95 research outputs found

    Towards Accurate One-Stage Object Detection with AP-Loss

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    One-stage object detectors are trained by optimizing classification-loss and localization-loss simultaneously, with the former suffering much from extreme foreground-background class imbalance issue due to the large number of anchors. This paper alleviates this issue by proposing a novel framework to replace the classification task in one-stage detectors with a ranking task, and adopting the Average-Precision loss (AP-loss) for the ranking problem. Due to its non-differentiability and non-convexity, the AP-loss cannot be optimized directly. For this purpose, we develop a novel optimization algorithm, which seamlessly combines the error-driven update scheme in perceptron learning and backpropagation algorithm in deep networks. We verify good convergence property of the proposed algorithm theoretically and empirically. Experimental results demonstrate notable performance improvement in state-of-the-art one-stage detectors based on AP-loss over different kinds of classification-losses on various benchmarks, without changing the network architectures. Code is available at https://github.com/cccorn/AP-loss.Comment: 13 pages, 7 figures, 4 tables, main paper + supplementary material, accepted to CVPR 201

    The emergence of global phase coherence from local pairing in underdoped cuprates

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    In conventional metal superconductors such as aluminum, the large number of weakly bounded Cooper pairs become phase coherent as soon as they start to form. The cuprate high critical temperature (TcT_c) superconductors, in contrast, belong to a distinctively different category. To account for the high TcT_c, the attractive pairing interaction is expected to be strong and the coherence length is short. Being doped Mott insulators, the cuprates are known to have low superfluid density, thus are susceptible to phase fluctuations. It has been proposed that pairing and phase coherence may occur separately in cuprates, and TcT_c corresponds to the phase coherence temperature controlled by the superfluid density. To elucidate the microscopic processes of pairing and phase ordering in cuprates, here we use scanning tunneling microscopy to image the evolution of electronic states in underdoped Bi2LaxSr2xCuO6+δ\rm Bi_2La_xSr_{2-x}CuO_{6+{\delta}}. Even in the insulating sample, we observe a smooth crossover from the Mott insulator to superconductor-type spectra on small islands with chequerboard order and emerging quasiparticle interference patterns following the octet model. Each chequerboard plaquette contains approximately two holes, and exhibits a stripy internal structure that has strong influence on the superconducting features. Across the insulator to superconductor boundary, the local spectra remain qualitatively the same while the quasiparticle interferences become long-ranged. These results suggest that the chequerboard plaquette with internal stripes plays a crucial role on local pairing in cuprates, and the global phase coherence is established once its spatial occupation exceeds a threshold

    Successful Remove of a Metal Axletree Causing Penile Strangulation in a 19-Year-Old Male by Degloving Operation

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    Penile strangulation caused by foreign bodies mostly occurs in adolescents and adult males. When it happens, foreign bodies are often not easy to be removed. Penile strangulation is a rarely described urological emergency, especially in the adolescent population. This paper demonstrates the successful removal of a metal axletree causing penile strangulation in a 19-year-old male with the help of degloving operation

    Intraspecific Aflatoxin Inhibition in Aspergillus flavus Is Thigmoregulated, Independent of Vegetative Compatibility Group and Is Strain Dependent

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    Biological control of preharvest aflatoxin contamination by atoxigenic stains of Aspergillus flavus has been demonstrated in several crops. The assumption is that some form of competition suppresses the fungus's ability to infect or produce aflatoxin when challenged. Intraspecific aflatoxin inhibition was demonstrated by others. This work investigates the mechanistic basis of that phenomenon. A toxigenic and atoxigenic isolate of A. flavus which exhibited intraspecific aflatoxin inhibition when grown together in suspended disc culture were not inhibited when grown in a filter insert-plate well system separated by a .4 or 3 µm membrane. Toxigenic and atoxigenic conidial mixtures (50∶50) placed on both sides of these filters restored inhibition. There was ∼50% inhibition when a 12 µm pore size filter was used. Conidial and mycelial diameters were in the 3.5–7.0 µm range and could pass through the 12 µm filter. Larger pore sizes in the initially separated system restored aflatoxin inhibition. This suggests isolates must come into physical contact with one another. This negates a role for nutrient competition or for soluble diffusible signals or antibiotics in aflatoxin inhibition. The toxigenic isolate was maximally sensitive to inhibition during the first 24 hrs of growth while the atoxigenic isolate was always inhibition competent. The atoxigenic isolate when grown with a green fluorescent protein (GFP) toxigenic isolate failed to inhibit aflatoxin indicating that there is specificity in the touch inhibiton. Several atoxigenic isolates were found which inhibited the GFP isolate. These results suggest that an unknown signaling pathway is initiated in the toxigenic isolate by physical interaction with an appropriate atoxigenic isolate in the first 24 hrs which prevents or down-regulates normal expression of aflatoxin after 3–5 days growth. We suspect thigmo-downregulation of aflatoxin synthesis is the mechanistic basis of intraspecific aflatoxin inhibition and the major contributor to biological control of aflatoxin contamination

    DNA Self-Assembly of Targeted Near-Infrared-Responsive Gold Nanoparticles for Cancer Thermo-Chemotherapy

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    Targeted cancer therapy: Inspired by the ability of DNA hybridization, a targeted near-infrared (NIR) light-responsive delivery system has been developed through simple DNA self-assembly (see picture; PEG=polyethylene glycol). This DNA-based platform shows the ability of releasing therapeutics upon near-infrared irradiation, and remarkable targeted thermo- and chemotherapeutic efficacy in vitro and in vivo.National Institutes of Health (U.S.) (Grant CA151884)Prostate Cancer Foundation (Program in Cancer Nanotherapeutics

    Effects of opioid-free anaesthesia on postoperative nausea and vomiting in patients undergoing video-assisted thoracoscopic surgery (OFA-PONV trial): study protocol for a randomised controlled trial

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    Abstract Background Postoperative nausea and vomiting (PONV) is a common complication after general anaesthesia and is associated with morbidity and prolonged length of stay. Growing evidence suggest that opioid-free general anaesthesia (OFA) may reduce PONV in various surgical settings. We aim to evaluate the efficacy of OFA on the incidence of PONV compared with opioid-based anaesthesia among adults undergoing thoracoscopic surgery. Methods This is a prospective, single-centre, randomised controlled trial comparing OFA and opioid-based anaesthesia for thoracoscopic surgery. A total of 168 adults will be randomised with a 1:1 ratio to receive either opioid-free anaesthesia or opioid-based anaesthesia. The primary outcome will be the incidence of PONV within 24 h after operation. The secondary outcomes will include the severity of PONV, quality of recovery, pain at rest, 6-min walking test, and health-related quality of life after operation. Discussion The benefit-risk of OFA for patients after operation is contradictory in previous studies, so further study is required. This trial will focus on the effect of OFA on the incidence of PONV in patients undergoing thoracoscopic surgery. This trial adopts uniformed PONV and perioperative pain management, standardised randomised and blind, clear-cut inclusion and exclusion criteria, and standardised scales to assess the severity of PONV after surgery, the quality of postoperative recovery, and the health status at 6 months. The findings of this study will help to provide references to promote early recovery of patients after lung surgery. Trial registration ClinicalTrials.gov NCT05411159. Registered on 9 June 2022
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