Assessment of scale interactions associated with wake meandering using bispectral analysis methodologies

Large atmospheric boundary layer fluctuations and smaller turbine-scale vorticity dynamics are separately hypothesized to initiate the wind turbine wake meandering phenomenon,a coherent,dynamic,turbine-scale oscillation of the far wake.Triadic interactions,the mechanism of energy transfers between scales,manifest as triples of wavenumbers or frequencies and can be characterized through bispectral analyses.The bispectrum,which correlates the two frequencies to their sum,is calculated by two recently developed multi-dimensional modal decomposition methods:scale-specific energy transfer method and bispectral mode decomposition.Large-eddy simulation of a utility-scale wind turbine in an atmospheric boundary layer with a broad range of large length-scales is used to acquire instantaneous velocity snapshots.The bispectrum from both methods identifies prominent upwind and wake meandering interactions that create a broad range of energy scales including the wake meandering scale.The coherent kinetic energy associated with the interactions shows strong correlation between upwind scales and wake meandering.

A Novel Multi-Stage Bispectral Deep Learning Method for Protein Family Classification

Complex proteins are needed for many biological activities.Folding amino acid chains reveals their properties and functions.They support healthy tissue structure,physiology,and homeostasis.Precision medicine and treatments require quantitative protein identification and function.Despite technical advances and protein sequence data exploration,bioinformatics’“basic structure”problem—the automatic deduction of a protein’s properties from its amino acid sequence—remains unsolved.Protein function inference from amino acid sequences is the main biological data challenge.This study analyzes whether raw sequencing can characterize biological facts.A massive corpus of protein sequences and the Globin-like superfamily’s related protein families generate a solid vector representation.A coding technique for each sequence in each family was devised using two representations to identify each amino acid precisely.A bispectral analysis converts encoded protein numerical sequences into images for better protein sequence and family discrimination.Training and validation employed 70%of the dataset,while 30%was used for testing.This paper examined the performance of multistage deep learning models for differentiating between sixteen protein families after encoding and representing each encoded sequence by a higher spectral representation image(Bispectrum).Cascading minimized false positive and negative cases in all phases.The initial stage focused on two classes(six groups and ten groups).The subsequent stages focused on the few classes almost accurately separated in the first stage and decreased the overlapping cases between families that appeared in single-stage deep learning classification.The single-stage technique had 64.2%+/-22.8%accuracy,63.3%+/-17.1%precision,and a 63.2%+/19.4%F1-score.The two-stage technique yielded 92.2%+/-4.9%accuracy,92.7%+/-7.0%precision,and a 92.3%+/-5.0%F1-score.This work provides balanced,reliable,and precise forecasts for all families in all measures.It ensured that the new model was resilient to family variances and provided high-scoring results.

An Innovative Bispectral Deep Learning Method for Protein Family Classification

Proteins are essential for many biological functions.For example,folding amino acid chains reveals their functionalities by maintaining tissue structure,physiology,and homeostasis.Note that quantifiable protein characteristics are vital for improving therapies and precision medicine.The automatic inference of a protein’s properties from its amino acid sequence is called“basic structure”.Nevertheless,it remains a critical unsolved challenge in bioinformatics,although with recent technological advances and the investigation of protein sequence data.Inferring protein function from amino acid sequences is crucial in biology.This study considers using raw sequencing to explain biological facts using a large corpus of protein sequences and the Globin-like superfamily to generate a vector representation.The power of two representations was used to identify each amino acid,and a coding technique was established for each sequence family.Subsequently,the encoded protein numerical sequences are transformed into an image using bispectral analysis to identify essential characteristics for discriminating between protein sequences and their families.A deep Convolutional Neural Network(CNN)classifies the resulting images and developed non-normalized and normalized encoding techniques.Initially,the dataset was split 70/30 for training and testing.Correspondingly,the dataset was utilized for 70%training,15%validation,and 15%testing.The suggested methods are evaluated using accuracy,precision,and recall.The non-normalized method had 70%accuracy,72%precision,and 71%recall.68%accuracy,67%precision,and 67%recall after validation.Meanwhile,the normalized approach without validation had 92.4%accuracy,94.3%precision,and 91.1%recall.Validation showed 90%accuracy,91.2%precision,and 89.7%recall.Note that both algorithms outperform the rest.The paper presents that bispectrum-based nonlinear analysis using deep learning models outperforms standard machine learning methods and other deep learning methods based on convolutional architecture.They offered the best inference performance as the proposed approach improves categorization and prediction.Several instances show successful multi-class prediction in molecular biology’s massive data.

