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Targeting phosphodiesterases for cognition enhancement:a translational approach
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作者 Jos PRICKAERTS 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第5期453-454,共2页
Cyclic adenosine monophosphate(cA MP) and/or cyclic guanosine monophosphate(cG MP)have been suggested to play specific roles in processes of memory. These cyclic nucleotides are hydrolyzed by specific enzymes,ie phosp... Cyclic adenosine monophosphate(cA MP) and/or cyclic guanosine monophosphate(cG MP)have been suggested to play specific roles in processes of memory. These cyclic nucleotides are hydrolyzed by specific enzymes,ie phosphodiesterases(PDEs). Thus,selective PDE inhibitors preventing the breakdown of cAMP and/or cGMP could improve memory. Studies with different timing of treatment with specific PDE inhibitors indicated that distinct underlying signaling pathways for early and late consolidation processes exist corresponding to specific time-windows for memory consolidation into longterm memory. There is evidence that the underlying mechanisms of PDE inhibition on the observed behavioral effects are independent of possible cerebrovascular effects. Most likely the underlying mechanisms are a cGMP/PKG pathway for early consolidation processes and a cAMP/PKA pathway for late consolidation processes. In addition,the early-phase cG MP/PKG signaling actually requires late-phase cAMP/PKA-signaling in long-term memory formation. Recently,the effects of specific PDE inhibitors are explored on other cognitive domains including acquisition processes/short-term memory and information processing. It will be shown that elevation of central cG MP levels or cA MP levels after treatment with a specific PDE inhibitor both improve acquisition processes/short-term memory. In vitro studying the effects of PDE inhibitors on long-term potentiation,the physiological substrate of memory,supportthe in vivo data and further show that AMPA receptor trafficking very likely mediates the memory enhancing effects. In a translational approach we initially also investigated the effects of cG MP elevation via PDE5 inhibition with vardenafil or sildenafil on cognition in humans. However,in contrast to studies with rodents and monkeys,PDE5 inhibition had no effect in humans on cognition including memory processes. It is clear that the transition of a drug from preclinical to clinical creates translational hurdles. Nevertheless,based on the expression patterns of its isoforms in the brain,PDE4,which is cAMP specific,appears more interesting for CNS targeting than PDE5. Indeed we found that a low dose of the PDE inhibitor roflumilast clearly improved cognition in humans. Interestingly,this pro-cognitive effect was not associated with emetic side effects(nausea,vomiting),which are commonly associated with PDE4 inhibition. Based on our data we suggest that the future for disease-specific PDE4 enzyme inhibition lies in the development of PDE4 isoform-specific inhibitors without emetic effects. Within the context as described above,the latest results of specific PDE inhibitors on cognitive processes will be presented and its implications will be discussed for finding and testing new cognition enhancers. 展开更多
关键词 PHOSPHODIESTERASES cognition MEMORY
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Natural Scene Classification Inspired by Visual Perception and Cognition Mechanisms
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作者 ZHANG Rui 《重庆理工大学学报(自然科学)》 CAS 2011年第7期24-43,共20页
The process of human natural scene categorization consists of two correlated stages: visual perception and visual cognition of natural scenes.Inspired by this fact,we propose a biologically plausible approach for natu... The process of human natural scene categorization consists of two correlated stages: visual perception and visual cognition of natural scenes.Inspired by this fact,we propose a biologically plausible approach for natural scene image classification.This approach consists of one visual perception model and two visual cognition models.The visual perception model,composed of two steps,is used to extract discriminative features from natural scene images.In the first step,we mimic the oriented and bandpass properties of human primary visual cortex by a special complex wavelets transform,which can decompose a natural scene image into a series of 2D spatial structure signals.In the second step,a hybrid statistical feature extraction method is used to generate gist features from those 2D spatial structure signals.Then we design a cognitive feedback model to realize adaptive optimization for the visual perception model.At last,we build a multiple semantics based cognition model to imitate human cognitive mode in rapid natural scene categorization.Experiments on natural scene datasets show that the proposed method achieves high efficiency and accuracy for natural scene classification. 展开更多
