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Adeno-associated viral vectors for modeling Parkinson's disease in non-human primates
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作者 Julia Chocarro José L.Lanciego 《Neural Regeneration Research》 2026年第1期224-232,共9页
The development of clinical candidates that modify the natural progression of sporadic Parkinson's disease and related synucleinopathies is a praiseworthy endeavor,but extremely challenging.Therapeutic candidates ... The development of clinical candidates that modify the natural progression of sporadic Parkinson's disease and related synucleinopathies is a praiseworthy endeavor,but extremely challenging.Therapeutic candidates that were successful in preclinical Parkinson's disease animal models have repeatedly failed when tested in clinical trials.While these failures have many possible explanations,it is perhaps time to recognize that the problem lies with the animal models rather than the putative candidate.In other words,the lack of adequate animal models of Parkinson's disease currently represents the main barrier to preclinical identification of potential disease-modifying therapies likely to succeed in clinical trials.However,this barrier may be overcome by the recent introduction of novel generations of viral vectors coding for different forms of alpha-synuclein species and related genes.Although still facing several limitations,these models have managed to mimic the known neuropathological hallmarks of Parkinson's disease with unprecedented accuracy,delineating a more optimistic scenario for the near future. 展开更多
关键词 adeno-associated viral vectors ALPHA-SYNUCLEIN DOPAMINE Lewy bodies NEURODEGENERATION NEUROMELANIN NEUROPATHOLOGY substantia nigra
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Insecticide resistance status of malaria vectors in endemic states of India(2017-2024):A scoping review
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作者 Kamaraju Raghavendra Poonam Sharma Velamuri +1 位作者 Vartika Singhal Roop Kumari 《Asian Pacific Journal of Tropical Medicine》 2025年第8期337-352,I0003-I0013,共27页
Objective:To collate and summarize phenotypic insecticide susceptibility data of Indian malaria vectors from 2017 to 2024,focusing on insecticides used in adult vector control,dichloro diphenyl trichloroethane,malathi... Objective:To collate and summarize phenotypic insecticide susceptibility data of Indian malaria vectors from 2017 to 2024,focusing on insecticides used in adult vector control,dichloro diphenyl trichloroethane,malathion,deltamethrin,alpha-cypermethrin,and permethrin to identify resistance patterns to different classes of insecticides.Methods:The data included information on vector species,location of the study(state/district),insecticide tested,mortality percentage,and susceptibility classification based on the World Health Organization interpretation criteria.Retrospective data were collected from peer-reviewed publications(2017-2024)and up to June 2025.The data were collated for five major malaria vector species,namely Anopheles(An.)culicifacies,An.fluviatilis,An.stephensi,An.baimaii,and An.minimus.Results:Insecticide susceptibility data were available from 86 districts across 16 Indian states for 40615 mosquitoes.The majority of the data was on An.culicifacies(n=28308),followed by An.stephensi(n=5611),An.fluviatilis(n=5967),An.baimaii(n=365),and An.minimus(n=364).Intensity bioassays revealed low to moderate resistance levels in An.culicifacies populations from selected districts in 3 states,Odisha,Madhya Pradesh,and Chhattisgarh against deltamethrin and alpha-cypermethrin.Conclusions:This review highlights spatial and species-level variations in insecticide susceptibility among Indian malaria vectors.The low to moderate intensity suggested that it may not yet be severe enough to cause operational failure with current vector control interventions.Continued monitoring of insecticide resistance,as well as the use of new-generation insecticides and interventions,is suggested to sustain vector control efficacy and manage insecticide resistance in malaria vectors to support India’s malaria elimination. 展开更多
关键词 Malaria vectors Insecticide resistance INDIA
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The Varieties of Semi-Conformal Vectors of Rank-One Even Lattice Vertex Operator Algebras
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作者 CHU Yan-jun GAO Yi-bo 《Chinese Quarterly Journal of Mathematics》 2025年第1期36-48,共13页
