17 research outputs found

    RACE: An Efficient Redundancy-aware Accelerator for Dynamic Graph Neural Network

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    Dynamic Graph Neural Network (DGNN) has recently attracted a significant amount of research attention from various domains, because most real-world graphs are inherently dynamic. Despite many research efforts, for DGNN, existing hardware/software solutions still suffer significantly from redundant computation and memory access overhead, because they need to irregularly access and recompute all graph data of each graph snapshot. To address these issues, we propose an efficient redundancy-aware accelerator, RACE, which enables energy-efficient execution of DGNN models. Specifically, we propose a redundancy-aware incremental execution approach into the accelerator design for DGNN to instantly achieve the output features of the latest graph snapshot by correctly and incrementally refining the output features of the previous graph snapshot and also enable regular accesses of vertices\u27 input features. Through traversing the graph on the fly, RACE identifies the vertices that are not affected by graph updates between successive snapshots to reuse these vertices\u27 states (i.e., their output features) of the previous snapshot for the processing of the latest snapshot. The vertices affected by graph updates are also tracked to incrementally recompute their new states using their neighbors\u27 input features of the latest snapshot for correctness. In this way, the processing and accessing of many graph data that are not affected by graph updates can be correctly eliminated, enabling smaller redundant computation and memory access overhead. Besides, the input features, which are accessed more frequently, are dynamically identified according to graph topology and are preferentially resident in the on-chip memory for less off-chip communications. Experimental results show that RACE achieves on average 1139× and 84.7× speedups for DGNN inference, with average 2242× and 234.2× energy savings, in comparison with the state-of-the-art software DGNN running on Intel Xeon CPU and NVIDIA A100 GPU, respectively. Moreover, for DGNN inference, RACE obtains on average 13.1×, 11.7×, 10.4×, and 7.9× speedup and 14.8×, 12.9×, 11.5×, and 8.9× energy savings over the state-of-the-art Graph Neural Network accelerators, i.e., AWB-GCN, GCNAX, ReGNN, and I-GCN, respectively

    Regional Agroclimate Characteristic and Its Multiple Teleconnections: A Case Study in the Jianghan Plain (JHP) Region

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    Agricultural production depends on local agroclimatic conditions to a great extent, affected by ENSO and other ocean-atmospheric climate modes. This paper analyzed the spatio-temporal distributions of climate elements in the Jianghan Plain (JHP), Central China, and explored the impacts from teleconnection patterns, aimed at providing references for dealing with climate change and guiding agricultural activities. Both linear and multifactorial regression models were constructed based on the frequentist quantile regression and Bayesian quantile regression method, with the daily meteorological data sets of 17 national stations in the plain and teleconnection climate characteristic indices. The results showed that precipitation in JHP had stronger spatial variability than evapotranspiration. El Niño probably induced less precipitation in summer while the weakening Arctic Oscillation might lead to more summertime precipitation. The Nash-Sutcliffe efficiency (NSE) of the multifactorial and linear regression model at the median level were 0.42–0.56 and 0.12–0.18, respectively. The mean relative error (MRE) ranged −2.95–−0.26% and −7.83–0.94%, respectively, indicating the much better fitting accuracy of the multiple climatic factors model. Meanwhile it confirmed that the agricultural climate in JHP was under the influence from multiple teleconnection patterns

    Surface Water–Groundwater Transformation Patterns in the Jianghan Plain after the Impoundment of the Three Gorges Project and the Opening of the Yangtze-to-Hanjiang Water Transfer Project

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    Understanding the law of surface water–groundwater conversion in the face of high-intensity human activities is still a challenge. In this study, we employed statistical and system dynamics methods to investigate the surface water–groundwater conversion law in the Jianghan Plain following the impoundment of the Three Gorges Project (TGP) and the Yangtze-to-Hanjiang Water Transfer Project (YHWTP). The groundwater level’s long data set was used for the first time to study the water level change and water exchange in the research region after the impoundment of the TGP and the delivery of water from the YHWTP. The findings suggest a significant decrease in the interannual trend of the surface water level and groundwater level in the research region. It was observed that a 1m rise in the surface water level can lead to a 0.11–0.38 m rise in the groundwater level. The water level fluctuation coefficients of the surface water level and groundwater level are influenced by the impoundment of the TGP and the water delivery from the YHWTP, causing them to increase and decrease, respectively. In general, the surface water recharges the groundwater in the studied region. The water exchanges between the surface water and groundwater in the Yangtze River’s main stream, the middle region of the Hanjiang Plain, and the lower reaches of the Hanjiang River are, on average, 10−2 m3/(d·m), 10−5 m3/(d·m), and 10−3 m3/(d·m) orders of magnitude, respectively. The water exchange in the Yangtze River’s main stream was reduced after TGP impoundment, and it was enhanced following YHWTP water delivery

    A Novel Carbon Dots/Thermo-Sensitive In Situ Gel for a Composite Ocular Drug Delivery System: Characterization, Ex-Vivo Imaging, and In Vivo Evaluation