Neuroprotective effect of bispectral index-guided fast-track anesthesia using sevoflurane combined with dexmedetomidine for intracranial aneurysm embolization

Dexmedetomidine has sedative, anxiolytic, analgesic, anti-sympathetic, and anti-shivering effects. Dexmedetomidine might be effective in combination with sevoflurane for anesthesia, but prospective randomized controlled clinical trials with which to verify this hypothesis are lacking. In total, 120 patients who underwent embolization of an intracranial aneurysm were recruited from Anhui Provincial Hospital and Renmin Hospital of Wuhan University of China and randomly allocated to two groups. After intraoperative administration of 2% to 3% sevoflurane inhalation, one group of patients received pump-controlled intravenous injection of 1.0 ~tg/kg dexmedetomidine for 15 minutes followed by maintenance with 0.3 ~tg/kg/h until the end of surgery; the other group of patients only underwent pump-controlled infusion of saline. Bispectral index monitoring revealed that dexmedetomidine-assisted anesthesia can shorten the recovery time of spon- taneous breathing, time to eye opening, and time to laryngeal mask removal. Before anesthetic induction and immediately after laryngeal mask airway removal, the glucose and lactate levels were low, the S100~ and neuron-specific enolase levels were low, the perioperative blood pressure and heart rate were stable, and postoperative delirium was minimal. These findings indicate that dexmedetomidine can effectively assist sevoflurane for anesthesia during surgical embolization of intracranial aneurysms, shorten the time to consciousness and extubation, reduce the stress response and energy metabolism, stabilize hemodynamic parameters, and reduce adverse reactions, thereby reducing the damage to the central nervous system. This trial was registered at the Chinese Clinical Trial Registry （http：//www.chictr.org. cn/） （registration number： ChiCTR-IPR- 16008113）.

Bispectral index in predicting the prognosis of patients with coma in intensive care unit

BACKGROUND: The bispectral(BIS) index is a processed electroencephalogram(EEG) parameter with extensive validation and demonstrated clinical utility. The study aimed to investigate the correlation between the BIS index and the prognosis of patients with coma in the ICU.METHODS: A total of 208 patients with coma in the ICU were enrolled in this study. According to the BIS value, the patients were divided into four groups: group I, BIS value 0 to 20; group II, BIS value 21 to 40; group III, BIS value 41 to 60; and group IV, BIS value greater than 60. The difference in BIS values with the differences in prognosis of patients with coma was compared between the four groups, and the prognosis of patients with coma was stratified into consciousness, coma, vegetative state, and brain death. Subsequently, the best cut-off score of BIS values calculated for determining the correlation between BIS value and mental state was proposed.RESULTS: There are no significant differences in the age and APACHE II scores between the four groups(P>0.05). An inverse correlation was observed between BIS value and mental state(r= –0.749, P=0.00). According to the ROC curve, as BIS value was greater than 42.5, there were higher sensitivity and specificity in conscious-coma patients.CONCLUSION: BIS value is correlated with the prognosis of patients with coma in ICU, and BIS value can be a useful marker for estimating the prognosis of comatose patients.

