Temporal-Mapping Photography for Event Cameras

Event cameras, or Dynamic Vision Sensors (DVS) are novel neuromorphic sensors that capture brightness changes as a continuous stream of ``events'' rather than traditional intensity frames. Converting sparse events to dense intensity frames faithfully has long been an ill-posed problem. Previous methods have primarily focused on converting events to video in dynamic scenes or with a moving camera. In this paper, for the first time, we realize events to dense intensity image conversion using a stationary event camera in static scenes. Different from traditional methods that mainly rely on event integration, the proposed Event-Based Temporal Mapping Photography (EvTemMap) measures the time of event emitting for each pixel. Then, the resulting Temporal Matrix is converted to an intensity frame with a temporal mapping neural network. At the hardware level, the proposed EvTemMap is implemented by combining a transmittance adjustment device with a DVS, named Adjustable Transmittance Dynamic Vision Sensor. Additionally, we collected TemMat dataset under various conditions including low-light and high dynamic range scenes. The experimental results showcase the high dynamic range, fine-grained details, and high-grayscale-resolution of the proposed EvTemMap, as well as the enhanced performance on downstream computer vision tasks compared to other methods. The code and TemMat dataset will be made publicly available.Comment: 17 pages, 10 figure

Measuring the Instability of China’s Financial System: Indices Construction and an Early Warning System

In this paper, employing several econometric techniques, we construct a financial stress index (CNFSI) and a financial conditions index (CNFCI) to measure the instability of China’s financial system. The indices are based on the monthly data collected from China’s inter-bank markets, stock markets, foreign exchange markets and debt markets. Using two indices, we identify the episodes of systemic financial stress, and then evaluate the indices. The empirical results suggest that the CNFSI performs better than the CNFCI. Furthermore, we propose four leading indicators for monitoring China’s financial instability, and provide a primary early warning system for China’s macroprudential regulations

Automatic Extraction Method of 3D Feature Guidelines for Complex Cultural Relic Surfaces Based on Point Cloud

Cultural relics line graphic serves as a crucial form of traditional artifact information documentation, which is a simple and intuitive product with low cost of displaying compared with 3D models. Dimensionality reduction is undoubtedly necessary for line drawings. However, most existing methods for artifact drawing rely on the principles of orthographic projection that always cannot avoid angle occlusion and data overlapping while the surface of cultural relics is complex. Therefore, conformal mapping was introduced as a dimensionality reduction way to compensate for the limitation of orthographic projection. Based on the given criteria for assessing surface complexity, this paper proposed a three-dimensional feature guideline extraction method for complex cultural relic surfaces. A 2D and 3D combined factor that measured the importance of points on describing surface features, vertex weight, was designed. Then the selection threshold for feature guideline extraction was determined based on the differences between vertex weight and shape index distributions. The feasibility and stability were verified through experiments conducted on real cultural relic surface data. Results demonstrated the ability of the method to address the challenges associated with the automatic generation of line drawings for complex surfaces. The extraction method and the obtained results will be useful for line graphic drawing, displaying and propaganda of cultural relics

Effects of pore widening vs oxygenation on capacitance of activated carbon in aqueous sodium sulfate electrolyte

The commercial activated carbon has a relatively low specific capacitance in the Na2SO4 electrolyte, which hinder the development of asymmetrical supercapacitors with high voltage. Re-activation and oxidative etching methods were applied to change the pore structure of activated carbon, respectively, to study the capacitive behavior of carbon in the Na2SO4 electrolyte. The pore distributions combining with capacitive properties deduce that 0.85 nm is the threshold diameter of the ion-accessible micropores for hydrated Na+ and SO42−. The specific capacitances of both the carbon materials by re-activation and oxidative etching methods are increased by 40 %, in comparison with the commercial activated carbon. The enhanced capacitive performances of the carbon materials were mainly attributed to the increased ion-accessible specific surface area and pseudocapacitance, respectively. The oxidative etching is a more facile and economical method for practice application. Combining with MnO2 as the positive electrode, the asymmetrical supercapacitor with a high voltage of 1.8 V exhibits a maximum specific cell capacitance of 50 F g–1 and specific energy of 22.5 Wh kg–1

Electroacupuncture at LI11 promotes jejunal motility via the parasympathetic pathway

Background: Gastrointestinal motility disorder has been demonstrated to be regulated by acupuncture treatment. The mechanisms underlying the effects of acupuncture stimulation of abdominal and lower limb acupoints on gastrointestinal motility have been thoroughly studied; however, the physiology underlying the effects of acupuncture on the forelimbs to mediate gastrointestinal motility requires further exploration. The aim of this study was to determine whether electroacupuncture (EA) at LI11 promotes jejunal motility, whether the parasympathetic pathway participates in this effect, and if so, which somatic afferent nerve fibres are involved.Methods: A manometric balloon was used to observe jejunal motility. The effects and mechanisms of EA at LI11 were explored in male Sprague-Dawley rats with or without drug administration (propranolol, clenbuterol, acetylcholine, and atropine) and with or without vagotomy. Three types of male mice (β1β2 receptor-knockout [β1β2 −/−] mice, M2M3 receptor-knockout [M2M3 −/−] mice and wild-type [WT] mice) were also studied by using different EA intensities (1, 2, 4, 6, and 8 mA). A total of 72 rats and 56 mice were included in the study.Results: EA at LI11 increased the contractile amplitude of jejunal motility in the majority of both rats and mice. However, EA at LI11 did not enhance jejunal motility in rats administered atropine, rats that underwent vagotomy, and M2M3 −‍‍/− mice (at all intensities). In WT mice, EA at LI11 significantly increased jejunal motility at all intensities except 1 mA, and a plateau was reached at intensities greater than 4 mA.Conclusion: Our results suggest that EA at LI11 promotes jejunal motility primarily by exciting the parasympathetic pathway, and that Aδ-fibres and C-fibres may play important roles in the process

