Given the extremely high inter-patient heterogeneity of acute myeloid leukemia(AML),the identification of biomarkers for prognostic assessment and therapeutic guidance is critical.Cell surface markers(CSMs)have been s...Given the extremely high inter-patient heterogeneity of acute myeloid leukemia(AML),the identification of biomarkers for prognostic assessment and therapeutic guidance is critical.Cell surface markers(CSMs)have been shown to play an important role in AML leukemogenesis and progression.In the current study,we evaluated the prognostic potential of all human CSMs in 130 AML patients from The Cancer Genome Atlas(TCGA)based on differential gene expression analysis and univariable Cox proportional hazards regression analysis.By using multi-model analysis,including Adaptive LASSO regression,LASSO regression,and Elastic Net,we constructed a 9-CSMs prognostic model for risk stratification of the AML patients.The predictive value of the 9-CSMs risk score was further validated at the transcriptome and proteome levels.Multivariable Cox regression analysis showed that the risk score was an independent prognostic factor for the AML patients.The AML patients with high 9-CSMs risk scores had a shorter overall and event-free survival time than those with low scores.Notably,single-cell RNA-sequencing analysis indicated that patients with high 9-CSMs risk scores exhibited chemotherapy resistance.Furthermore,PI3K inhibitors were identified as potential treatments for these high-risk patients.In conclusion,we constructed a 9-CSMs prognostic model that served as an independent prognostic factor for the survival of AML patients and held the potential for guiding drug therapy.展开更多
Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating du...Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response.This paper proposes an augmented Bayesian multi-model inference(BMMI)coupled with GSA methodology(BMMI-GSA)to address this issue by estimating the imprecision in the momentindependent sensitivity indices of rock structures arising from the small size of input data.The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties.The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo’s indices by employing a reweighting approach on candidate probabilistic models.The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India.The proposed methodology was superior to the conventional GSA(neglects all epistemic uncertainties)and Bayesian coupled GSA(B-GSA)(neglects model uncertainty)due to its capability to incorporate the uncertainties in both model type and parameters of properties.Imprecise Borgonovo’s indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates,which makes the user more informed in the data collection efforts.Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes.The accurate importance ranking of properties was only possible via samples of large sizes.Further,the impact of the prior knowledge in terms of prior ranges and distributions was significant;hence,any related assumption should be made carefully.展开更多
This research paper compares Excel and R language for data analysis and concludes that R language is more suitable for complex data analysis tasks.R language’s open-source nature makes it accessible to everyone,and i...This research paper compares Excel and R language for data analysis and concludes that R language is more suitable for complex data analysis tasks.R language’s open-source nature makes it accessible to everyone,and its powerful data management and analysis tools make it suitable for handling complex data analysis tasks.It is also highly customizable,allowing users to create custom functions and packages to meet their specific needs.Additionally,R language provides high reproducibility,making it easy to replicate and verify research results,and it has excellent collaboration capabilities,enabling multiple users to work on the same project simultaneously.These advantages make R language a more suitable choice for complex data analysis tasks,particularly in scientific research and business applications.The findings of this study will help people understand that R is not just a language that can handle more data than Excel and demonstrate that r is essential to the field of data analysis.At the same time,it will also help users and organizations make informed decisions regarding their data analysis needs and software preferences.展开更多
