347 research outputs found

    Consensus disturbance rejection for Lipschitz nonlinear multi-agent systems with input delay: a DOBC approach

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    In this paper, a new predictor-based consensus disturbance rejection method is proposed for high-order multi agent systems with Lipschitz nonlinearity and input delay. First, a distributed disturbance observer for consensus control is developed for each agent to estimate the disturbance under the delay constraint. Based on the conventional predictor feedback approach, a non-ideal predictor based control scheme is constructed for each agent by utilizing the estimate of the disturbance and the prediction of the relative state information. Then, rigorous analysis is carried out to ensure that the extra terms associated with disturbances and nonlinear functions are properly considered. Sufficient conditions for the consensus of the multi-agent systems with disturbance rejection are derived based on the analysis in the framework of Lyapunov-Krasovskii functionals. A simulation example is included to demonstrate the performance of the proposed control scheme. (C) 2016 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.National Natural Science Foundation of China [61673034]SCI(E)ARTICLE1,SI298-31535

    Learning to Detect Noisy Labels Using Model-Based Features

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    Label noise is ubiquitous in various machine learning scenarios such as self-labeling with model predictions and erroneous data annotation. Many existing approaches are based on heuristics such as sample losses, which might not be flexible enough to achieve optimal solutions. Meta learning based methods address this issue by learning a data selection function, but can be hard to optimize. In light of these pros and cons, we propose Selection-Enhanced Noisy label Training (SENT) that does not rely on meta learning while having the flexibility of being data-driven. SENT transfers the noise distribution to a clean set and trains a model to distinguish noisy labels from clean ones using model-based features. Empirically, on a wide range of tasks including text classification and speech recognition, SENT improves performance over strong baselines under the settings of self-training and label corruption

    Real-time equilibrium reconstruction by neural network based on HL-3 tokamak

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    A neural network model, EFITNN, has been developed capable of real-time magnetic equilibrium reconstruction based on HL-3 tokamak magnetic measurement signals. The model processes inputs from 68 channels of magnetic measurement data gathered from 1159 HL-3 experimental discharges, including plasma current, loop voltage, and the poloidal magnetic fields measured by equilibrium probes. The outputs of the model feature eight key plasma parameters, alongside high-resolution (129×129129\times129) reconstructions of the toroidal current density JPJ_{\text P} and poloidal magnetic flux profiles Ψrz\Psi_{rz}. Moreover, the network's architecture employs a multi-task learning structure, which enables the sharing of weights and mutual correction among different outputs, and lead to increase the model's accuracy by up to 32%. The performance of EFITNN demonstrates remarkable consistency with the offline EFIT, achieving average R2=0.941,0.997R^2 = 0.941, 0.997 and 0.9590.959 for eight plasma parameters, Ψrz\Psi_{rz} and JPJ_{\text P}, respectively. The model's robust generalization capabilities are particularly evident in its successful predictions of quasi-snowflake (QSF) divertor configurations and its adept handling of data from shot numbers or plasma current intervals not previously encountered during training. Compared to numerical methods, EFITNN significantly enhances computational efficiency with average computation time ranging from 0.08ms to 0.45ms, indicating its potential utility in real-time isoflux control and plasma profile management

    Influence of physical activity home environment on fundamental movement skills development in Chinese preschoolers: mediating role of moderate-to-vigorous physical activity