Imprints of Sagittarius accretion event: Young O-rich stars and discontinuous chemical evolution in Milky Way disc

The Milky Way has undergone significant transformations in its early history, characterised by violent mergers and the accretion of satellite galaxies. Among these events, the infall of the satellite galaxy Gaia-Enceladus/Sausage is recognised as the last major merger event, fundamentally altering the evolution of the Milky Way and shaping its chemo-dynamical structure. However, recent observational evidence suggests that the Milky Way remains undergone notable events of star formation in the past 4 Gyr, which is thought to be triggered by the perturbations from Sagittarius dwarf galaxy (Sgr). Here we report chemical signatures of the Sgr accretion event in the past 4 Gyr, using the [Fe/H] and [O/Fe] ratios in the thin disc, which is reported for the first time. It reveals that the previously discovered V-shape structure of age-[Fe/H] relation varies across different Galactic locations and has rich substructures. Interestingly, we discover a discontinuous structure at z$_{\rm max}$ $<$ 0.3 kpc, interrupted by a recent burst of star formation from 4 Gyr to 2 Gyr ago. In this episode, we find a significant rise in oxygen abundance leading to a distinct [O/Fe] gradient, contributing to the formation of young O-rich stars. Combined with the simulated star formation history and chemical abundance of Sgr, we suggest that the Sgr is an important actor in the discontinuous chemical evolution of the Milky Way disc.Comment: 17 pages, 15 figures. Under review at Nature Communication

The effect of water temperature on the pathogenicity of decapod iridescent virus 1 (DIV1) in Litopenaeus vannamei

Decapod iridescent virus 1 (DIV1) has caused huge losses to the shrimp breeding industry in recent years as a new shrimp virus. In this study, white leg shrimp, Litopenaeus vannamei, were cultured at different temperatures (26 ± 1 °C and 32 ± 1 °C) and the same salinity, then infected with DIV1 by intramuscular injection to determine the effects of water temperature on viral infection. The DIV1 copy counts in the gills, hepatopancreas, pleopods, intestines, and muscles of L. vannamei were measured in samples collected at 6, 12, and 24 h post-infection (hpi), and the survival rate of L. vannamei was assessed every 6 h after infection. At 96 hpi, the survival rates of L. vannamei in the high (32 ± 1 ℃) and standard (26 ± 1 ℃) water temperature groups were 2.22% and 4.44%, respectively. The peak time of mortality in the high-water temperature group was 6 h earlier than in the standard water temperature group. After 24 hours of DIV1 infection, the DIV1 copy counts in the standard water temperature treatment group were significantly higher than those in the high-water temperature treatment group. The tissues with the highest virus copy counts in the standard and high-temperature groups were the intestines (2.9×1011 copies/g) and muscles (7.0×108 copies/g). The effect of temperature on the pathogenicity of DIV1 differs from that of other previously studied viruses, such as white spot syndrome virus, Taura syndrome virus, and infectious hypodermal and hematopoietic necrosis virus, because the high-water temperature did not mitigate the damage caused by DIV1 infection

Prognostic value of neutrophil-to-lymphocyte ratio in breast cancer

AbstractInflammation is an essential component of pathogenesis and progression of cancer. A high neutrophil-to-lymphocyte ratio (NLR) is considered as a prognostic indicator for breast cancer. This meta-analysis was conducted to establish the overall accuracy of the NLR test in the diagnosis of breast cancer. A comprehensive search of the literature was conducted by using PubMed, Web of Science and China National Knowledge Infrastructure (CNKI). Published studies dating up to July 2014 and 4,293 patients were enrolled in the present study. In order to evaluate the association between NLR and overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS) or cancer specific survival (CSS), the hazard ratios (HRs) and their 95% confidence intervals (CIs) were extracted. OS was the primary outcome. The results suggested that increased NLR was a strong predictor for OS with HR of 2.28 (95% CI=1.08–4.80, Pheterogeneity<0.001). Stratified analyses indicated that a high NLR appeared to be a negative prognostic marker in Caucasian populations (HR=4.53, 95% CI=3.11–6.60, Pheterogeneity=0.096), multivariate analysis method (HR=2.10, 95% CI=1.52–2.89, Pheterogeneity=0.591), and mixed metastasis (HR=4.53, 95% CI=3.11–6.60, Pheterogeneity=0.096). Elevated NLR was associated with a high risk for DFS (HR=1.38, 95% CI=1.09–1.74, Pheterogeneity=0.050) and in subgroups of multivariate analysis (HR=1.64, 95% CI=1.25–2.14, Pheterogeneity=0.545) and mixed metastasis (HR=1.99, 95% CI=1.28–3.09, Pheterogeneity=0.992). In summary, NLR could be considered as a predictive factor for patients with breast cancer