Parameter uncertainty and sensitivity evaluation of copula-based multivariate hydroclimatic risk assessment

Extensive uncertainties exist in hydroclimatic risk analysis. Especially in multivariate hydrologic risk inferences, uncertainties in individual hydroclimatic extremes such as floods and their dependence structure may lead to bias and uncertainty in future hydrologic risk predictions. In this study, a parameter uncertainty and sensitivity evaluation (PUSE) framework is proposed to quantify parameter uncertainties and then reveal their contributions to the multivariate hydroclimatic risk predictions. The predictive risks are finally generated by “integrating†the values over the posterior distributions of the parameters. The proposed approach was applied for bivariate risk analysis of compound floods at the Xiangxi River to characterize the concurrence probabilities of flood peaks and volumes. The results demonstrate that the proposed approach can quantify uncertainties in a copula-based multivariate risk analysis and characterize effects and contributions of parameters in marginal and dependence structures on the multivariate hydroclimatic risk predictions. In terms of the bivariate risk for flood peak and volume at the Xiangxi River, uncertainties in model parameters would lead to noticeable uncertainties even for moderate floods. The performances of the copula model for flood peak-volume at Xiangxi River are mainly affected by the uncertainties in location parameters of the two individual flood variables. Also, parameter uncertainty in the dependence structure (i.e., copula) would also poses explicit impacts on performance of the copula-based risk analyses model. These uncertainties would result into higher bivariate predictive risks than the values obtained by “optimal/deterministic†predictions. This indicates that uncertain- ties are required to be considered to provide reliable multivariate hydroclimatic risk predictions.National Key Research and Development Plan (2016YFA0601502), and the Royal Society International Exchanges Program (No. IES\R2\202075)

Management of Drinking Water Source in Rural Communities under Climate Change

In rural communities where central public water supply systems can hardly reach, the acquisition and management of safe drinking water sources are challenging due to population growth, environmental pollution, and climate change. Numerous endeavours have been made over the past several decades to help rural communities manage drinking water sources and obtain safe drinking water under climate change, which are summarized in this review. Firstly, the crises of rural drinking water safety under climate change are overviewed based on the extensive investigation of recent studies on rural water security. Second, the sustainable management of rural drinking water sources are systematically reviewed, mainly focusing on issues of water quality assessments, drinking water quantity and quality improvement, system maintenance and community management, and decision making in rural regions across the world. Finally, knowledge gaps of recent endeavors are highlighted, emerging threats and complications to water security under climate change are identified and perspectives for future works are discussed.This research was supported by the Natural Science and Engineering Research Council of Canada, and the National Foreign Expert Project (G2021111016L and (G2021111017L)

Loss of heterozygosity in multistage carcinogenesis of esophageal carcinoma at high-incidence area in Henan Province, China

Aim: Microsatellites are the repeated DNA sequences scattered widely within the genomes and closely linked with many important genes. This study was designed to characterize the changes of microsatellite DNA loss of heterozygosity (LOH) in esophageal carcinogenesis. Methods: Allelic deletions in 32 cases of matched precancerous, cancerous and normal tissues were examined by syringe microdissection under an anatomic microscope and microsatellite polymorphism analysis using 15 polymorphic markers on chromosomes 3p, 5q, 6p, 9p, 13q, 17p, 17q and 18q. Results: Microsatellite DNA LOH was observed in precancerous and cancerous tissues, except D9S1752. The rate of LOH increased remarkably with the lesions progressed from basal cell hyperplasia (BCH) to squamous cell carcinoma (SCC) (P60%). LOH loci were different in precancerous and cancerous tissues. LOH in D3S1234 and TP53 was the common event in different lesions from the same patients. Conclusion: Microsatellite DNA LOH occurs in early stage of human esophageal carcinogenesis, even in BCH. With the lesion progressed, gene instability increases, the accumulation of this change may be one of the important mechanisms driving precancerous lesions to cancer. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

A coupled ensemble filtering and probabilistic collocation approach for uncertainty quantification of hydrological models

