152 research outputs found
Unlocking the Power of Open Set : A New Perspective for Open-Set Noisy Label Learning
Learning from noisy data has attracted much attention, where most methods
focus on closed-set label noise. However, a more common scenario in the real
world is the presence of both open-set and closed-set noise. Existing methods
typically identify and handle these two types of label noise separately by
designing a specific strategy for each type. However, in many real-world
scenarios, it would be challenging to identify open-set examples, especially
when the dataset has been severely corrupted. Unlike the previous works, we
explore how models behave when faced with open-set examples, and find that
\emph{a part of open-set examples gradually get integrated into certain known
classes}, which is beneficial for the separation among known classes. Motivated
by the phenomenon, we propose a novel two-step contrastive learning method CECL
(Class Expansion Contrastive Learning) which aims to deal with both types of
label noise by exploiting the useful information of open-set examples.
Specifically, we incorporate some open-set examples into closed-set classes to
enhance performance while treating others as delimiters to improve
representative ability. Extensive experiments on synthetic and real-world
datasets with diverse label noise demonstrate the effectiveness of CECL
Spatio-Temporal Patterns and Impacts of Sediment Variations in Downstream of the Three Gorges Dam on the Yangtze River, China
Spanning the Yangtze River of China, the Three Gorges Dam (TGD) has received considerable concern worldwide with its potential impacts on the downstream side of the dam. This work investigated the spatio-temporal variations of suspended sediment concentration (SSC) at the downstream section of Yichang-to-Chenglingji from 2002 to 2015. A random forest model was developed to estimate SSC using MODIS ground reflectance products, and the spatio-temporal distributions of SSC were retrieved with this model to investigate the characteristics of water-silt variation. Our results revealed that, relatively, SSC before 2003 was evenly distributed in the downstream Yangtze River, while this spatial distribution pattern changed ce 2003 when the dam started storing water. Temporally, the SSC demonstrated a W-shaped curve of seasonal variation as one peak occurred in September and two troughs in March and November, and showed a significantly decreasing trend after three-stage impoundment. After official operation of the TGD in 2009, the SSC was reduced by over 40% than before 2003. Spatially, the most significant changes occurred in the upper Jingjiang section, where the SSC dropped by 45%. During all stages of impoundment, the water impoundment to 135 m in 2003 had the most significant impact on suspended sediment. The decreased SSC has led to emerging risks of bank failure, aggravated erosion of water front and aggressive down-cutting erosion along the downstream of the dam, as well as other ecological and environmental issues that require urgent attention by the government
NMI inhibits cancer stem cell traits by downregulating hTERT in breast cancer.
N-myc and STAT interactor (NMI) has been proved to bind to different transcription factors to regulate a variety of signaling mechanisms including DNA damage, cell cycle and epithelial-mesenchymal transition. However, the role of NMI in the regulation of cancer stem cells (CSCs) remains poorly understood. In this study, we investigated the regulation of NMI on CSCs traits in breast cancer and uncovered the underlying molecular mechanisms. We found that NMI was lowly expressed in breast cancer stem cells (BCSCs)-enriched populations. Knockdown of NMI promoted CSCs traits while its overexpression inhibited CSCs traits, including the expression of CSC-related markers, the number of CD44+CD24- cell populations and the ability of mammospheres formation. We also found that NMI-mediated regulation of BCSCs traits was at least partially realized through the modulation of hTERT signaling. NMI knockdown upregulated hTERT expression while its overexpression downregulated hTERT in breast cancer cells, and the changes in CSCs traits and cell invasion ability mediated by NMI were rescued by hTERT. The in vivo study also validated that NMI knockdown promoted breast cancer growth by upregulating hTERT signaling in a mouse model. Moreover, further analyses for the clinical samples demonstrated that NMI expression was negatively correlated with hTERT expression and the low NMI/high hTERT expression was associated with the worse status of clinical TNM stages in breast cancer patients. Furthermore, we demonstrated that the interaction of YY1 protein with NMI and its involvement in NMI-mediated transcriptional regulation of hTERT in breast cancer cells. Collectively, our results provide new insights into understanding the regulatory mechanism of CSCs and suggest that the NMI-YY1-hTERT signaling axis may be a potential therapeutic target for breast cancers
Unveiling the immune symphony: decoding colorectal cancer metastasis through immune interactions
Colorectal cancer (CRC), known for its high metastatic potential, remains a leading cause of cancer-related death. This review emphasizes the critical role of immune responses in CRC metastasis, focusing on the interaction between immune cells and tumor microenvironment. We explore how immune cells, through cytokines, chemokines, and growth factors, contribute to the CRC metastasis cascade, underlining the tumor microenvironment’s role in shaping immune responses. The review addresses CRC’s immune evasion tactics, especially the upregulation of checkpoint inhibitors like PD-1 and CTLA-4, highlighting their potential as therapeutic targets. We also examine advanced immunotherapies, including checkpoint inhibitors and immune cell transplantation, to modify immune responses and enhance treatment outcomes in CRC metastasis. Overall, our analysis offers insights into the interplay between immune molecules and the tumor environment, crucial for developing new treatments to control CRC metastasis and improve patient prognosis, with a specific focus on overcoming immune evasion, a key aspect of this special issue
Selective Generation of Dopaminergic Precursors from Mouse Fibroblasts by Direct Lineage Conversion.