关键词 natural scene classification visual perception model visual cognition model
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Blind recognition of k/n rate convolutional encoders from noisy observation 被引量:14
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作者 Li Huang Wengu Chen +1 位作者 Enhong Chen Hong Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期235-243,共9页
Blind recognition of convolutional codes is not only essential for cognitive radio, but also for non-cooperative context. This paper is dedicated to the blind identification of rate k/n convolutional encoders in a noi... Blind recognition of convolutional codes is not only essential for cognitive radio, but also for non-cooperative context. This paper is dedicated to the blind identification of rate k/n convolutional encoders in a noisy context based on Walsh-Hadamard transformation and block matrix (WHT-BM). The proposed algorithm constructs a system of noisy linear equations and utilizes all its coefficients to recover parity check matrix. It is able to make use of fault-tolerant feature of WHT, thus providing more accurate results and achieving better error performance in high raw bit error rate (BER) regions. Moreover, it is more computationally efficient with the use of the block matrix (BM) method. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Cognitive radio CONVOLUTION Convolutional codes Error correction Hadamard matrices Hadamard transforms Linear transformations Mathematical transformations Matrix algebra Signal encoding
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Automatic radar antenna scan type recognition based on limited penetrable visibility graph 被引量:2
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作者 LIU Songtao LEI Zhenshuo +1 位作者 GE Yang WEN Zhenming 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第2期437-446,共10页
To address the problem of the weak anti-noise and macro-trend extraction abilities of the current methods for identifying radar antenna scan type,a recognition method for radar antenna scan types based on limited pene... To address the problem of the weak anti-noise and macro-trend extraction abilities of the current methods for identifying radar antenna scan type,a recognition method for radar antenna scan types based on limited penetrable visibility graph(LPVG)is proposed.Firstly,seven types of radar antenna scans are analyzed,which include the circular scan,sector scan,helical scan,raster scan,conical scan,electromechanical hybrid scan and two-dimensional electronic scan.Then,the time series of the pulse amplitude in the radar reconnaissance receiver is converted into an LPVG network,and the feature parameters are extracted.Finally,the recognition result is obtained by using a support vector machine(SVM)classifier.The experimental results show that the recognition accuracy and noise resistance of this new method are improved,where the average recognition accuracy for radar antenna type is at least 90%when the signalto-noise ratio(SNR)is 5 dB and above. 展开更多
关键词 antenna scan type limited penetrable visibility graph(LPVG) support vector machine(SVM) cognitive electronic warfare
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Role of PDE4D splice variants in the mediation of antidepressant and cognition-enhancing actions and its mechanisms
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作者 JIN Zeng-liang WANG Zhen-zhen +2 位作者 XU Yuan-yuan YANG Wei-xing LI Yun-feng 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第5期457-458,共2页
