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The reliability of morphometric discriminant functions in determining the sex of Chilean flamingos Phoenicopterus chilensis
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作者 Diego MONTALTI Maricel GRA A GRILLI +1 位作者 René E. MARAGLIANO Guillermo CASSINI 《Current Zoology》 SCIE CAS CSCD 2012年第6期851-855,共5页
Monomorphic birds cannot be sexed visually and discriminant functions on the basis of external morphological variations are frequently used. Our objective was to evaluate the reliability of sex classification function... Monomorphic birds cannot be sexed visually and discriminant functions on the basis of external morphological variations are frequently used. Our objective was to evaluate the reliability of sex classification functions created from structural measurements of Chilean flamingos Phoenicopterus chilensis museum skins for the gender assignment of live birds. Five measurements were used to develop four discriminant functions: culmen, bill height and width, tarsus length and middle toe claw. The functions were tested on a sample of live flamingos from a zoo. The best classification for museum flamingos was given by a function using tarsus length, bill width and middle toe claw (97%). However, this function did not give the best classification for the zoo-based flamingos (81%) which had the best sex assignment by a function including measurements of tarsus, culmen and bill height and width (85%). This shows that a function giving good results in the sample from which it originated may not be as good when applied to another group of animals. Our study emphasizes the need for assessing the accuracy of a function by testing it with other methods to ensure its suitability when being applied . 展开更多
关键词 MORPHOMETRICS discriminant function Sexual dimorphism Sex classification
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Correct Classification Rates in Multi-Category Discriminant Analysis of Spatial Gaussian Data 被引量:1
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作者 Lina Dreiziene Kestutis Ducinskas Laura Paulioniene 《Open Journal of Statistics》 2015年第1期21-26,共6页
This paper discusses the problem of classifying a multivariate Gaussian random field observation into one of the several categories specified by different parametric mean models. Investigation is conducted on the clas... This paper discusses the problem of classifying a multivariate Gaussian random field observation into one of the several categories specified by different parametric mean models. Investigation is conducted on the classifier based on plug-in Bayes classification rule (PBCR) formed by replacing unknown parameters in Bayes classification rule (BCR) with category parameters estimators. This is the extension of the previous one from the two category cases to the multi-category case. The novel closed-form expressions for the Bayes classification probability and actual correct classification rate associated with PBCR are derived. These correct classification rates are suggested as performance measures for the classifications procedure. An empirical study has been carried out to analyze the dependence of derived classification rates on category parameters. 展开更多
关键词 Gaussian Random Field Bayes Classification Rule Pairwise discriminant Function Actual Correct Classification Rate
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Predicting the non-breeding distributions of the two Asian subspecies of Black-tailed Godwit using morphological information
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作者 Bing-Run Zhu Mo A.Verhoeven +10 位作者 Chris J.Hassell Katherine K-S Leung Dmitry Dorofeev Qiang Ma Krairat Eiamampai Jonathan T.Coleman Uchrakhzaya Tserenbat Gankhuyag Purev-Ochir David Li Zhengwang Zhang Theunis Piersma 《Avian Research》 SCIE CSCD 2023年第1期1-6,共6页
Until recently,Limosa limosa melanuroides was thought to be the only subspecies of Black-tailed Godwit in the East Asian-Australasian Flyway.For this reason,all previous occurrences and counts of Black-tailed Godwits ... Until recently,Limosa limosa melanuroides was thought to be the only subspecies of Black-tailed Godwit in the East Asian-Australasian Flyway.For this reason,all previous occurrences and counts of Black-tailed Godwits in the flyway have been assigned to melanuroides.However,a larger-bodied subspecies,bohaii,has recently been discovered in the flyway.As a result,the occurrence of Black-tailed Godwits in the flyway needs to be reconsidered such that the specific distribution of each subspecies becomes known.To this end,we developed a simple discriminant function to assign individuals to subspecies based on their bill and wing length.Cross-validation with individuals known to be bohaii or melanuroides,based on molecular analysis,showed the developed function to be 97.7%accurate.When applied to measurements of godwits