Tracking moving wideband sound sources is one of the most challenging issues in the acoustic array signal processing which is based on the direction of arrival(DOA) estimation. Compressive sensing(CS) is a recent theo...Tracking moving wideband sound sources is one of the most challenging issues in the acoustic array signal processing which is based on the direction of arrival(DOA) estimation. Compressive sensing(CS) is a recent theory exploring the signal sparsity representation, which has been proved to be superior for the DOA estimation. However, the spatial aliasing and the offset at endfire are the main obstacles for CS applied in the wideband DOA estimation. We propose a particle filter based compressive sensing method for tracking moving wideband sound sources. First, the initial DOA estimates are obtained by wideband CS algorithms. Then, the real sources are approximated by a set of particles with different weights assigned. The kernel density estimator is used as the likelihood function of particle filter. We present the results for both uniform and random linear array. Simulation results show that the spatial aliasing is disappeared and the offset at endfire is reduced. We show that the proposed method can achieve satisfactory tracking performance regardless of using uniform or random linear array.展开更多
Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acqu...Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.展开更多
The presence of feacal-derived pathogens in water is responsible for several infectious diseases and deaths worldwide. As a solution, sources of fecal pollution in waters must be accurately assessed, properly determin...The presence of feacal-derived pathogens in water is responsible for several infectious diseases and deaths worldwide. As a solution, sources of fecal pollution in waters must be accurately assessed, properly determined and strictly controlled. However, the exercise has remained challenging due to the existing overlapping characteristics by different members of faecal coliform bacteria and the inadequacy of information pertaining to the contribution of seasonality and weather condition on tracking the possible sources of pollution. There are continued ef forts to improve the Faecal Contamination Source Tracking(FCST) techniques such as Microbial Source Tracking(MST). This study aimed to make contribution to MST by evaluating the efficacy of combining site specific quantification of faecal contamination indicator bacteria and detection of DNA markers while accounting for seasonality and weather conditions' eff ects in tracking the major sources of faecal contamination in a freshwater system(Donghu Lake, China). The results showed that the use of cyd gene in addition to lacZ and uidA genes differentiates E. coli from other closely related faecal bacteria. The use of selective media increases the pollution source tracking accuracy. BSA addition boosts PCR detection and increases FCST efficiency. Seasonality and weather variability also influence the detection limit for DNA markers.展开更多
Sand-dust storm is a special natural disaster that frequently occurs in deserts and their surrounding areas. With the data published onSurface Meteorological Monthly Bulletin andSurface Chart during 1971–1996, the te...Sand-dust storm is a special natural disaster that frequently occurs in deserts and their surrounding areas. With the data published onSurface Meteorological Monthly Bulletin andSurface Chart during 1971–1996, the temporal-spatial distribution and annual variation of sand-dust storms are analyzed on the basis of the case study of atmospheric processes. Furthermore, the tracks and source areas of sand-dust storms are determined with the aid of GIS. The results show that except some parts of Qinghai Province and Inner Mongolia as well as Beijing, sand-dust storms decrease apparently in time and space in recent decades in China. Sand-dust storms occur most frequently in spring, especially in April. According to their source areas, sand-dust storms are classified into two types, i.e., the inner-source and outer-source sand-dust storms. Most of the outer-source sand-dust storms move along the north and west tracks. The north-track outer-source sand-dust storms always intrude into China across the Sino-Mongolian border from Hami, a city in the eastern part ofXinjiang, to Xilin Gol, a league in Inner Mongolia, while the west-track ones intrude into China from both southern and northern Xinjiang. The source lands of inner-source sand-dust storms concentrate in the Taklimakan Desert and its surrounding areas in southern Xinjiang, southern part of the Junggar Basin in north of Xinjiang, the Hexi Corridor in western Gansu Province, the dry deserts of Inner Mongolia and the Qaidam Basin in Qinghai.展开更多