In this paper,we shall study structures of even lattice vertex operator algebras by using the geometry of the varieties of their semi-conformal vectors.We first give the varieties of semi-conformal vectors of a family... In this paper,we shall study structures of even lattice vertex operator algebras by using the geometry of the varieties of their semi-conformal vectors.We first give the varieties of semi-conformal vectors of a family of vertex operator algebras V_(√kA_(1)) associated to rank-one positive definite even lattices √kA_(1) for arbitrary positive integers k to characterize these even lattice vertex operator algebras.In such a family of lattice vertex operator algebras V_(√kA_(1)),the vertex operator algebra V_(√2A_(1)) is different from others.Hence we describe the varieties of semi-conformal vectors of V_(√2A_(1)) and the fixed vertex operator subalgebra V^(+)√2A_(1).Moreover,as applications,we study the relations between vertex operator algebras V_(√kA_(1) )and L_(sl_(2))(k,0)for arbitrary positive integers k by the viewpoint of semi-conformal homomorphisms of vertex operator algebras.For case k=2,in the series of rational simple affine vertex operator algebras L_(sl_(2))(k,0)for positive integers k,we show that L_(sl_(2))(2,0)is a unique frame vertex operator algebra with rank 3. 展开更多
关键词 Vertex operator algebra Semi-conformal vector Affine variety
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A novel BaEVRless-LV packaging system for the production of lentiviral vectors for clinical-grade CAR-NK cell manufacturing
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作者 Yinyin Zhang Minghuan Zhang +5 位作者 Mengyuan Li Lihong Zong Qian Ye Wen Lei Wenhai Deng Wenbin Qian 《Cancer Biology & Medicine》 2025年第2期137-143,共7页
Chimeric antigen receptor natural killer(CAR-NK)cell therapy is an alternative immunotherapy that provides robust tumor-eliminating effects without inducing life-threatening toxicities and graft-versus-host disease.CA... Chimeric antigen receptor natural killer(CAR-NK)cell therapy is an alternative immunotherapy that provides robust tumor-eliminating effects without inducing life-threatening toxicities and graft-versus-host disease.CAR-NK cell therapy has enabled the development of“off-the-shelf”products that bypass the lengthy and expensive cell manufacturing process1. 展开更多
关键词 LENTIVIRAL packaging vectors alternative immunotherapy chimeric antigen receptor natural system cell manufacturing process NOVEL
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Comprehensive Evaluation on Atmospheric Motion Vectors from Fengyun-4B Geostationary Satellite and Their Application in the South China Sea Monsoon Onset
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作者 PAN Qiao-ying WANG Gang +3 位作者 ZHOU Run-dong MIN Min ZHANG Xiao-hu MOU Xiao-xuan 《Journal of Tropical Meteorology》 2025年第6期647-660,共14页
Although the Chinese new-generation Fengyun-4B(FY-4B) geostationary satellite Atmospheric Motion Vector(AMV) products became operational in June 2022, their accuracy and utility remain largely unexamined. This study c... Although the Chinese new-generation Fengyun-4B(FY-4B) geostationary satellite Atmospheric Motion Vector(AMV) products became operational in June 2022, their accuracy and utility remain largely unexamined. This study comprehensively evaluates FY-4B AMV products for August and October 2023, as well as January and April 2024,exploring their application in monitoring the South China Sea Summer Monsoon(SCSSM) onset. The results indicate that AMV products derived from the upper-level water vapor absorption channel(AMV_WV) and the infrared channel(AMV_IR) demonstrate high accuracy when compared with ERA5 reanalysis data. The root mean square error(RMSE) is mostly between 4.5 m s^(–1)and 6.4 m s^(–1), with coefficients of determination(R2) values ranging from 0.7 to 0.8, indicating the overall reliability of FY-4B AMVs. The observation errors of AMVs exhibit significant vertical structure characteristics. Specifically, the AMV_WV products demonstrate superior accuracy above 350 h Pa, while the AMV_IR products exhibit reduced errors in the layers between 200–500 h Pa and 700–950 h Pa. Spatially, most areas exhibit low observation errors for AMVs, while clear-sky weather and deep convective cloud systems can increase errors. A lack of clouds or water vapor may reduce the number of observation samples in some areas, leading to unstable RMSE performance, which is particularly evident for AMV_WV RMSE around 25°–30°N in January and near 25°S in August. Deep convective cloud systems can influence AMV retrieval results, leading to systematic observation errors, especially for the infrared channel.Additionally, AMV_WV is more reliable during the daytime, with a lower RMSE compared to nighttime, while AMV_IR exhibits a diverging diurnal variation pattern. Finally, the FY-4B AMV_WV products were applied to monitor the SCSSM event in 2024. Significant zonal wind direction reversal characteristics were observed in key regions around the onset date,indicating that AMVs can serve as effective indicators for monitoring the SCSSM onset. 展开更多