captured at 22 sites across 9 countries in East-Southeast Asia and Australia,we found that bohaii and melanuroides occurred at most sites and overlapped in their distribution from Kamchatka to Australia.We examined photos from all along the flyway to verify this surprising result,confirming that both subspecies co-occur in most locations.Based on these results,we hypothesise that bohaii and melanuroides from the west of their breeding ranges mostly migrate over Chinese mainland.Birds of both subspecies from the east of their ranges are expected to migrate along the Pacific Ocean.We encourage ringing groups in East-Southeast Asia and Australia to use this simple method to keep adding knowledge about Black-tailed Godwits in the East Asian-Australasian Flyway. 展开更多
关键词 DFA discriminant function analysis East Asian-Australasian Flyway Limosa limosa
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Prognostic and diagnostic scoring models in acute alcoholassociated hepatitis:A review comparing the performance of different scoring systems
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作者 Jad Mitri Mohammad Almeqdadi Raffi Karagozian 《World Journal of Hepatology》 2023年第8期954-963,共10页
Alcohol-associated hepatitis(AAH)is a severe form of liver disease caused by alcohol consumption.In the absence of confounding factors,clinical features and laboratory markers are sufficient to diagnose AAH,rule out a... Alcohol-associated hepatitis(AAH)is a severe form of liver disease caused by alcohol consumption.In the absence of confounding factors,clinical features and laboratory markers are sufficient to diagnose AAH,rule out alternative causes of liver injury and assess disease severity.Due to the elevated mortality of AAH,assessing the prognosis is a radical step in management.The Maddrey discriminant function(MDF)is the first established clinical prognostic score for AAH and was commonly used in the earliest AAH clinical trials.A MDF>32 indicates a poor prognosis and a potential benefit of initiating corticosteroids.The model for end stage liver disease(MELD)score has been studied for AAH prognostication and new evidence suggests MELD may predict mortality more accurately than MDF.The Lille score is usually combined to MDF or MELD score after corticosteroid initiation and offers the advantage of assessing response to treatment a 4-7 d into the course.Other commonly used scores include the Glasgow Alcoholic Hepatitis Score and the Age Bilirubin international normalized ratio Creatinine model.Clinical AAH correlate adequately with histologic severity scores and leave little indication for liver biopsy in assessing AAH prognosis.AAH presenting as acute on chronic liver failure(ACLF)is so far prognosticated with ACLF-specific scoring systems.New artificial intelligence-generated prognostic models have emerged and are being studied for use in AAH.Acute kidney injury(AKI)is one possible complication of AAH and is significantly associated with increased AAH mortality.Predicting AKI and alcohol relapse are important steps in the management of AAH.The aim of this review is to discuss the performance and limitations of different scoring models for AAH mortality,emphasize the most useful tools in prognostication and review predictors of recurrence. 展开更多
关键词 Alcohol-associated hepatitis Prognostic scores MORTALITY Maddrey discriminant function Model for end stage liver disease Acute kidney injury
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Pentoxifylline versus prednisolone for severe alcoholic hepatitis:A randomized controlled trial 被引量:26
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作者 Binay Krishna De Subhabrata Gangopadhyay +3 位作者 Deep Dutta Sumanta Das Baksi Adyapad Pani Pramit Ghosh 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第13期1613-1619,共7页
AIM: To compare the efficacy of pentoxifylline and prednisolone in the treatment of severe alcoholic hepatitis, and to evaluate the role of different liver function scores in predicting prognosis.METHODS: Sixty-eigh... AIM: To compare the efficacy of pentoxifylline and prednisolone in the treatment of severe alcoholic hepatitis, and to evaluate the role of different liver function scores in predicting prognosis.METHODS: Sixty-eight patients with severe alcoholic hepatitis (Maddrey score ≥ 32) received pentoxifylline (n = 34, group Ⅰ) or prednisolone (n = 34, group Ⅱ) for 28 d in a randomized double-blind controlled study, and subsequently in an open study (with a tapering dose of prednisolone) for a total of 3 mo, and were followed up over a period of 12 mo.RESULTS: Twelve patients in group Ⅱ died at the end of 3 mo in contrast to five patients in group Ⅰ. The probability of dying at the end of 3 mo was higher in group Ⅱ as compared to group Ⅰ (35.29% vs 14.71%, P = 0.04; log rank test). Six patients in group I developed hepatorenal syndrome as compared to none in group Ⅰ. Pentoxifylline was associated with a significantly lower model for end-stage liver disease (MELD) score at the end of 28 d of therapy (15.53± 3.63 vs 17.78± 4.56, P=0.04). Higher baseline Maddrey score was associated with increased mortality.CONCLUSION: Reduced mortality, improved risk-benefit profile and renoprotective effects of pentoxifylline compared with prednisolone suggest that pentoxifylline is superior to prednisolone for treatment of severe alcoholic hepatitis. 展开更多