●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the trackin...●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the tracking results can achieve high precision.●Dryland was the main source of sediment deposition based on the result of FEAST.Sediment source tracing can accurately provide a theoretical basis for controlling soil erosion effectively,by identifying the most serious types of land use.Traditional sediment tracing methods are based on physical,chemical,biological,and composite fingerprinting,which have not included microbes.As high-throughput sequencing becomes more prevalent,microorganisms can provide more information than what we think.Thus,whether the microorganism can also be used as a special fingerprint factor for sediment source identification during soil erosion,we have tested it by using microbial source tracking tool FEAST to quantify the microbe contribution from five types of eroded land(including dryland,urban,paddy field,forest and grassland)to the depositional areas(Niubitan)in the Yuanjiang basin.The source microbial community in the erosive area was heterogeneous,and assembly process analysis further demonstrated that the source tracking results could reach higher accuracy.The results of FEAST showed that dryland(35.50%),urban(17.21%),paddy field(8.14%),and forest(1.07%)were the major contributors to Niubitan.Our results follow the general soil erosion rules and prove its validity.Taken together,a new perspective is provided by these results for tracing sediment sources in erosion-sedimentary systems.展开更多
Three tributaries of the Grand River watershed (Ontario, Canada), each representing different watershed types (urban, agricultural/rural, and mixed land-use) were examined to understand the spatial, temporal, and host...Three tributaries of the Grand River watershed (Ontario, Canada), each representing different watershed types (urban, agricultural/rural, and mixed land-use) were examined to understand the spatial, temporal, and host-source distribution of the waterborne pathogen, Cryptosporidium. Cryptosporidium was frequently found throughout the study (73%, 65/89) with occurrence and concentrations observed to be similar among the varying watershed types. However, applying advanced genotyping techniques, marked differences in dominant host sources could be observed in each watershed. The agricultural/rural and mixed land-use watersheds were dominated by genotypes typically associated with cattle (i.e., C. andersoni), while the urban watershed had the highest diversity of Cryptosporidium genotypes with a variety of wildlife as the common source of contamination (e.g., muskrat and cervine genotypes). A similar seasonal trend observed in the urban, agricultural, and mixed land-use watershed suggests that factors beyond specific land use activities (e.g. autumn manure spreading) may influence the timing and concentration of Cryptosporidium in these streams. Corresponding genotyping results provided additional insight into source inputs during these seasonal peaks, indicating that wildlife may be important seasonal contributors to Cryptosporidium contamination in these streams. Despite the abundance of Cryptosporidium in these watersheds, most of the genotypes observed were of limited human health importance. This study provides evidence regarding the significance of including genotyping results into studies examining waterborne Cryptosporidium. Using this technique can provide a greater understanding of the risk to the population using water sources, as well as provide insight into the probable sources and timing of contamination. This ancillary information can contribute to implementation of targeted management strategies to further protect sources of drinking water and recreation areas.展开更多
Project Trackdown is an investigative environmental program aimed at tracking sources of polychlorinated biphenyl (PCB) contamination in Great Lakes tributaries. The program uses a multimedia weight of evidence approa...Project Trackdown is an investigative environmental program aimed at tracking sources of polychlorinated biphenyl (PCB) contamination in Great Lakes tributaries. The program uses a multimedia weight of evidence approach for identifying sources of PCBs to the environment. PCB concentrations in environmental media (sediment, water, suspended sediment and soil), passive samplers and/or exposed biota (mussels, young-of-the-year fish and benthic invertebrates) are used in combination to evaluate bioavailability and identify local anomalies within a tributary. These lines of evidence can be assessed with simple chemometric techniques and fingerprinting of PCB congener profiles, and, combined with anecdotal information such as land use history and tributary alterations, may be used to identify ongoing and locally controllable sources of PCBs to the Great Lakes. The program was successful at developing environmental triggers to differentiate potential source areas from background PCB conditions in urban areas, allowing efforts to focus on identifying active ongoing sources of PCB contamination. Project Trackdown has been carried out in three tributaries to Lake Ontario (Cataraqui River, Etobicoke Creek and Twelve Mile Creek) and two tributaries that flow into the Detroit River (Turkey Creek and Little River). Local ongoing PCB sources have been identified in four projects, leading to abatement or remediation measures. As a collaborative initiative between the Ontario Ministry of the Environment and Environment Canada, Project Trackdown has successfully identified several PCB sources leading to substantial cleanup efforts aimed ultimately at reducing PCB contamination to the Great Lakes.展开更多
