The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new...The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new variety has been extended in most of areas of China. The management of genetically improved strains, including the genetic markers for identification is needed urgently. RAPD analysis was conducted and their conversion to SCAR markers was developed. From NEW GIFT Nile tilapia, two strain-specific RAPD bands, S304624 bp and S36568 bp were identified. The strain-specific RAPD bands were gel-purified, cloned, and sequenced. Locus-specific primers were then designed to amplify the strain-specific bands. PCR amplification was conducted to test the variations in allele frequencies of two converted SCAR markers among the NEW GIFT Nile tilapia and its base strains, as well as 7 additional farmed strains worldwide. The frequency of SCAR marker Ⅰ （553 bp） was 85.7% in NEW GIFT Nile tilapia, but 16.7% in the base strain. The frequency of SCAR marker Ⅱ （558 bp） was 91.4% in NEW GIFT Nile tilapia, but 0% 70% in the 7 other strains. In order to confirm the utility of these two markers, an examination was conducted for a wild population from Egypt, resulted the frequency of SCAR Ⅰ and Ⅱ was 10% and 70%, respectively, much lower than that of New GIFT strain. The increase in allele frequency of these two SCAR markers suggests that these markers might be genetically linked to the quantitative trait loci （QTL） underlining the performance traits by long term selection, and indicate the bright potential of SCAR marker technology for tracking generations during selection progress and for distinguishing among genetically improved strain and other strains.展开更多
In this article, we propose a novel, multilevel, dynamic factor model, to determine endogenously clustered regions for the investigation of regional clustering and synchronization of provincial business fluctuations i...In this article, we propose a novel, multilevel, dynamic factor model, to determine endogenously clustered regions for the investigation of regional clustering and synchronization of provincial business fluctuations in China. The parameter identification and model estimation was conducted using the Markov Chain Monte Carlo method. We then conducted an empirical study of the provincial business fluctuations in China(31 Chinese provinces are considered except Hong Kong, Macao, and Taiwan due to the data unavailability), which were sampled from January 2000 to December 2015. Our results indicated that these provinces could be clustered into four regions: leading, coincident, lagging, and overshooting. In comparison with traditional geographical divisions, this novel clustering into four regions enabled the regional business cycle synchronization to be more accurately captured. Within the four regional clusters it was possible to identify substantial heterogeneities among regional business cycle fluctuations, especially during the periods of the 2008 financial crisis and the ‘four-trillion economic stimulus plan'.展开更多
Background and aims:The differential diagnosis between Crohn’s disease(CD)and ischemic colitis(ISC)is important as their clinical management is different.ISC can easily be misdiagnosed as CD,especially in elderly pop...Background and aims:The differential diagnosis between Crohn’s disease(CD)and ischemic colitis(ISC)is important as their clinical management is different.ISC can easily be misdiagnosed as CD,especially in elderly populations.The distinctive radiographic features of the two disease entities have not been investigated.The aim of this study is to assess the utility of computed tomographic enterography(CTE)in the differential diagnosis between CD and ISC.Methods:Patients with confirmed CD and ISC were identified through an electronic medical record search of the Cleveland Clinic Foundation.Patients who had undergone CTE,with or without concurrent colonoscopy and histopathological specimens,were included in this study.CTE images were blindly re-reviewed by an expert gastrointestinal radiologist.The sensitivities,specificities,accuracies and positive and negative predictive values for each of the CTE findings in differentiating CD from ISC were estimated.Kappa coefficients(j)were calculated tomeasure diagnosis agreement between CTE and the reference standard.Results:A total of 34 eligible patients were included in this study with 17 having CD and 17 having ISC.In differentiating CD from ISC,the presence ofmucosal hyperenhancement and absence of the“target sign”on CTE showed a sensitivity of 100% each for CD,while the two radiographic features yielded a low specificity of 35.3%and 76.5%,respectively.The presence of stricture had a lower sensitivity of 64.7% for the detection of CD but had a high specificity of 100%.In distinguishing CD fromISC,the accuracy of presence ofmucosal hyperenhancement,stricture and absence of target sign were 67.7%,82.4% and 88.2%,respectively.The combination of the presence ofmucosal hyperenhancement and the absence of the target sign achieved an accuracy of 100%for distinguishing CD from ISC.There was a good correlation between CTE and the reference standard for distinguishing CD fromISC(k=0.882).Conclusions:CTE appeared to be clinically useful in distinguishing CD from ISC.展开更多
