•We find that groundtruth foreground masks can greatly benefit tasks such as WSOL and WSOD.•A previous literature claimed that WSOL is an ill-posed problem with classification models and ...classification labels. We propose WSFL (weakly supervised foreground learning) which learns foreground masks in a weakly supervised fashion (i.e., no extra supervision). With the help of the WSFL task, we can avoid the ill-posed problem in WSOL.•Applying WSFL to WSOL and WSOD, our method establishes new state-of-the-art results for both tasks. We achieve 74.37% Top-1 localization accuracy on CUB-200 and we achieve 55.7% mAP on VOC2007.
Modern deep learning models require large amounts of accurately annotated data, which is often difficult to satisfy. Hence, weakly supervised tasks, including weakly supervised object localization (WSOL) and detection (WSOD), have recently received attention in the computer vision community. In this paper, we motivate and propose the weakly supervised foreground learning (WSFL) task by showing that both WSOL and WSOD can be greatly improved if groundtruth foreground masks are available. More importantly, we propose a complete WSFL pipeline with low computational cost, which generates pseudo boxes, learns foreground masks, and does not need any localization annotations. With the help of foreground masks predicted by our WSFL model, we achieve 74.37% correct localization accuracy on CUB for WSOL, and 55.7% mean average precision on VOC07 for WSOD, thereby establish new state-of-the-art for both tasks. Our WSFL model also shows excellent transfer ability.
Sarcopenia is a common disorder that leads to a progressive decrease in skeletal muscle function in elderly people. Exercise effectively prevents or delays the onset and progression of sarcopenia. ...However, the molecular mechanisms underlying how exercise intervention improves skeletal muscle atrophy remain unclear. In this study, we found that 21‐month‐old zebrafish had a decreased swimming ability, reduced muscle fibre cross‐sectional area, unbalanced protein synthesis, and degradation, increased oxidative stress, and mitochondrial dysfunction, which suggests zebrafish are a valuable model for sarcopenia. Eight weeks of exercise intervention attenuated these pathological changes in sarcopenia zebrafish. Moreover, the effects of exercise on mitochondrial dysfunction were associated with the activation of the AMPK/SIRT1/PGC‐1α axis and 15‐PGDH downregulation. Our results reveal potential therapeutic targets and indicators to treat age‐related sarcopenia using exercise intervention.
Exercise reduce zebrafish sarcopenia may by activating the AMPK/SIRT1/PGC‐1α axis and down‐regulating 15‐PGDH to improve mitochondrial function. Aging induces oxidative stress and mitochondrial dysfunction in skeletal muscle, reducing myofibre cross‐sectional area, imbalance in protein synthesis and degradation, and, ultimately, muscle atrophy. Exercise inhibited oxidative stress and improved mitochondrial function may via AMPK/SIRT1/PGC‐1α axis activation and 15‐PGDH downregulation, effectively preventing age‐related sarcopenia (Created with BioRender.com.).
Obesity is a highly prevalent disease that can induce metabolic syndrome and is associated with a greater risk of muscular atrophy. Mitochondria play central roles in regulating the physiological ...metabolism of skeletal muscle; however, whether a decreased mitochondrial function is associated with impaired muscle function is unclear. In this study, we evaluated the effects of a high-fat diet on muscle mitochondrial function in a zebrafish model of sarcopenic obesity (SOB). In SOB zebrafish, a significant decrease in exercise capacity and skeletal muscle fiber cross-sectional area was detected, accompanied by high expression of the atrophy-related markers Atrogin-1 and muscle RING-finger protein-1. Zebrafish with SOB exhibited inhibition of mitochondrial biogenesis and fatty acid oxidation as well as disruption of mitochondrial fusion and fission in atrophic muscle. Thus, our findings showed that muscle atrophy was associated with SOB-induced mitochondrial dysfunction. Overall, these results showed that the SOB zebrafish model established in this study may provide new insights into the development of therapeutic strategies to manage mitochondria-related muscular atrophy.