OBJECTIVE Phosphodiesterase 4(PDE4),specific for cyclicAMP(cAMP)-hydrolyzing,has four isoforms(PDE4A-D) with at least 25 splice variants. PDE4 inhibitors produce definite antidepressant-like and cognitive-enhancing ef... OBJECTIVE Phosphodiesterase 4(PDE4),specific for cyclicAMP(cAMP)-hydrolyzing,has four isoforms(PDE4A-D) with at least 25 splice variants. PDE4 inhibitors produce definite antidepressant-like and cognitive-enhancing effects. However,none of PDE4 inhibitors has yet been approved for clinical utility so far due to the concomitant side effects. The present research is to explore the splice variants of PDE4 D responsible for antidepressant-like and cognitive-enhancing effects of PDE4 inhibitors but not side effects. METHODS Long-form PDE4 Ds were silenced by the bilateral microinfusion of lentiviral vector containing mi RNAs(4Dmi R) into the prefrontal cortex(PFC),PDE4D4 or D5 was overexpressed by the bilateral microinfusion of lentiviral vector containing full c DNA into hippocampus. Antidepressant-like behaviors were measured by tail-suspension test(TST),forced swimming test(FST)and chronic unpredictable stress model. Cognitive behaviors were measured by the novel object recognition test(NOR) and Morris water maze test(MWM) in both normal mice and the mice with chronic unpredictable stress-induced memory deficits. The emetic potential was evaluated by the assessment of the anaesthetic reversal effect,a surrogate of the emesis test in non-vomiting species. The expressions of PDE4 isoforms/splice variants and cAMP level were examined by Western-blot and ELISA analysis. The dendritic complexity and spine density were assessed by Golgi staining. RESULTS(1)High and specific expression of EGFP(green,indicator of 4Dmi R expression) in PFC was observed under fluorescence microscopy.(2) 4Dmi R significantly down-regulated PDE4D4/5 splice variants,but not PDE4 A,PDE4 B or PDE4D1/2/3.(3) 4Dmi R treatments significantly increased cAMP signaling and dendritic complexity in PFC.(4) Rolipram and/or 4Dmi R treatments significantly decreased immobility in TST and FST.(5) Rolipram and/or 4Dmi R treatments reversed the depressive-like behaviors in chronically stressed mice,including the reduced sucrose preference,prolonged latency to novelty-suppressed feeding and increased immobility in FST.(6) Rolipram and/or 4Dmi R treatments significantly increased the recognition index in NOR task and both the entries and durations in MWM task.(7) Rolipram and/or 4Dmi R treatments reversed the memory deficits in chronically stressed mice,including the reduced the recognition index in NOR task and the decreased durations in MWM task.(8) Rolipram and/or 4DmiR treatments reversed the decreased cA MP signaling,dendritic complexity and spine density.(9) Rolipram or plus 4Dmi R treatment significantly decreased the duration of anaesthesia in the alpha2 adrenergic receptor-mediated anesthesia,but not 4Dmi R treatment alone.(10)Hippocampal overexpression of PDE4D5,but not PDE4D4,produced depressive-like and cognitive defect behaviors,which were reversed by rolipram.The measurements including cAMP signaling,dendritic complexity and in vivo hippocampal LTP,showed the same changes. CONCLUSION Long-form PDE4 Ds,especially the PDE4D5,are the major isoforms responsible for antidepressant-like and cognitive-enhancing effects with little side effects. The critical roles of long-form PDE4 Ds are mediated by their regulation of cAMP signaling pathway and neuroplasticity. 展开更多
关键词 phosphodiesterase 4D RNA interference overexpressions ANTIDEPRESSANT cognitive prefrontal cortex HIPPOCAMPUS
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A Radar Countermeasure Modeling Method Incorporating Cognitive Bias
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作者 Wang Rui Li Xiangyang +2 位作者 Wang Dong Ma Hongguang Zhang Zhili 《系统仿真学报》 北大核心 2025年第4期1090-1101,共12页
Cognitive bias,stemming from electronic measurement error and variability in human perception,exists in cognitive electronic warfare and affects the outcomes of conflicts.In this paper,the dynamic game approach is emp... Cognitive bias,stemming from electronic measurement error and variability in human perception,exists in cognitive electronic warfare and affects the outcomes of conflicts.In this paper,the dynamic game approach is employed to develop a model for cognitive bias induced by incomplete information and measurement errors in cognitive radar countermeasures.The payoffs for both parties are calculated using the radar's anti-jamming strategy matrix A and the jammer's jamming strategy matrix B.With perfect Bayesian equilibrium,a dynamic radar countermeasure model is established,and the impact of cognitive bias is analyzed.Drawing inspiration from the cognitive bias analysis method used in stock market trading,a cognitive bias model for cognitive radar countermeasures is introduced,and its correctness is mathematically proved.A gaming scenario involving the AN/SPY-1 radar and a smart jammer is set up to analyze the influence of cognitive bias on game outcomes.Simulation results validate the effectiveness of the proposed method. 展开更多