关键词 atmospheric motion vectors Fengyun-4B geostationary satellite the South China Sea monsoon onset
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Stem cell therapy for intervertebral disc degeneration:Clinical progress with exosomes and gene vectors
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作者 Zhi-Peng Li Han Li +13 位作者 Yu-Hua Ruan Peng Wang Meng-Ting Zhu Wei-Ping Fu Rui-Bo Wang Xiao-Dong Tang Qi Zhang Sen-Li Li He Yin Cheng-Jin Li Yi-Gong Tian Rui-Ning Han Yao-Bin Wang Chang-Jiang Zhang 《World Journal of Stem Cells》 2025年第4期20-35,共16页
Intervertebral disc degeneration is a leading cause of lower back pain and is characterized by pathological processes such as nucleus pulposus cell apoptosis,extracellular matrix imbalance,and annulus fibrosus rupture... Intervertebral disc degeneration is a leading cause of lower back pain and is characterized by pathological processes such as nucleus pulposus cell apoptosis,extracellular matrix imbalance,and annulus fibrosus rupture.These pathological changes result in disc height loss and functional decline,potentially leading to disc herniation.This comprehensive review aimed to address the current challenges in intervertebral disc degeneration treatment by evaluating the regenerative potential of stem cell-based therapies,with a particular focus on emerging technologies such as exosomes and gene vector systems.Through mechanisms such as differentiation,paracrine effects,and immunomodulation,stem cells facilitate extracellular matrix repair and reduce nucleus pulposus cell apoptosis.Despite recent advancements,clinical applications are hindered by challenges such as hypoxic disc environments and immune rejection.By analyzing recent preclinical and clinical findings,this review provided insights into optimizing stem cell therapy to overcome these obstacles and highlighted future directions in the field. 展开更多
关键词 EXOSOMES Extracellular matrix repair Gene vector system Hypoxic environment Intervertebral disc degeneration Mesenchymal stem cells Regenerative medicine Stem cell therapy
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Energy-efficient MPCC Using Centroid-synthesized Virtual Voltage Vectors for IM Drives in Electric Vehicles
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作者 Rinki Roy Chowdhury G Koperundevi 《CES Transactions on Electrical Machines and Systems》 2025年第3期352-362,共11页
This paper presents an improved,energy-efficient Model Predictive Current Control(MPCC)strategy based on centroid-based virtual voltage vector synthesis for three-phase inverter-fed induction motor drives in electric ... This paper presents an improved,energy-efficient Model Predictive Current Control(MPCC)strategy based on centroid-based virtual voltage vector synthesis for three-phase inverter-fed induction motor drives in electric vehicle(EV)applications.Unlike conventional finite-set MPCC methods that rely on cost function evaluation over discrete switching states,the proposed approach eliminates the need for look-up tables by employing a pre-defined set of virtual vectors.These centroid-based virtual voltage vectors are synthesized by combining two adjacent active vectors and two nonzero voltage vectors in opposite directions adjacent to the sector replacing the traditional switching set.They approximate the reference voltage vector in both magnitude and phase angle,thereby reducing current tracking error through a simplified cost function.The number of candidate vectors is reduced,preserving computational efficiency.Furthermore,the scheme ensures zero average common-mode voltage(CMV)per sampling interval by completely avoiding zero-voltage vectors(ZVVs).The proposed method reduces torque ripple by up to 17%compared to the conventional approach and lowers stator current total harmonic distortion(THD)by 37%,while ensuring evenly distributed switching transitions among inverter legs.This results in reduced switching losses and enhanced drive efficiency-particularly advantageous in EV applications.Experimental validation under the high-speed extra urban driving cycle(EUDC)and low-speed ECE-R15 cycle,including torque ripple and energy consumption analysis,confirms the effectiveness of the approach,achieving an overall efficiency of 83.3%. 展开更多