Sarcopenia is a common skeletal muscle degenerative disease characterized by decreased skeletal muscle mass and mitochondrial dysfunction that involves microRNAs (miR) as regulatory factors in ...various pathways. Exercise reduces age-related oxidative damage and chronic inflammation and increases autophagy, among others. Moreover, whether aerobic exercise can regulate mitochondrial homeostasis by modulating the miR-128/insulin-like growth factor-1 (IGF-1) signaling pathway and can improve sarcopenia requires further investigation. Interestingly, zebrafish have been used as a model for aging research for over a decade due to their many outstanding advantages. Therefore, we established a model of zebrafish sarcopenia using d-galactose immersion and observed substantial changes, including reduced skeletal muscle cross-sectional area, increased tissue fibrosis, decreased motility, increased skeletal muscle reactive oxygen species, and notable alterations in mitochondrial morphology and function. We found that miR-128 expression was considerably upregulated, where as Igf1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha were significantly downregulated; moreover, mitochondrial homeostasis was reduced. Four weeks of aerobic exercise delayed sarcopenia progression and prevented the disruption of mitochondrial function and homeostasis. The genes related to atrophy and miR-128 were downregulated, Igf1 expression was considerably upregulated, and the phosphorylation levels of Pi3k, Akt, and Foxo3a were upregulated. Furthermore, mitochondrial respiration and homeostasis were enhanced. In conclusion, aerobic exercise improved skeletal muscle quality and function via the miR-128/IGF-1 signaling pathway, consequently ameliorating mitochondrial homeostasis in aging skeletal muscle.
Diagram of the mechanism by which aerobic exercise resists sarcopenia via the miR-128/IGF1 signaling pathway. Display omitted
•D-gal immersion induces senescence and, consequently, sarcopenia in zebrafish.•Regular aerobic exercise can effectively combat the process of sarcopenia.•Mitochondrial homeostasis is improved via the miR-128/IGF-1 signaling pathway.
Apparent personality analysis (APA) is an important problem of personality computing, and furthermore, automatic APA becomes a hot and challenging topic in computer vision and multimedia. In this ...paper, we propose a deep learning solution to APA from short video sequences. In order to capture rich information from both the visual and audio modality of videos, we tackle these tasks with our Deep Bimodal Regression (DBR) framework. In DBR, for the visual modality, we modify the traditional convolutional neural networks for exploiting important visual cues. In addition, taking into account the model efficiency, we extract audio representations and build a linear regressor for the audio modality. For combining the complementary information from the two modalities, we ensemble these predicted regression scores by both early fusion and late fusion. Finally, based on the proposed framework, we come up with a solution for the Apparent Personality Analysis competition track in the ChaLearn Looking at People challenge in association with ECCV 2016. Our DBR is the winner (first place) of this challenge with 86 registered participants. Beyond the competition, we further investigate the performance of different loss functions in our visual models, and prove non-convex loss functions for regression are optimal on the human-labeled video data.
A fiber optofluidic interferometer based on an optical microbubble-on-tip (μBoT) structure is developed. The generation process and sensing mechanism of this μBoT sensor are very different from ...traditional optical fiber sensors. The μBoT is a hybrid solid/liquid/gas microstructure generated by heating a fiber tip with laser and can be easily regenerated with low cost and good repeatability. Carbon nanotube film is optically deposited on the fiber end face to increase the laser absorption, thus enhances the efficiency of the μBoT generation. The diameter of the μBoT interferometer increases with time, leading to a decrease in the free spectral range (FSR). By measuring the FSR, the temperature and flow rate sensing are demonstrated. A temperature sensitivity of -1146 pm/°C is achieved, which is two orders of magnitude higher than that of the widely used fiber Bragg gratings. A lower limit of detection of 10 nL/min and a resolution of 0.03 nL/min for the flow rate sensing are obtained, which is better than that of the state-of-the-art microfluidic flowmeters. Our study will open a door to the development of novel reconfigurable fiber optofluidic sensors.
