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Grassland-type ecosystem stability in China differs under the influence of drought and wet events

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Journal of Arid Land 2024年第5期16卷 615-631页

作者： cao Wenyu BAI Jianjun YU Leshan School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China International Business School Shaanxi Normal UniversityXi'an 710119China

Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a major threat to global ecological stability. Variations in stability among different ecosystemshave been confirmed, but it remains unclear whether there are differences in stability within the sameterrestrial vegetation ecosystem under the influence of climate events in different directions and intensities.China's grassland ecosystem includes most grassland types and is a good choice for studying this issue.This study used the Standardized Precipitation Evapotranspiration Index-12 (SPEI-12) to identify thedirections and intensities of different types of climate events, and based on Normalized DifferenceVegetation Index (NDVI), calculated the resistance and resilience of different grassland types for 30consecutive years from 1990 to 2019 (resistance and resilience are important indicators to measurestability). Based on a traditional regression model, standardized methods were integrated to analyze theimpacts of the intensity and duration of drought and wet events on vegetation stability. The resultsshowed that meadow steppe exhibited the highest stability, while alpine steppe and desert steppe had thelowest overall stability. The stability of typical steppe, alpine meadow, temperate meadow was at anintermediate level. Regarding the impact of the duration and intensity of climate events on vegetationecosystem stability for the same grassland type, the resilience of desert steppe during drought was mainlyaffected by the duration. In contrast, the impact of intensity was not significant. However, alpine steppewas mainly affected by intensity in wet environments, and duration had no significant impact. Ourconclusions can provide decision support for the future grassland ecosystem governance.

关键词： grassland ecosystem stability resistance resilience different climate types drought climate event wet climate event

Curve Classification Based onMean-Variance Feature Weighting and Its Application

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Computers, Materials & Continua 2024年第5期79卷 2465-2480页

作者： Zewen Zhang Sheng Zhou Chunzheng cao School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing210044China Center for Applied Mathematics of Jiangsu Province Nanjing University of Information Science and TechnologyNanjing210044China

The classification of functional data has drawn much attention in recent years.The main challenge is representing infinite-dimensional functional data by finite-dimensional features while utilizing those features to achieve better classification accuracy.In this paper,we propose a mean-variance-based(MV)feature weighting method for classifying functional data or functional curves.In the feature extraction stage,each sample curve is approximated by B-splines to transfer features to the coefficients of the spline basis.After that,a feature weighting approach based on statistical principles is introduced by comprehensively considering the between-class differences and within-class variations of the coefficients.We also introduce a scaling parameter to adjust the gap between the weights of features.The new feature weighting approach can adaptively enhance noteworthy local features while mitigating the impact of confusing features.The algorithms for feature weighted K-nearest neighbor and support vector machine classifiers are both provided.Moreover,the new approach can be well integrated into existing functional data classifiers,such as the generalized functional linear model and functional linear discriminant analysis,resulting in a more accurate classification.The performance of the mean-variance-based classifiers is evaluated by simulation studies and real data.The results show that the newfeatureweighting approach significantly improves the classification accuracy for complex functional data.

关键词： Functional data analysis classification feature weighting B-splines

Zeros of Complete Symmetric Polynomials over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1772-1788页

作者： cao Wei Minnan Normal University School of Mathematics and Statistics

Wan and Zhang(2021) obtained a nontrivial lower bound for the number of zeros of complete symmetric polynomials over finite fields, and proposed a problem whether their bound can be improved. In this paper, the author improves Wan-Zhang’s bound from three aspects. The proposed results are based on the estimates related to the number of certain permutations and the value sets of non-permutation polynomials associated to the complete symmetric polynomial. And the author believes that there are still possibilities to improve the bounds and hence Wan-Zhang’s bound.

关键词： Complete symmetric polynomial finite field permutation polynomial value set

Current controversies in glia-to-neuron conversion therapy in neurodegenerative diseases

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Neural Regeneration Research 2024年第4期19卷 723-724页

作者： Peng cao Jianan Li Zhuxi Liu Guobiao Liang Department of Neurosurgery General Hospital of the Northern Theater Command of Chinese People's Liberation Army Key Laboratory of Precision Medical Research on Major Chronic Disease Shengjing Hospital of China Medical University

Loss of neurons and disruption of neural circuits are associated with many neurological diseases,including neurodegenerative diseases and mental disorders.The most prevalent pathological feature of neurodegenerative diseases is the aggregate loss of certain neuronal populations.For example,the loss of dopamine(DA)neurons in the substantia nigra pars compacta has been defined as a pathological hallmark of Parkinson’s disease(PD;Kamath et al.,2022).