关键词 Alcoholic hepatitis PENTOXIFYLLINE PREDNISOLONE Maddrey discriminant function score Model for end-stage liver disease score Glasgowalcoholic hepatitis score
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Prevalence and Early Signs of Autism Spectrum Disorder(ASD) among 18-36 Month Old Children in Tianjin of China 被引量:7
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作者 HUANG Jun Ping CUI Shan Shan +3 位作者 HAN Yu IRVA Hertz-Picciotto QI Li Hong ZHANG Xin 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第6期453-461,共9页
Objective The aim of this study is to estimate the prevalence of autism spectrum disorder (ASD) among 18-36 month old children in the Tianjin Municipality of China, and to identify early signs of autistic children a... Objective The aim of this study is to estimate the prevalence of autism spectrum disorder (ASD) among 18-36 month old children in the Tianjin Municipality of China, and to identify early signs of autistic children and the predictability of each individual symptom. Methods A total of 8 000 children were screened to do a questionnaire based on CHAT modified to include more early signs of autism at the age of 28-36 months. Then the at-risk children were reexamined 1.5 years later and ASD children were identified based on DSM-IV. Early signs of autism were analyzed retrospectively by using discriminant function analysis performed among ASD children, children not followed up and children followed up but failing to meet ASD criteria. Results Three hundred and sixty seven children were screened as being at-risk to ASD, and 22 of them were identified as having ASD in the subsequent diagnosis. The prevalence of ASD was 27.5 per 10 000 in Tianjin of China with a male to female ratio of 4:1. Items addressing social interactions and communications had higher predictability than other items to distinguish autistic children from non-autistic ones. Pretend play, functional play, showing and reading parents' facial expressions distinguished autistic children from those not followed up, nevertheless those followed up but failing to meet ASD criteria were not included.Conclusion The prevalence of ASD found in our study was lower than that reported in some studies by western researchers. Autism has its specific symptoms, such as deficits in social awareness, social relatedness, and social referencing. 展开更多
关键词 Autism spectrum disorder PREVALENCE Early signs discriminant function analysis
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Alcoholic hepatitis: A comprehensive review of pathogenesis and treatment 被引量:5
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作者 Maneerat Chayanupatkul Suthat Liangpunsakul 《World Journal of Gastroenterology》 SCIE CAS 2014年第20期6279-6286,共8页
Alcoholic hepatitis(AH)is an acute hepatic inflammation associated with significant morbidity and mortality.Current evidence suggests that the pathogenesis is the end result of the complex interplay between ethanol me... Alcoholic hepatitis(AH)is an acute hepatic inflammation associated with significant morbidity and mortality.Current evidence suggests that the pathogenesis is the end result of the complex interplay between ethanol metabolism,inflammation and innate immunity.Several clinical scoring systems have been derived to predict the clinical outcomes of patients with AH;such as Child-Turcotte-Pugh score,the Maddrey discriminant function,the Lille Model,the model for end stage liver disease scores,and the Glasgow alcoholic hepatitis score.At present,Corticosteroids or pentoxifylline are the current pharmacologic treatment options;though the outcomes from the therapies are poor.Liver trans-plantation as the treatment of alcoholic hepatitis remains controversial,and in an era of organ shortage current guidelines do not recommend transplantation as the treatment option.Because of the limitations in the therapeutic options,it is no doubt that there is a critical need for the newer and more effective pharmacological agents to treat AH. 展开更多
关键词 Alcoholic hepatitis PATHOGENESIS Treatment Model for end stage liver disease discriminant function Lille Model Glasgow alcoholic hepatitis score Liver transplantation
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SPEECH EMOTION RECOGNITION USING MODIFIED QUADRATIC DISCRIMINATION FUNCTION 被引量:9
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作者 Zhao Yan Zhao Li Zou Cairong Yu Yinhua 《Journal of Electronics(China)》 2008年第6期840-844,共5页