Current methods of order tracking, such as synchronous resampling, Gabor filtering, and Vold-Kalman filtering have undesirable traits. Each method has two or more of the following deficiencies: requires measurement or...Current methods of order tracking, such as synchronous resampling, Gabor filtering, and Vold-Kalman filtering have undesirable traits. Each method has two or more of the following deficiencies: requires measurement or estimate of rotational speed over time, failure to isolate the contribution of crossing orders in the vicinity of the crossing time, large computational expense, end effects. In this work a new approach to the order tracking problem is taken. The Second Order Blind Identification (SOBI) algorithm is applied to synthesized data. The technique is shown to be very successful at isolating crossing orders and circumvents all of the above deficiencies. The method has its own restric-tions: multiple sensors are required and sensors must be mounted on a structure that responds quasi-statically to exci-tation of the rotational system.展开更多
In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival ...In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival (DOA) tracking algorithms. On the other hand, although the DOA estimation methods based on the Maximum Likelihood (ML) principle have higher resolution than the beamforming and the subspace based methods, prohibitively heavy computation limits their practical applications. This letter first proposes a new suboptimal DOA estimation algorithm that combines the advantages of the lower complexity of subspace algorithm and the high accuracy of ML based algo- rithms, and then proposes a Kalman filtering based tracking algorithm to model the dynamic property of directional changes for mobile terminals in such a way that the association between the estimates made at different time points is maintained. At each stage during tracking process, the current suboptimal estimates of DOA are treated as measurements, predicted and updated via a Kalman state equation, hence adaptive tracking of moving MS can be carried out without the need to perform unduly heavy computations. Computer simulation results show that this proposed algorithm has better per- formance of DOA estimation and tracking of MS than the conventional ML or subspace based algo- rithms in terms of accuracy and robustness.展开更多
The pharmaco-dynamic action of plant-derived drugs still remains a big challenge in the field of pharmacology. This applies especially for the discovering of the possible mechanism of action. With respect to the brain...The pharmaco-dynamic action of plant-derived drugs still remains a big challenge in the field of pharmacology. This applies especially for the discovering of the possible mechanism of action. With respect to the brain, surrogate parameters may be very helpful. Non-invasive pharmaco-EEG has been proven to provide valid information on drug effects in general. Fast dynamic EEG recording with epoch length of 364 ms has now been achieved in combination with Eye-Tracking in order to elucidate single scenes during cognitive and emotional challenges (EnkephaloVision). The present investigation deals with the psychophysiological characterization of the effect of a plant-derived preparation marketed in Germany under the name of PASCOFLAIR® containing 425 mg of passionflower extract in subjects suffering from examination anxiety. Forty healthy volunteer subjects (17 men and 23 woman), with ages varying between 18 and 40 years (26 ± 6.726 for men and 25 ± 5.397 for women) were included into the study when having a score higher than 60 in the PAF (PrÜfungsangstfragebogen). Spectral power analysis of pre-drug data with respect to beta waves revealed a significant correlation to the score of the PAF. Increases of delta, theta and beta waves as induced by 4 cognitive and 4 emotional challenges were attenuated in the presence of 2 tablets of PASCOFLAIR® already 45 minutes after intake in a statistically significant manner in comparison to placebo. Regarding attenuation of beta1 and beta2 spectral power, effects on glutamatergic and GABAergic neurotransmission, respectively, can be suspected according to our knowledge of frequency—transmitter relations. Accordingly, this attenuation must be interpreted as ability to counteract examination induced stress symptoms. Results confirm and extend earlier experimental data showing a calming action of PASCOFLAIR®.展开更多
基金supported by the NFSC Grants 51375385 and 51675425Natural Science Basic Research Plan in Shaanxi Province of China Grants 2016JZ013
文摘Tracking moving wideband sound sources is one of the most challenging issues in the acoustic array signal processing which is based on the direction of arrival(DOA) estimation. Compressive sensing(CS) is a recent theory exploring the signal sparsity representation, which has been proved to be superior for the DOA estimation. However, the spatial aliasing and the offset at endfire are the main obstacles for CS applied in the wideband DOA estimation. We propose a particle filter based compressive sensing method for tracking moving wideband sound sources. First, the initial DOA estimates are obtained by wideband CS algorithms. Then, the real sources are approximated by a set of particles with different weights assigned. The kernel density estimator is used as the likelihood function of particle filter. We present the results for both uniform and random linear array. Simulation results show that the spatial aliasing is disappeared and the offset at endfire is reduced. We show that the proposed method can achieve satisfactory tracking performance regardless of using uniform or random linear array.