Long-term imbalance between fatigue and recovery may eventually lead to muscle weakness or even atrophy. We previously reported that excessive exercise induces pathological cardiac hypertrophy. ...However, the effect of excessive exercise on the skeletal muscles remains unclear. In the present study, we successfully established an excessive-exercise-induced skeletal muscle atrophy zebrafish model, with decreased muscle fiber size, critical swimming speed, and maximal oxygen consumption. High-throughput RNA-seq analysis identified differentially expressed genes in the model system compared with control zebrafish. Gene ontology and KEGG enrichment analysis revealed that the upregulated genes were enriched in autophagy, homeostasis, circadian rhythm, response to oxidative stress, apoptosis, the p53 signaling pathway, and the FoxO signaling pathway. Protein–protein interaction network analysis identified several hub genes, including keap1b, per3, ulk1b, socs2, esrp1, bcl2l1, hsp70, igf2r, mdm2, rab18a, col1a1a, fn1a, ppih, tpx2, uba5, nhlrc2, mcm4, tac1, b3gat3, and ddost, that correlate with the pathogenesis of skeletal muscle atrophy induced by excessive exercise. The underlying regulatory pathways and muscle-pressure-response-related genes identified in the present study will provide valuable insights for prescribing safe and accurate exercise programs for athletes and the supervision and clinical treatment of muscle atrophy induced by excessive exercise.
General anesthetics were first used over 170 years ago; however, the mechanisms of how general anesthetics induce loss of consciousness (LOC) remain unclear. Ciprofol, a novel intravenous anesthetic, ...has been developed by incorporating cyclopropyl into the chemical structure of propofol. This modification offers the benefits of rapid onset and minimal injection pain. Recent studies have revealed that the glutamatergic neurons of the lateral habenula (LHb) play a crucial role in modulating the LOC induced by propofol and sevoflurane. Nevertheless, the specific involvement of LHb in the anesthetic effects of ciprofol remains uncertain. Here, using targeted recombination in active populations (TRAP) combined with electroencephalogram/electromyography recordings and the righting reflex behavioral test, our study revealed that intravenous infusion of ciprofol for 1 h could lead to the induction of c-Fos expression in the LHb in mice. The combination of TRAP and gene ablation, aimed at selectively ablating ciprofol-activated neurons in the LHb, has been shown to facilitate the emergence of ciprofol anesthesia and decrease the proportion of delta waves during the emergence phase. Chemogenetic inhibition of these neurons produced a comparable effect, whereas chemogenetic activation resulted in the opposite outcome. Chemogenetic activation of ciprofol-activated neurons in the LHb delays the emergence of anesthesia and induces a deep hypnotic state during the emergence phase. Taken together, our findings suggest that LHb ciprofol-activated neurons modulate the state of consciousness and could potentially be targeted to manipulate consciousness during ciprofol anesthesia.
Microbubbles have broad applications for optofluidic devices, optical manipulation, and sensing. Here we report a series of experimental observations, demonstrating the controllable generation and ...assembly of microbubbles by using an optical fiber-coupled laser. The microbubbles can be photothermally generated with high efficiency in deionized water, without adding light-absorbing nanomaterials. The temporal evolution and assembled pattern, quantified by diameter, number and density of the microbubbles, can be flexibly controlled by the surface area of liquid, the insertion depth of fiber, and the laser power for heating. Good repeatability is confirmed for the microbubble generation. This kind of microbubble may have the potential for sensing, microstructure formation, etc.
Laser Powder Bed Fusion (LPBF) is a promising metal additive manufacturing technology based on layer by layer powder spreading, and powder bed uniformity has a great influence on the forming quality. ...By Discrete Element Method and powder spreading experiment, the interaction and movement between powder were studied during powder spreading, including powder jamming, rebound, splash, eddy, and empty powder area. Additionally, five kinds of powder spreading schemes were explored, and the new process of one-way reciprocating with tri-splint blade was designed to change the motion state of powder spreading from “blade pushing powder” to “blade holding powder.” By increasing the distance between the blade and the working platform form 0 to 20 µm with the distance between the upper surface of the substrate and the working platform 50 µm, defects such as powder splash and empty powder decreased. And the uniform powder bed of aluminum alloy powder was achieved with the new process of one-way reciprocating with tri-splint blade structure.
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