48 research outputs found

    Automated Interactive Visualization on Abstract Concepts in Computer Science

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    The paper presents CSVisFrame, a framework formaking visualizations, which solves the understanding difficultyon learning abstract concepts in computer science including datastructures and algorithms. With the framework, instructors anddevelopers can develop all varieties of interactive visualizations,with which students can learn and understand abstract conceptsin computer science more easily.CSVisFrame has been applied to both offline and onlinecomputer courses. Students from Sichuan Normal Universityhave enjoyed visualizations based on CSVisFrame in their AlgorithmDesign and Analysis course, and thousands of students ofJisuanke have benefitted from online CSVisFrame-based visualizedcomputer science courses. The effectiveness of CSVisFramebasedvisualizations has been demonstrated by our sample survey,which shows that visualizations are widely accepted, and almostall students can achieve a better learning. CSVisFrame is opensourced1,and demonstrations based on CSVisFrame are free2

    Accelerating Machine Learning Inference with GPUs in ProtoDUNE Data Processing

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    We study the performance of a cloud-based GPU-accelerated inference server to speed up event reconstruction in neutrino data batch jobs. Using detector data from the ProtoDUNE experiment and employing the standard DUNE grid job submission tools, we attempt to reprocess the data by running several thousand concurrent grid jobs, a rate we expect to be typical of current and future neutrino physics experiments. We process most of the dataset with the GPU version of our processing algorithm and the remainder with the CPU version for timing comparisons. We find that a 100-GPU cloud-based server is able to easily meet the processing demand, and that using the GPU version of the event processing algorithm is two times faster than processing these data with the CPU version when comparing to the newest CPUs in our sample. The amount of data transferred to the inference server during the GPU runs can overwhelm even the highest-bandwidth network switches, however, unless care is taken to observe network facility limits or otherwise distribute the jobs to multiple sites. We discuss the lessons learned from this processing campaign and several avenues for future improvements.Comment: 13 pages, 9 figures, matches accepted versio

    Lactate dehydrogenase is associated with flow-mediated dilation in hypertensive patients

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    Abstract The level of lactate dehydrogenase (LDH) has been proved to be positively associated with albuminuria, which represents glomerular endothelial damage in hypertension (HTN). In this study, the relationship between LDH and endothelial function evaluated by flow-mediated dilation (FMD) was investigated in hypertensives. 1507 subjects (aged 61.2 ± 12.5 years) were enrolled. All hypertensives (n = 1216) were subdivided into 3 groups: LDH1 (lowest tertile of LDH, n = 399), LDH2 (mediate tertile of LDH, n = 409) and LDH3 (highest tertile of LDH, n = 408). Meanwhile, 291 normotensives served as controls. FMD of right anterior tibial artery was assessed by high-resolution color Doppler ultrasound. The level of LDH in hypertensives was significantly higher than normotensives (p < 0.001). Whereas, FMD was obviously more blunted in hypertensives (p < 0.001). There was an increasing trend of FMD < 8% from control, LDH1, LDH2 to LDH3 group (χ 2 = 36.751, p < 0.001). Stepwise multiple liner regression analysis demonstrated an independent correlation between LDH and FMD in hypertensives (β =  − 0.145, p < 0.05). After stratified analysis, the relevance persisted in the male, young and middle-aged, hypertensives with grade 2 HTN, duration of HTN < 3 years, metabolic syndrome and those without statin therapy. In conclusion, the level of LDH was inversely correlated with FMD among hypertensives. Those hypertensives with increased LDH need to be scanned for target organ damage, such as microalbuminuria and endothelial dysfunction, and more frequent following up are also recommended

    Relationship between lactate dehydrogenase and albuminuria in Chinese hypertensive patients