关键词 Common mode voltage(CMV) Induction motor(IM) Total harmonic distortions(THD) Zero-voltage vector(ZVV)
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Programmable mixed-kernel based on MoTe_(2)/MoS_(2)heterojunction for support vector machine learning
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作者 Xinyu Huang Jiapeng Du +3 位作者 Langlang Xu Lei Tong Xiangxiang Yu Lei Ye 《Journal of Semiconductors》 2026年第3期110-116,共7页
The von Neumann bottleneck in conventional computing architectures presents a significant challenge for data-inten-sive artificial intelligence applications.A promising approach involves designing specialized hardware... The von Neumann bottleneck in conventional computing architectures presents a significant challenge for data-inten-sive artificial intelligence applications.A promising approach involves designing specialized hardware with on-chip parameter tunability,which directly accelerates machine learning functions.This work demonstrates a continuously tunable mixed-kernel function physically realized within a van der Waals heterostructure.We designed and fabricated a MoTe_(2)/MoS_(2)type-Ⅱvertical heterojunction phototransistor,which exhibits a non-monotonic,Gaussian-like optoelectronic response owing to its unique inter-layer charge transfer mechanism.This intrinsic physical behavior directly maps to a mixed-kernel function combining Gaussian and Sigmoid characteristics.Furthermore,the hardware kernel can be continuously modulated by in-situ tuning of external opti-cal stimuli.The mixed-kernel exhibited exceptional performance,achieving precision,accuracy,and area under the curve(AUC)values of 95.8%,96%,and 0.9986,respectively,significantly outperforming conventional kernels.By successfully embedding a complex,adaptable mathematical function into the intrinsic physical properties of a single device,this work pioneers a novel pathway toward next-generation,energy-efficient intelligent systems with hardware-level adaptability. 展开更多
关键词 programmable mixed-kernel HETEROJUNCTION support vector machine
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Support Vector-Guided Class-Incremental Learning:Discriminative Replay with Dual-Alignment Distillation
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作者 Moyi Zhang Yixin Wang Yu Cheng 《Computers, Materials & Continua》 2026年第3期2040-2061,共22页
Modern intelligent systems,such as autonomous vehicles and face recognition,must continuously adapt to new scenarios while preserving their ability to handle previously encountered situations.However,when neural netwo... Modern intelligent systems,such as autonomous vehicles and face recognition,must continuously adapt to new scenarios while preserving their ability to handle previously encountered situations.However,when neural networks learn new classes sequentially,they suffer from catastrophic forgetting—the tendency to lose knowledge of earlier classes.This challenge,which lies at the core of class-incremental learning,severely limits the deployment of continual learning systems in real-world applications with streaming data.Existing approaches,including rehearsalbased methods and knowledge distillation techniques,have attempted to address this issue but often struggle to effectively preserve decision boundaries and discriminative features under limited memory constraints.To overcome these limitations,we propose a support vector-guided framework for class-incremental learning.The framework integrates an enhanced feature extractor with a Support Vector Machine classifier,which generates boundary-critical support vectors to guide both replay and distillation.Building on this architecture,we design a joint feature retention strategy that combines boundary proximity with feature diversity,and a Support Vector Distillation Loss that enforces dual alignment in decision and semantic spaces.In addition,triple attention modules are incorporated into the feature extractor to enhance representation power.Extensive experiments on CIFAR-100 and Tiny-ImageNet demonstrate effective improvements.On CIFAR-100 and Tiny-ImageNet with 5 tasks,our method achieves 71.68%and 58.61%average accuracy,outperforming strong baselines by 3.34%and 2.05%.These advantages are consistently observed across different task splits,highlighting the robustness and generalization of the proposed approach.Beyond benchmark evaluations,the framework also shows potential in few-shot and resource-constrained applications such as edge computing and mobile robotics. 展开更多
关键词 Class-incremental learning catastrophic forgetting support vector machine knowledge distillation
