331 research outputs found

    Hybrid Graph Neural Networks for Crowd Counting

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    Crowd counting is an important yet challenging task due to the large scale and density variation. Recent investigations have shown that distilling rich relations among multi-scale features and exploiting useful information from the auxiliary task, i.e., localization, are vital for this task. Nevertheless, how to comprehensively leverage these relations within a unified network architecture is still a challenging problem. In this paper, we present a novel network structure called Hybrid Graph Neural Network (HyGnn) which targets to relieve the problem by interweaving the multi-scale features for crowd density as well as its auxiliary task (localization) together and performing joint reasoning over a graph. Specifically, HyGnn integrates a hybrid graph to jointly represent the task-specific feature maps of different scales as nodes, and two types of relations as edges:(i) multi-scale relations for capturing the feature dependencies across scales and (ii) mutual beneficial relations building bridges for the cooperation between counting and localization. Thus, through message passing, HyGnn can distill rich relations between the nodes to obtain more powerful representations, leading to robust and accurate results. Our HyGnn performs significantly well on four challenging datasets: ShanghaiTech Part A, ShanghaiTech Part B, UCF_CC_50 and UCF_QNRF, outperforming the state-of-the-art approaches by a large margin.Comment: To appear in AAAI 202

    A Novel Porous Carrier Found in Nature for Nanocomposite Materials Preparation: A Case Study of Artemia Egg Shell-Supported TiO 2 for Formaldehyde Removal

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    Artemia egg shells have an asymptotic sized pore structure (pore diameter: 500 nm-2500 nm), which could be used as a porous carrier for the preparation of nanocomposite materials. The objective of the present study was to prepare shell-supported TiO 2 using a naturally porous carrier, Artemia egg shell, and to exhibit a case study of shell-supported TiO 2 for formaldehyde removal. Characterization of shell-TiO 2 using SEM-EDS, TEM, and XRD proved that Artemia shell with asymptotic reduction pores (pore diameter: 500 nm-2500 nm) can be used as the carrier for nanocomposite materials. Artemia egg shell-supported TiO 2 in polycrystalline-like nanostructures can be used for the high efficiency removal (adsorption and degradation) of formaldehyde under visible light. Our results suggest that iron, one of the shell's components, should broaden the absorption of visible light and enhance the photocatalytic efficiency of nanotitanium dioxide under visible light. Due to their interesting absorption and formaldehyde removal qualities, Artemia egg shell, as a novel naturally porous carrier for nanocomposite materials preparation, especially in the preparation of nanocatalysts, is worthy of further study

    circFBXW7 attenuates malignant progression in lung adenocarcinoma by sponging miR-942-5p

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    Background: As a type of non-coding RNA, circular RNAs (circRNAs) are considered to be functional molecules associated with human cancers. An increasing number of circRNAs have been verified in malignant progression in a number of cancers. The circRNA, circFBXW7, has been proven to play an important role in tumor proliferation and metastasis. However, whether circFBXW7 influences progression in lung adenocarcinoma (LUAD) remains unclear. Methods: Quantitative real-time reverse transcriptase PCR (qRT-PCR) was used to verify circFBXW7 in LUAD cell lines and LUAD tissues. Kaplan-Meier analysis was then used to compare the disease-free survival (DFS) and overall survival (OS) of these LUAD patients. The biological function of circFBXW7 was examined by overexpression and knockdown of circFBXW7 using MTT assay, EdU assay, wound-healing assay, and Transwell in vitro assays. To explore the mechanism of the circFBXW7, RNA pull-down assay, dual luciferase reporter assay, and RNA immunoprecipitation (RIP) assay were employed to examine the interaction between circFBXW7 and miR-942-5p. Western blot was used to study the fundamental proteins associated with the epithelial-mesenchymal transition (EMT) pathway. In vivo studies with BALB/c nude mice subcutaneously injected with cells stably overexpressing circFBXW7 were performed to further validate the in vitro results. Results: circFBXW7 was downregulated in LUAD cell lines and tissues, and LUAD patients with lower levels had shorter DFS and OS. The in vitro study showed that circFBXW7 overexpression inhibited proliferation and migration of A549 and HCC2279 cell lines. These results were confirmed by circFBXW7 knockdown, which showed the reverse effect. The in vivo model showed that the circRNA levels influenced the tumor growth. Finally, we determined that circFBXW7 target miRNA-942-5p which regulates the EMT gene BARX2. The modulation of circFBXW7 levels produced significant changes in EMT genes in vitro and in vivo. Conclusions: Our findings showed that circFBXW7 inhibits proliferation and migration by controlling the miR-942-5p/BARX2 axis in LUAD cell lines and its levels correlates with patient survival suggesting that regulating circFBXW7 could have therapeutic value in treating LUAD patients

    Patterning graphene nanostripes in substrate-supported functionalized graphene: A promising route to integrated, robust, and superior transistors

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    It is promising to apply quantum-mechanically confined graphene systems in field-effect transistors. High stability, superior performance, and large-scale integration are the main challenges facing the practical application of graphene transistors. Our understandings of the adatom-graphene interaction combined with recent progress in the nanofabrication technology indicate that very stable and high-quality graphene nanostripes could be integrated in substrate-supported functionalized (hydrogenated or fluorinated) graphene using electron-beam lithography. We also propose that parallelizing a couple of graphene nanostripes in a transistor should be preferred for practical application, which is also very useful for transistors based on graphene nanoribbon.Comment: Frontiers of Physics (2012) to be publishe