Quadratic Discrimination Function (QDF) is commonly used in speech emotion recognition, which proceeds on the premise that the input data is normal distribution. In this paper, we propose a transformation to normali... Quadratic Discrimination Function (QDF) is commonly used in speech emotion recognition, which proceeds on the premise that the input data is normal distribution. In this paper, we propose a transformation to normalize the emotional features, emotion recognition. Features based on prosody then derivate a Modified QDF (MQDF) to speech and voice quality are extracted and Principal Component Analysis Neural Network (PCANN) is used to reduce dimension of the feature vectors. The results show that voice quality features are effective supplement for recognition, and the method in this paper could improve the recognition ratio effectively. 展开更多
关键词 Speech emotion recognition Principal Component Analysis Neural Network (PCANN) Modified Quadratic Discrimination Function (MQDF)
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Rapid Identification for Drought Resistance of Wheat Using Near-infrared Diffuse Reflectance Spectroscopy 被引量:3
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作者 冯伟森 吴少辉 +7 位作者 谷运红 张园 高海涛 王卫东 张灵帅 张学品 马飞 张灿军 《Agricultural Science & Technology》 CAS 2012年第12期2615-2619,共5页
[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drou... [Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drought resistance were selected and were classified according to their drought resistance grades determined by the Technical Specification of Identification and Evaluation for Drought Resistance in Wheat (GB/T 21127-2007). In addition, the harvested wheat seed samples were spectrally analyzed with FOSS NIRSystems5000 near-infrared spectrum analyzer for grain quality (full spectrum analyzer) and then the forecasted regression equations were established. [Result] After the establishment of a database and validation, dis- criminated functions were obtained. The determination coefficient (RSQ) and coeffi- cients of determination for cross validation (1-VR) in the discriminant function built with seed samples from water stress area were 0.846 0 and 0.781 8, respectively, which indicated that the consistency between drought resistance and spectral charac- teristics in wheat varieties was good, and there was high correlation between the near-infrared diffuse reflectance spectra of seeds and the drought resistance in wheat. [Conclusiou] Under water stress condition, it is feasible to establish a conve- nient, rapid and no-damage identification system for the drought resistance in wheat by using the near-infrared diffuse reflectance spectrum technique to scan wheat seeds. 展开更多
关键词 Near-infrared diffuse reflectance spectroscopy Identification for wheat drought resistance discriminant function
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Predicting utility of a model for end stage liver disease in alcoholic liver disease 被引量:1
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作者 Aspasia S Soultati Spyridon P Dourakis +3 位作者 Alexandra Alexopoulou Melanie Deutsch Larissa Vasilieva Athanasios J Archimandritis 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第25期4020-4025,共6页
AIM: To validate the statistic utility of both the Maddrey Discriminant Function score and the Model for End-Stage Liver Disease as predictors of short term (30 d and 90 d) mortality in patients with alcoholic hepa... AIM: To validate the statistic utility of both the Maddrey Discriminant Function score and the Model for End-Stage Liver Disease as predictors of short term (30 d and 90 d) mortality in patients with alcoholic hepatitis and to assess prognostic factors among clinical characteristics and laboratory variables of patients with alcoholic hepatitis. METHODS: Thirty-four patients with the diagnosis of alcoholic hepatitis admitted to Hippokration University Hospital of Athens from 2000 to 2005 were assessed in the current retrospective study and a statistical analysis was conducted. RESULTS: 30- and 90-d mortality rates were reported at 5.9% (2/34) and 14.7% (5/34), respectively. Significant correlation was demonstrated for the Model for End- Stage Liver Disease (P30 = 0.094, P90 = 0.046) and the Maddrey Discriminant Function score (P30 = 0.033, P90 = 0.038) with 30- and 90-d mortality whereas a significant association was also established for alanine aminotrans- ferase (P = 0.057), fibrin degradation products (P = 0.048) and C-reactive protein (P = 0.067) with 90-d mortality. For 30-d mortality the Area Under the Curve was 0.969 (95%CI: 0.902-1.036, P = 0.028) for the Model for End-Stage Liver Disease score and 0.984 (95%CI: 0.942-1.027, P = 0.023) for the Maddrey Discriminant Function score with the optimal cut off point of 30.5 (sensitivity 1, specificity 0.937) and 108.68 (sensitivity 1, specificity 0.969), respectively. Accordingly, for 