Efficacy of Bispectral index-monitored closed-loop targeted-controlled infusion of propofol for laparoscopic radical operation for gastric cancer

Objective:To discuss the efficacy of Bispectral index (BIS)-monitored closed-loop targeted-controlled infusion of propofol for laparoscopic radical operation for gastric cancer.Methods:A total of 106 patients with primary gastric cancer who underwent laparoscopic radical operation for gastric cancer in our hospital between August 2015 and February 2018 were chosen as the research subjects and divided into the control group (n=53) and the observation group (n=53) according to the different anesthesia methods. Control group of patients received BIS-monitored manually adjusted targeted-controlled infusion concentration of propofol, and observation group of patients received BIS-monitored closed-loop targeted-controlled infusion of propofol. The differences in hemodynamic index levels as well as serum contents of inflammatory factors and stress hormones were compared between the two groups of patients before anesthesia (T0), 30 min after surgery started (T1) and 30 min before surgery ended (T2).Results:At T0, the differences in hemodynamic index levels as well as serum contents of inflammatory factors and stress hormones were not statistically significant between the two groups. At T1 and T2, hemodynamic indexes MAP and HR levels of observation group were lower than those of control group at the corresponding time points;serum inflammatory factors sICAM-1, IL-1β, IL-8 and TNF-α contents were lower than those of control group at the corresponding time points;serum stress hormones Cor, T4 and glucagon contents were lower than those of control group at the corresponding time points.Conclusion: BIS-monitored closed-loop targeted-controlled infusion of propofol can effectively stabilize the intraoperative hemodynamics and inhibit the systemic inflammatory stress response in patients with laparoscopic radical operation for gastric cancer.

A NEW METHOD OF BISPECTRAL ESTIMATION FOR TRANSIENT SIGNAL

Estimation of model parameter for transient signal is very important in many aspects. This paper presents a new Markov ARMA model Q-slice estimation algorithm for transient signal based on bispectrum. Simulation results show that this new method has some special features, such as higher estimation precision, lower amount of calculation, higher fitting effect even in lower signal-to-noise ratio (SNR) situation.

Man-Computer Interactive Method on Cloud Classification Based on Bispectral Satellite Imagery

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Comparison of Entropy vs. Bispectral Index Anesthetic Depth Monitoring during Isoflurane Anesthesia in Living Donor Liver Transplantation: Observational Study

Liver transplantation (LT) recipients are known to require less anesthetic agents. Providing minimally required anesthetics while avoiding awareness is especially important in LT recipients because it would help manage perioperative hemodynamic instability with less vasopressor and fast track recovery. This study aims to compare state entropy (SE) against bispectral index (BIS) during isoflurane anesthesia in LT. We adjusted anesthesia to BIS values 40 - 60, and compared it with concomitant SE values. BIS, SE values, and anesthetic requirements according to liver failure severity, etiology and LT stages were analyzed. For BIS-SE differences, SE value that is different from the concomitant BIS by more than 15 was defined as a significant disagreement. Mann Whitney, Kruskal Wallis test and a Poisson exact test were used for analysis. The BIS-SE pair sets of 2895 from 38 patients were analyzed. BIS, SE values and anesthetic requirements were significantly lower in MELD ≥ 20 (p < 0.001 in all) and in alcoholic etiology (p < 0.001 in all). For BIS-SE differences, 320 disagreement data pairs were seen at a rate of 1.33 times/hr (95% CI = [1.19, 1.48], p < 0.001). A significant disagreement was delineated in MELD score ≥ 20 (3.04 times/hr, CI = [2.64, 3.49], p < 0.001), alcoholic etiology (3.19 times/hr, [2.67, 3.78], p < 0.001) and postreperfusion stage (1.63 times/hr, [1.43, 1.85], p < 0.001). In these significant BIS-SE differences, 95.9% (307/320 disagreement data pairs) showed higher BIS than SE. In conclusion, in high MELD and alcoholic etiology, anesthetic requirements were significantly less, and BIS and SE showed great discrepancy with lower SE values. Therefore, when SE monitoring is used during LT, anesthesiologists may need to consider that in high MELD and alcoholic etiology, SE tends to show lower values than the concomitant BIS values that are within optimal anesthetic depth ranges.