    The MALATANG Survey : The L GAS-L IR Correlation on Sub-kiloparsec Scale in Six Nearby Star-forming Galaxies as Traced by HCN J = 4 → 3 and HCO + J = 4 → 3

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    This is an author-created, un-copyedited version of an article published in The Astrophysical Journal. The Version of Record is available online at https://doi.org/10.3847/1538-4357/aac512.We present HCN J = 4→3 and HCO+ J = 4→3 maps of six nearby star-forming galaxies, NGC 253, NGC 1068, IC 342, M82, M83, and NGC 6946, obtained with the James Clerk Maxwell Telescope as part of the MALATANG survey. All galaxies were mapped in the central 2×2 region at 14 (FWHM) resolution (corresponding to linear scales of ∼0.2-1.0 kpc). The LIR-Ldense relation, where the dense gas is traced by the HCN J = 4→3 and the HCO+ J = 4→3 emission, measured in our sample of spatially resolved galaxies is found to follow the linear correlation established globally in galaxies within the scatter. We find that the luminosity ratio, LIR/Ldense, shows systematic variations with LIR within individual spatially resolved galaxies, whereas the galaxy-integrated ratios vary little. A rising trend is also found between LIR/Ldense ratio and the warm-dust temperature gauged by the 70 μm/100 μm flux ratio. We find that the luminosity ratios of IR/HCN (4-3) and IR/HCO+ (4-3), which can be taken as a proxy for the star formation efficiency (SFE) in the dense molecular gas (SFE dense), appear to be nearly independent of the dense gas fraction ( f dense) for our sample of galaxies. The SFE of the total molecular gas (SFEmol) is found to increase substantially with f dense when combining our data with those on local (ultra)luminous infrared galaxies and high-z quasars. The mean LHCN(4-3) LHCO+(4-3) line ratio measured for the six targeted galaxies is 0.9±0.6. No significant correlation is found for the L'HCN(4-3) L'HCO+(4-3) ratio with the star formation rate as traced by L IR, nor with the warm-dust temperature, for the different populations of galaxies.Peer reviewe

    Vitamin B12 Levels in Methamphetamine Addicts

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    Objective: It has been established that reduced vitamin B12 serum levels are associated with cognitive decline and mental illness. The chronic use of methamphetamine (MA), which is a highly addictive drug, can induce cognitive impairment and psychopathological symptoms. There are few studies addressing the association of MA with vitamin B12 serum levels. This study examined whether the serum levels of B12 are associated with MA addiction.Methods: Serum vitamin B12, homocysteine (Hcy), glucose and triglyceride concentrations were measured in 123 MA addicts and 108 controls. In addition, data were collected on their age, marital status, level of education and Body Mass Index (BMI) for all participants. In the patient group, the data for each subject were collected using the Fagerstrom Test for Nicotine Dependence (FTND), the Alcohol Use Disorders Identification Test (AUDIT), and a drug use history, which included the age of onset, total duration of MA use, the number of relapses and addiction severity.Results: Our results showed that MA addicts had lower vitamin B12 levels (p < 0.05) than those of healthy controls, but Hcy levels were not significantly different between the two groups (p > 0.05). Serum B12 levels were negatively correlated with the number of relapses in the MA group. Furthermore, binary logistics regression analysis indicated that the B12 was an influencing factor contributing to addiction severity.Conclusion: The findings of this study suggest that some MA addicts might have vitamin B12 deficiency, and serum B12 levels may be involved in the prognosis of MA addiction

    The MALATANG Survey : Dense Gas and Star Formation from High Transition HCN and HCO+ maps of NGC253

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.To study the high-transition dense-gas tracers and their relationships to the star formation of the inner ∼\sim 2 kpc circumnuclear region of NGC253, we present HCN J=4−3J=4-3 and HCO+J=4−3^+ J=4-3 maps obtained with the James Clerk Maxwell Telescope (JCMT). With the spatially resolved data, we compute the concentration indices r90/r50r_{90}/r_{50} for the different tracers. HCN and HCO+^+ 4-3 emission features tend to be centrally concentrated, which is in contrast to the shallower distribution of CO 1-0 and the stellar component. The dense-gas fraction (fdensef_\text{dense}, traced by the velocity-integrated-intensity ratios of HCN/CO and HCO+^+/CO) and the ratio R31R_\text{31} (CO 3-2/1-0) decline towards larger galactocentric distances, but increase with higher SFR surface density. The radial variation and the large scatter of fdensef_\text{dense} and R31R_\text{31} imply distinct physical conditions in different regions of the galactic disc. The relationships of fdensef_\text{dense} versus Σstellar\Sigma_\text{stellar}, and SFEdense_\text{dense} versus Σstellar\Sigma_\text{stellar} are explored. SFEdense_\text{dense} increases with higher Σstellar\Sigma_\text{stellar} in this galaxy, which is inconsistent with previous work that used HCN 1-0 data. This implies that existing stellar components might have different effects on the high-JJ HCN and HCO+^+ than their low-JJ emission. We also find that SFEdense_\text{dense} seems to be decreasing with higher fdensef_\text{dense}, which is consistent with previous works, and it suggests that the ability of the dense gas to form stars diminishes when the average density of the gas increases. This is expected in a scenario where only the regions with high-density contrast collapse and form stars.Peer reviewe
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