90-d mortality the Area Under the Curve was 0.762 (95%CI: 0.559-0.965, P = 0.065) for the Model for End-Stage Liver Disease score and 0.752 (95%CI: 0.465-1.038, P = 0.076) for the Maddrey Discriminant Function score with the optimal cut off point of 19 (sensitivity 0.6, specificity 0.6) and 92 (sensitivity 0.6, specificity 0.946), respectively. The observed Kaplan Meier survival rates for different score-categories were compared with logrank tests and higher score values were correlated with a lower survival. CONCLUSION: Equivalency of the Model for End-Stage Liver Disease and the Maddrey Discriminant Function score is implied by the current study, verified by the plotted Receiver Operative Curves and the estimated survival rates. A statistically significant utility of C-reactive protein, fibrin degradation products and alanine aminotransferase as independent predictors of 90-d mortality has also been verified. 展开更多
关键词 Alcoholic liver disease Alcoholic hepatitis Maddrey discriminant function score Model for end-stage liver disease score
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Identification of vocal individuality in male cuckoos using different analytical techniques 被引量:1
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作者 Yang Li Canwei Xia +2 位作者 Huw Lloyd Donglai Li Yanyun Zhang 《Avian Research》 CSCD 2017年第3期134-140,共7页
Background: Individuality in vocalizations may provide an effective tool for surveying populations of the Common Cuckoo(Cuculus canorus) but there remains few data on which technique to use to identify individuality. ... Background: Individuality in vocalizations may provide an effective tool for surveying populations of the Common Cuckoo(Cuculus canorus) but there remains few data on which technique to use to identify individuality. In this research, we compared the within-and between-individual variation in cuckoo calls using two different analytical methods, and discuss the feasibility of using call individuality to count male cuckoos within a population.Methods: We recorded vocalization from 13 males, and measured 15 spectro-temporal variables for each call. The majority of these call variables(n = 12) have greater variation between individuals than within individual. We first calculated the similarity(Pearson's R) for each paired calls in order to find a threshold that could distinguish calls emitted from the same or different males, and then counted the number of males based on this distinction. Second, we used the more widely accepted technique of discriminant function analysis(DFA) to identify individual male cuckoos, and compared the correct rate of classifying individuals between the two analytical methods.Results: Similarity of paired calls from the same male was significantly higher than from different males. Under a relatively broad threshold interval, we achieved a high(>90%) correct rate to distinguish calls and an accurate estimate of male numbers. Based on banded males(n = 3), we found the similarity of paired calls from different days was lower when compared with paired calls from the same day, but this change did not obscure individual identification, as similarity values of paired calls from different days were still larger than the threshold used to distinguish calls from the same or different males. DFA also yielded a high rate(91.9%) of correct classification of individuals.Conclusions: Our study suggests that identifying individual vocalizations can form the basis of an appropriate survey method for counting male cuckoos within a population, provided the performance of different analytical techniques are compared. 展开更多
关键词 Vocal individuality Avian acoustics Common Cuckoo Correlation analysis discriminant function analysis
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Mineralogical and geochemical characteristics of Miocene pelitic sedimentary rocks from the south-western part of the Pannonian Basin System(Croatia):Implications for provenance studies 被引量:2
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作者 Anita Grizelj Zoran Peh +2 位作者 Darko Tibljas Marijan Kovacic Tomislav Kurecic 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第1期65-80,共16页