Based on the analysis of rice planting and export development in Heilongjiang Province in 2013-2021,this paper comprehensively used three export competitiveness analysis methods,namely,trade competitiveness index,reve...Based on the analysis of rice planting and export development in Heilongjiang Province in 2013-2021,this paper comprehensively used three export competitiveness analysis methods,namely,trade competitiveness index,revealed comparative advantage(RCA)analysis and international market share analysis,to compare the four major rice exporters in the world and the three major rice export provinces and cities in China.Besides,it evaluated the rice export competitiveness of Heilongjiang Province from multiple perspectives.It analyzed the reasons for low competitiveness in terms of export product structure,export market structure,production and processing technology,and brand building.Finally,it is recommended to clarify the positioning of rice export quality and take more measures to ensure product quality;improve the level of industrialization of rice production and processing,and extend the rice industry chain;develop diversified rice export markets and improve export flexibility;adhere to the principle of"opening the door and going out",expand the international popularity of high-quality brands,so as to enhance the rice export competitiveness of Heilongjiang Province.展开更多
This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An...This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.展开更多
The high intraspecies heterogeneity of Baciillus coagulans leads to significant phenotypic differences among different strains.Thus,6 B.coagulans strains were tested in the present study using an irritable bowel syndr...The high intraspecies heterogeneity of Baciillus coagulans leads to significant phenotypic differences among different strains.Thus,6 B.coagulans strains were tested in the present study using an irritable bowel syndrome(IBS)animal model to determine whether the IBS-alleviating effects of B.coagulans strains are strain-specific.The results of this study showed that the ingestion of B.coagulans GBI-30,6086,and B.coagulans CCFM1041 significantly alleviated IBS symptoms in mice.In contrast,other B.coagulans strains showed no or limited alleviating effects on IBS symptoms.According to our experimental results,the two main common features of these strains were as follows:1)The resistance of vegetative cells to bile salts,and 2)ability to synthesize specific lipids and secondary metabolites.Screening strains based on these two indicators may greatly reduce costs and provide a basis for mining new functional B.coagulans strains.Our results also suggest that administration of B.coagulans could significantly regulate microbiota dysbiosis in animal models.Moreover,the close relationships between the gut microbiota,gut microbiota metabolites,and IBS were further confirmed in this study.展开更多
Cardiovascular Diseases (CVDs) pose a significant global health challenge, necessitating accurate risk prediction for effective preventive measures. This comprehensive comparative study explores the performance of tra...Cardiovascular Diseases (CVDs) pose a significant global health challenge, necessitating accurate risk prediction for effective preventive measures. This comprehensive comparative study explores the performance of traditional Machine Learning (ML) and Deep Learning (DL) models in predicting CVD risk, utilizing a meticulously curated dataset derived from health records. Rigorous preprocessing, including normalization and outlier removal, enhances model robustness. Diverse ML models (Logistic Regression, Random Forest, Support Vector Machine, K-Nearest Neighbor, Decision Tree, and Gradient Boosting) are compared with a Long Short-Term Memory (LSTM) neural network for DL. Evaluation metrics include accuracy, ROC AUC, computation time, and memory usage. Results identify the Gradient Boosting Classifier and LSTM as top performers, demonstrating high accuracy and ROC AUC scores. Comparative analyses highlight model strengths and limitations, contributing valuable insights for optimizing predictive strategies. This study advances predictive analytics for cardiovascular health, with implications for personalized medicine. The findings underscore the versatility of intelligent systems in addressing health challenges, emphasizing the broader applications of ML and DL in disease identification beyond cardiovascular health.展开更多
This article reflects on the process of transcribing spoken interaction and makes a comparative analysis of two different varieties of spoken interaction(casual conver- sation and institutional talk). By doing so, it ...This article reflects on the process of transcribing spoken interaction and makes a comparative analysis of two different varieties of spoken interaction(casual conver- sation and institutional talk). By doing so, it reveals how the different purposes of speech result in their distinctive characteristics, and shows how language is struc- tured to construct ideational meanings(Field) and interpersonal meanings(Tenor) that define each context.展开更多
This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments ...This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.展开更多
Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it int...Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it into wider usage within the field of medicine.Salvia Linn.(S.Linn.)is a large genus of Labiatae that includes important medicinal plants.In this herbgenomics study,the complete chloroplast(cp)genomes of two Salvia spp.—namely,S.przewalskii and S.bulleyana,which are used as a surrogate for S.miltiorrhiza—were sequenced and compared with those of two other reported Salvia spp.—namely,S.miltiorrhiza and S.japonica.The genome organization,gene number,type,and repeat sequences were compared.The annotation results showed that both Salvia plants contain 114 unique genes,including 80 protein-coding,30 transfer RNA(tRNA),and four ribosomal RNA(rRNA)genes.Repeat sequence analysis revealed 21 forward and 22 palindromic sequences in both Salvia cp genomes,and 17 and 21 tandem repeats in S.przewalskii and S.bulleyana,respectively.A synteny comparison of the Salvia spp.cp genomes showed a high degree of sequence similarity in the coding regions and a relatively high divergence of the intergenic spacers.Pairwise alignment and single-nucleotide polymorphism(SNP)analyses found some candidate fragments to identify Salvia spp.,such as the intergenic region of the trnV–ndhC,trnQ–rps16,atpI–atpH,psbA–ycf3,ycf1,rpoC2,ndhF,matK,rpoB,rpoA,and accD genes.All of the results—including the repeat sequences and SNP sites,the inverted repeat(IR)region border,and the phylogenetic analysis—showed that S.przewalskii and S.bulleyana are extremely similar from a genetic standpoint.The cp genome sequences of the two Salvia spp.reported here will pave the way for breeding,species identification,phylogenetic evolution,and cp genetic engineering studies of Salvia medicinal plants.展开更多
The knowledge of Martian salts has gone through substantial changes during the past decades. In the 70th of last century, Viking landers have noticed the existence of salts on Mars. Several salt species have been sugg...The knowledge of Martian salts has gone through substantial changes during the past decades. In the 70th of last century, Viking landers have noticed the existence of salts on Mars. Several salt species have been suggested from then on, such as sulfates and chlorides. However, their origin was a mystery due to the lack of observations. The recent explorations and related studies at the beginning of this century revealed that the crustal composition of Mars is similar to that of Earth, and it was hypothesized that almost one third of Martian surface was covered by oceans and lakes in the early stage of Mars. The huge water bodies may have dissolved a large quantity of ions from Martian primary rocks during the whole Noachian and Hesperian epoch. After the enormous drought event happened during the late Hesperian and the early Amazonian, these dissolved ions have formed huge salts deposits and most of them were preserved on Mars until today. To date, carbonates, sulfates, chlorides have all been detected by orbital remote sensing and by landers and rovers. However, the salt mineral assemblages on Mars seems to have some differences from those on Earth, e.g., rich in sulfates and lack of massive carbonates. To explain this difference, we propose that most of the surface carbonates precipitated from the ancient oceans may have been dissolved by the later ubiquitous acidic fluids originated from the global volcanism in the Hesperian era, and formed the enormous sulfate deposits as detected, and this hypothesis seems to be supported by the evidence that most of the sulfate deposits distribute around the Tharsis volcanic province while the survived carbonates located far from it. This process can release most of the carbon on Mars to the atmosphere in the form of CO2 and then be erased by the late heavy bombardments, which might have profound influence on the climate change happened in the Hesperian age. The positive correlation between the GRS results of the potassium distributions and the distribution of chlorides on Mars, together with the high Br concentration measured from the evaporate sediments at two Mars exploration rover landing sites, indicate that the brines in the regions where the chlorides deposited may have reached the stage for potassium salts deposition, thus we propose for the first time that potassium salts deposits might be prevalent in these regions.展开更多