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    BackgroundResearch on how the physical activity home environment affects fundamental movement skills (FMS) in preschool children in China is limited. However, the role of moderate-to-vigorous physical activity (MVPA) in this relationship is still unclear. This study aims to analyze gender differences in FMS, explore associations between the physical activity home environment, MVPA, and FMS, and investigate MVPA's mediating role in these relationships.MethodsWe recruited 169 preschool children (95 boys, 74 girls; mean age 4.9 years) from four kindergartens in Hengyang, China. The Family Environment Scale on Motor Development for Preschool Urban Children (FESMPD) assessed physical activity home environment. Objective measurement of MVPA used ActiGraph wGT3-BT accelerometers. The Test of Gross Motor Development-3 (TGMD-3) evaluated FMS. Statistical analyses were conducted using the PROCESS macro in SPSS, with sociodemographic variables as controls.ResultsBoys exhibited significantly higher levels of MVPA, parenting style, locomotor skills, and object control skills compared to girls (P < 0.05). MVPA, parenting style, and FMS showed positive correlations (R = 0.355–0.568, P < 0.05). Similarly, MVPA was positively correlated with the physical activity home environment (β = 0.237–0.568, P < 0.05). Parenting style emerged as a significant predictor of children's MVPA levels (β = 0.956, P < 0.001), and MVPA was a predictor of the development ofFMS and its subdomains (β = 0.097–0.207, P < 0.05). Furthermore, MVPA partially mediated the relationship between parenting style and the development of FMS in preschool children. The physical environment was also a significant predictor of children's MVPA (β = 0.637, P < 0.05), and in turn, MVPA predicted the development of FMS and its subdomains (β = 0.188–0.343, P < 0.01). Notably, MVPA fully mediated the relationship between the physical environment and the development of FMS.ConclusionOverall, this study highlights the important roles of physical activity home environments and individual levels of MVPA in developing FMS in preschool children, noting significant gender differences. Parenting style greatly affects both MVPA and FMS development, while the physical environment fully mediates this relationship. Collaborative efforts among kindergartens, families, and communities are essential to support MVPA and improve FMS development

    Risk prediction model establishment with tri-phasic CT image features for differential diagnosis of adrenal pheochromocytomas and lipid-poor adenomas: Grouping method

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    ObjectivesThe purpose of this study was to establish a risk prediction model for differential diagnosis of pheochromocytomas (PCCs) from lipid-poor adenomas (LPAs) using a grouping method based on tri-phasic CT image features.MethodsIn this retrospective study, we enrolled patients that were assigned to a training set (136 PCCs and 183 LPAs) from two medical centers, along with an external independent validation set (30 PCCs and 54 LPAs) from another center. According to the attenuation values in unenhanced CT (CTu), the lesions were divided into three groups: group 1, 10 HU < CTu ≤ 25 HU; group 2, 25 HU < CTu ≤ 40 HU; and group 3, CTu > 40 HU. Quantitative and qualitative CT imaging features were calculated and evaluated. Univariate, ROC, and binary logistic regression analyses were applied to compare these features.ResultsCystic degeneration, CTu, and the peak value of enhancement in the arterial and venous phase (DEpeak) were independent risk factors for differential diagnosis of adrenal PCCs from LPAs. In all subjects (groups 1, 2, and 3), the model formula for the differentiation of PCCs was as follows: Y = -7.709 + 3.617*(cystic degeneration) + 0.175*(CTu ≥ 35.55 HU) + 0.068*(DEpeak ≥ 51.35 HU). ROC curves were drawn with an AUC of 0.95 (95% CI: 0.927–0.973) in the training set and 0.91 (95% CI: 0.860–0.929) in the external validation set.ConclusionA reliable and practical prediction model for differential diagnosis of adrenal PCCs and LPAs was established using a grouping method

    Examining the relationship between meeting 24-hour movement behaviour guidelines and mental health in Chinese preschool children

