SPColor: Semantic Prior Guided Exemplar-based Image Colorization

Exemplar-based image colorization aims to colorize a target grayscale image based on a color reference image, and the key is to establish accurate pixel-level semantic correspondence between these two images. Previous methods search for correspondence across the entire reference image, and this type of global matching is easy to get mismatch. We summarize the difficulties in two aspects: (1) When the reference image only contains a part of objects related to target image, improper correspondence will be established in unrelated regions. (2) It is prone to get mismatch in regions where the shape or texture of the object is easily confused. To overcome these issues, we propose SPColor, a semantic prior guided exemplar-based image colorization framework. Different from previous methods, SPColor first coarsely classifies pixels of the reference and target images to several pseudo-classes under the guidance of semantic prior, then the correspondences are only established locally between the pixels in the same class via the newly designed semantic prior guided correspondence network. In this way, improper correspondence between different semantic classes is explicitly excluded, and the mismatch is obviously alleviated. Besides, to better reserve the color from reference, a similarity masked perceptual loss is designed. Noting that the carefully designed SPColor utilizes the semantic prior provided by an unsupervised segmentation model, which is free for additional manual semantic annotations. Experiments demonstrate that our model outperforms recent state-of-the-art methods both quantitatively and qualitatively on public dataset

Exemplar-based Video Colorization with Long-term Spatiotemporal Dependency

Exemplar-based video colorization is an essential technique for applications like old movie restoration. Although recent methods perform well in still scenes or scenes with regular movement, they always lack robustness in moving scenes due to their weak ability in modeling long-term dependency both spatially and temporally, leading to color fading, color discontinuity or other artifacts. To solve this problem, we propose an exemplar-based video colorization framework with long-term spatiotemporal dependency. To enhance the long-term spatial dependency, a parallelized CNN-Transformer block and a double head non-local operation are designed. The proposed CNN-Transformer block can better incorporate long-term spatial dependency with local texture and structural features, and the double head non-local operation further leverages the performance of augmented feature. While for long-term temporal dependency enhancement, we further introduce the novel linkage subnet. The linkage subnet propagate motion information across adjacent frame blocks and help to maintain temporal continuity. Experiments demonstrate that our model outperforms recent state-of-the-art methods both quantitatively and qualitatively. Also, our model can generate more colorful, realistic and stabilized results, especially for scenes where objects change greatly and irregularly

Targeting Enceladus' Geyser vents using penetrators employing biomimetic plume sniffing

The icy moons of the solar system represent the most promising targets for astrobiological exploration. Direct access to the geyser vents of Enceladus would be highly desirable to acquire pristine biological samples but considered very challenging. The location of the landing target, one of the plume sources, is unknown a priori that must be inferred by the landing vehicle itself during the descent. We present an approach that offers the prospect of targeting the source of the Enceladian icy plumes using one or more penetrators. Penetrators are small missile-type entry descent and landing vehicles that can carry modest scientific instruments capable of withstanding impact into the subsurface. By continuously measuring the concentration of the icy plume, the penetrator can locate the plume source and target it for impact. The penetrators' trajectory and plume source localization are addressed. Calculations of the sphere of influence, the free fall time and the penetrator impact velocity are input parameters from which we design three types of descent profiles. The descent profile involves vectoring-in-forward-flight (viffing) - it may be ballistic (with minimal ?V cost), planar viffing (with modest ?V costs), a hybrid approach of nested boxes (with intermediate ?V cost) or quasi-spiral (with highest ?V cost) for which we present trajectory maneuver simulations. The simulations illustrate that the quasi-spiral profile is favored and is tolerable with modest ?V costs traded with targeting accuracy. We determine that the proposed vectoring-in-forward flight (viffing) maneuvers is feasible and permits accurate targeting of Enceladus' subsurface vents

LncRNA SNHG5 promotes cervical cancer progression by regulating the miR-132/SOX4 pathway