This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were ...This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were determined and compared with those from Semporna(Malaysia),Sabah(Malaysia),Petchburi(Thailand),and two other species of seaweeds(Malaysia).The results showed that the polysaccharide and protein contents of C.lentillifera from Hainan(44.82%±0.98%and 12.5%±0.70%),Shandong(43.22%±1.42%and 14.7%±0.72%),Petchburi(59.27%±2.31%and 12.49%±0.30%),and Sabah(44.02%±2.01%and 19.38%±1.48%)were higher than those of Eucheuma cottonii(26.49%±3.01%and 9.76%±1.33%)and Sargassum polycystum(33.49%±1.70%and 5.40%±0.07%),respectively.The polyunsaturated fatty acid contents in C.lentillifera from Hainan(29.98%)and Shandong(22.11%)were higher than that in Semporna(16.76%±0.27%),Sabah(9.49%),and S.polycystum(20.34%±0.43%),but lower than that in E.cottonii(51.55%±0.57%).In Caulerpa lentillifera of Hainan and Shandong provinces,the essential amino acid(EAA)/total amino acid(TAA)ratios were 35.22%and 38.78%,respectively;and the EAA/ETAA ratios were 54.36%and 63.35%,respectively.The EAA composition of C.lentillifera was close to the ideal model of Food and Agriculture Organization/World Health Organization.C.lentillifera was rich in mineral elements,including calcium((3315.85±127.55)mg(100 g)^-1 and(3728.35±92.38)mg(100 g)^-1),magnesium((6715.74±82.58)mg(100 g)^-1 and(8128.59±242.72)mg(100 g)^-1),and trace elements,including iron((510.65±5.47)mg(100 g)^-1 and(1972.97±183.35)mg(100 g)^-1),selenium((1.04±0.08)mg(100 g)^-1 and(0.83±0.15)mg(100 g)^-1),and zinc((33.90±0.13)mg(100 g)^-1 and(11.75±2.05)mg(100 g)^-1).These results showed that C.lentillifera was more nutritious than S.polycystum or E.cottonii in terms of polysaccharide,protein,and fatty acid contents.Furthermore,both C.lentillifera species collected from Hainan and Shandong provinces show more basic nutrients.Therefore,C.lentillifera has important development and application prospects.展开更多
To examine accuracy of body composition predicted by the Multi-Frequency Bioelectric Impedance Analysis (MF-BIA) compared with the Dual-energy X-ray Absorptiometry (DXA) in adults with obese. We measured body comp...To examine accuracy of body composition predicted by the Multi-Frequency Bioelectric Impedance Analysis (MF-BIA) compared with the Dual-energy X-ray Absorptiometry (DXA) in adults with obese. We measured body composition of 749 adults with obese both by the MF-BIA and DXA. The Lin's concordance correlation and the Bland-Altman plots were used to examine the consistency. The concordance correlation coefficient of %BF between the MF-BIA and DXA in men and women was 0.560, and 0.669, respectively. Compared with the DXA, the MF-BIA significantly underestimated %BF by 4.33% in men (P 〈 0.001), however overestimated %BF by 0.50% in women (P 〈 0.001). After corrected by the correction equations established in this study, the differences were significantly decreased. Therefore, the MF-BIA (TANITA MC-180) may need to be corrected in estimating body composition for adults with obese.展开更多
In the present study,the complete genomes of four common(4/EV71/Wenzhou/CHN/2014,15/EV71/Wenzhou/CHN/2014,116/EV71/Wenzhou/CHN/2014,and 120/EV71/Wenzhou/CHN/2014)and two virulent(11/EV71/Wenzhou/CHN/2014and 109/EV7...In the present study,the complete genomes of four common(4/EV71/Wenzhou/CHN/2014,15/EV71/Wenzhou/CHN/2014,116/EV71/Wenzhou/CHN/2014,and 120/EV71/Wenzhou/CHN/2014)and two virulent(11/EV71/Wenzhou/CHN/2014and 109/EV71/Wenzhou/CHN/2014)enterovirus 71(EV71)isolates were sequenced and described.They are 7405 bp in length and belong to EV71 sub-genotype C4 (C4a cluster).展开更多
The male-sterile line has been largely used in the hybrid seed production of pepper, which can effectively improve the efficiency of hybrid seed production. However, the formation mechanism of male sterility in pepper...The male-sterile line has been largely used in the hybrid seed production of pepper, which can effectively improve the efficiency of hybrid seed production. However, the formation mechanism of male sterility in pepper remains unclear. In the present study, we compared the gene expression patterns between pepper cytoplasmic male sterile line 9704 A and its maintainer 9704 B during floral bud development using RNA sequencing technology. A total of 547 976 and 2 416 Differentially Expressed Genes(DEGs) were identified in the stage S1, S2 and S3, respectively,and more than 70% of the DEGs were down-regulated in the sterile line. Gene Ontology(GO), and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were performed to further understand the functions of these identified DEGs. The results showed that the DEGs were mainly enriched in pathways of starch and sucrose metabolism, pentose and glucuronate interconversions. A number of genes, such as MS1, PME5, ATPB, and lots of transcription factors were found down-regulated in the sterile line, and we also identified a series of genes with large differences in expression patterns between sterile line and maintainer line. Collectively, our findings laid a foundation for further molecular breeding in pepper and provided new insights into its mechanism underlying the male sterility.展开更多