关键词： diseases degenerative al.

GLI1 and PTTG1 expression in colorectal carcinoma patients undergoing radical surgery and their correlation with lymph node metastasis

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1328-1335页

作者： Feng cao Yang-Yan Chen Hong-Cheng Wang Department of Care Section Beijing Geriatric HospitalBeijing 100095China Research Department Shanghai Zhangjiang Institute of Medical InnovationShanghai 200000China Care Department Beijing Geriatric HospitalBeijing 100095China

BACKGROUND Few studies have investigated the expression of GLI1 and PTTG1 in patients undergoing radical surgery for colorectal carcinoma(CRC)and their association with lymph node metastasis(LNM).Therefore,more relevant studies and analyses need to be conducted.AIM To explore GLI1 and PTTG1 expression in patients undergoing radical surgery for CRC and their correlation with LNM.METHODS This study selected 103 patients with CRC admitted to our hospital between April 2020 and April 2023.Sample specimens of CRC and adjacent tissues were collected to determine the positive rates and expression levels of GLI1 and PTTG1.The correlation of the two genes with patients’clinicopathological data(e.g.,LNM)was explored,and differences in GLI1 and PTTG1 expression between patients with LNM and those without were analyzed.Receiver operating characteristic(ROC)curves were plotted to evaluate the predictive potential of the two genes for LNM in patients with CRC.RESULTS Significantly higher positive rates and expression levels of GLI1 and PTTG1 wereobserved in CRC tissue samples compared with adjacent tissues.GLI1 and PTTG1 were strongly linked to LNM in patients undergoing radical surgery for CRC,with higher GLI1 and PTTG1 levels found in patients with LNM than in those without.The areas under the ROC curve of GLI1 and PTTG1 in assessing LNM in patients with CRC were 0.824 and 0.811,respectively.CONCLUSION GLI1 and PTTG1 expression was upregulated in patients undergoing radical surgery for CRC and are significantly related to LNM in these patients.Moreover,high GLI1 and PTTG1 expression can indicate LNM in patients with CRC undergoing radical surgery.The expression of both genes has certain diagnostic and therapeutic significance.

关键词： Colorectal carcinoma GLI1 PTTG1 Radical resection Lymph node metastasis

Aging Mongolian pine plantations face high risks of drought-induced growth decline:evidence from both individual tree and forest stand measurements

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Journal of Forestry Research 2024年第2期35卷 109-120页

作者： Mingyong Li Leilei Yang Yu cao Dedong Wu Guangyou Hao CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016People’s Republic of China Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Liaoning ProvinceShenyang 110016People’s Republic of China Daqinggou Ecological Research Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Research Institute of Sand Control and Utilization Liaoning ProvinceFuxin 123000People’s Republic of China

Discerning vulnerability differences among different aged trees to drought-driven growth decline or to mortality is critical to implement age-specific countermeasures for forest management in water-limited areas.An important species for afforestation in dry environments of northern China,Mongolian pine(Pinus sylvestris var.mongolica Litv.)has recently exhibited growth decline and dieback on many sites,particularly pronounced in old-growth plantations.However,changes in response to drought stress by this species with age as well as the underlying mechanisms are poorly understood.In this study,tree-ring data and remotely sensed vegetation data were combined to investigate variations in growth at individual tree and stand scales for young(9-13 years)and aging(35-52 years)plantations of Mongolian pine in a water-limited area of northern China.A recent decline in tree-ring width in the older plantation also had lower values in satellited-derived normalized difference vegetation indices and normalized difference water indices relative to the younger plantations.In addition,all measured growth-related metrics were strongly correlated with the self-calibrating Palmer drought severity index during the growing season in the older plantation.Sensitivity of growth to drought of the older plantation might be attributed to more severe hydraulic limitations,as reflected by their lower sapwood-and leaf-specific hydraulic conductivities.Our study presents a comprehensive view on changes of growth with age by integrating multiple methods and provides an explanation from the perspective of plant hydraulics for growth decline with age.The results indicate that old-growth Mongolian pine plantations in water-limited environments may face increased growth declines under the context of climate warming and drying.