The Bispectral Index Interest during General Anesthesia at the University Hospital of Parakou (Republic of Benin) in 2019

Background: The bispectral index (BIS) derived from the electroencephalogram is an additional means of monitoring the depth of narcosis. Objective: To compare the monitoring of the depth of narcosis by the BIS associated with clinical data versus standard monitoring at the University Hospital of Parakou in Benin in 2019. Methods: This was an observational study for descriptive and analytical purposes with prospective data collection, carried out in general surgery and intensive care unit for 4 months. The inclusion criteria were: an age ≥ 18 years, an ASA score ≤ 3, surgery under general anesthesia and informed consent of the patient. Two groups were formed: non-BIS group monitored by clinical parameters (PA, FC, FR, EtCO2, and SpO2) only and BIS group monitored by bispectral index in addition to clinical parameters. Patients were seen 48 hours after the procedure. Results: 36 patients were collected. The mean age was 40.63 ± 16.77 years with a sex ratio of 3. ASA 1 patients represented 86.11% of the sample and ASA2 patients 13.89%. The average doses of Propofol were not significantly reduced in the BIS group (p = 0.555). On the other hand, the period of intraoperative recovery (p-value = 0.007) and the NVPO (p = 0.043;OR = 0.10;95% CI [0.01 - 0.97]) were significantly reduced by the use of BIS. One case of intraoperative memorization (2.78%) was however found in the BIS group. Conclusion: The bispectral index makes it possible to significantly reduce the risk of intraoperative awakening and PONV, and not significantly reduce the consumption of Propofol.

Analysis of the Precision of Bispectral Estimation Methods

In order to evaluate the accuracy of bispectral estimation method, signals of cosine function were adopted. Because the cosine signals’ three order moment spectrum and three order cumulant spectrum are zero, Non zero part of the bispectrum estimated by no matter which method is the estimation error. Through the comparison of three kinds of estimation methods: the direct method, indirect method and AR parameter method, errors of various estimation methods were obtained, then changing the values of different parameters in all methods, and observing the bispectral error values changes with the parameters, so as to provide a basis for the various bispectrum estimation method and the selection.

Bispectral index monitoring prevent awareness during total intravenous anesthesia： a prospective, randomized, double-blinded, multi-center controlled trial

Background Awareness is a serious complication of general anesthesia. In China, the incidence of intraoperative awareness was 1% in patients undergoing total intravenous anesthesia （TIVA）. In this study, we compared the incidence of awareness between Bispectral index （BIS）-guided and routine TIVA protocol and evaluated the effect of BIS on preventing awareness. Methods A prospective, randomized, double-blinded, multicenter controlled trial was performed. Patients （〉18 years of age） undergoing TIVA were randomly divided into BIS-guided group （Group A, BIS was monitored and recommended to maintain between 40-60） and control group （Group B, BIS was monitored but the screen was covered）. The intraoperative BIS values were downloaded and the BIS trends of confirmed awareness cases were analyzed to determine whether light anesthesia existed. Results Of the total 5228 patients, 2919 patients were assigned to Group A and 2309 to Group B. Four cases of confirmed awareness （0.14%） were reported in the BIS-guided group and 15 （0.65%） in the control group （P=-0.002, OR=0.21, 95% confidence intervals： 0.07-0.63）. The incidence of possible awareness （0.14% vs. 0.26%, P=0.485） and dreaming （3.1% vs. 3.1%, P=0.986） was comparable between BIS-guided group and the control group. Among the 19 confirmed awareness cases, intraoperative BIS trends of six cases were downloaded and identified. Five of them showed signs of light anesthesia as BIS 〉60 and lasted 19-106 minutes, whereas one case had a stable BIS trend and the values were within 60 during the operation. Another five awareness cases were reviewed for anesthesia procedures, of which improper light anesthesia were confirmed. Conclusions BIS-guided TIVA （BIS was recommended to maintain between 40-60） decreased the risk of awareness compared with routine TIVA. The main reason for awareness was light anesthesia.