Members of Veratrum are perennial herbs widely used in traditional Chinese medicine to induce vomiting,resolve blood stasis and relieve pain.However,the intrageneric classification and phylogenetic relationships withi...Members of Veratrum are perennial herbs widely used in traditional Chinese medicine to induce vomiting,resolve blood stasis and relieve pain.However,the intrageneric classification and phylogenetic relationships within Veratrum have long been controversial due to the complexity of morphological variations and lack of high-resolution molecular markers.In this study,we reevaluated the infrageneric relationships with the genus Veratrum using complete chloroplast genome sequence data.Herein,the complete cp genomes of ten species of Veratrum were newly sequenced and characterized.The complete cp genomes of ten species of Veratrum had the typical quadripartite structure,ranging from 151,597 bp to 153,711 bp in size and comprising a total of 135 genes.The structure of Veratrum cp genomes(i.e.,gene order,content,and genome components)was highly similar across species.The number of simple sequence repeats(SSRs)ranged from 63 to 7&and of long repeats ranged from 31 to 35.Eight highly divergent regions(ndhF,psbC-psbZ,psbK-psbl,rpoB-tmCjGCA,tmK_UUU-tmQ_UUG,tmS_GCU-tmG_UCC,tmT_UGU-tmL_UAA and ycfl)were identified and are potentially useful for the DNA barcoding of Veratrum.Phylogenetic analysis among 29 taxa based on cp genomes,total genes,protein-coding genes and intergenic regions strongly supported the monophyly of Veratrum.The circumscription and relationships of the infrageneric taxa of Veratrum were well-presented with great resolution.These results will facilitate the identification,taxonomy,and utilization of Veratrum plants as well as the evolutionary studies of Melanthiaceae.展开更多
Taking three typical farmers' specialized cooperatives in Jingyuan County of Gansu Province as example,this paper compared with the operating mode of three cooperatives and their position in the agricultural indus...Taking three typical farmers' specialized cooperatives in Jingyuan County of Gansu Province as example,this paper compared with the operating mode of three cooperatives and their position in the agricultural industry chain,and analyzed operating characteristics,problems,and similarities of three cooperatives and their functions in the agricultural industry chain.The study indicated that the farmers' specialized cooperatives can accurately find their position in the agricultural industry chain.This is helpful for raising their comprehensive competitiveness and it is very important to manage the survival and development of farmers' specialized cooperatives,which is of utmost importance to their effective operation.According to this study,the government should strengthen its support,speed up the cultivation of new-type professional farmers,while farmers' specialized cooperatives should grasp the operating characteristics,locate themselves and integrate multi-resources.These are effective measures for promoting healthy operation of farmers' specialized cooperatives.展开更多
Ginkgo biloba is a famous living“fossil”and has played an important role in the evolution of the Plant Kingdom.Here,the complete chloroplast genome of G.biloba was sequenced and analysed.The chloroplast genome was 1...Ginkgo biloba is a famous living“fossil”and has played an important role in the evolution of the Plant Kingdom.Here,the complete chloroplast genome of G.biloba was sequenced and analysed.The chloroplast genome was 156,990 bp long and predicted to encode 134 genes including 85 protein-coding genes,41 tRNA genes and 8 rRNA genes.The chloroplast genome has a typical quadripartite structure with a pair of inverted repeat regions(IRa and IRb,17,732 bp),a large(LSC,99,259 bp)and small single(SSC,22,267 bp)copy region.After an extensive comparison to previously published gymnosperm plastomes,the gene content and organisation of G.biloba showed high divergence,although part was relatively conserved.The two typical IR regions in the G.biloba chloroplast genome were relatively shorter because it the ycf2 gene.In addition,it was obvious that the IR regions and gene loss were responsible for changes in chloroplast genome size and structure stability,which influenced plastome evolution in different gymnosperms.Phylogenetic analysis revealed that G.biloba is sister to cycads rather than to gnetophytes,cupressophytes,and Pinaceae.Overall,the study showed that the genomic characteristics of G.biloba would be of great help in the further research on the taxonomy,species identification and evolutionary history of gymnosperms,especially for their position in plant systematics and evolution.展开更多