基金Supported by the Ministry of Science and Technology of Inner Mongolia, China (20110504)
文摘Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.
基金Supported by the National Natural Science Foundation of China(Nos.31670465,31370504)
文摘The presence of feacal-derived pathogens in water is responsible for several infectious diseases and deaths worldwide. As a solution, sources of fecal pollution in waters must be accurately assessed, properly determined and strictly controlled. However, the exercise has remained challenging due to the existing overlapping characteristics by different members of faecal coliform bacteria and the inadequacy of information pertaining to the contribution of seasonality and weather condition on tracking the possible sources of pollution. There are continued ef forts to improve the Faecal Contamination Source Tracking(FCST) techniques such as Microbial Source Tracking(MST). This study aimed to make contribution to MST by evaluating the efficacy of combining site specific quantification of faecal contamination indicator bacteria and detection of DNA markers while accounting for seasonality and weather conditions' eff ects in tracking the major sources of faecal contamination in a freshwater system(Donghu Lake, China). The results showed that the use of cyd gene in addition to lacZ and uidA genes differentiates E. coli from other closely related faecal bacteria. The use of selective media increases the pollution source tracking accuracy. BSA addition boosts PCR detection and increases FCST efficiency. Seasonality and weather variability also influence the detection limit for DNA markers.
基金National Key Developing Program for Basic Sciences, No. G1999043505
文摘Sand-dust storm is a special natural disaster that frequently occurs in deserts and their surrounding areas. With the data published onSurface Meteorological Monthly Bulletin andSurface Chart during 1971–1996, the temporal-spatial distribution and annual variation of sand-dust storms are analyzed on the basis of the case study of atmospheric processes. Furthermore, the tracks and source areas of sand-dust storms are determined with the aid of GIS. The results show that except some parts of Qinghai Province and Inner Mongolia as well as Beijing, sand-dust storms decrease apparently in time and space in recent decades in China. Sand-dust storms occur most frequently in spring, especially in April. According to their source areas, sand-dust storms are classified into two types, i.e., the inner-source and outer-source sand-dust storms. Most of the outer-source sand-dust storms move along the north and west tracks. The north-track outer-source sand-dust storms always intrude into China across the Sino-Mongolian border from Hami, a city in the eastern part ofXinjiang, to Xilin Gol, a league in Inner Mongolia, while the west-track ones intrude into China from both southern and northern Xinjiang. The source lands of inner-source sand-dust storms concentrate in the Taklimakan Desert and its surrounding areas in southern Xinjiang, southern part of the Junggar Basin in north of Xinjiang, the Hexi Corridor in western Gansu Province, the dry deserts of Inner Mongolia and the Qaidam Basin in Qinghai.
基金The National Natural Science Foundation of China provided funding for this project(U19A2047).
