features. Only the latter is used, which enhances the
effectiveness of the feature representation for subsequent classification and
regression tasks. Extensive experiments on four UAV benchmarks, including
UAV123@10fps, DTB70, UAVDT and VisDrone2018, show that our DR-MIM tracker
significantly outperforms state-of-the-art UAV tracking methods
Decrease of Plasma Platelet-Activating Factor Acetylhydrolase Activity in Lipopolysaccharide Induced Mongolian Gerbil Sepsis Model
Platelet-activating factor (PAF) plays an important role in the pathogenesis of sepsis, and the level of plasma PAF acetylhydrolase (pPAF-AH), which inactivates PAF, decreases in sepsis patients except for the sepsis caused by severe leptospirosis. Usually, increase of pPAF-AH activity was observed in lipopolysaccharide (LPS)-induced Syrian hamster and rat sepsis models, while contradictory effects were reported for mouse model in different studies. Here, we demonstrated the in vivo effects of LPS upon the change of pPAF-AH activity in C57BL/6 mice and Mongolian gerbils. After LPS-treatment, the clinical manifestations of Mongolian gerbil model were apparently similar to that of C57BL/6 mouse sepsis model. The pPAF-AH activity increased in C57BL/6 mice after LPS induction, but decreased in Mongolian gerbils, which was similar to that of the human sepsis. It thus suggests that among the LPS-induced rodent sepsis models, only Mongolian gerbil could be used for the study of pPAF-AH related to the pathogenesis of human sepsis. Proper application of this model might enable people to clarify the underline mechanism accounted for the contradictory results between the phase II and phase III clinical trials for the administration of recombinant human pPAF-AH in the sepsis therapy
Single-Cell Rna Sequencing Deconvolutes the in Vivo Heterogeneity of Human Bone Marrow-Derived Mesenchymal Stem Cells
Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stromal cells that have a critical role in the maintenance of skeletal tissues such as bone, cartilage, and the fat in bone marrow. In addition to providing microenvironmental support for hematopoietic processes, BM-MSCs can differentiate into various mesodermal lineages including osteoblast/osteocyte, chondrocyte, and adipocyte that are crucial for bone metabolism. While BM-MSCs have high cell-to-cell heterogeneity in gene expression, the cell subtypes that contribute to this heterogeneity in vivo in humans have not been characterized. To investigate the transcriptional diversity of BM-MSCs, we applied single-cell RNA sequencing (scRNA-seq) on freshly isolated CD271+ BM-derived mononuclear cells (BM-MNCs) from two human subjects. We successfully identified LEPRhi CD45low BM-MSCs within the CD271+ BM-MNC population, and further codified the BM-MSCs into distinct subpopulations corresponding to the osteogenic, chondrogenic, and adipogenic differentiation trajectories, as well as terminal-stage quiescent cells. Biological functional annotations of the transcriptomes suggest that osteoblast precursors induce angiogenesis coupled with osteogenesis, and chondrocyte precursors have the potential to differentiate into myocytes. We also discovered transcripts for several clusters of differentiation (CD) markers that were either highly expressed (e.g., CD167b, CD91, CD130 and CD118) or absent (e.g., CD74, CD217, CD148 and CD68) in BM-MSCs, representing potential novel markers for human BM-MSC purification. This study is the first systematic in vivo dissection of human BM-MSCs cell subtypes at the single-cell resolution, revealing an insight into the extent of their cellular heterogeneity and roles in maintaining bone homeostasis
KwaiYiiMath: Technical Report
Recent advancements in large language models (LLMs) have demonstrated
remarkable abilities in handling a variety of natural language processing (NLP)
downstream tasks, even on mathematical tasks requiring multi-step reasoning. In
this report, we introduce the KwaiYiiMath which enhances the mathematical
reasoning abilities of KwaiYiiBase1, by applying Supervised Fine-Tuning (SFT)
and Reinforced Learning from Human Feedback (RLHF), including on both English
and Chinese mathematical tasks. Meanwhile, we also constructed a small-scale
Chinese primary school mathematics test set (named KMath), consisting of 188
examples to evaluate the correctness of the problem-solving process generated
by the models. Empirical studies demonstrate that KwaiYiiMath can achieve
state-of-the-art (SOTA) performance on GSM8k, CMath, and KMath compared with
the similar size models, respectively.Comment: technical report. arXiv admin note: text overlap with
arXiv:2306.16636 by other author
H2S gas sensing performance and mechanisms using CuO-Al2O3 composite films based on both surface acoustic wave and chemiresistor techniques
Surface acoustic wave and chemiresistor based gas sensors integrated with a sensing layer of sol-gel CuO-Al2O3 composite film were fabricated and their performance and mechanisms for H2S sensing were characterized and compared. In the composite film, CuO nanoparticles provide active sites for adsorption and reaction of H2S molecules while Al2O3 nanoparticles help to form a uniform and mesoporous film structure, both of which enhance the sensitivity of the sensors by providing numerous active CuO surfaces. Through the comparative studies, the SAW based H2S sensor operated at room temperature showed a lower detection limit, higher sensitivity, better linearity and good selectivity to H2S gas with its concentration ranging from 5 ppb to 100 ppm, compared with those of the chemiresistor sensor, which are mainly attributed to the effective mass sensing properties of the SAW sensor, because a minor change in the mass of the film caused by adsorbed H2S molecules would lead to a significant and monotonous change of the resonant frequency of the SAW devices