Salinity is one of the most important abiotic stresses that adversely affects crop growth and productivity. A subtractive suppression hybridization (SSH) library were constructed from the roots of salt-sensitive Yul...Salinity is one of the most important abiotic stresses that adversely affects crop growth and productivity. A subtractive suppression hybridization (SSH) library were constructed from the roots of salt-sensitive Yulu cultivar melon seedlings under salt stress; 557 high-quality expressed sequence tags (ESTs) were randomly sequenced, with an average size of 428 bp, which assembled into 68 contigs and 315 singletons. Compared with our previous SSH library generated from the salt-tolerant Bingxuecui cultivar, the proportion of transcripts involved in metabolism, protein fate, cellular communication/signal transduction mechanisms, and cell rescue/defense were 4, 1.46, 0.94, and 0.4% higher, respectively, in the salt-tolerant cultivar than the in salt-sensitive cultivar. Quantitative real-time PCR analysis of eleven transcripts revealed temporal variations in their expression in the two cultivars under salt stress. One NAC gene (JZ477011) was heterologously expressed in yeast for functional characterization, and enhanced the sensitivity of yeast cells to high-salinity to salt stress and inhibited their growth. Information regards to their functions would aid in the understanding of response mechanisms to saline stress and in the development of molecular markers for selecting salt-tolerant melon cultivars.展开更多
In this study, the Palmer Drought Severity Index (PDSI) was used to analyze the average and extreme dry/wet states of Asia and North America from 1953 to 2003. The results indicate that the two continents underwent ...In this study, the Palmer Drought Severity Index (PDSI) was used to analyze the average and extreme dry/wet states of Asia and North America from 1953 to 2003. The results indicate that the two continents underwent drying trends during this period. Compared with North America, Asia showed more severe drought trends. However, more significant and regular seasonal variation for drought was found in North America. The driest regions in Asia were located in the northern region of China, Mongolia, and eastern mid-Siberian plateau. Most regions in central North America were relatively wetter than other regions. The northern and southwestern regions of North America, as well as the Atlantic and Pacific coastal areas, experienced the most drought during this period. A sharp increase of the drought area and the number of extreme drought events took place from 1997 to 2003 in both Asia and North America. Severe drought events were more likely to occur during the summer on both continents. Asia had the most extreme drought events during July, but North America reached its highest drought frequency from June to September. In Asia, a persistent increasing trend of extreme drought emerged throughout the studied period. However, a more complex evolution of drought emerged in North America: a decreasing trend appeared before the mid-1960s and an increasing trend appeared after the late 1970s. A relatively steady dry/wet status was observed between the mid-1960s and the late 1970s. The role of exceptional, extreme drought events with respect to the La Nin?a event was considered during 1997–2003.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.32200590 to K.L.,81972358 to Q.W.,91959113 to Q.W.,and 82372897 to Q.W.)the Natural Science Foundation of Jiangsu Province(Grant No.BK20210530 to K.L.).
文摘Given the extremely high inter-patient heterogeneity of acute myeloid leukemia(AML),the identification of biomarkers for prognostic assessment and therapeutic guidance is critical.Cell surface markers(CSMs)have been shown to play an important role in AML leukemogenesis and progression.In the current study,we evaluated the prognostic potential of all human CSMs in 130 AML patients from The Cancer Genome Atlas(TCGA)based on differential gene expression analysis and univariable Cox proportional hazards regression analysis.By using multi-model analysis,including Adaptive LASSO regression,LASSO regression,and Elastic Net,we constructed a 9-CSMs prognostic model for risk stratification of the AML patients.The predictive value of the 9-CSMs risk score was further validated at the transcriptome and proteome levels.Multivariable Cox regression analysis showed that the risk score was an independent prognostic factor for the AML patients.The AML patients with high 9-CSMs risk scores had a shorter overall and event-free survival time than those with low scores.Notably,single-cell RNA-sequencing analysis indicated that patients with high 9-CSMs risk scores exhibited chemotherapy resistance.Furthermore,PI3K inhibitors were identified as potential treatments for these high-risk patients.In conclusion,we constructed a 9-CSMs prognostic model that served as an independent prognostic factor for the survival of AML patients and held the potential for guiding drug therapy.