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    BackgroundLimited research has explored the relationship between adhering to 24-h Movement Behaviour guidelines and mental health in Chinese preschool children. The objectives of this study encompassed two primary goals: (1) to investigate the adherence of preschool children in China to the 24-h Movement Behaviour guidelines; and (2) to analyze the relationship between fulfilling various combinations of these guidelines and mental health, identifying the most advantageous combination.MethodsUtilizing a convenience sampling approach, this study included 205 preschool children (117 boys and 88 girls, average age 4.8 ± 0.51 years) from five kindergartens in Hengyang, Hunan Province. The physical activity (PA) and sedentary behaviour of preschool children were objectively assessed using waist-worn accelerometers, while sleep duration and screen time were reported by the children's parents. To evaluate mental health, the parent version of the internationally validated Strength and Difficulties Questionnaire (SDQ) was employed, which measures externalizing problems, internalizing problems, and prosocial behaviour. Employing Mplus 8.0 for Structural Equation Modeling analysis, while controlling for demographic variables, the study explored the connection between preschool children's mental health and their adherence to the 24-h Movement Behaviour guidelines.ResultsWorryingly, merely 14.6% of preschoolers met the recommended guidelines for all three aspects (PA, sleep duration, and screen time). Positive correlations were identified between meeting PA guidelines and displaying prosocial behaviour (β = 0.184; p < 0.05), while screen time adherence exhibited a negative correlation with externalizing problems (β = −0.207; p < 0.05). Similarly, there was a negative association between sleep duration adherence and externalizing problems (β = −0.191; p < 0.05). Meeting all three recommended guidelines was notably linked to enhanced prosocial behaviour (β = 0.464; p < 0.05), while following the screen time and sleep duration guidelines was negatively associated with externalizing problems (β = −0.246; p < 0.05).ConclusionThis study underscores the limited adherence of Chinese preschoolers to the comprehensive 24-h Movement Behaviour guidelines. Noteworthy findings include the positive influence of PA on prosocial behaviour, alongside the significant roles that sleep duration and screen time play in mitigating externalizing problems within this age group. Alignment with the 24-h Movement Behaviour guidelines is associated with more favorable mental health indicators in preschoolers

    Isotemporal substitution effect of 24-hour movement behavior on the mental health of Chinese preschool children

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    The 24-h movement behavior of preschoolers comprises a spectrum of activities, including moderate-to-vigorous intensity physical activity (MVPA), light-intensity physical activity (LPA), screen-based sedentary behavior (SCSB), non-screen-based sedentary behavior (NSCSB), and sleep. While previous research has shed light on the link between movement behaviors and children’s mental health, the specific impacts on the unique demographic of Chinese preschoolers remain underexplored. This study significantly contributes to the literature by exploring how 24-h movement behavior affects the mental health of preschoolers in a Chinese context. The study involved205 Chinese preschool children (117 boys and 88 girls) between the ages of 3 and 6 years wore accelerometers to measure their LPA, MVPA, and sedentary behavior (SB), while their parents reported the time spent on sleep and SCSB. The parents also completed the Strength and Difficulties Questionnaire to assess their children’s mental health. The study used compositional regression and isotemporal substitution models to examine the relationship between the various components of 24-h movement behavior and mental health. The results showed that greater NCSSB compared to MVPA, LPA, sleep, and SCSB was associated with good prosocial behavior and lower scores on externalizing problems. This highlights the potential of NSCSB as a beneficial component in the daily routine of preschoolers for fostering mental well-being. Replacing 15 min of sleep and SCSB with 15 min of NSCSB was associated with a decrease of 0.24 and 0.15 units, respectively, in externalizing problems. Reallocating 15 min of sleep to NSCSB was linked to an increase of 0.11 units in prosocial behavior. There were no significant substitution effects between LPA and MVPA time with any other movement behavior on prosocial behavior and externalizing problems. Given the positive associations observed, further longitudinal studies are necessary to explore the link between 24-h movement behavior and mental health in preschool children

    Successful transplantation of guinea pig gut microbiota in mice and its effect on pneumonic plague sensitivity

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    Microbiota-driven variations in the inflammatory response are predicted to regulate host responses to infection. Increasing evidence indicates that the gastrointestinal and respiratory tracts have an intimate relationship with each other. Gut microbiota can influence lung immunity whereby gut-derived injurious factors can reach the lungs and systemic circulation via the intestinal lymphatics. The intestinal microbiota’s ability to resist colonization can be extended to systemic infections or to pathogens infecting distant sites such as the lungs. Unlike the situation with large mammals, the microtus Yersinia pestis 201 strain exhibits strong virulence in mice, but nearly no virulence to large mammals (such as guinea pigs). Hence, to assess whether the intestinal microbiota from guinea pigs was able to affect the sensitivity of mice to challenge infection with the Y. pestis 201 strain, we fed mice with guinea pig diets for two months, after which they were administered 0.5 ml of guinea pig fecal suspension for 30 days by oral gavage. The stools from each mouse were collected on days 0, 15, and 30, DNA was extracted from them, and 16S rRNA sequencing was performed to assess the diversity and composition of the gut microbiota. We found that the intestinal microbiota transplants from the guinea pigs were able to colonize the mouse intestines. The mice were then infected with Yersinia pestis 201 by lung invasion, but no statistical difference was found in the survival rates of the mice that were colonized with the guinea pig’s gut microbiota and the control mice. This indicates that the intestinal microbiota transplantation from the guinea pigs did not affect the sensitivity of the mice to pneumonic plague