Comparison of C50 for Propofol-remifentanil Target-controlled Infusion and Bispectral Index at Loss of Consciousness and Response to Painful Stimulus in Elderly and Young Patients

Background：In this prospective randomized study,we compared the predicted blood and effect-site C50 for propofol and remifentanil target-controlled infusion （TCI） and the bispectral index （BIS） values at loss of consciousness （LOC） and response to a standard noxious painful stimulus （LOS） in elderly and young patients,respectively.We hypothesized that the elderly patients will require lower target concentration of both propofol and remifentanil at above two clinical end-points.Methods：There were 80 American Society of Anesthesiologists （ASA） physical status Ⅰ Ⅱ unpremedicated patients enrolled in this study,they were divided into elderly group （age ≥65 years,n =40） and young group （aged 18-54 years,n =40）.Propofol was initially given to a predicted blood concentration of 1.2 μg/ml and thereafter increased by 0.3 μg/ml every 30 s until Observer＇s Assessment of Alertness and Sedation score was 1.The propofol level was kept constant,and remifentanil was given to provide a predict blood concentration of 2.0 ng/ml,and then increased by 0.3 ng/ml every 30 s until loss of response to a tetanic stimulus.BIS （version 3.22,BIS Quattro sensor） was also recorded.Results：In elderly group,the propofol effect-site C50 at LOC of was 1.5 （1.4-1.6） μg/ml,was significantly lower than that of young group,which was 2.2 （2.1-2.3） μg/ml,the remifentanil effect-site C50 at LOS was 3.5 （3.3-3.7） ng/ml in elderly patients,was similar with 3.7 （3.6-3.8） ng/ml in young patients.Fifty percent of patients lost consciousness at a BIS value of 57.3 （56.4-58.1）,was similar with that of young group,which was 55.2 （54.0-56.3）.Conclusion：In elderly patients,the predicted blood and effect-site concentrations of propofol at LOC were lower than that of young patients.At same sedation status,predicted blood and effect-site concentrations of remifentanil required at LOS were similar in elderly and young patients.BIS were not affected by age.Low-propofol/high-opioid may be optional TCI strategy for elderly patients.

Comparison of the ability of wavelet index and bispectral index for reflecting regain of consciousness in patients undergone surgery

Background Wavelet index （WLI） is a new parameter for monitoring depth of anesthesia based on Wavelet analysis. We observed the change of WLI and bispectral index （BIS） in patients regain of consciousness （ROC） in the absence of frontalis electromyographic （EMG） interference. The aim of this study was to compare the ability of WLI and BIS for reflecting ROC in patients undergone surgery. Methods Twelve patients who were scheduled for maxillofacial surgeries were enrolled in the study. BIS and WLI values were monitored continually. After being given midazolam and remifentanil, patients were asked to squeeze the investigator＇s hand ever 30 seconds. Patients were continuously given propofol until loss of consciousness （LOC1）. Tunstalrs isolated forearm technique was used to test the surgical consciousness in patients. After total muscle relaxation endotracheal intubations were performed, and the patients were connected to a ventilator. Then, propofol was withdrawn until the patients showed regain of consciousness （ROC1） and an awareness reaction. After the command test, patients were readministered with propofol until loss of consciousness （LOC2）. After surgery, all of the sedatives were withdrawn, and the patients were let to regain consciousness （ROC2）, Results The BIS values of twelve patients at ROC1 after using muscle relaxant were much lower than those at LOC1 and ROC2 without using muscle relaxant, showing statistical significance （P 〈0.05）. Meanwhile, the WLI values of twelve patients at ROC1 after using muscle relaxant were much higher than those at LOC1 and equal to ROC2 without using muscle relaxant, showing statistical significances （P 〈0.05） between ROC1 and LOCI. Conclusions This study showed that under muscle relaxation or facial paralysis, when there is no EMG signal, BIS can not accurately reflect regain of consciousness in surgical patients, but WLI can reflect it accurately. So WLI may have advantages for reflecting state of consciousness in surgical patients.

Changes in the Bispectral Index in Response to Loss of Consciousness and No Somatic Movement to Nociceptive Stimuli in Elderly Patients