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Yaw stabilization and maneuvering control of tailless flying wing by co-directional fluidic thrust vectoring
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作者 Liu ZHANG Meng HE 《Chinese Journal of Aeronautics》 2026年第1期66-77,共12页
Fluidic Thrust Vectoring(FTV)is used for the yaw attitude control of tailless flying wing,which can significantly improve stealth performance,maneuverability and lateral/heading maneuverability.The FTV control scheme ... Fluidic Thrust Vectoring(FTV)is used for the yaw attitude control of tailless flying wing,which can significantly improve stealth performance,maneuverability and lateral/heading maneuverability.The FTV control scheme of co-directional secondary flow was designed based on a 30 kgf thrust turbojet engine,an equivalent rudder deflection control variable of Mass Flow Combination(MFC)was proposed,and a control model was established to form a FTV control system scheme,which was integrated with the flight control system of a 100 kg tailless flying wing with medium aspect ratio to achieve closed-loop control of the yaw attitude based on FTV.The heading stability augmentation and maneuvering control characteristics and time response characteristics of tailless flying wing by FTV were quantitatively studied through virtual flight test in a wind tunnel at a wind speed of 35 m/s.The results show that the control strategy based on MFC achieves bidirectional continuous and stable control of thrust vector angle in a range of±11°,and the thrust vector angle varies monotonically with MFC;the co-directional FTV realizes bidirectional continuous and stable control of the yaw attitude of tailless flying wing,without longitudinal/lateral coupling moment.The increment of the maximum yawing moment coefficient is 0.0029,the maximum yaw rate is 7.55(°)/s,and the response time of the yaw rate of the vectoring nozzle actuated by the secondary flow is about 0.06 s,which satisfies the heading stability augmentation and maneuvering control response requirements of the aircraft with statically unstable heading,and provides new control means for the heading rudderless attitude control of tailless flying wing. 展开更多
关键词 Thrust vectoring Flow control Coanda effect Flying-wing aircraft Flight tests Yaw control
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Using mixed kernel support vector machine to improve the predictive accuracy of genome selection
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作者 Jinbu Wang Wencheng Zong +6 位作者 Liangyu Shi Mianyan Li Jia Li Deming Ren Fuping Zhao Lixian Wang Ligang Wang 《Journal of Integrative Agriculture》 2026年第2期775-787,共13页
The advantages of genome selection(GS) in animal and plant breeding are self-evident.Traditional parametric models have disadvantage in better fit the increasingly large sequencing data and capture complex effects acc... The advantages of genome selection(GS) in animal and plant breeding are self-evident.Traditional parametric models have disadvantage in better fit the increasingly large sequencing data and capture complex effects accurately.Machine learning models have demonstrated remarkable potential in addressing these challenges.In this study,we introduced the concept of mixed kernel functions to explore the performance of support vector machine regression(SVR) in GS.Six single kernel functions(SVR_L,SVR_C,SVR_G,SVR_P,SVR_S,SVR_L) and four mixed kernel functions(SVR_GS,SVR_GP,SVR_LS,SVR_LP) were used to predict genome breeding values.The prediction accuracy,mean squared error(MSE) and mean absolute error(MAE) were used as evaluation indicators to compare with two traditional parametric models(GBLUP,BayesB) and two popular machine learning models(RF,KcRR).The results indicate that in most cases,the performance of the mixed kernel function model significantly outperforms that of GBLUP,BayesB and single kernel function.For instance,for T1 in the pig dataset,the predictive accuracy of SVR_GS is improved by 10% compared to GBLUP,and by approximately 4.4 and 18.6% compared to SVR_G and SVR_S respectively.For E1 in the wheat dataset,SVR_GS achieves 13.3% higher prediction accuracy than GBLUP.Among single kernel functions,the Laplacian and Gaussian kernel functions yield similar results,with the Gaussian kernel function performing better.The mixed kernel function notably reduces the MSE and MAE when compared to all single kernel functions.Furthermore,regarding runtime,SVR_GS and SVR_GP mixed kernel functions run approximately three times faster than GBLUP in the pig dataset,with only a slight increase in runtime compared to the single kernel function model.In summary,the mixed kernel function model of SVR demonstrates speed and accuracy competitiveness,and the model such as SVR_GS has important application potential for GS. 展开更多
