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
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
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
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
OBJECTIVE To explore the effect and mechanisms of LW-AFC,a new formula derived fromLiuwei Dihuang decoction,on chronic unpredictable mild stress(CUMS)-induced mood and cogni.tion impairment in mice.METHODS C57 BL/6 J ...OBJECTIVE To explore the effect and mechanisms of LW-AFC,a new formula derived fromLiuwei Dihuang decoction,on chronic unpredictable mild stress(CUMS)-induced mood and cogni.tion impairment in mice.METHODS C57 BL/6 J mice were randomly placed into seven groups(n=10):normal control group,CUMS group,Fluoxetine(10 mg·kg^(-1),once per day) group,Liuwei Dihuang decoction group(LW,10 g·kg^(-1),once per day),and LW-AFC(0.8 g·kg^(-1),1.6 g·kg^(-1),3.2 g·kg^(-1),once per day) group.The stressed group was given CUMS for 4 weeks to set up a chronic multiple-stressed model.LW and LW-AFC was oral administered a week prior to CUMS and until the end of the study(a total of 35 d),while fluoxetine was administrated orally for 4 weeks.The anxiety behavior was analyzed using the open field test(OFT) and elevated plus maze test(EPM).The depression behavior was ana.lyzed using the sucrose preference test(SPT) and forced swimming test(FST).Spatial cognition was evaluated using Morris water maze(MWM) test and working memory was evaluated using new object recognition test(NORT).RESULTS CUMS for 28 d increased depressive-and anxiety-like behaviors.LW-AFC(1.6 g·kg^(-1)) significantly increased the numbers of entries into the open arm and time in the open arm of CUMS mice(P<0.05).LW-AFC(3.2 g·kg^(-1)) increased sucrose consumption and de.creased the immobility time of FST(P<0.01) of CUMS mice.The MWM test showed that spatial learning andmemory in CUMS mice were remarkably affected relative to controls,whereas LW-AFC(3.2 g·kg^(-1)) im.proves cognitive functions(P<0.05).CONCLUSION The mood and theability of learning and memory of thestressed group can be affected after exposure to CUS.Oral administration of LW-AFC significant.ly improved CUMS-induced impairments of mood and cognition in mice.展开更多
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
A restricted combination is a kind of language phenomena.It is important in language.It is relatively-stationary phrase.Though it is conposed of more than one word,its meaning isn't only literal meaning expressed ...A restricted combination is a kind of language phenomena.It is important in language.It is relatively-stationary phrase.Though it is conposed of more than one word,its meaning isn't only literal meaning expressed by the words,but holistic.The whole isn't equal to the part.In the process of understanding restricted combinations,holistic congnition can play an important role.展开更多
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
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
Cognitive radio（CR） technology is considered to be an effective solution to allocate spectrum resources,whereas the primary users of a network do not fully utilize available frequency bands.Spectrum auction framewor...Cognitive radio（CR） technology is considered to be an effective solution to allocate spectrum resources,whereas the primary users of a network do not fully utilize available frequency bands.Spectrum auction framework has been recognized as an effective way to achieve dynamic spectrum access.From the perspective of spectrum auction,multi-band multi-user auction provides a new challenge for spectrum management.This paper proposes an auction framework based on location information for multi-band multi-user spectrum allocation.The performance of the proposed framework is compared with that of traditional auction framework based on a binary interference model as a benchmark.Simulation results show that primary users will obtain more total system revenue by selling their idle frequency bands to secondary users and the spectrum utilization of the proposed framework is more effective and fairer.展开更多
This paper investigates the jamming sensing performance of the simultaneous transmit and receive based cognitive anti-jamming(SCAJ) receiver impaired by phase noise in local oscillators(LO) over fading channels. First...This paper investigates the jamming sensing performance of the simultaneous transmit and receive based cognitive anti-jamming(SCAJ) receiver impaired by phase noise in local oscillators(LO) over fading channels. Firstly, energy detection(ED)based on the jamming to noise ratio(JNR) of the high frequency bands SCAJ receiver with phase noise under different channels is analyzed. Then, the probabilities of jamming detection and false alarm in closed-form for the SCAJ receiver are derived. Finally,the modified Bayesian Cramer-Rao bound(BCRB) of jamming sensing for the SCAJ receiver is presented. Simulation results show that the performance degradation of the SCAJ system due to phase noise is more severe than that due to the channel fading in the circumstances where the signal bandwidth(BW) is kept a constant. Moreover, the signal BW has an effect on the phase noise in LO, and the jamming detection probability of the wideband SCAJ receiver with lower phase noise outperforms that of the narrowband receiver using the same center frequency. Furthermore,an accurate phase noise estimation and compensation scheme can improve the jamming detection capability of the SCAJ receiver in high frequency bands and approach to the upper bound.展开更多