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    We developed a potential composite ocular drug delivery system for the topical administration of diclofenac sodium (DS). The novel carbon dot CDC-HP was synthesized by the pyrolysis of hyaluronic acid and carboxymethyl chitosan through a one-step hydrothermal method and then embedded in a thermosensitive in situ gel of poloxamer 407 and poloxamer 188 through swelling loading. The physicochemical characteristics of these carbon dots were investigated. The results of the in vitro release test showed that this composite ocular drug delivery system (DS-CDC-HP-Gel) exhibited sustained release for 12 h. The study of the ex vivo fluorescence distribution in ocular tissues showed that it could be used for bioimaging and tracing in ocular tissues and prolong precorneal retention. Elimination profiles in tears corresponded to the study of ex vivo fluorescence imaging. The area under the curve of DS in the aqueous humor in the DS-CDC-HP-Gel group was 3.45-fold that in the DS eye drops group, indicating a longer precorneal retention time. DS-CDC-HP with a positive charge and combined with a thermosensitive in situ gel might strengthen adherence to the corneal surface and prolong the ocular surface retention time to improve the bioavailability. This composite ocular delivery system possesses potential applications in ocular imaging and drug delivery

    Easy Synthesis and Characterization of Novel Carbon Dots Using the One-Pot Green Method for Cancer Therapy

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    In this study, hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) were used for the synthesis of novel targeted nanocarrier carbon dots (CDC-H) with photo-luminescence using a one-step hydrothermal method. Doxorubicin (DOX), a common chemotherapeutic agent, was loaded with the CDC-H through electrostatic interactions to form DOX–CDC-H complexes as a targeted antitumor drug delivery system. The synthesized CDC-H show a particle size of approximately 6 nm and a high fluorescence quantum yield of 11.64%. The physical and chemical character properties of CDC-H and DOX–CDC-H complexes were investigated using various techniques. The results show that CDC-H have stable luminescent properties and exhibit excellent water solubility. The in vitro release study showed that DOX–CDC-H exhibited pH-dependent release for 24 h. Confocal laser scanning microscopy was applied to investigate the potential of CDC-H for cell imaging and the cellular uptake of DOX–CDC-H in different cells (NIH-3T3 and 4T1 cells), and the results confirmed the target cell imaging and cellular uptake of DOX–CDC-H by specifically binding the CD44 receptors on the surface of tumor cells. The r MTT results suggest that the DOX–CDC-H complex may induce apoptosis in 4T1 cells, reducing the cytotoxicity of free DOX-induced apoptosis. In vivo antitumor experiments of DOX–CDC-H exhibited enhanced tumor cancer therapy. CDC-H have potential applications in bioimaging and antitumor drug delivery

    Study on the Diversity of Fungal and Bacterial Communities in Continuous Cropping Fields of Chinese Chives (Allium tuberosum)

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    In this study, high-throughput sequencing technology was used to analyse the diversity and composition of fungal and bacterial communities in continuous cropping soil of Chinese chives. The soil nutrient was also measured to explore the rationality of current fertilization management. These results can provide a basis for the prevention and control of the continuous cropping obstacles of Chinese chives and further scientific management. Soil samples from fields continuously cropped with Chinese chives for one year, three years, and five years were collected and analysed. The results showed that the nutrient content of TP, AP, AK and TK increased significantly with increasing continuous cropping years. Short-term continuous cropping soil nutrients have not deteriorated. Alpha-diversity analysis showed that significant differences were not found in the diversity of the fungal and bacterial community among different years. Ascomycota, Basidiomycota and Mortierellomycota were the three most dominant fungal phyla. Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteria were the dominant bacterial phyla. Continuous cropping makes Fusarium increase, and the beneficial bacteria Pseudomonas decreased significantly. According to the correlation heat map analysis of environmental factors, excessive phosphorus may lead to the increase of Fusarium, potassium may promote the proliferation of beneficial bacteria in the continuous cropping process, and it is necessary to regulate the application of phosphate and potassium fertilizer

    The Sound of Silence: The Continuing Legal Debate over Class Action Rescission under TILA

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    This paper analyzes federal law on the issue of whether consumers of mortgage products can sue as a class to rescind a mortgage loan under the Truth in Lending Act. Embedded in this question are deeper economic issues about the cost and availability of credit in the United States, and about who should bear the risk of faulty mortgage disclosures. The Truth in Lending Act governs these matters as an existing statutory scheme that provides pre-bankruptcy and pre-default remedies to consumers of credit

    Manipulating local coordination of copper single atom catalyst enables efficient CO2-to-CH4 conversion

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    Abstract Electrochemical CO2 conversion to methane, powered by intermittent renewable electricity, provides an entrancing opportunity to both store renewable electric energy and utilize emitted CO2. Copper-based single atom catalysts are promising candidates to restrain C-C coupling, suggesting feasibility in further protonation of CO* to CHO* for methane production. In theoretical studies herein, we find that introducing boron atoms into the first coordination layer of Cu-N4 motif facilitates the binding of CO* and CHO* intermediates, which favors the generation of methane. Accordingly, we employ a co-doping strategy to fabricate B-doped Cu-N x atomic configuration (Cu-N x B y ), where Cu-N2B2 is resolved to be the dominant site. Compared with Cu-N4 motifs, as-synthesized B-doped Cu-N x structure exhibits a superior performance towards methane production, showing a peak methane Faradaic efficiency of 73% at −1.46 V vs. RHE and a maximum methane partial current density of −462 mA cm−2 at −1.94 V vs. RHE. Extensional calculations utilizing two-dimensional reaction phase diagram analysis together with barrier calculation help to gain more insights into the reaction mechanism of Cu-N2B2 coordination structure
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