Fifty-two samples of Miocene pelitic sedimentary rock from outcrops on Medvednica,Moslavacka Gora and Psunj Mts.,and boreholes in the Sava Depression and the Pozega Sub-depression were investigated.These sediments for... Fifty-two samples of Miocene pelitic sedimentary rock from outcrops on Medvednica,Moslavacka Gora and Psunj Mts.,and boreholes in the Sava Depression and the Pozega Sub-depression were investigated.These sediments formed in different marine(with normal and reduced salinity),brackish,and freshwater environments,depending on the development stage of the Pannonian Basin System.Carbonate minerals,clay minerals and quartz are the main constituents of all pelitic sedimentary rocks,except in those from Moslavacka Gora Mt in which carbonate minerals are not present.Feldspars,pyrite,opal-CT,and hematite are present as minor constituents in some rocks.Besides calcite,dependent on the sedimentary environment and diagenetic changes,high-magnesium calcite,aragonite,dolomite and ankerite/Cadolomite are also present.Smectite or illite-smectite is the main clay minerals in the samples.Minor constituents,present in almost all samples,are detrital illite and kaolinite.In some samples chlorite is also present in a low amount.Major elements,trace elements and rare earth elements patterns used in provenance analysis show that all analysed samples have a composition similar to the values of the upper continental crust(UCC).The contents of major and trace elements as well as SiO2/Al2O3,K2O/Al2O3,Na2O/K2O,Eu/Eu*,La/Sc,Th/Sc,La/Co Th/Co,Th/Cr,Ce/Ce* and LREE/HREE ratios,show that the analysed pelitic sedimentary rocks were formed by weathering of different types of mostly acidic(silicic),i.e.felsic rocks. 展开更多
关键词 Mineralogy Chemical composition MioceneProvenance discriminant function analysis Pannonian Basin System
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Quantitative structure-activity study on the reductive dehalogenation potency of the halogenated aromatics
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作者 Huang Qingguo Wang Liansheng Han Shuokui(Department of Environmental Science and Technology, Nanjing University , Nanjing 210008 , China) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1995年第2期183-189,共7页
Quantitativestructure-activitystudyonthereductivedehalogenationpotencyofthehalogenatedaromaticsHuangQingguo;... Quantitativestructure-activitystudyonthereductivedehalogenationpotencyofthehalogenatedaromaticsHuangQingguo;WangLiansheng;Han... 展开更多
关键词 quantitative structure - activity relationship(QSAR) halogenated arornatics dehalogenation poten-cy discriminant function.
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Pharmacotherapy of acute alcoholic hepatitis in clinical practice
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作者 Ludovico Abenavoli Natasa Milic +1 位作者 Samir Rouabhia Giovanni Addolorato 《World Journal of Gastroenterology》 SCIE CAS 2014年第9期2159-2167,共9页
Severe alcoholic hepatitis(AH)is an acute form of alcohol induced liver disease with a poor prognosis that is seen in the patients who consume large quantities of alcohol.The diagnosis of AH is based on the appropriat... Severe alcoholic hepatitis(AH)is an acute form of alcohol induced liver disease with a poor prognosis that is seen in the patients who consume large quantities of alcohol.The diagnosis of AH is based on the appropriate alcohol intake history and is supported with clinical and histological features,and several scoring systems.Glucocorticoids are the mainstay for treating severe AH with pentoxifylline used as an alternative to steroids in addition to total alcohol abstinence.Liver transplantation is a possible therapeutic option for severe AH.Among the anti-craving medications able to improve abstinence rate,baclofen seems to be effective and safe in the alcoholic patients affected by severe liver damage. 展开更多
关键词 Severe alcoholic hepatitis Maddrey’ s discriminant function Glucocorticoids Baclofen Orthotopic liver transplantation Alcoholic liver disease
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Morphological Variation of Donax spp. from Five Beaches in Prachaupkhirikhan, Thailand
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作者 S. Manatrinon O. U. Thonglor A. Boonyapakdee 《Journal of Agricultural Science and Technology(A)》 2011年第8期1109-1111,共3页
Five hundred samples ofDonax spp. were collected from five beaches (Khao Tao, Sea Pine Garden, Pran Buri Forest Park, Sam Roi Yod, and Sam Phraya) in Prachaupkhirikhan province, Thailand. Five morphological variable... Five hundred samples ofDonax spp. were collected from five beaches (Khao Tao, Sea Pine Garden, Pran Buri Forest Park, Sam Roi Yod, and Sam Phraya) in Prachaupkhirikhan province, Thailand. Five morphological variables of each individual were measured and analyzed to reveal morphological variation. The discriminant function analysis of morphology suggested a clear separation into two groups. The individuals from Khao Tao and Sea Pine Garden were grouped together while individuals from Pran Buri Forest Park, Sam Roi Yod and Sam Phraya were classified into the same group. The classification function of discriminant function analysis suggested that 70% of Khao Tao population, 70% of Sea Pine Garden population, 67% of Pran Buri Forest Park population, 64% of Sam Roi Yod population and 34% of Sam Phraya population of Donax spp. could be correctly reassigned by morphology. The misclassification individuals of Sam Phraya population were assigned to Pran Buri Forest Park and Sam Roi Yod population with the correct assignment 38% and 27%, respectively. The results obtained in this study based on morphological variation indicated that Khao Tao and Sea Pine Garden populations ofDonax spp. should be treated as separated units from the other three populations for conservation management. However, the result should be confirmed again as genetic level. 展开更多
