143 research outputs found
Introspective Deep Metric Learning for Image Retrieval
This paper proposes an introspective deep metric learning (IDML) framework
for uncertainty-aware comparisons of images. Conventional deep metric learning
methods produce confident semantic distances between images regardless of the
uncertainty level. However, we argue that a good similarity model should
consider the semantic discrepancies with caution to better deal with ambiguous
images for more robust training. To achieve this, we propose to represent an
image using not only a semantic embedding but also an accompanying uncertainty
embedding, which describes the semantic characteristics and ambiguity of an
image, respectively. We further propose an introspective similarity metric to
make similarity judgments between images considering both their semantic
differences and ambiguities. The proposed IDML framework improves the
performance of deep metric learning through uncertainty modeling and attains
state-of-the-art results on the widely used CUB-200-2011, Cars196, and Stanford
Online Products datasets for image retrieval and clustering. We further provide
an in-depth analysis of our framework to demonstrate the effectiveness and
reliability of IDML. Code is available at: https://github.com/wzzheng/IDML.Comment: The extended version of this paper is accepted to T-PAMI. Source code
available at https://github.com/wzzheng/IDM
OPERA: Omni-Supervised Representation Learning with Hierarchical Supervisions
The pretrain-finetune paradigm in modern computer vision facilitates the
success of self-supervised learning, which tends to achieve better
transferability than supervised learning. However, with the availability of
massive labeled data, a natural question emerges: how to train a better model
with both self and full supervision signals? In this paper, we propose
Omni-suPErvised Representation leArning with hierarchical supervisions (OPERA)
as a solution. We provide a unified perspective of supervisions from labeled
and unlabeled data and propose a unified framework of fully supervised and
self-supervised learning. We extract a set of hierarchical proxy
representations for each image and impose self and full supervisions on the
corresponding proxy representations. Extensive experiments on both
convolutional neural networks and vision transformers demonstrate the
superiority of OPERA in image classification, segmentation, and object
detection. Code is available at: https://github.com/wangck20/OPERA.Comment: Source code available at: https://github.com/wangck20/OPER
Transcriptional suppression of breast cancer resistance protein (BCRP) by wild-type p53 through the NF-κB pathway in MCF-7 cells
AbstractBreast cancer resistance protein (BCRP) has been shown to confer multidrug resistance, but the mechanisms of its regulation are poorly understood. Here, we investigate the effects of wild-type and mutant p53, and nuclear factor kappa-B (NF-κB) (p50) on BCRP promoter activity in MCF-7 cells. Our results demonstrated that wild-type p53 markedly suppressed BCRP activity and enhanced the chemosensitivity of cells to mitoxantrone, whereas mutant p53 had little inhibitory effect. After inhibition of NF-κB, similar results were obtained. Following knockdown of endogenous p53, BCRP and p50 expressions were increased, and the chemosensitivity of the cells to mitoxantrone was decreased. We conclude that wild-type p53 acts as a negative regulator of BCRP gene transcription
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