Natural Science Foundation of China (Nos. 51190095 and 51225904) and the Program for Innovative Research Team in University (IRT1127)

Development of a copula-based particle filter (CopPF) approach for hydrologic data assimilation under consideration of parameter interdependence

National Natural Science Foundation of China, the National Key Research and Development Plan, and the Natural Sciences and Engineering Research Council of Canad

Coupling the two-level programming and copula for optimizing energy-water nexus system management – A case study of Henan Province

National Natural Science Foundation of China (51909239), the Key Research Project of Henan Higher Education Institution (20A570001) and the Postdoctoral Foundation of Henan Province (1901008

Development of integrated approaches for hydrological data assimilation through combination of ensemble Kalman filter and particle filter methods

Natural Science Foundation of China; National Key Research and Development Plan; Natural Sciences and Engineering Research Council of Canada

Parameter uncertainty and temporal dynamics of sensitivity for hydrologic models: A hybrid sequential data assimilation and probabilistic collocation method

This research was supported by the Natural Science Foundation of China (Nos. 51190095 and 51225904) and the Program for Innovative Research Team in University (IRT1127)

食管癌原發灶與淋巴結轉移灶細胞染色體變化特征的比較

BACKGROUND & OBJECTIVE: Local lymph node and blood metastasis could occur at early stage of esophageal squamous cell carcinoma (ESCC), which may be the key factors of its recurrence and poor prognosis. However, the mechanism of ESCC metastasis is unclear. This study was to analyze the genetic changes in primary lesion and lymph node metastases of ESCC, to screen for and locate ESCC metastasis-related genes. METHODS: Genomic alterations in 15 pairs of primary lesions and matched metastatic lymph nodes of ESCC were analyzed by comparative genomic hybridization (CGH). RESULTS: In the 15 pairs of tissues, the most common chromosomal alterations were the gains of 3q, 8q, 6p, 20p, 5p, 18p, 2p, 2q and 1q, and the losses of 10p, 10q, 17p, 18q, 4p and 13q. Of these changes, the most significant finding was the gain of 6p with a frequency of 47% in metastatic lymph nodes and 13% in primary lesions, and the gain of 20p with a frequency of 73% in metastatic lymph nodes and 33% in primary lesions. The second interesting finding was the loss of 10p with a frequency of 53% in metastatic lymph nodes and 13% in primary lesions, and the loss of 10q with a frequency of 47% in metastatic lymph nodes and 13% in primary lesions. CONCLUSION: The gains of 6p and 20p and the losses of 10p and 10q are common genomic alterations in primary lesion and lymph node metastases of ESCC, which may code ESCC metastasis-related genes.背景與目的:食管癌早期可發生局部淋巴或血行轉移,這是導致復發和預后差的主要原因。但是,食管癌轉移發生的分子機制尚不清楚。本研究旨在分析食管癌原發灶和淋巴結轉移灶腫瘤細胞染色體變化的特征,尋找或定位與食管癌轉移相關基因,加深對其轉移機制的了解。方法:應用比較基因組雜交技術(comparativegenomichybridization,CGH)分析15例食管癌患者原發灶和其對應的淋巴結轉移灶的染色體基因組改變。結果:最常見染色體DNA拷貝數增加的部位是3q,8q,6p,20p,5p,18p,2p,2q,1q;常見的染色體DNA拷貝數丟失的部位是10p,10q,17p,18q,4p,13q。其中,最有意義的發現是6p增加(原發灶:2/15,13%,轉移灶:7/15,47%),20p增加(原發灶:5/15,33.3%,轉移灶:11/15,73.3%)。第二個發現是10p丟失(原發灶:2/15,13.3%,轉移灶:8/15,53%),10q丟失(原發灶:2/15,13.3%,轉移灶:7/15,46.6%)。結論:食管癌原發灶和淋巴結轉移灶細胞染色體基因組改變最顯著的部位是6p,20p的增加和10p,10q的丟失;這些部位可能存在與食管癌細胞淋巴結轉移相關的基因。link_to_subscribed_fulltex