关键词 genome selection machine learning support vector machine kernel function mixed kernel function
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Asymmetric Voltage Vector-based Initial Rotor Position Detection in Four-switch Inverter Fed BLDC Motors
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作者 Xinmin Li Kun Liu +2 位作者 Lu Zhou Tingna Shi Wei Chen 《CES Transactions on Electrical Machines and Systems》 2026年第1期77-86,共10页
In position-sensorless brushless direct current(DC)motors(BLDCMs)fed by a four-switch three-phase(FSTP)inverter,only two phases are fully controlled,while the remaining phase is tied to the midpoint of the split DC-li... In position-sensorless brushless direct current(DC)motors(BLDCMs)fed by a four-switch three-phase(FSTP)inverter,only two phases are fully controlled,while the remaining phase is tied to the midpoint of the split DC-link capacitors.The voltage pulses required by inductance-based initial position detection can cause unequal discharge of the series capacitors,shifting the neutral-point voltage away from half of DC-link voltage(U_(dc)/2).This neutral-point drift breaks the spatial symmetry of the inverter voltage vectors,so the 360°electrical period can no longer be evenly partitioned into six sectors during initial rotor position detection.To address this issue,this paper proposes a detection-pulse injection sequence that explicitly accounts for the asymmetric voltage vectors of the FSTP inverter.With the proposed sequence,the initial rotor position can be identified within a 30°electrical sector.The method requires no additional voltage or current sensors,and experimental results confirm its feasibility. 展开更多
关键词 Brushless direct current(DC)motor(BLDCM) Four-switch three-phase(FSTP)inverter Asymmetric voltage vector Initial position detection
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A Convolutional Neural Network-Based Deep Support Vector Machine for Parkinson’s Disease Detection with Small-Scale and Imbalanced Datasets
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作者 Kwok Tai Chui Varsha Arya +2 位作者 Brij B.Gupta Miguel Torres-Ruiz Razaz Waheeb Attar 《Computers, Materials & Continua》 2026年第1期1410-1432,共23页
Parkinson’s disease(PD)is a debilitating neurological disorder affecting over 10 million people worldwide.PD classification models using voice signals as input are common in the literature.It is believed that using d... Parkinson’s disease(PD)is a debilitating neurological disorder affecting over 10 million people worldwide.PD classification models using voice signals as input are common in the literature.It is believed that using deep learning algorithms further enhances performance;nevertheless,it is challenging due to the nature of small-scale and imbalanced PD datasets.This paper proposed a convolutional neural network-based deep support vector machine(CNN-DSVM)to automate the feature extraction process using CNN and extend the conventional SVM to a DSVM for better classification performance in small-scale PD datasets.A customized kernel function reduces the impact of biased classification towards the majority class(healthy candidates in our consideration).An improved generative adversarial network(IGAN)was designed to generate additional training data to enhance the model’s performance.For performance evaluation,the proposed algorithm achieves a sensitivity of 97.6%and a specificity of 97.3%.The performance comparison is evaluated from five perspectives,including comparisons with different data generation algorithms,feature extraction techniques,kernel functions,and existing works.Results reveal the effectiveness of the IGAN algorithm,which improves the sensitivity and specificity by 4.05%–4.72%and 4.96%–5.86%,respectively;and the effectiveness of the CNN-DSVM algorithm,which improves the sensitivity by 1.24%–57.4%and specificity by 1.04%–163%and reduces biased detection towards the majority class.The ablation experiments confirm the effectiveness of individual components.Two future research directions have also been suggested. 展开更多
关键词 Convolutional neural network data generation deep support vector machine feature extraction generative artificial intelligence imbalanced dataset medical diagnosis Parkinson’s disease small-scale dataset
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GoVector:I/O-高效的高维向量近邻查询缓存策略
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作者 周依杰 林圣原 +4 位作者 巩树凤 余松 范书豪 张岩峰 于戈 《软件学报》 北大核心 2026年第3期1021-1036,共16页