关键词 Morphological variation discriminant function analysis Donax spp. Prachaupkhirikhan
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Parameterization of the freeze/thaw discriminant function algorithm using dense in-situ observation network data 被引量:1
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作者 Pingkai Wang Tianjie Zhao +4 位作者 Jiancheng Shi Tongxi Hu Alexandre Roy Yubao Qiu Hui Lu 《International Journal of Digital Earth》 SCIE EI 2019年第8期980-994,共15页
The near-surface soil freeze–thaw(FT)transition is an important factor affecting land-atmosphere exchanges,hydrology and carbon cycles.Thus,effectively monitoring the temporal–spatial changes of soil FT processes is... The near-surface soil freeze–thaw(FT)transition is an important factor affecting land-atmosphere exchanges,hydrology and carbon cycles.Thus,effectively monitoring the temporal–spatial changes of soil FT processes is crucial to climate change and environment research.Several approaches have been developed to detect the soil FT state from satellite observations.The discriminant function algorithm(DFA)uses temperature and emissivity information from Advanced Microwave Scanning Radiometer Enhanced(AMSR-E)passive microwave satellite observations.Although it is well validated,it was shown to be insufficiently robust for all land conditions.In this study,we use in-situ observed soil temperature and AMSR-E brightness temperature to parameterize the DFA for soil FT state detection.We use the in-situ soil temperature records at 5 cm selected from available dense networks in the Northern Hemisphere as a reference.Considering the distinction between ascending and descending orbits,two different sets of parameters were acquired for each frequency pair.The validation results indicate that the overall discriminant accuracy of the new function can reach 90%.We further compared the Advanced Microwave Scanning Radiometer 2 discriminant results using the new function to the Soil Moisture Active Passive freeze/thaw product,and a reasonable consistency between them was found. 展开更多
关键词 Soil freeze–thaw state discriminant function algorithm AMSR-E AMSR2 SMAP
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Sediment provenance discrimination in northern Okinawa Trough during the last 24 ka and paleoenvironmental implication:rare earth elements evidence 被引量:12
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作者 徐兆凯 李铁刚 +3 位作者 常凤鸣 CHOI Jinyong LIM Dhongil 徐方建 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第11期1184-1190,共7页
Rare earth elements (REE) compositions and discriminant function were successfully used to examine high resolution sediment source changes in the northern Okinawa Trough over the last 24.1 ka, especially for the inf... Rare earth elements (REE) compositions and discriminant function were successfully used to examine high resolution sediment source changes in the northern Okinawa Trough over the last 24.1 ka, especially for the influence from the Yellow River and the Tsushima Warm Current (TWC) that has not been well solved. Variations of these parameters were clearly divided into three distinct depositional units. During Interval 1 (24.1-16.0 ka BP), the paleo-Yellow River and the paleo-Yangtze River mouths were situated near the studied area and could have played major roles in the sedimentation therein. In Interval 2 (16.0-7.3 ka BP), these river mouths gradually retreated with global sea-level rise, leading to less fluvial inputs from them to the northern Okinawa Trough. Meanwhile, formation of the TWC could carry some sediment loads of Taiwan to the studied core, especially during its late phase (8.0-7.3 ka BP). Modem oceanographic conditions, with a predominance of the TWC, were finally established since the beginning of Interval 3, causing more ten'igenous contribution from Taiwan to the studied area. Subsequently, modem depositional environments mainly influenced by the Yellow River, the Yangtze River, and the TWC were finally formed. 展开更多
关键词 sediment provenance discriminant function rare earth elements Tsushima Warm Current northern Okinawa Trough
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Assessing Soil Properties and Landforms in the Mai-Negus Catchment, Northern Ethiopia 被引量:3
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作者 Gebreyesus Brhane TESFAHUNEGN Lulseged TAMENE Paul L.G.VLEK 《Pedosphere》 SCIE CAS CSCD 2016年第5期745-759,共15页