关键词 cognitive electronic warfare cognitive bias radar countermeasure dynamic game perfect Bayesian equilibrium
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聋童执行功能发展:聋童与正常儿童的比较 被引量:26
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作者 李一员 吴睿明 +2 位作者 胡兴旺 李红 P D Zelazo 《心理学报》 CSSCI CSCD 北大核心 2006年第3期356-364,共9页
利用标准Dimensional Change Card Sort任务(DCCS),对76名智力正常的3-8岁聋童和78名3-5.5岁的正常儿童进行了对比测试,旨在考察聋童执行功能发展的年龄特征与发展水平。结果发现,3岁组的聋童和正常儿童在DCCS任务上的表现没有显... 利用标准Dimensional Change Card Sort任务(DCCS),对76名智力正常的3-8岁聋童和78名3-5.5岁的正常儿童进行了对比测试,旨在考察聋童执行功能发展的年龄特征与发展水平。结果发现,3岁组的聋童和正常儿童在DCCS任务上的表现没有显著性差异,但正常儿童在4-4.5岁时进入一个迅速发展期,而聋童要在6岁时才有快速的发展,到7岁后才相当于正常儿童5岁的发展水平,大约滞后2年。研究认为,造成聋童执行功能发展滞后的原因主要有:(1)语言符号系统和聋童特有的符号系统之间可能存在的差异;(2)聋童可能存在计划和灵活性的缺陷;(3)聋童可能存在命名和标识策略上的困难和注意机制的缺陷。结合关于聋童心理理论发展滞后于正常儿童7年以上的报道,心理理论发展和执行功能发展在聋童身上表现出较大的不一致性。 展开更多
关键词 聋童 执行功能 心理理论 认知复杂性与控制(Cognitive Complexity and Control ccc) 选择性注意
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Research progresses of resting-state functional MRI in mild cognitive impairment and Alzheimer's disease 被引量:5
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作者 DUAN Huanqin LI Linqin QIU Lihua 《中国医学影像技术》 CSCD 北大核心 2024年第8期1254-1257,共4页
Alzheimer's disease(AD)is a prevalent neurodegenerative disease characterized by cognitive decline in the early stage.Mild cognitive impairment(MCI)is considered as an intermediate stage between normal aging and A... Alzheimer's disease(AD)is a prevalent neurodegenerative disease characterized by cognitive decline in the early stage.Mild cognitive impairment(MCI)is considered as an intermediate stage between normal aging and AD.In recent years,studies related to resting-state functional MRI(rs-fMRI)indicated that the occurrence and development process of MCI and AD might be closely linked to spontaneous brain activity and alterations in functional connectivity among brain regions,and rs-fMRI could provide important reference for specific diagnosis and early treatment of MCI and AD.The research progresses of rs-fMRI for MCI and AD were reviewed in this article. 展开更多
关键词 Alzheimer disease cognition disorders magnetic resonance imaging
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Analysis and Research on Information Design of the Smart Community Pension Service 被引量:2
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作者 Chen Hao 《学术界》 CSSCI 北大核心 2018年第8期268-280,共13页
In the research on the smart community pension service,it is found that the problems encountered in the promotion of the smart pension can not be solved in the short term because of the lack of information and the acc... In the research on the smart community pension service,it is found that the problems encountered in the promotion of the smart pension can not be solved in the short term because of the lack of information and the acceptance of the intelligent products by the elderly. This paper puts forward the research ideas based on the cognitive characteristics and demand prediction of the specific population. Focusing on the research on the pension needs of people born in the 1960 s or 1970 s,it provides support for the solution of smart pension services in the peak period of aging population in the future. 展开更多
关键词 SMART COMMUNITY PENSION needs cognition of the ELDERLY information design DEMAND forecasting
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Modeling of cognitive framework in time-stressed decision making 被引量:3
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作者 Wang Li Wang Mingzhe 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第5期992-1000,共9页
An approach for modeling a human cognitive framework in time-stressed decision making is presented. The recognitive and metacognitive processes that represent the cognitive framework are modeled by the colored Petri n... An approach for modeling a human cognitive framework in time-stressed decision making is presented. The recognitive and metacognitive processes that represent the cognitive framework are modeled by the colored Petri nets (CPNs). A structural and behavioral analysis method is adopted to obtain the static and dynamic property used to verify the CPNs model of the cognitive framework. Finally, an example from the command and control radar recognition system is used to evaluate the feasibility and availability of the CPNs model adopted in practical systems. 展开更多
关键词 cognitive framework metacognition colored Petri nets modeling and verification decision making.