On the basis of analyzing the present conditions of country high school English teaching, this paper attempts to justify the feasibility of Cognitive Approach’s application to the country high school English teaching...On the basis of analyzing the present conditions of country high school English teaching, this paper attempts to justify the feasibility of Cognitive Approach’s application to the country high school English teaching and discusses its operation in detail.展开更多
OBJECTIVE A causal relationshiphas been postulated between cholinergic dysfunction and the progression of cognitive decline in neurodegenerative disorders. However,the cause of the cognitive dysfunction remains unclea...OBJECTIVE A causal relationshiphas been postulated between cholinergic dysfunction and the progression of cognitive decline in neurodegenerative disorders. However,the cause of the cognitive dysfunction remains unclear. METHODS Gab1^(loxP/loxP) were bred with ChAT-Cre mice to generate ChAT-Cre; Gab1^(f/f) mice. Excitability of cholinergic neurons wererecorded using whole-cel patch clump. A series of behavioral analyses were used to address the changes of cognitive function in ChAT-Cre; Gab1^(f/f) mice. Neurochemical changes on brain of conditional knockout mice were evaluated by using immunohistochemistry and Western blotting analysis. RESULTS Grb2-associated-binding protein 1(Gab1) is adocking/scaffolding molecule known to play an important role in cell growth and survival. Here,wereport that Gab1 is decreased in cholinergic neurons in a mousemodel of AD. We found that selective downregulation of Gab1 in the septum impaired learning and memory and hippocampal long-term potentiation,whereas overexpression of Gab1 in the same area rescued the cognitive deficitsseen in ChAT-Cre; Gab1^(f/f) and APP^(swe)/PS1 mice.^(18)F-FDGmicroP ET imaging data indicated that Gab1 treatment had no effect on metabolic activity of glucose in APPswe/PS1 mice. Moreover,we identify abnormal function of SKchannelscontributes to increased firing in cholinergic neuronsof ChAT-Cre; Gab1^(f/f) mice. CONCLUSION Gab1 signaling may serve as a potential treatment target for neurological disorders involving dysfunction of central cholinergic neurons.展开更多
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
A joint power control and relay selection scheme is considered for a cooperative and cognitive radio system where a secondary network shares spectrum with the primary network. In the secondary network, two secondary u...A joint power control and relay selection scheme is considered for a cooperative and cognitive radio system where a secondary network shares spectrum with the primary network. In the secondary network, two secondary users （SUs） communicate with each other via an assist relay. The main point is to provide the best system performance to SUs while maintaining the interference power at primary user （PU） under a certain level. Using convex optimization, a closed-form solution is obtained when optimizing the power allocation among the two nodes and relay. Based on this result, a joint power control and relay selection scheme with fewer variable dimensions is proposed to maximize the achievable rate of the secondary system. Simulation results demonstrate that the sum rate of the cognitive two-way relay network increases compared with a random relay selection and fixed power allocation.展开更多
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
基金supported by the National Natural Science Foundation of China(1127105011371183+2 种基金61403036)the Science and Technology Development Foundation of CAEP(2013A04030202013B0403068)
基金supported by the China Postdoctoral Science Foundation(2015M572694,2016T90979).
文摘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.
文摘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.
文摘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.
文摘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.
文摘OBJECTIVE To explore the effect and mechanisms of LW-AFC,a new formula derived fromLiuwei Dihuang decoction,on chronic unpredictable mild stress(CUMS)-induced mood and cogni.tion impairment in mice.METHODS C57 BL/6 J mice were randomly placed into seven groups(n=10):normal control group,CUMS group,Fluoxetine(10 mg·kg^(-1),once per day) group,Liuwei Dihuang decoction group(LW,10 g·kg^(-1),once per day),and LW-AFC(0.8 g·kg^(-1),1.6 g·kg^(-1),3.2 g·kg^(-1),once per day) group.The stressed group was given CUMS for 4 weeks to set up a chronic multiple-stressed model.LW and LW-AFC was oral administered a week prior to CUMS and until the end of the study(a total of 35 d),while fluoxetine was administrated orally for 4 weeks.The anxiety behavior was analyzed using the open field test(OFT) and elevated plus maze test(EPM).The depression behavior was ana.lyzed using the sucrose preference test(SPT) and forced swimming test(FST).Spatial cognition was evaluated using Morris water maze(MWM) test and working memory was evaluated using new object recognition test(NORT).RESULTS CUMS for 28 d increased depressive-and anxiety-like behaviors.LW-AFC(1.6 g·kg^(-1)) significantly increased the numbers of entries into the open arm and time in the open arm of CUMS mice(P<0.05).LW-AFC(3.2 g·kg^(-1)) increased sucrose consumption and de.creased the immobility time of FST(P<0.01) of CUMS mice.The MWM test showed that spatial learning andmemory in CUMS mice were remarkably affected relative to controls,whereas LW-AFC(3.2 g·kg^(-1)) im.proves cognitive functions(P<0.05).CONCLUSION The mood and theability of learning and memory of thestressed group can be affected after exposure to CUS.Oral administration of LW-AFC significant.ly improved CUMS-induced impairments of mood and cognition in mice.
文摘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.