文摘●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the tracking results can achieve high precision.●Dryland was the main source of sediment deposition based on the result of FEAST.Sediment source tracing can accurately provide a theoretical basis for controlling soil erosion effectively,by identifying the most serious types of land use.Traditional sediment tracing methods are based on physical,chemical,biological,and composite fingerprinting,which have not included microbes.As high-throughput sequencing becomes more prevalent,microorganisms can provide more information than what we think.Thus,whether the microorganism can also be used as a special fingerprint factor for sediment source identification during soil erosion,we have tested it by using microbial source tracking tool FEAST to quantify the microbe contribution from five types of eroded land(including dryland,urban,paddy field,forest and grassland)to the depositional areas(Niubitan)in the Yuanjiang basin.The source microbial community in the erosive area was heterogeneous,and assembly process analysis further demonstrated that the source tracking results could reach higher accuracy.The results of FEAST showed that dryland(35.50%),urban(17.21%),paddy field(8.14%),and forest(1.07%)were the major contributors to Niubitan.Our results follow the general soil erosion rules and prove its validity.Taken together,a new perspective is provided by these results for tracing sediment sources in erosion-sedimentary systems.
文摘Three tributaries of the Grand River watershed (Ontario, Canada), each representing different watershed types (urban, agricultural/rural, and mixed land-use) were examined to understand the spatial, temporal, and host-source distribution of the waterborne pathogen, Cryptosporidium. Cryptosporidium was frequently found throughout the study (73%, 65/89) with occurrence and concentrations observed to be similar among the varying watershed types. However, applying advanced genotyping techniques, marked differences in dominant host sources could be observed in each watershed. The agricultural/rural and mixed land-use watersheds were dominated by genotypes typically associated with cattle (i.e., C. andersoni), while the urban watershed had the highest diversity of Cryptosporidium genotypes with a variety of wildlife as the common source of contamination (e.g., muskrat and cervine genotypes). A similar seasonal trend observed in the urban, agricultural, and mixed land-use watershed suggests that factors beyond specific land use activities (e.g. autumn manure spreading) may influence the timing and concentration of Cryptosporidium in these streams. Corresponding genotyping results provided additional insight into source inputs during these seasonal peaks, indicating that wildlife may be important seasonal contributors to Cryptosporidium contamination in these streams. Despite the abundance of Cryptosporidium in these watersheds, most of the genotypes observed were of limited human health importance. This study provides evidence regarding the significance of including genotyping results into studies examining waterborne Cryptosporidium. Using this technique can provide a greater understanding of the risk to the population using water sources, as well as provide insight into the probable sources and timing of contamination. This ancillary information can contribute to implementation of targeted management strategies to further protect sources of drinking water and recreation areas.
文摘Project Trackdown is an investigative environmental program aimed at tracking sources of polychlorinated biphenyl (PCB) contamination in Great Lakes tributaries. The program uses a multimedia weight of evidence approach for identifying sources of PCBs to the environment. PCB concentrations in environmental media (sediment, water, suspended sediment and soil), passive samplers and/or exposed biota (mussels, young-of-the-year fish and benthic invertebrates) are used in combination to evaluate bioavailability and identify local anomalies within a tributary. These lines of evidence can be assessed with simple chemometric techniques and fingerprinting of PCB congener profiles, and, combined with anecdotal information such as land use history and tributary alterations, may be used to identify ongoing and locally controllable sources of PCBs to the Great Lakes. The program was successful at developing environmental triggers to differentiate potential source areas from background PCB conditions in urban areas, allowing efforts to focus on identifying active ongoing sources of PCB contamination. Project Trackdown has been carried out in three tributaries to Lake Ontario (Cataraqui River, Etobicoke Creek and Twelve Mile Creek) and two tributaries that flow into the Detroit River (Turkey Creek and Little River). Local ongoing PCB sources have been identified in four projects, leading to abatement or remediation measures. As a collaborative initiative between the Ontario Ministry of the Environment and Environment Canada, Project Trackdown has successfully identified several PCB sources leading to substantial cleanup efforts aimed ultimately at reducing PCB contamination to the Great Lakes.