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Learning Strategies in Chinese EFL Learners' Reading Comprehension 被引量:1
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作者 汪建丽 《陕西师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2002年第S1期356-358,共3页
According to schema theory resulting from the psycholinguistic model of reading,comprehending a text is an interactive process between the reader background knowledge and the text. This article first views the psychol... According to schema theory resulting from the psycholinguistic model of reading,comprehending a text is an interactive process between the reader background knowledge and the text. This article first views the psycholinguistic model of reading and research in learning strategies, then discusses the application of socioaffective,cognitive, metacognitive learning strategies in Chinese EFL learners’ reading comprehension. 展开更多
关键词 schema theory learning strategy socioaffective COGNITIVE metacognitive
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Shiology System-to Establish Inclusion and Juxtaposition Relationships Within Shiance 被引量:1
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作者 Liu Guangwei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第3期85-96,共12页
The construction of shiology system is the premise for comprehensively solving the issues of human shiance.The core of the construction of the shiology system is to reveal the inclusion and juxtaposition of relationsh... The construction of shiology system is the premise for comprehensively solving the issues of human shiance.The core of the construction of the shiology system is to reveal the inclusion and juxtaposition of relationships within shiance based on a comprehensive understanding of human shiance issues.The shiology system discussed in this paper is a four-level discipline system with the basic structure of shiology triangle composed of eaters'demands,food acquisition and shiance order,and it is currently in the form of"1-3-13-36".From a longitudinal point of view,53 inclusion relationships are established among disciplines at all levels.Horizontally,53 juxtapositions are established between disciplines at the same level.The shiology system is bounded by human shiance issues,not involving non-shiance issues areas.Human cognition of shiance and shiance issues must go through three historical stages as fragmented cognition,block-based cognition and holistic cognition.The construction of the shiology system marks that humans have entered the stage of"holistic cognition"of shiance.As the Chinese proverb goes,"food is the paramount necessity of the people".Shiology system interprets its connotation and extension.To solve shiance issues holistically,it need to ensure food security,enable people to eat healthy,and foster an enduring and stable society.And shiology system is a global public product which comprehensively solves shiance issues. 展开更多
关键词 SYSTEM eater FOOD shiance order shiance shiology shiance cognition shiology system
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认知神经模拟对二语习得的启示 被引量:1
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作者 齐振海 李娜 《北京第二外国语学院学报》 2010年第12期19-23,共5页
认知科学认为认知是一种生物学现象,与身体的其他系统共同进化,并且源自人类与环境的交互作用。有机体的生物特性以及有机体所处的物理环境与社会环境都会对认知起到重要的作用。因此,语言、认知及思维不仅根植于有机体的身体性,而且也... 认知科学认为认知是一种生物学现象,与身体的其他系统共同进化,并且源自人类与环境的交互作用。有机体的生物特性以及有机体所处的物理环境与社会环境都会对认知起到重要的作用。因此,语言、认知及思维不仅根植于有机体的身体性,而且也根植于有机体的感觉运动系统。本文以认知科学研究为理论背景,阐释语言认知神经模拟理论,试图揭示语言背后的认知神经机制及模拟系统,并且对二语习得研究具有启示性作用。 展开更多
关键词 认知神经机制 模拟系统 二语习得研究 启示 SLA Cognitive 有机体 认知科学 阐释语言 运动系统 物理环境 生物学现象 生物特性 身体性 社会环境 模拟理论 理论背景 科学研究 交互作用 共同进化
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基于统计可信度的压缩感知协作频谱检测算法
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作者 李娜 陈松 李鸥 《电讯技术》 北大核心 2014年第1期23-28,共6页
压缩感知为认知无线电的宽频谱感知提供了一种新的方法和思路。基于压缩感知的原理,提出了一种多认知用户协作场景下基于用户统计可信度的协作频谱检测算法。该算法使用正交匹配协作追踪算法获得认知区域内的频谱占用情况,根据不同认知... 压缩感知为认知无线电的宽频谱感知提供了一种新的方法和思路。基于压缩感知的原理,提出了一种多认知用户协作场景下基于用户统计可信度的协作频谱检测算法。该算法使用正交匹配协作追踪算法获得认知区域内的频谱占用情况,根据不同认知用户频谱检测的历史准确度综合判定用户感知结果的统计可信度。仿真结果表明,该算法在不同用户数、不同采样值、不同信噪比变化范围下其检测性能均优于传统算术平均方法,有效改善了检测性能。 展开更多
关键词 认知无线电 压缩感知 协作频谱检测 统计可信度 检测性能 COGNITIVE radio( CR)
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CA-30,an active fraction derived from Liuwei Dihuang Decoction,ameliorates cognitive deterioration via intestinal microbiome
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作者 ZHOU Wen-xia WANG Jian-hui +3 位作者 LEI Xi ZHANG Xiao-rui CHENG Xiao-rui ZHANG Yong-xiang 《中国药理学与毒理学杂志》 CAS 北大核心 2019年第9期654-655,共2页