基金one of the reseach results of scientific research project in Shanghai University of Engineering Science A Study of English and Chinese Restricted Combinations in Phrase Structures(A-0501-12-30)
文摘A restricted combination is a kind of language phenomena.It is important in language.It is relatively-stationary phrase.Though it is conposed of more than one word,its meaning isn't only literal meaning expressed by the words,but holistic.The whole isn't equal to the part.In the process of understanding restricted combinations,holistic congnition can play an important role.
基金supported by the National Natural Science Foundation of China (60874068)
文摘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.
基金supported by the National Natural Science Foundation of China (61073183)the Natural Science Foundation for the Youth of Heilongjiang Province (QC2012C070)
文摘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.
基金supported by the Beijing Natural Science Foundation of China (4102050)
文摘Cognitive radio（CR） technology is considered to be an effective solution to allocate spectrum resources,whereas the primary users of a network do not fully utilize available frequency bands.Spectrum auction framework has been recognized as an effective way to achieve dynamic spectrum access.From the perspective of spectrum auction,multi-band multi-user auction provides a new challenge for spectrum management.This paper proposes an auction framework based on location information for multi-band multi-user spectrum allocation.The performance of the proposed framework is compared with that of traditional auction framework based on a binary interference model as a benchmark.Simulation results show that primary users will obtain more total system revenue by selling their idle frequency bands to secondary users and the spectrum utilization of the proposed framework is more effective and fairer.
基金supported by the Program of the Aeronautical Science Foundation of China(2013ZC15003)
文摘This paper investigates the jamming sensing performance of the simultaneous transmit and receive based cognitive anti-jamming(SCAJ) receiver impaired by phase noise in local oscillators(LO) over fading channels. Firstly, energy detection(ED)based on the jamming to noise ratio(JNR) of the high frequency bands SCAJ receiver with phase noise under different channels is analyzed. Then, the probabilities of jamming detection and false alarm in closed-form for the SCAJ receiver are derived. Finally,the modified Bayesian Cramer-Rao bound(BCRB) of jamming sensing for the SCAJ receiver is presented. Simulation results show that the performance degradation of the SCAJ system due to phase noise is more severe than that due to the channel fading in the circumstances where the signal bandwidth(BW) is kept a constant. Moreover, the signal BW has an effect on the phase noise in LO, and the jamming detection probability of the wideband SCAJ receiver with lower phase noise outperforms that of the narrowband receiver using the same center frequency. Furthermore,an accurate phase noise estimation and compensation scheme can improve the jamming detection capability of the SCAJ receiver in high frequency bands and approach to the upper bound.
文摘On the basis of analyzing the present conditions of country high school English teaching, this paper attempts to justify the feasibility of Cognitive Approach’s application to the country high school English teaching and discusses its operation in detail.
文摘OBJECTIVE A causal relationshiphas been postulated between cholinergic dysfunction and the progression of cognitive decline in neurodegenerative disorders. However,the cause of the cognitive dysfunction remains unclear. METHODS Gab1^(loxP/loxP) were bred with ChAT-Cre mice to generate ChAT-Cre; Gab1^(f/f) mice. Excitability of cholinergic neurons wererecorded using whole-cel patch clump. A series of behavioral analyses were used to address the changes of cognitive function in ChAT-Cre; Gab1^(f/f) mice. Neurochemical changes on brain of conditional knockout mice were evaluated by using immunohistochemistry and Western blotting analysis. RESULTS Grb2-associated-binding protein 1(Gab1) is adocking/scaffolding molecule known to play an important role in cell growth and survival. Here,wereport that Gab1 is decreased in cholinergic neurons in a mousemodel of AD. We found that selective downregulation of Gab1 in the septum impaired learning and memory and hippocampal long-term potentiation,whereas overexpression of Gab1 in the same area rescued the cognitive deficitsseen in ChAT-Cre; Gab1^(f/f) and APP^(swe)/PS1 mice.^(18)F-FDGmicroP ET imaging data indicated that Gab1 treatment had no effect on metabolic activity of glucose in APPswe/PS1 mice. Moreover,we identify abnormal function of SKchannelscontributes to increased firing in cholinergic neuronsof ChAT-Cre; Gab1^(f/f) mice. CONCLUSION Gab1 signaling may serve as a potential treatment target for neurological disorders involving dysfunction of central cholinergic neurons.
基金supported by the National Natural Science Foundation of China(60874068).
文摘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.
基金supported by the National Natural Science Foundation of China (61250005)Jiangxi Postdoctoral Science Foundation(2013KY07)
文摘A joint power control and relay selection scheme is considered for a cooperative and cognitive radio system where a secondary network shares spectrum with the primary network. In the secondary network, two secondary users （SUs） communicate with each other via an assist relay. The main point is to provide the best system performance to SUs while maintaining the interference power at primary user （PU） under a certain level. Using convex optimization, a closed-form solution is obtained when optimizing the power allocation among the two nodes and relay. Based on this result, a joint power control and relay selection scheme with fewer variable dimensions is proposed to maximize the achievable rate of the secondary system. Simulation results demonstrate that the sum rate of the cognitive two-way relay network increases compared with a random relay selection and fixed power allocation.
文摘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.