基于图结构的高维向量索引(索引图)因其高效的近似最近邻搜索能力,已成为大规模向量检索的主流方法.索引图执行近似最近邻搜索(approximate nearest neighbor search,ANNS)的过程分为两个阶段:第1阶段从入口点出发快速定位到查询向量附... 基于图结构的高维向量索引(索引图)因其高效的近似最近邻搜索能力,已成为大规模向量检索的主流方法.索引图执行近似最近邻搜索(approximate nearest neighbor search,ANNS)的过程分为两个阶段:第1阶段从入口点出发快速定位到查询向量附近区域;第2阶段在查询向量附近搜索离其最近的k个向量.然而,由于索引图需存储大量邻接关系,导致内存开销大,因此实际部署时通常需将其存储于外存.当执行近似最近邻搜索时,按需加载索引图和向量数据会导致频繁发生I/O操作,并成为检索性能的主要瓶颈(I/O时间占90%以上).现有系统利用入口点及其附近邻居被高频访问的特性,采用静态缓存策略将入口点及其若干跳邻居预先缓存在内存中,以减少第1阶段的I/O访问.然而分析发现,第2阶段为了获取更高精度的检索结果,需访问大量与查询向量相关的图顶点,成为I/O开销的主要来源.由于第2阶段的访问顶点随查询向量动态变化,现有静态缓存策略难以有效命中,导致其在此阶段几乎失效.针对此问题,设计了一个静态-动态混合缓存策略GoVector,其核心设计体现在:(1)静态缓存区预加载入口点及其高频近邻;(2)动态缓存区自适应地缓存第2阶段中空间局部性高的顶点.为了进一步适配第2阶段中以向量相似性为导向的搜索过程,设计了基于向量空间相似性磁盘布局策略,通过重排顶点存储顺序,使相似向量在物理存储上聚集于相同或相邻磁盘页,从而显著提升数据访问的局部性.这种双重优化机制使得缓存命中率得到显著提升,有效降低了整体I/O开销.在多个公开数据集上的实验结果表明,当召回率为90%时,相较于当前最先进的基于磁盘的索引图系统,GoVector实现I/O次数平均降低46%、查询吞吐率提升1.73倍、延迟下降42%. 展开更多
关键词 高维向量 近似最近邻搜索 索引图
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A Preliminary Analysis on the Construction and Expression of Eukaryotic Expression Vectors of Mytilin and Myticin from Mytilus coruscus 被引量:10
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作者 武梅 范美华 +2 位作者 廖智 石戈 王日昕 《Agricultural Science & Technology》 CAS 2010年第7期72-75,共4页
[Objective] The aim was to study the construction and expression of eukaryotic expression vectors of antibacterial peptides (mytilin and myticin) from Mytilus coruscus.[Method] By the screening of antibacterial pept... [Objective] The aim was to study the construction and expression of eukaryotic expression vectors of antibacterial peptides (mytilin and myticin) from Mytilus coruscus.[Method] By the screening of antibacterial peptide genes of mytilin and myticin of Mytilus coruscus,five antibacterial peptide genes were selected.Then,the relative eukaryotic expressing vectors were constructed by the use of PCR technique and DNA recombinant technology.Subsequently,they were transferred in to S78 Saccharomyces cerevisia by using LiAC transformation method,and then preliminary expressing analysis was carried out.[Result] Five eukaryotic expressing vectors of antibacterial peptides from Mytilus coruscus were successfully constructed,and the results of mRNA detection revealed that the five antibacterial peptides from Mytilus coruscus were successfully transcribed.[Conclusion] The results provide a basis for using genetic engineering to express antibacterial peptides of mytilin and myticin from Mytilus coruscus,and for developing the further study of antibacterial peptides from Mytilus coruscus based on this. 展开更多
关键词 Mytilus coruscus Antibiotic peptide Mytilin Myticin Expression vector
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利用i-vectors构建区分性话者模型的话者确认 被引量:3
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作者 方昕 李辉 刘青松 《小型微型计算机系统》 CSCD 北大核心 2014年第3期685-688,共4页
对于电话手机语音的文本无关话者确认,运用联合因子分析构建话者信息子空间与信道信息子空间来进行失配信道补偿取得了较好的效果.然而研究表明,信道信息子空间仍然包含了可以用来区分话者的信息.因此,本文运用一种既包含话者信息又包... 对于电话手机语音的文本无关话者确认,运用联合因子分析构建话者信息子空间与信道信息子空间来进行失配信道补偿取得了较好的效果.然而研究表明,信道信息子空间仍然包含了可以用来区分话者的信息.因此,本文运用一种既包含话者信息又包含信道信息的全变量信息子空间来提取i-vectors低维特征矢量,再运用类内协方差规整进行失配信道补偿,最后用补偿后的i-vectors特征矢量构建支持向量机话者模型.在NIST08数据库上实验表明,本文所构建系统的性能在等误识率和最小检测代价函数上有相对近70%的提高. 展开更多
关键词 话者确认 全变量信息子空间 类内协方差规整 支持向量机 i—vectors
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Cloning of Cotton Delta-12 Oleate Desaturase Gene FAD2-1 and Construction of Its ihpRNA and amiRNA Interference Vectors 被引量:1
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作者 赵立群 李红岺 +3 位作者 李仁 李蔚 华金平 郭仰东 《Agricultural Science & Technology》 CAS 2012年第11期2281-2283,2286,共4页
Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cott... Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed. 展开更多
关键词 Cotton delta-12 oleate desaturase gene GhFAD2-1 ihpRNA interferencevector amiRNA interference vector High oleic acid contents
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Construction of Prokaryotic Expression Vectors of EBP1 Gene from Nervilia Fordii (Hance) Schltr. 被引量:1
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作者 黄琼林 何瑞 +1 位作者 詹若挺 陈蔚文 《Agricultural Science & Technology》 CAS 2012年第6期1211-1214,共4页