Alzheimer disease(AD)is the leading cause of dementia that affects millions of elderly people worldwide.The currently available therapies have limited efficacy.Liuwei Dihuang formula(LW),a classical traditional Chines... Alzheimer disease(AD)is the leading cause of dementia that affects millions of elderly people worldwide.The currently available therapies have limited efficacy.Liuwei Dihuang formula(LW),a classical traditional Chinese medicine(TCM)prescription,has long been used to treat various diseases,including dementia.A great number of pharmacological studies have showed that LW and its active fractions had beneficial effects on AD associated cognitive impairments.Our recent study found that LW,especially its oligosaccharide fraction CA-30,could improve the gastrointestinal microbiota dysbiosis in senescence-accelerated mouse prone 8(SAMP8),an AD mouse model.Here,we sought to determine the effects of CA-30 on the composition and function of the intestinal microbiome in SAMP8 mice.Administration with CA-30 decreased the degree of senescence,increased the nest building and locomotor activity,ameliorated the impairments in object recognition,spatial learningand memory behavour,and decreased the active avoidance response in SAMP8 mice.Meanwhile,CA-30 improvedthe cytokine and hormone secretion and lymphocyte subset dysregulation in SAMP8 mice.Moreover,we found that CA-30 altered the abundance of 4 genera and 10 newborn genera.Advantageous changes in carbohydrate-active enzymes of SAMP8 mice following CA-30 treatment,especially GH85,were also noted.We further found that 7 genera were significantly correlated with the NIM network and cognitive performance.CA-30 influenced the relative abundance of these intestinal microbiomes in SAMP8 mice and restored them to SAMR1 mouse levels.CA-30 ameliorated the intestinal microbiome,rebalanced the NIM network,improved the AD-like cognitive impairments in SAMP8,and might thus be a potential therapeutic agent for AD. 展开更多
关键词 Alzheimer disease CA-30 OLIGOSACCHARIDE SAMP8 intestinal microbiome cognition neuroendocrine immunomodulation
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Phosphodiesterase 1:a unique therapeutic target with multiple potential indications
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作者 Larry WENNOGLE 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第5期452-453,共2页
Cyclic-nucleotide phosphodiesterase 1(PDE1) is a unique enzyme family hydrolyzing both cyclic guanosine monophosphate(cGMP) and cyclic adenosine monophosphate(cAMP) intra-cellular signaling molecules. A unique aspect ... Cyclic-nucleotide phosphodiesterase 1(PDE1) is a unique enzyme family hydrolyzing both cyclic guanosine monophosphate(cGMP) and cyclic adenosine monophosphate(cAMP) intra-cellular signaling molecules. A unique aspect of this enzyme family is its activation by calcium-calmodulin upon excitation of excitatory cells such as neurons and cardiomyocytes. In chronic degenerative diseases such as Parkinson disease,Alzheimer disease and heart failure,over-stimulation and chronic excessive levels of intra-cellular calcium leads to cell death. Targeting the PDE1 enzyme family with enzyme inhibitors is a novel approach to develop therapeutic agents for degenerative disorders. ITI-214 is a potent,and selective PDE1 inhibitor that has been tested in four human clinical trials. It is safe and well tolerated even at high dose levels that lead to high plasma and cerebral spinal fluid levels. In animal models,ITI-214 has cognitive enhancing properties as demonstrated in the rat novel object recognition model. Using a unilateral 6-hydroxy-dopamine lesion mouse model,the cylinder test readout of front paw use indicated that ITI-214 displays L-DOPA sparing effects ITI-214 reverses catalepsy induced by the potent dopamine D2 receptor antagonist haloperidol,indicating potential applications in Parkinson disease and as an adjunctive treatment in schizophrenia. Aspects of the Intra-Cellular Therapies PDE1 inhibitor program wil be outlined and the potential application to multiple therapeutic areas wil be discussed. 展开更多
关键词 cyclic-nucleotide phosphodiesterase 1 calmodulin-activation cognition DEGENERATIVE THERAPIES
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Fuzzy Methodology for Taxonomy and Knowledge Base Design
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作者 Paul P. Wang & Fuji Lai(Fuzzy Logic Research Laboratory, Department of Electrical Engineering Duke University, Box 90291, Durham, North Carolina 27708-0291)email: { ppw@ee.duke.edu & flai @acpub.duke.edu } . 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1996年第2期1-23,共23页
This paper summarizes the research results dealing with washer and nut taxonomy and knowledge base design, making the use of fuzzy methodology. In particular, the theory of fuzzy membership functions, similarity matri... This paper summarizes the research results dealing with washer and nut taxonomy and knowledge base design, making the use of fuzzy methodology. In particular, the theory of fuzzy membership functions, similarity matrices, and the operation of fuzzy inference play important roles.A realistic set of 25 washers and nuts are employed to conduct extensive experiments and simulations.The investigation includes a complete demonstration of engineering design. The results obtained from this feasibility study are very encouraging indeed because they represent the lower bound with respect to performance, namely correctrecognition rate, of what fuzzy methodology can do. This lower bound shows high recognition rate even with noisy input patterns, robustness in terms of noise tolerance, and simplicity in hardware implementation. Possible future works are suggested in the conclusion. 展开更多