Degeneration of midbrain dopaminergic (DA) neurons is a key pathological event of Parkinson\u27s disease (PD). Limited adult dopaminergic neurogenesis has led to novel therapeutic strategies such as transplantation of dopaminergic precursors (DPs). However, this strategy is currently restrained by a lack of cell source, the tendency for the DPs to become a glial-restricted state, and the tumor formation after transplantation. Here, we demonstrate the direct conversion of mouse fibroblasts into induced DPs (iDPs) by ectopic expression of Brn2, Sox2 and Foxa2. Besides expression with neural progenitor markers and midbrain genes including Corin, Otx2 and Lmx1a, the iDPs were restricted to dopaminergic neuronal lineage upon differentiation. After transplantation into MPTP-lesioned mice, iDPs differentiated into DA neurons, functionally alleviated the motor deficits, and reduced the loss of striatal DA neuronal axonal termini. Importantly, no iDPs-derived astrocytes and neoplasia were detected in mouse brains after transplantation. We propose that the iDPs from direct reprogramming provides a safe and efficient cell source for PD treatment
OnUVS: Online Feature Decoupling Framework for High-Fidelity Ultrasound Video Synthesis
Ultrasound (US) imaging is indispensable in clinical practice. To diagnose
certain diseases, sonographers must observe corresponding dynamic anatomic
structures to gather comprehensive information. However, the limited
availability of specific US video cases causes teaching difficulties in
identifying corresponding diseases, which potentially impacts the detection
rate of such cases. The synthesis of US videos may represent a promising
solution to this issue. Nevertheless, it is challenging to accurately animate
the intricate motion of dynamic anatomic structures while preserving image
fidelity. To address this, we present a novel online feature-decoupling
framework called OnUVS for high-fidelity US video synthesis. Our highlights can
be summarized by four aspects. First, we introduced anatomic information into
keypoint learning through a weakly-supervised training strategy, resulting in
improved preservation of anatomical integrity and motion while minimizing the
labeling burden. Second, to better preserve the integrity and textural
information of US images, we implemented a dual-decoder that decouples the
content and textural features in the generator. Third, we adopted a
multiple-feature discriminator to extract a comprehensive range of visual cues,
thereby enhancing the sharpness and fine details of the generated videos.
Fourth, we constrained the motion trajectories of keypoints during online
learning to enhance the fluidity of generated videos. Our validation and user
studies on in-house echocardiographic and pelvic floor US videos showed that
OnUVS synthesizes US videos with high fidelity.Comment: 14 pages, 13 figures and 6 table
Direct Conversion of Mouse Astrocytes Into Neural Progenitor Cells and Specific Lineages of Neurons
Background: Cell replacement therapy has been envisioned as a promising treatment for neurodegenerative diseases. Due to the ethical concerns of ESCs-derived neural progenitor cells (NPCs) and tumorigenic potential of iPSCs, reprogramming of somatic cells directly into multipotent NPCs has emerged as a preferred approach for cell transplantation.
Methods: Mouse astrocytes were reprogrammed into NPCs by the overexpression of transcription factors (TFs) Foxg1, Sox2, and Brn2. The generation of subtypes of neurons was directed by the force expression of cell-type specific TFs Lhx8 or Foxa2/Lmx1a.
Results: Astrocyte-derived induced NPCs (AiNPCs) share high similarities, including the expression of NPC-specific genes, DNA methylation patterns, the ability to proliferate and differentiate, with the wild type NPCs. The AiNPCs are committed to the forebrain identity and predominantly differentiated into glutamatergic and GABAergic neuronal subtypes. Interestingly, additional overexpression of TFs Lhx8 and Foxa2/Lmx1a in AiNPCs promoted cholinergic and dopaminergic neuronal differentiation, respectively.