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    Abstract Lactate dehydrogenase (LDH) has been reported to be positively correlated with albuminuria assessed by urinary albumin‐to‐creatinine ratio (UACR) in patients with sickle cell disease; both LDH and albuminuria are positively associated with the severity of hypertension (HTN). Here, a cross‐sectional study was performed to investigate the association between LDH and albuminuria in Chinese hypertensives. A total of 1169 Chinese individuals (aged 58.0 ± 11.5 years, 60.4% male), who were admitted to our hospital, were included in this study. Based on the level of LDH, all hypertensives (n = 802) were divided into three groups: HTN1 (lowest tertile of LDH, n = 264), HTN2 (mediate tertile of LDH, n = 268), and HTN3 (highest tertile of LDH, n = 270). Hypertensives with hyperhomocysteinemia were defined as hypertensives with homocysteine ≥15μmol/L. Meanwhile, 367 normotensives served as controls. Compared with normotensives, the levels of LDH and UACR were significantly higher in hypertensives (p < .05). There was an increasing trend of albuminuria (UACR ≥30 mg/g) from control, HTN1, HTN2 to HTN3 group (4% vs. 12.1% vs. 14.9% vs. 19.6%, χ2 = 38.886, p < .001). Stepwise multiple regression analysis showed an independent association between LDH and UACR in patients with HTN (β = 0.085, p < .05), but not in normotensives. After further stratification in hypertensive patients, this correlation remained in the male (β = 0.161, p < .001), elderly (age ≥65 years, β = 0.174, p < .001) and especially hypertensives with hyperhomocysteinemia (β = 0.402, p < .001). LDH combined with white blood cell (WBC) counts was observed to have better discrimination for albuminuria than creatinine united with cystatin C in hypertensives according to receiver operation characteristic curves (area under curve: 0.637 vs. 0.535, z = 2.563, p = .0104). In conclusion, the level of LDH was associated with albuminuria in Chinese patients with HTN, particularly in hypertensives with hyperhomocysteinemia. LDH combined with WBC provided better prediction of albuminuria than routine renal function assessment in hypertensives. Further studies are needed to confirm LDH as an early marker for the risk of kidney involvement among hypertensives

    Local-Induction-Heating Bending Process of B1500HS Thin-Walled Rectangular Steel Tubes: A Simulation and Experimental Investigation

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    To lighten and stiffen the structural components used in automobile bodies, the variable curvature local-induction-heating bending forming (VC-LIHBF) technology was developed. However, few studies have been conducted on the optimization of the structural and geometric parameters of the inductor and the parameters of the LIHBF process. This paper focuses on the improvement of the cross-sectional distortion and the forming limit of the thin-walled rectangular steel tubes (TWRSTs) without the mandrel support. In this work, a coupled thermo-mechanical finite element analysis (FEA) method is developed to investigate the structural and geometric parameters of the inductor and the deformation behavior during VC-LIHBF. The temperature distribution is calculated by the electromagnetic and heat transfer analysis, and the stress distribution is obtained by the deformation analysis. Experiments were carried out to validate the reliability of the proposed finite element model (FEM). The results indicate that the forming quality of the TWRST is significantly affected by the structural and geometric parameters of the inductor, the feed rate of the tube, the push speed of the bending roller and the distance between the inductor and the bending roller. The appropriate inductor and process parameters for a B1500HS TWRST were determined. The findings of this study may provide important guidance for practical manufacturing via the LIHBF process