Soil degradation is a serious environmental problem in Ethiopia. However, little information is documented on indicators such as variations in soil properties across different landforms in a catchment. This study was ... Soil degradation is a serious environmental problem in Ethiopia. However, little information is documented on indicators such as variations in soil properties across different landforms in a catchment. This study was aimed to assess soil properties and their changes across sites with different erosion statuses, and identify landscape positions that require prior management attention in the Mai-Negus catchment, northern Ethiopia. Three types of erosion-status sites(stable, eroding and aggrading) were identified using reconnaissance surveys, and then the corresponding soil samples were collected and analyzed. The major soil properties were significantly varied(P ≤ 0.05) among the three erosion-status sites. The highest soil p H, organic carbon, total nitrogen, cation exchange capacity, iron and zinc were recorded from the aggrading sites in the reservoir and valley landforms of the study catchment. A higher bulk density was generally recorded in the eroding sites, whereas a lower value was observed in the aggrading sites. The highest sand content was observed in the eroding sites of the mountain followed by the central ridge landform. The paired mean difference and the correlation matrix of most soil properties between the different erosion statuses also showed significant differences. About 95% of the erosionstatus sites were correctly classified by the discriminant function, indicating that the field survey-based classification was acceptable for decision making. On the basis of this study, suitable interventions should thus be introduced to the prioritized landforms, which are the mountain and central ridge, and eroding sites with severely degraded soil properties across the catchment. 展开更多
关键词 aggrading site discriminant function eroding site erosion status landscape soil property variability stable site
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Paleoenvironmental Changes in the Northern Okinawa Trough since 25 ka BP:REE and Organic Carbon Evidence 被引量:3
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作者 徐兆凯 李铁刚 +3 位作者 南青云 于心科 李安春 Jinyong Choi 《Journal of Earth Science》 SCIE CAS CSCD 2012年第3期297-310,共14页
Paleoenvironmental changes in the northern Okinawa trough covering the last 25 ka were synthetically reconstructed using REE and organic carbon indices of core CSH1.Variations of these parameters revealed three distin... Paleoenvironmental changes in the northern Okinawa trough covering the last 25 ka were synthetically reconstructed using REE and organic carbon indices of core CSH1.Variations of these parameters revealed three distinct intervals of major sediment provenance changes that can be related to sea-level fluctuation and Tsushima Warm Current evolution.Interval 1(16-24.7 ka BP) is characterized by dominantly fluvial discharge from the Changjiang(Yangtze River) and Huanghe(Yellow River) as well as high primary productivity.In Interval 2(7.3-16 ka BP),the Changjiang and Huanghe mouths regressed with sea-level rising.The newly formed Tsushima Warm Current could carry some sediment loads of Taiwan to the study core,especially during its late phase(7.3-8.2 ka BP).Modern oceanographic conditions were finally established since the beginning of Interval 3,leading to more terrigenous contribution from Taiwan,whereas low sea-surface productivity in the study area. 展开更多
关键词 paleoenvironmental change the northern Okinawa trough Tsushima Warm Current REE discriminant function.
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Measurement of the spatial resolution and the relative density resolution in an industrial cone-beam micro computed tomography system 被引量:3
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作者 王燕芳 阙介民 +5 位作者 曹大泉 孙翠丽 赵维 魏存峰 史戎坚 魏龙 《Chinese Physics C》 SCIE CAS CSCD 2013年第7期93-100,共8页
The spatial resolution and the relative density resolution are the two most critical indicators in CT system. The method recommended in the ASTM E1695-95 and GJB 5311-2004 is only suitable to the fan-beam CT system. I... The spatial resolution and the relative density resolution are the two most critical indicators in CT system. The method recommended in the ASTM E1695-95 and GJB 5311-2004 is only suitable to the fan-beam CT system. In this paper, for industrial cone-beam micro CT system, we will adopt the edge response function (ERF) created by the step edges of a steel ball to measure the system 3D PSF and MTF. To describe the contrast discrimination function more accurately, we will first propose to extend the two-dimensional measurement region to the three-dimensional space. Our experimental spatial resolution is (55.56+0.56) lp/mm and the relative density resolution is 1% within 300 μm×300 μm×300 μm according to the 3σ rule. 展开更多
关键词 micro computed tomography point spread function contrast discrimination function modulationtransfer function
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