基金National Tilapia Industry Technical System(nycytx-48-3)National Tilapia Seed Program(nyhyzx07-044-01)
文摘The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new variety has been extended in most of areas of China. The management of genetically improved strains, including the genetic markers for identification is needed urgently. RAPD analysis was conducted and their conversion to SCAR markers was developed. From NEW GIFT Nile tilapia, two strain-specific RAPD bands, S304624 bp and S36568 bp were identified. The strain-specific RAPD bands were gel-purified, cloned, and sequenced. Locus-specific primers were then designed to amplify the strain-specific bands. PCR amplification was conducted to test the variations in allele frequencies of two converted SCAR markers among the NEW GIFT Nile tilapia and its base strains, as well as 7 additional farmed strains worldwide. The frequency of SCAR marker Ⅰ （553 bp） was 85.7% in NEW GIFT Nile tilapia, but 16.7% in the base strain. The frequency of SCAR marker Ⅱ （558 bp） was 91.4% in NEW GIFT Nile tilapia, but 0% 70% in the 7 other strains. In order to confirm the utility of these two markers, an examination was conducted for a wild population from Egypt, resulted the frequency of SCAR Ⅰ and Ⅱ was 10% and 70%, respectively, much lower than that of New GIFT strain. The increase in allele frequency of these two SCAR markers suggests that these markers might be genetically linked to the quantitative trait loci （QTL） underlining the performance traits by long term selection, and indicate the bright potential of SCAR marker technology for tracking generations during selection progress and for distinguishing among genetically improved strain and other strains.
基金Under the auspices of the National Natural Science Foundation of China(No.71371160)the Program for Changjiang Youth Scholars(No.Q2016131)the Program for New Century Excellent Talents in University(No.NCET-13-0509)
文摘In this article, we propose a novel, multilevel, dynamic factor model, to determine endogenously clustered regions for the investigation of regional clustering and synchronization of provincial business fluctuations in China. The parameter identification and model estimation was conducted using the Markov Chain Monte Carlo method. We then conducted an empirical study of the provincial business fluctuations in China(31 Chinese provinces are considered except Hong Kong, Macao, and Taiwan due to the data unavailability), which were sampled from January 2000 to December 2015. Our results indicated that these provinces could be clustered into four regions: leading, coincident, lagging, and overshooting. In comparison with traditional geographical divisions, this novel clustering into four regions enabled the regional business cycle synchronization to be more accurately captured. Within the four regional clusters it was possible to identify substantial heterogeneities among regional business cycle fluctuations, especially during the periods of the 2008 financial crisis and the ‘four-trillion economic stimulus plan'.
文摘Background and aims:The differential diagnosis between Crohn’s disease(CD)and ischemic colitis(ISC)is important as their clinical management is different.ISC can easily be misdiagnosed as CD,especially in elderly populations.The distinctive radiographic features of the two disease entities have not been investigated.The aim of this study is to assess the utility of computed tomographic enterography(CTE)in the differential diagnosis between CD and ISC.Methods:Patients with confirmed CD and ISC were identified through an electronic medical record search of the Cleveland Clinic Foundation.Patients who had undergone CTE,with or without concurrent colonoscopy and histopathological specimens,were included in this study.CTE images were blindly re-reviewed by an expert gastrointestinal radiologist.The sensitivities,specificities,accuracies and positive and negative predictive values for each of the CTE findings in differentiating CD from ISC were estimated.Kappa coefficients(j)were calculated tomeasure diagnosis agreement between CTE and the reference standard.Results:A total of 34 eligible patients were included in this study with 17 having CD and 17 having ISC.In differentiating CD from ISC,the presence ofmucosal hyperenhancement and absence of the“target sign”on CTE showed a sensitivity of 100% each for CD,while the two radiographic features yielded a low specificity of 35.3%and 76.5%,respectively.The presence of stricture had a lower sensitivity of 64.7% for the detection of CD but had a high specificity of 100%.In distinguishing CD fromISC,the accuracy of presence ofmucosal hyperenhancement,stricture and absence of target sign were 67.7%,82.4% and 88.2%,respectively.The combination of the presence ofmucosal hyperenhancement and the absence of the target sign achieved an accuracy of 100%for distinguishing CD from ISC.There was a good correlation between CTE and the reference standard for distinguishing CD fromISC(k=0.882).Conclusions:CTE appeared to be clinically useful in distinguishing CD from ISC.