Conclusions: Our studies suggest that astrocytes can be converted into AiNPCs and lineage-committed AiNPCs can acquire differentiation potential of other lineages through forced expression of specific TFs. Understanding the impact of the TF sets on the reprogramming and differentiation into specific lineages of neurons will provide valuable strategies for astrocyte-based cell therapy in neurodegenerative diseases
Soybean Breeding on Seed Composition Trait
Soybean is a most important crop providing edible oil and plant protein source for human beings, in addition to animal feed because of high protein and oil content. This review summarized the progresses in the QTL mapping, candidate gene cloning and functional analysis and also the regulation of soybean oil and seed storage protein accumulation. Furthermore, as soybean genome has been sequenced and released, prospects of multiple omics and advanced biotechnology should be combined and applied for further refine research and high-quality breeding
Dynamic changes in fecal microbiota in donkey foals during weaning: From pre-weaning to post-weaning
IntroductionA better understanding of the microbiota community in donkey foals during the weaning transition is a prerequisite to optimize gut function and improve feed efficiency. The objective of the present study was to investigate the dynamic changes in fecal microbiota in donkey foals from pre-to post-weaning period.MethodsA total of 27 fecal samples of donkey foals were collected in the rectum before morning feeding at pre-weaning (30 days of age, PreW group, n = 9), dur-weaning (100 days of age, DurW group, n = 9) and post-weaning (170 days of age, PostW group, n = 9) period. The 16S rRNA amplicon sequencing were employed to indicate the microbial changes during the weaning period.ResultsIn the present study, the cessation of breastfeeding gradually and weaning onto plant-based feeds increased the microbial diversity and richness, with a higher Shannon, Ace, Chao and Sobs index in DurW and PostW than in PreW (p < 0.05). The predominant bacterial phyla in donkey foal feces were Firmicutes (>50.5%) and Bacteroidota (>29.5%), and the predominant anaerobic fungi and archaea were Neocallimastigomycota and Euryarchaeota. The cellulolytic related bacteria including phylum Firmicutes, Spirochaetota and Fibrobacterota and genus norank_f_F082, Treponema, NK4A214_group, Lachnospiraceae_AC2044_group and Streptococcus were increased from pre-to post-weaning donkey foals (p < 0.05). Meanwhile, the functions related to the fatty acid biosynthesis, carbohydrate metabolism and amino acid biosynthesis were significantly enriched in the fecal microbiome in the DurW and PostW donkeys. Furthermore, the present study provided the first direct evidence that the initial colonization and establishment of anaerobic fungi and archaea in donkey foals began prior to weaning. The relative abundance of Orpinomyces were the highest in DurW donkey foals among the three groups (p < 0.01). In terms of archaea, the abundance of Methanobrevibacter were higher in PreW than in DurW and PostW (p < 0.01), but the abundance of Methanocorpusculum were significantly increased in DurW and PostW compared to PreW donkey foals (p < 0.01).DiscussionAltogether, the current study contributes to a comprehensive understanding of the development of the microbiota community in donkey foals from pre-to post-weaning period, which may eventually result in an improvement of the digestion and feed efficiency in donkeys
Segment Anything Model for Medical Images?
The Segment Anything Model (SAM) is the first foundation model for general
image segmentation. It designed a novel promotable segmentation task, ensuring
zero-shot image segmentation using the pre-trained model via two main modes
including automatic everything and manual prompt. SAM has achieved impressive
results on various natural image segmentation tasks. However, medical image
segmentation (MIS) is more challenging due to the complex modalities, fine
anatomical structures, uncertain and complex object boundaries, and wide-range
object scales. SAM has achieved impressive results on various natural image
segmentation tasks. Meanwhile, zero-shot and efficient MIS can well reduce the
annotation time and boost the development of medical image analysis. Hence, SAM
seems to be a potential tool and its performance on large medical datasets
should be further validated. We collected and sorted 52 open-source datasets,
and build a large medical segmentation dataset with 16 modalities, 68 objects,
and 553K slices. We conducted a comprehensive analysis of different SAM testing
strategies on the so-called COSMOS 553K dataset. Extensive experiments validate
that SAM performs better with manual hints like points and boxes for object
perception in medical images, leading to better performance in prompt mode
compared to everything mode. Additionally, SAM shows remarkable performance in
some specific objects and modalities, but is imperfect or even totally fails in
other situations. Finally, we analyze the influence of different factors (e.g.,
the Fourier-based boundary complexity and size of the segmented objects) on
SAM's segmentation performance. Extensive experiments validate that SAM's
zero-shot segmentation capability is not sufficient to ensure its direct
application to the MIS.Comment: 23 pages, 14 figures, 12 table
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