Background The long non-coding RNA (lncRNA) small nucleolar RNA host gene 5 (SNHG5) has been verified as a crucial regulator in many types of tumours but not clear in cervical cancer (CC). This study aims to investigate the effect and further mechanisms of lncRNA SNHG5 in CC. Methods The expression of SNHG5 and miR-132, as well as SOX4 (sex-determining region Y-box 4) mRNA expression were determined by quantitative real-time PCR (qRT-PCR). The protein level of SOX4 and epithelial-mesenchymal transition (EMT)-related proteins were evaluated by western blot. Then, Edu and Transwell assay were performed to assess the proliferation, migration and invasion of CC cells. RNA immunoprecipitation (RIP) and RNA pull-down assay were conducted to explore the relationship between SNHG5 and miR-132. Results SNHG5 and SOX4 were upregulated, and miR-132 was downregulated in CC tissues and cell lines. SNHG5 was positively correlated with FIGO stage (p = .003) and lymph node metastasis (p = .001). Pearson’s correlation analysis conveyed that SNHG5 was positively correlated with SOX4, and miR-132 was negatively correlated with SOX4 and SNHG5. Knockdown of SNHG5 in vitro reduced CC cell proliferation, migration and invasion through regulating miR-132. Moreover, overexpression of miR-132 restrained CC cell proliferation, migration, and invasion through targeting SOX4, and SNHG5 enhanced SOX4 expression via negatively regulating miR-132. Conclusion SNHG5 promotes SOX4 expression to accelerate CC cell proliferation, migration and invasion through negatively regulating miR-132

Temporal Consistent Automatic Video Colorization via Semantic Correspondence

Video colorization task has recently attracted wide attention. Recent methods mainly work on the temporal consistency in adjacent frames or frames with small interval. However, it still faces severe challenge of the inconsistency between frames with large interval.To address this issue, we propose a novel video colorization framework, which combines semantic correspondence into automatic video colorization to keep long-range consistency. Firstly, a reference colorization network is designed to automatically colorize the first frame of each video, obtaining a reference image to supervise the following whole colorization process. Such automatically colorized reference image can not only avoid labor-intensive and time-consuming manual selection, but also enhance the similarity between reference and grayscale images. Afterwards, a semantic correspondence network and an image colorization network are introduced to colorize a series of the remaining frames with the help of the reference. Each frame is supervised by both the reference image and the immediately colorized preceding frame to improve both short-range and long-range temporal consistency. Extensive experiments demonstrate that our method outperforms other methods in maintaining temporal consistency both qualitatively and quantitatively. In the NTIRE 2023 Video Colorization Challenge, our method ranks at the 3rd place in Color Distribution Consistency (CDC) Optimization track

Urolithin A protects severe acute pancreatitis‐associated acute cardiac injury by regulating mitochondrial fatty acid oxidative metabolism in cardiomyocytes

Abstract Severe acute pancreatitis (SAP) often develops into acute cardiac injury (ACI), contributing to the high mortality of SAP. Urolithin A (UA; 3,8‐dihydroxy‐6H‐dibenzopyran‐6‐one), a natural polyphenolic compound, has been extensively studied and shown to possess significant anti‐inflammatory effects. Nevertheless, the specific effects of UA in SAP‐associated acute cardiac injury (SACI) have not been definitively elucidated. Here, we investigated the therapeutic role and mechanisms of UA in SACI using transcriptomics and untargeted metabolomics analyses in a mouse model of SACI and in vitro studies. SACI resulted in severely damaged pancreatic and cardiac tissues with myocardial mitochondrial dysfunction and mitochondrial metabolism disorders. UA significantly reduced the levels of lipase, amylase and inflammatory factors, attenuated pathological damage to pancreatic and cardiac tissues, and reduced myocardial cell apoptosis and oxidative stress in SACI. Moreover, UA increased mitochondrial membrane potential and adenosine triphosphate production and restored mitochondrial metabolism, but the efficacy of UA was weakened by the inhibition of CPT1. Therefore, UA can attenuate cardiac mitochondrial dysfunction and reduce myocardial apoptosis by restoring the balance of mitochondrial fatty acid oxidation metabolism. CPT1 may be a potential target. This study has substantial implications for advancing our understanding of the pathogenesis and drug development of SACI

Role of neutrophil extracellular traps in inflammatory evolution in severe acute pancreatitis

Abstract. Severe acute pancreatitis (SAP) is a life-threatening acute abdominal disease with two peaks of death: the first in the early stage, characterized by systemic inflammatory response-associated organ failure; and the second in the late stage, characterized by infectious complications. Neutrophils are the main immune cells participating in the whole process of SAP. In addition to the traditional recognition of neutrophils as the origination of chemokine and cytokine cascades or phagocytosis and degranulation of pathogens, neutrophil extracellular traps (NETs) also play an important roles in inflammatory reactions. We reviewed the role of NETs in the occurrence and development of SAP and its fatal complications, including multiple organs injury, infected pancreatic necrosis, and thrombosis. This review provides novel insights into the involvement of NETs throughout the entire process of SAP, showing that targeting NETs might be a promising strategy in SAP treatment. However, precision therapeutic options targeting NETs in different situations require further investigation