文摘Current methods of order tracking, such as synchronous resampling, Gabor filtering, and Vold-Kalman filtering have undesirable traits. Each method has two or more of the following deficiencies: requires measurement or estimate of rotational speed over time, failure to isolate the contribution of crossing orders in the vicinity of the crossing time, large computational expense, end effects. In this work a new approach to the order tracking problem is taken. The Second Order Blind Identification (SOBI) algorithm is applied to synthesized data. The technique is shown to be very successful at isolating crossing orders and circumvents all of the above deficiencies. The method has its own restric-tions: multiple sensors are required and sensors must be mounted on a structure that responds quasi-statically to exci-tation of the rotational system.
文摘In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival (DOA) tracking algorithms. On the other hand, although the DOA estimation methods based on the Maximum Likelihood (ML) principle have higher resolution than the beamforming and the subspace based methods, prohibitively heavy computation limits their practical applications. This letter first proposes a new suboptimal DOA estimation algorithm that combines the advantages of the lower complexity of subspace algorithm and the high accuracy of ML based algo- rithms, and then proposes a Kalman filtering based tracking algorithm to model the dynamic property of directional changes for mobile terminals in such a way that the association between the estimates made at different time points is maintained. At each stage during tracking process, the current suboptimal estimates of DOA are treated as measurements, predicted and updated via a Kalman state equation, hence adaptive tracking of moving MS can be carried out without the need to perform unduly heavy computations. Computer simulation results show that this proposed algorithm has better per- formance of DOA estimation and tracking of MS than the conventional ML or subspace based algo- rithms in terms of accuracy and robustness.
文摘The pharmaco-dynamic action of plant-derived drugs still remains a big challenge in the field of pharmacology. This applies especially for the discovering of the possible mechanism of action. With respect to the brain, surrogate parameters may be very helpful. Non-invasive pharmaco-EEG has been proven to provide valid information on drug effects in general. Fast dynamic EEG recording with epoch length of 364 ms has now been achieved in combination with Eye-Tracking in order to elucidate single scenes during cognitive and emotional challenges (EnkephaloVision). The present investigation deals with the psychophysiological characterization of the effect of a plant-derived preparation marketed in Germany under the name of PASCOFLAIR® containing 425 mg of passionflower extract in subjects suffering from examination anxiety. Forty healthy volunteer subjects (17 men and 23 woman), with ages varying between 18 and 40 years (26 ± 6.726 for men and 25 ± 5.397 for women) were included into the study when having a score higher than 60 in the PAF (PrÜfungsangstfragebogen). Spectral power analysis of pre-drug data with respect to beta waves revealed a significant correlation to the score of the PAF. Increases of delta, theta and beta waves as induced by 4 cognitive and 4 emotional challenges were attenuated in the presence of 2 tablets of PASCOFLAIR® already 45 minutes after intake in a statistically significant manner in comparison to placebo. Regarding attenuation of beta1 and beta2 spectral power, effects on glutamatergic and GABAergic neurotransmission, respectively, can be suspected according to our knowledge of frequency—transmitter relations. Accordingly, this attenuation must be interpreted as ability to counteract examination induced stress symptoms. Results confirm and extend earlier experimental data showing a calming action of PASCOFLAIR®.
基金国家自然科学基金项目“青藏高原东南缘晚更新世以来地球关键带演化过程”(42361144879)“青藏高原及周缘新生代大陆风化沉积记录研究”(41991323)+4 种基金青藏高原第二次综合科学考察研究任务七“高原生长与演化”专题四“碰撞以来古地理格局与构造地貌过程”(2019QZKK0704)云南省科技领军人才项目“建设云南省地球系统科学重点实验室”(202005AB160008)云南省基础研究计划项目重点项目“滇西南晚更新世和平文化人类植物利用及环境适应性”(202301BF070001-005)兴滇英才支持计划“滇西史前人类植物资源利用及其环境适应性”Queensland-Chinese Academy of Sciences Collaborative Science Fund“Past Asian-Australian MonsoonVariability”(QCAS036,045GJHZ2023001MI)。