    Development and validation of a nomogram for arterial stiffness

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    Abstract Even though as a gold standard for noninvasive measurement of arterial stiffness, carotid‐femoral pulse wave velocity (cfPWV) is not widely used in primary healthcare institutions due to time‐consuming and unavailable equipment. The aim of this study was to develop a convenient and low‐cost nomogram model for arterial stiffness screening. A cross‐sectional study was undertaken in the department of general practice, the First Affiliated Hospital of Fujian Medical University. Arterial stiffness was defined as cfPWV ≥ 10 m/s. A total of 2717 participants were recruited to construct the nomogram using the least absolute shrinkage and selection operator and logistic regressions. Receiver operating characteristic (ROC) curve, calibration curve, decision curve analysis, clinical impact curve were used to evaluate the performance of the model. The model was validated internally and externally (399 participants) by bootstrap method. Arterial stiffness was identified in 913 participants (33.60%). Age, sex, waist to hip ratio, systolic blood pressure, duration of diabetes, heart rate were selected to construct the nomogram model. Good discrimination and accuracy were exhibited with area under curve of 0.820 (95% CI 0.803–0.837) in ROC curve and mean absolute error = 0.005 in calibration curve. A positive net benefit was shown in decision curve analysis and clinical impact curve. A satisfactory agreement was displayed in internal validation and external validation. The low cost and user‐friendly nomogram is suitable for arterial stiffness screening in primary healthcare institutions

    Development of a nomogram for screening the risk of left ventricular hypertrophy in Chinese hypertensive patients

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    Left ventricular hypertrophy (LVH) is an important risk factor for cardiovascular morbidity and mortality in hypertensives. Therefore, early identification of at‐risk patients is necessary. The objective of this study was to estimate the risk of LVH among Chinese hypertensives by designing a nomogram. 832 hypertensives were divided into two groups based on the presence of LVH. The least absolute shrinkage and selection operator (LASSO) regression and multivariable logistic regression were successively applied for optimal variable selection and nomogram construction. Discrimination power, calibration, and clinical usefulness were evaluated using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis. Internal validation was performed using the bootstrap method. The nomogram included five predictors, namely gender, duration of hypertension, age, body mass index (BMI), and systolic blood pressure. The area under the ROC curve (AUC) was 0.724 (95% CI: 0.687‐0.761), indicating moderate discrimination. The calibration curve showed an excellent agreement between the predicted LVH and the actual LVH probability. The risk threshold between 5% and 72% according to the decision curve analysis, and the nomogram is clinically beneficial. Internal validation by bootstrapping with 1000 samples showed a good C‐index of 0.715, which suggested that the predictive abilities for the training set and testing set were in consistency. Our study proposed a nomogram that can be utilized to assess the LVH risk rapidly for Chinese hypertensives. This tool could be useful in identifying patients at high risk for LVH. Further studies are required to ascertain the stability and applicability of this nomogram

    Analysis of the association between dietary patterns and nonalcoholic fatty liver disease in a county in Guangxi

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    Abstract Background This study aims to investigate the relationship between different dietary patterns and non-alcoholic fatty liver disease (NAFLD). Methods Residents over 30 years old in the ecological longevity cohort in Gongcheng Yao Autonomous County, Guangxi Province were the research objects selected from 2018 to 2019. Physical examination, baseline population survey, and food frequency questionnaire (FFQ) survey were conducted. Dietary patterns were analyzed by factor analysis. Influencing factors of NAFLD were analyzed by multiple logistic regression. Results NAFLD was diagnosed in 241 of 2664 participants based on ultrasonography, and the detection rate was 9.0%. Factor analysis yielded a total of three dietary patterns, namely, traditional Chinese, Western, and cereal-potato dietary patterns. Results of multivariate logistic regression analysis showed that after adjusting for confounding factors, participants in the highest quartile of the Western dietary pattern exhibited a higher prevalence of NAFLD (OR = 2.799; 95% CI: 1.620–4.837; p < 0.05) than participants in the lowest quartile. Participants in the highest quartile of the cereal-potato pattern exhibited a decreased risk of NAFLD compared with those in the lowest quartile (OR = 0.581; 95% CI: 0.371–0.910, p < 0.05). The traditional Chinese patterns did not show any association with the risk of NAFLD. Conclusions The Western dietary pattern increases the risk of NAFLD, whereas the cereal-potato dietary pattern reduces the risk of NAFLD. It is important for the prevention and control of NAFLD to adhere to the cereal-potato dietary
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