Background： Bispectral index （BIS） is considered very useful to guide anesthesia care in elderly patients, but its use is controversial for the evaluation of the adequacy of analgesia.This study compared the BIS changes in response to loss of consciousness （LOC） and loss of somatic response （LOS） to nociceptive stimuli between elderly and young patients receiving intravenous target-controlled infusion （TCI） of propofol and remifentanil.Methods： This study was performed on 52 elderly patients （aged 65-78 years） and 52 young patients （aged 25-58 years）, American Society of Anesthesiologists physical status Ⅰ or Ⅱ.Anesthesia was induced with propofol administered by TCI.A standardized noxious electrical stimulus （transcutaneous electrical nerve stimulation, [TENS]） was applied （50 Hz, 80 mA, 0.25 ms pulses for 4 s） to the ulnar nerve at increasing remifentanil predicted effective-site concentration （Ce） until patients lost somatic response to TENS.Changes in awake, prestimulus, poststimulus BIS, heart rate, mean arterial pressure, pulse oxygen saturation, predicted plasma concentration, Ce of propofol, and remifentanil at both LOC and LOS clinical points were investigated.Results： BISLOC in elderly group was higher than that in young patient group （65.4 ＆#177; 9.7 vs.57.6 ＆#177; 12.3） （t =21.58, P 〈 0.0001） after TCI propofol, and the propofol Ce at LOC was 1.6 ＆#177; 0.3 μg/ml in elderly patients, which was significantly lower than that in young patients （2.3 ＆#177; 0.5 μg/ml） （t =7.474, P 〈 0.0001）.As nociceptive stimulation induced BIS to increase, the mean of BIS maximum values after TENS was significantly higher than that before TENS in both age groups （t =8.902 and t =8.019, P 〈 0.0001）.With increasing Ce of remifentanil until patients lost somatic response to TENS, BISLOS was the same as the BISLOC in elderly patients （65.6 ＆#177; 10.7 vs.65.4 ＆#177; 9.7）, and there were no marked differences between elderly and young patient groups in BISawake, BISLOS, and Ce of remifentanil required for LOS.Conclusion： In elderly patients, BIS can be used as an indicator for hypnotic-analgesic balance and be helpful to guide the optimal administration of propofol and remifentanil individually.

Evaluation of entropy for monitoring the depth of anesthesia ：ompared with bispectral index： a multicenter clinical trial

Background As a new electroencephalogram （EEG） signal processing technique for monitoring the depth of anesthesia, entropy consists of two indices： reaction entropy （RE） and state entropy （SE）. Our study compared entropy with classical bispectral index （BIS） in reduction of myoelectrical interference and noxious stimuli with EEG signals. Methods Two hundred and eighty patients （ASA I-II, 18-60 years old） undergoing scheduled surgeries from seven medical centers were enrolled. Anesthesia induction was managed with propofol via the target-controlled infusion （TCI） system. The results of BIS, RE, SE, mean arterial pressure （MAP） and heart rate （HR） were recorded before anesthesia induction, at the moment of unconsciousness, before and 2 minutes after administration of muscle relaxant, and before and one and three minutes after the tracheal intubation. Results The values of half maximum effective concentrations （EC50）, 5% effective concentrations （EC05） and 95% effective concentrations （EC95） of propofol effect-site concentration at the onset of unconsciousness were 1.2 （1.1-1.3 μg/ml）, 2.5 （2.4-2.5 μg/ml） and 3.7 （3.7-3.8 μg/ml）, while those of the predicted plasma propofol concentration were 2.8 （2.7-2.9 μg/ml）, 3.9 （3.8-3.9 μg/ml） and 4.9 （4.8-5.0μg/ml）, respectively. The values of BIS, SE and RE were 62, 59 and 63 when 50% of patients lost consciousness, and 79, 80, 85 and 42, 37, 44, respectively, when 5% and 95% of patients were unconscious. The values of BIS, RE and SE dropped two minutes after the injection of muscle relaxant, but there were no significant differences between RE and SE. MAP and HR increased visibly, which indicated a reaction to tracheal intubation; the values of BIS, RE and SE, however, did not display any significant changes. Conclusions This large-sample multicentric study confirmed the values of RE and SE as approximating BIS value, at the onset of unconsciousness during propofol TCI anesthesia. After elimination of myoelectrical activation, all values of RE, SE and BIS decreased significantly and the three indices were less sensitive to noxious stimuli than cardiovascular responses.

