3,593 research outputs found
Hourglass Face Detector for Hard Face
Face detection is an upstream task of facial image analysis. In many real-world scenarios, we need to detect small, occluded or dense faces that are hard to detect, but hard face detection is a challenging task in particular considering the balance between accuracy and inference speed for real-world applications. This paper proposes an Hourglass Face Detector (HFD) for hard face by developing a deep one-stage fully-convolutional hourglass network, which achieves an excellent balance between accuracy and inference speed. To this end, the HFD firstly shrinks a feature map by a series of stridden convolutional layers rather than pooling layers, so that useful subtle information is preserved better. Secondly, it exploits context information by merging fine-grained shallow feature maps with deep ones full of semantic information, making a better fusion of detailed information and semantic information to achieve a better detection of small faces. Moreover, the HFD exploits prior and multiscale information from the training data to enhance its scale-invariance and adaptability of anchor scales. Compared with the SSH and S3FD methods, the HFD can achieve a better performance in average precision on detecting hard faces as well as a quicker inference. Experiments on the WIDER FACE and FDDB datasets demonstrate the superior performance of our proposed method
Landau-Zener-Stuckelberg interference in a multi-anticrossing system
We propose a universal analytical method to study the dynamics of a
multi-anticrossing system subject to driving by one single large-amplitude
triangle pulse, within its time scales smaller than the dephasing time. Our
approach can explain the main features of the Landau-Zener-Stuckelberg
interference patterns recently observed in a tripartite system [Nature
Communications 1:51 (2010)]. In particular, we focus on the effects of the size
of anticrossings on interference and compare the calculated interference
patterns with numerical simulations. In addition, Fourier transform of the
patterns can extract information on the energy level spectrum.Comment: 6 pages, 5 figure
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Hypericin enhances β-lactam antibiotics activity by inhibiting sarA expression in methicillin-resistant Staphylococcus aureus.
Bacteremia is a life-threating syndrome often caused by methicillin-resistant Staphylococcus aureus (MRSA). Thus, there is an urgent need to develop novel approaches to successfully treat this infection. Staphylococcal accessory regulator A (SarA), a global virulence regulator, plays a critical role in pathogenesis and β-lactam antibiotic resistance in Staphylococcus aureus. Hypericin is believed to act as an antibiotic, antidepressant, antiviral and non-specific kinase inhibitor. In the current study, we investigated the impact of hypericin on β-lactam antibiotics susceptibility and mechanism(s) of its activity. We demonstrated that hypericin significantly decreased the minimum inhibitory concentrations of β-lactam antibiotics (e.g., oxacillin, cefazolin and nafcillin), biofilm formation and fibronectin binding in MRSA strain JE2. In addition, hypericin significantly reduced sarA expression, and subsequently decreased mecA, and virulence-related regulators (e.g., agr RNAâ
˘) and genes (e.g., fnbA and hla) expression in the studied MRSA strain. Importantly, the in vitro synergistic effect of hypericin with β-lactam antibiotic (e.g., oxacillin) translated into in vivo therapeutic outcome in a murine MRSA bacteremia model. These findings suggest that hypericin plays an important role in abrogation of β-lactam resistance against MRSA through sarA inhibition, and may allow us to repurpose the use of β-lactam antibiotics, which are normally ineffective in the treatment of MRSA infections (e.g., oxacillin)
Distribution of Spectral Lags in Gamma Ray Bursts
Using the data acquired in the Time To Spill (TTS) mode for long gamma-ray
bursts (GRBs) collected by the Burst and Transient Source Experiment on board
the Compton Gamma Ray Observatory (BATSE/CGRO), we have carefully measured
spectral lags in time between the low (25-55 keV) and high (110-320 keV) energy
bands of individual pulses contained in 64 multi-peak GRBs. We find that the
temporal lead by higher-energy gamma-ray photons (i.e., positive lags) is the
norm in this selected sample set of long GRBs. While relatively few in number,
some pulses of several long GRBs do show negative lags. This distribution of
spectral lags in long GRBs is in contrast to that in short GRBs. This apparent
difference poses challenges and constraints on the physical mechanism(s) of
producing long and short GRBs. The relation between the pulse peak count rates
and the spectral lags is also examined. Observationally, there seems to be no
clear evidence for systematic spectral lag-luminosity connection for pulses
within a given long GRB.Comment: 20 pages, 4 figure
Contributions of prognostic factors to socioeconomic disparities in cancer survival : protocol for analysis of a cohort with linked data