    The clinical outcome of pembrolizumab for patients with recurrent or metastatic squamous cell carcinoma of the head and neck: a single center, real world study in China

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    BackgroundThe KEYNOTE-048 and KEYNOTE-040 study have demonstrated the efficacy of pembrolizumab in recurrent or metastatic squamous cell carcinoma of the head and neck (R/M HNSCC), we conducted this real-world study to investigate the efficacy of pembrolizumab in patients with R/M HNSCC.MethodsThis is a single-center retrospective study conducted in the Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Shanghai, China). Between December 2020 and December 2022, a total of 77 patients with R/M HNSCC were included into analysis. The primary endpoint of the study was overall survival (OS), and the secondary endpoints were progression-free survival (PFS), overall response rate (ORR)and toxicity.Efficacy was assessed according to RECIST version 1.1.SPSS 27.0 and GraphPad Prism 8.0 software were utilized to perform the statistical analysis.ResultsBy the cut-off date (February 28, 2023), the median OS,PFS and ORR were 15.97 months,8.53 months and 48.9% in patients treated with the pembrolizumab regimen in the first line therapy. Among these patients, 17 patients received pembrolizumab with cetuximab,and 18 received pembrolizumab with chemotherapy.We observed no significant differences between two groups neither in median OS (13.9 vs 19.4 months, P=0.3582) nor PFS (unreached vs 8.233 months, P= 0.2807). In the ≥2nd line therapy (n=30), the median OS, PFS and ORR were 5.7 months, 2.58 months and 20% respectively. Combined positive score (CPS) was eligible from 54 patients. For first line therapy, the median OS and PFS were 14.6 and 8.53 months in patients with CPS ≥1, and median OS and PFS were 14.6 and 12.33 months in patients with CPS ≥20. The immune-related adverse events (irAEs) were occurred in the 31 patients (31/77, 40.26%), and the most common potential irAEs were hypothyroidism (25.97%), and pneumonitis (7.79%).ConclusionOur real-world results indicated that pembrolizumab regimen is a promising treatment in patients with R/M HNSC

    The KREEP-rich circum-Lalande region: A candidate landing area for future lunar crewed missions

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    The lunar magma ocean hypothesis suggests that the primordial KREEP (an acronym of potassium (K), rare earth element (REE), and phosphorus (P)) was the final product of fractional crystallization. However, the primordial KREEP (a.k.a. urKREEP) has never been identified in previous lunar samples or meteorites. The Moon is the focus of many countries’ and agencies’ space exploration plans, and with the advancement of technology, crewed missions have been proposed. We propose two candidate landing sites, located respectively in the northwest (9.5°W, 0.9°S) and southeast (11.1°W, 6.2°S) of Lalande crater (8.6°W, 4.5°S), for future crewed missions, with the primary goal of sampling the speculated urKREEP. Both sites are situated on the Th- (a critical marker of KREEP) and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium, respectively. Their geolocations at the low latitude on the lunar nearside, the flat surface, and the low rock abundance suggest the sites are safe for landing and meet the needs of real-time Earth–Moon communication. The astronauts could perform many extravehicular activities, such as collecting KREEP-rich samples, screening clast samples, and drilling regolith cores, to gather a variety of samples, such as Lalande ejecta, basalts, Copernicus ejecta, and regolith. The returned samples are valuable to explore the speculated urKREEP, to reveal the relationship between heat-producing elements and volcanism, to refine the lunar cratering chronology function, and to investigate volatiles in the regolith
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