[Objective] To construct prokaryotic expression vectors encoding gene Erb3binding protein (EBP1), which plays important roles in regulating plant organ size from Nervilia fordii (Hance) Schltr. [Methods] PCR produ... [Objective] To construct prokaryotic expression vectors encoding gene Erb3binding protein (EBP1), which plays important roles in regulating plant organ size from Nervilia fordii (Hance) Schltr. [Methods] PCR products of NfEBP1 with particular restriction sites and expression vectors, pET-28 and pET-16b were digested. Ligation, transformation and selection were performed to construct the recombinant plasmids pET-28-NfEBP1 and pET-16-NfEBP1. The recombinant plasmids were transformed into E. coli BL21 using heat -shock transformation. [Results] Recombinant plasmids pET-28-NfEBP1-1188 and pET-16-NfEBP1-1188 were constructed and transformed into expressional host cells, E. coli BL21, and validated by colony PCR, sequencing and double digestion. [Conclusion] Prokaryotic expression vectors of EBP1 gene from N. fordii were successfully constructed, which laid the foundation for characterization of the gene function. 展开更多
关键词 Nervilia fordii (Hance) Schltr. Coding gene of Erb3-binding protein (EBP1) Prokaryotic expression vector
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A Composite Approach of Radar Echo Extrapolation Based on TREC Vectors in Combination with Model-Predicted Winds 被引量:18
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作者 梁巧倩 冯业荣 +4 位作者 邓文剑 胡胜 黄燕燕 曾沁 陈子通 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第5期1119-1130,共12页
Extending the lead time of precipitation nowcasts is vital to improvements in heavy rainfall warning, flood mitigation, and water resource management. Because the TREC vector (tracking radar echo by correlation) rep... Extending the lead time of precipitation nowcasts is vital to improvements in heavy rainfall warning, flood mitigation, and water resource management. Because the TREC vector (tracking radar echo by correlation) represents only the instantaneous trend of precipitation echo motion, the approach using derived echo motion vectors to extrapolate radar reflectivity as a rainfall forecast is not satisfactory if the lead time is beyond 30 minutes. For longer lead times, the effect of ambient winds on echo movement should be considered. In this paper, an extrapolation algorithm that extends forecast lead times up to 3 hours was developed to blend TREC vectors with model-predicted winds. The TREC vectors were derived from radar reflectivity patterns in 3 km height CAPPI (constant altitude plan position indicator) mosaics through a cross-correlation technique. The background steering winds were provided by predictions of the rapid update assimilation model CHAF (cycle of hourly assimilation and forecast). A similarity index was designed to determine the vertical level at which model winds were applied in the extrapolation process, which occurs via a comparison between model winds and radar vectors. Based on a summer rainfall case study, it is found that the new algorithm provides a better forecast. 展开更多
关键词 radar motion vector rapid update assimilation model extrapolation nowcast
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Exploration of larvicidal and adult emergence inhibition activities of Ricinus communis seed extract against three potential mosquito vectors in Kolkata,India 被引量:9
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作者 Shyamapada Mandal 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2010年第8期605-609,共5页
Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectors Anopheles stephensi(An. slephensi),Culex quinquefa... Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectors Anopheles stephensi(An. slephensi),Culex quinquefasciatus(Cx.quinquefasciatus) and Aedes albopictus(Ae.albopictus) in India.Methods:The R.communis seed extract was tested,employing WHO procedure,against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations(2-64μg/mL):the 24 h LC<sub>50</sub> values of the R.communis seed extract were determined following Probit analysis.The larval killing,antipupation and adult emergence inhibition rates of the test extract,using a single concentration of 2μLC<sub>50</sub>,were studied at different time periods(24-72 h):the extract toxicity was tested against a fish.Oreochromis niloticus(O.niloticus).Results:The R.communis seed extract exhibited larvicidal effects with 100%killing activities at concentrations 32-64μg/mL,and with LC<sub>50</sub> values 7.10.11.64 and 16.84μg/mL for Cx.quinquefasciatus,An.stephensi and Ae.albopictus larvae,respectively. When the larvae were treated with the extract at a single concentration of 2×LC<sub>50</sub>,significant differences were observed,compared to control groups,in rate of pupation(P【0.001) as well as in adult formation(P【0.001).Conclusions:The present findings suggest that the R.communis seed extract provided an excellent potential for controlling An.stephensi,Cx.quinquefasciatus and Ae. albopictus mosquito vectors. 展开更多
关键词 RICINUS communis MOSQUITO vectors LARVICIDAL activity PROBIT analysis Adult emergence INHIBITION
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