Introduction Socioeconomic disparities in cancer survival have been reported in many developed countries, including Australia. Although some international studies have investigated the determinants of these socioeconomic disparities, most previous Australian studies have been descriptive, as only limited relevant data are generally available. Here, we describe a protocol for a study to use data from a large-scale Australian cohort linked with several other health-related databases to investigate several groups of factors associated with socioeconomic disparities in cancer survival in New South Wales (NSW), Australia, and quantify their contributions to the survival disparities. Methods and analysis The Sax Institute's 45 and Up Study participants completed a baseline questionnaire during 2006-2009. Those who were subsequently diagnosed with cancer of the colon, rectum, lung or female breast will be included. This study sample will be identified by linkage with NSW Cancer Registry data for 2006-2013, and their vital status will be determined by linking with cause of death records up to 31 December 2015. The study cohort will be divided into four groups based on each of the individual education level and an area-based socioeconomic measure. The treatment received will be obtained through linking with hospital records and Medicare and pharmaceutical claims data. Cox proportional hazards models will be fitted sequentially to estimate the percentage contributions to overall socioeconomic survival disparities of patient factors, tumour and diagnosis factors, and treatment variables. Ethics and dissemination This research is covered by ethical approval from the NSW Population and Health Services Research Ethics Committee. Results of the study will be disseminated to different interest groups and organisations through scientific conferences, social media and peer-reviewed articles
Effects of Lactic Acid Bacteria on the Quality of \u3cem\u3eAchnatherum splendens\u3c/em\u3e Silage
Achnatherum splendens is an important forage for ruminant animals, but it has a high fiber content, and there is little information about the quality of Achnatherum splendens silage. This experiment was undertaken to study the effects of lactic acid bacteria on the quality of Achnatherum splendens (AS) silage
Electrochemical activity of nitrogen-containing groups in organic molecule electrode materials and their improvement strategies
Published online: January 12, 2021In recent years, due to their structural diversity, adjustability, versatility, and excellent electrochemical properties, organic compounds with nitrogen-containing groups (OCNs) have become some of the most promising organic electrode materials. The nitrogen-containing groups acting as electrochemical active sites include carbonânitrogen groups, nitrogenânitrogen groups, nitrogenâoxygen groups in OCNs, and nitrogen-containing groups in covalent organic frameworks. The molecular structure regulation of OCNs with nitrogen-containing groups acting as electrochemical active centers can suppress dissolution in electrolytes, increase electronic conductivity, and improve the kinetics of redox reactions. The kinetics behavior and electrochemical characteristics of OCN electrode materials in alkali metal rechargeable batteries with organic electrolytes are reviewed, and the related relationships between the structure and electrochemical properties of OCNs are the core of this review. Herein, the electrochemical reaction mechanisms and the strategies to improve the electrochemical activity of nitrogen-containing groups in OCNs are clarified, and the conjugate molecular structure of OCNs is shown to be an important direction for improvement. These results will have implications for research on electrode materials and provide more choices for rechargeable batteries. Moreover, this work will guide the study of more efficient OCNs that can be used as electrode materials.Qianchuan Yu, Zhihuan Xue, Meichen Li, Peimeng Qiu, Changgang Li, Shengping Wang, Jingxian Yu, Hiroki Nara, Jongbeom Na, and Yusuke Yamauch
Vesicle Size Regulates Nanotube Formation in the Cell
Intracellular membrane nanotube formation and its dynamics play important roles for cargo transportation and organelle biogenesis. Regarding the regulation mechanisms, while much attention has been paid on the lipid composition and its associated protein molecules, effects of the vesicle size has not been studied in the cell. Giant unilamellar vesicles (GUVs) are often used for in vitro membrane deformation studies, but they are much larger than most intracellular vesicles and the in vitro studies also lack physiological relevance. Here, we use lysosomes and autolysosomes, whose sizes range between 100 nm and 1 Îźm, as model systems to study the size effects on nanotube formation both in vivo and in vitro. Single molecule observations indicate that driven by kinesin motors, small vesicles (100-200 nm) are mainly transported along the tracks while a remarkable portion of large vesicles (500-1000 nm) form nanotubes. This size effect is further confirmed by in vitro reconstitution assays on liposomes and purified lysosomes and autolysosomes. We also apply Atomic Force Microscopy (AFM) to measure the initiation force for nanotube formation. These results suggest that the size-dependence may be one of the mechanisms for cells to regulate cellular processes involving membrane-deformation, such as the timing of tubulation-mediated vesicle recycling
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