IMPROVED MAN-COMPUTER INTERACTIVE CLASSIFICATION OF CLOUDS BASED ON BISPECTRAL SATELLITE IMAGERY

In this paper,improvement on man-computer interactive classification of clouds based on hispeetral satellite imagery has been synthesized by using the maximum likelihood automatic clustering(MLAC)and the unit feature space classification(UFSC)approaches.The improved classification not only shortens the time of sample-training in UFSC method,but also eliminates the inevitable shortcomings of the MLAC method.(e.g.,1.sample selecting and training is confined only to one cloud image:2.the result of clustering is pretty sensitive to the selection of initial cluster center:3.the actual classification basically can not satisfy the supposition of normal distribution required by MLAC method;4.errors in classification are difficult to be modified.) Moreover,it makes full use of the professionals'accumulated knowledge and experience of visual cloud classifications and the cloud report of ground observation,having ensured both the higher accuracy of classification and its wide application as well.

Cloud Parameters Retrieved by the Bispectral Reflectance Algorithm and Associated Applications

Retrieval of cloud parameters is fundamental for descriptions of the cloud process in weather and cloud models, and is also the base for theoretical and applicational investigations on weather modification, aerosol- cloud-precipitation interaction, cloud-radiative climate effects, and so on. However, it is still difficult to ob- rain full information of cloud parameters over a wide area under the current level of science and technology. Luckily, parameters at the top of clouds can be retrieved with the satellite spectrum remote sensing, which is useful in obtaining global cloud properties. In this paper, cloud parameters retrieved by the bispectral reflectance （BSR） method and other methods developed on the basis of the BSR are briefly summarized. Recent advances in studies on the indirect effects of aerosol on cloud parameters are reviewed. The rela- tionships among cloud parameters and precipitation intensity, type, and structure are elaborated on, based upon the pixel-level merged datasets derived from daily measurements of precipitation radar and visible and infrared scanner, together with cloud parameters retrieved by the BSR. It is revealed that cloud particle effective radius and liquid water path near cloud tops are effective to identify the thickness and intensity of convective precipitating clouds. Furthermore, the differences in cloud parameters and precipitation intensity for precipitating and non-precipitating clouds over land and ocean are compared in this paper.

The analysis of heart sounds by using bispectral technique

An advanced signal processing technique, higher-order spectra, is proposed to in vestigate the nonlinear coupling phenomena of the heart sounds. To extract more higher-order information of the heart sounds, a non-Gaussian AR model is selected for parametric bispectral estimation in analyzing several kinds of heart sounds. The non-Gaussian AR model of the sound signals is llsed to detect quadratic nonlinear interactions and to classify two patterns of heart sounds in terms of the parametric bispectral estimate. The bispectral cross-correlation is employed to the order determination of the model. Several real heart sound data are imple mented to show that the quadratic nonlinearity exist in both normal and clinical heart sounds.It was found that bispectral techniques are effective and useful tools in analyzing heart sounds and other acoustical signals

BIS Monitoring on Intraoperative Awareness： A Meta-analysis

Intraoperative awareness is a very serious complication of general anesthesia. Several studies have evaluated the potential association between bispectral index （BIS） and intraoperative awareness, however, the results obtained were controversial. Therefore, we performed a metaanalysis to further assess the association between the BIS monitoring and the incidence of intraoperative awareness. A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to Feb. 2017. A total of five studies with 17 432 cases and 16 749 controls were included. An odds ratio （OR） and a 95% confidence interval （CI） were calculated to examine the strength of the association. The results showed that in the overall analysis, the association between the BIS monitoring and the incidence of intraoperative awareness was not significant （OR=0.58, 95% CI= 0.22-1.58, P=0.29）. A stratified analysis by comparing different anesthesia methods revealed that BIS monitoring group showed a lower incidence of intraoperative awareness in patients with intravenous anesthesia when compared with non-BIS monitoring group （OR=0.20, 95% CI=0.08-0.49, P=-0.0004）, whereas there was no statistically significant difference in the incidence of intraoperative awareness between BIS and non-BIS monitoring groups in patients with inhalation anesthesia （OR=1. 13, 95% CI=0.56- 2.26, P=-0.73）. In conclusion, our meta-analysis showed that BIS monitoring had no appreciable advantage in the reduction of the intraoperative awareness incidence in inhalation anesthesia, while showed a remarkable superiority in intravenous anesthesia.