关键词： Tree age Drought stress Mongolian pine plantation Tree rings Remote sensing Plant hydraulics

Formal Verification of Data Modifications in Cloud Block Storage Based on Separation Logic

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Chinese Journal of Electronics 2024年第1期33卷 112-127页

作者： Bowen ZHANG Zhao JIN Hanpin WANG Yongzhi cao Key Laboratory of High Confidence Software Technologies (MOE) School of Computer Science Peking University School of Computer and Artificial Intelligence Zhengzhou University School of Computer Science and Cyber Engineering Guangzhou University

Cloud storage is now widely used, but its reliability has always been a major concern. Cloud block storage(CBS) is a famous type of cloud storage. It has the closest architecture to the underlying storage and can provide interfaces for other types. Data modifications in CBS have potential risks such as null reference or data loss.Formal verification of these operations can improve the reliability of CBS to some extent. Although separation logic is a mainstream approach to verifying program correctness, the complex architecture of CBS creates some challenges for verifications. This paper develops a proof system based on separation logic for verifying the CBS data modifications. The proof system can represent the CBS architecture, describe the properties of the CBS system state, and specify the behavior of CBS data modifications. Using the interactive verification approach from Coq, the proof system is implemented as a verification tool. With this tool, the paper builds machine-checked proofs for the functional correctness of CBS data modifications. This work can thus analyze the reliability of cloud storage from a formal perspective.

关键词： Formal verification Separation logic Cloud block storage Verification tool Coq

The Investigation of Data Voting Algorithm for Train Air-Braking System Based on Multi-Classification SVM and ANFIS

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Chinese Journal of Electronics 2024年第1期33卷 274-281页

作者： Juhan WANG Ying GAO Yuan cao Tao TANG School of Electronics and Information Engineering Beijing Jiaotong University Graduate Department China Academy of Railway Science National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University

The pressure data of the train air braking system is of great significance to accurately evaluate its operation state. In order to overcome the influence of sensor fault on the pressure data of train air braking system, it is necessary to design a set of sensor fault-tolerant voting mechanism to ensure that in the case of a pressure sensor fault, the system can accurately identify and locate the position of the faulty sensor, and estimate the fault data according to other normal data. A fault-tolerant mechanism based on multi-classification support vector machine(SVM) and adaptive network-based fuzzy inference system(ANFIS) is introduced. Multi-classification SVM is used to identify and locate the system fault state, and ANFIS is used to estimate the real data of the fault sensor. After estimation, the system will compare the real data of the fault sensor with the ANFIS estimated data. If it is similar,the system will recognize that there is a false alarm and record it. Then the paper tests the whole mechanism based on the real data. The test shows that the system can identify the fault samples and reduce the occurrence of false alarms.

关键词： Multi-classification support vector machine Adaptive network-based fuzzy inference system Train air braking system Fault-tolerant voting Multi-sensors

Deep neural network based on multi-level wavelet and attention for structured illumination microscopy

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Journal of Innovative Optical Health Sciences 2024年第2期17卷 12-23页

作者： Yanwei Zhang Song Lang Xuan cao Hanqing Zheng Yan Gong School of Biomedical Engineering(Suzhou)Division of Life Sciencesand Medicine University of Science and Technology of China Hefei Anhui230026P.R.China Suzhou Institute of Biomedical Engineering and Technology Chinese Academy of Sciences Suzhou Jiangsu 215163P.R.China School of Physical Science and Technology Suzhou University of Science and Technology Suzhou Jiangsu 215009P.R.China

Structured illumination microscopy(SIM)is a popular and powerful super-resolution(SR)technique in biomedical research.However,the conventional reconstruction algorithm for SIM heavily relies on the accurate prior knowledge of illumination patterns and signal-to-noise ratio(SNR)of raw images.To obtain high-quality SR images,several raw images need to be captured under high fluorescence level,which further restricts SIM’s temporal resolution and its applications.Deep learning(DL)is a data-driven technology that has been used to expand the limits of optical microscopy.In this study,we propose a deep neural network based on multi-level wavelet and attention mechanism(MWAM)for SIM.Our results show that the MWAM network can extract high-frequency information contained in SIM raw images and accurately integrate it into the output image,resulting in superior SR images compared to those generated using wide-field images as input data.We also demonstrate that the number of SIM raw images can be reduced to three,with one image in each illumination orientation,to achieve the optimal tradeoff between temporal and spatial resolution.Furthermore,our MWAM network exhibits superior reconstruction ability on low-SNR images compared to conventional SIM algorithms.We have also analyzed the adaptability of this network on other biological samples and successfully applied the pretrained model to other SIM systems.

关键词： Super-resolution reconstruction multi-level wavelet packet transform residual channel attention selective kernel attention