关键词 Feature extraction Pattern recognition Fuzzy set theory TAXONOMY Fuzzy similarity matrix Industrial washer and nut classification Knowledge base design Database transformation Cognitive science Industrial part identification
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Modeling of combined Bayesian networks and cognitive framework for decision-making in C2 被引量:8
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作者 Li Wang Mingzhe Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第5期812-820,共9页
The command and control(C2) is a decision-making process based on human cognition,which contains operational,physical,and human characteristics,so it takes on uncertainty and complexity.As a decision support approac... The command and control(C2) is a decision-making process based on human cognition,which contains operational,physical,and human characteristics,so it takes on uncertainty and complexity.As a decision support approach,Bayesian networks(BNs) provide a framework in which a decision is made by combining the experts' knowledge and the specific data.In addition,an expert system represented by human cognitive framework is adopted to express the real-time decision-making process of the decision maker.The combination of the Bayesian decision support and human cognitive framework in the C2 of a specific application field is modeled and executed by colored Petri nets(CPNs),and the consequences of execution manifest such combination can perfectly present the decision-making process in C2. 展开更多
关键词 Bayesian networks decision support cognitive framework command and control colored Petri nets.
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An adaptive waveform-detection threshold joint optimization method for target tracking 被引量:5
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作者 王宏强 夏洪恩 +1 位作者 程永强 王璐璐 《Journal of Central South University》 SCIE EI CAS 2013年第11期3057-3064,共8页
The joint optimization of detection threshold and waveform parameters for target tracking which comes from the idea of cognitive radar is investigated for the modified probabilistic data association(MPDA)filter.The tr... The joint optimization of detection threshold and waveform parameters for target tracking which comes from the idea of cognitive radar is investigated for the modified probabilistic data association(MPDA)filter.The transmitted waveforms and detection threshold are adaptively selected to enhance the tracking performance.The modified Riccati equation is adopted to predict the error covariance which is used as the criterion function,while the optimization problem is solved through the genetic algorithm(GA).The detection probability,false alarm probability and measurement noise covariance are all considered together,which significantly improves the tracking performance of the joint detection and tracking system.Simulation results show that the proposed adaptive waveform-detection threshold joint optimization method outperforms the adaptive threshold method and the fixed parameters method,which will reduce the tracking error.The average reduction of range error between the adaptive joint method and the fixed parameters method is about 0.6 m,while that between the adaptive joint method and the adaptive threshold only method is about 0.3 m.Similar error reduction occurs for the velocity error and acceleration error. 展开更多
关键词 cognitive radar adaptive waveform selection target tracking joint optimization detection-tracking system
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Improved spectrum sharing algorithm based on feedback control information in cognitive radio networks 被引量:5
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作者 Yibing Li Rui Yang +1 位作者 Fang Ye Zhenguo Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第4期564-570,共7页
In order to avoid the system performance deterioration caused by the wireless fading channel and imperfect channel estimation in cognitive radio networks, the spectrum sharing problem with the consideration of feedbac... In order to avoid the system performance deterioration caused by the wireless fading channel and imperfect channel estimation in cognitive radio networks, the spectrum sharing problem with the consideration of feedback control information from the primary user is analyzed. An improved spectrum sharing algorithm based on the combination of the feedback control information and the optimization algorithm is proposed. The relaxation method is used to achieve the approximate spectrum sharing model, and the spectrum sharing strategy that satisfies the individual outage probability constraints can be obtained iteratively with the observed outage probability. Simulation results show that the proposed spectrum sharing algorithm can achieve the spectrum sharing strategy that satisfies the outage probability constraints and reduce the average outage probability without causing maximum transmission rate reduction of the secondary user. 展开更多
关键词 cognitive radio spectrum sharing power control feedback control information.
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