文摘Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response.This paper proposes an augmented Bayesian multi-model inference(BMMI)coupled with GSA methodology(BMMI-GSA)to address this issue by estimating the imprecision in the momentindependent sensitivity indices of rock structures arising from the small size of input data.The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties.The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo’s indices by employing a reweighting approach on candidate probabilistic models.The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India.The proposed methodology was superior to the conventional GSA(neglects all epistemic uncertainties)and Bayesian coupled GSA(B-GSA)(neglects model uncertainty)due to its capability to incorporate the uncertainties in both model type and parameters of properties.Imprecise Borgonovo’s indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates,which makes the user more informed in the data collection efforts.Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes.The accurate importance ranking of properties was only possible via samples of large sizes.Further,the impact of the prior knowledge in terms of prior ranges and distributions was significant;hence,any related assumption should be made carefully.
文摘This research paper compares Excel and R language for data analysis and concludes that R language is more suitable for complex data analysis tasks.R language’s open-source nature makes it accessible to everyone,and its powerful data management and analysis tools make it suitable for handling complex data analysis tasks.It is also highly customizable,allowing users to create custom functions and packages to meet their specific needs.Additionally,R language provides high reproducibility,making it easy to replicate and verify research results,and it has excellent collaboration capabilities,enabling multiple users to work on the same project simultaneously.These advantages make R language a more suitable choice for complex data analysis tasks,particularly in scientific research and business applications.The findings of this study will help people understand that R is not just a language that can handle more data than Excel and demonstrate that r is essential to the field of data analysis.At the same time,it will also help users and organizations make informed decisions regarding their data analysis needs and software preferences.
基金Social Science Planning Project of Xi an City(JG140)Bidding Project of Buchang Xixian Economic Research Institute(SMZX202113).
文摘Based on the analysis of rice planting and export development in Heilongjiang Province in 2013-2021,this paper comprehensively used three export competitiveness analysis methods,namely,trade competitiveness index,revealed comparative advantage(RCA)analysis and international market share analysis,to compare the four major rice exporters in the world and the three major rice export provinces and cities in China.Besides,it evaluated the rice export competitiveness of Heilongjiang Province from multiple perspectives.It analyzed the reasons for low competitiveness in terms of export product structure,export market structure,production and processing technology,and brand building.Finally,it is recommended to clarify the positioning of rice export quality and take more measures to ensure product quality;improve the level of industrialization of rice production and processing,and extend the rice industry chain;develop diversified rice export markets and improve export flexibility;adhere to the principle of"opening the door and going out",expand the international popularity of high-quality brands,so as to enhance the rice export competitiveness of Heilongjiang Province.
文摘This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20200084)the National Natural Science Foundation of China(31871773 and 31820103010)+1 种基金the Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province and Key Talents Project of“Strengthening Health through Science and Education”of Wuxi Health and Family Planning Commission(ZDRC039)Top Talents Project of“Six-one Project”for High-level Health Talents in Jiangsu Province(LGY2018016)。
文摘The high intraspecies heterogeneity of Baciillus coagulans leads to significant phenotypic differences among different strains.Thus,6 B.coagulans strains were tested in the present study using an irritable bowel syndrome(IBS)animal model to determine whether the IBS-alleviating effects of B.coagulans strains are strain-specific.The results of this study showed that the ingestion of B.coagulans GBI-30,6086,and B.coagulans CCFM1041 significantly alleviated IBS symptoms in mice.In contrast,other B.coagulans strains showed no or limited alleviating effects on IBS symptoms.According to our experimental results,the two main common features of these strains were as follows:1)The resistance of vegetative cells to bile salts,and 2)ability to synthesize specific lipids and secondary metabolites.Screening strains based on these two indicators may greatly reduce costs and provide a basis for mining new functional B.coagulans strains.Our results also suggest that administration of B.coagulans could significantly regulate microbiota dysbiosis in animal models.Moreover,the close relationships between the gut microbiota,gut microbiota metabolites,and IBS were further confirmed in this study.
文摘Cardiovascular Diseases (CVDs) pose a significant global health challenge, necessitating accurate risk prediction for effective preventive measures. This comprehensive comparative study explores the performance of traditional Machine Learning (ML) and Deep Learning (DL) models in predicting CVD risk, utilizing a meticulously curated dataset derived from health records. Rigorous preprocessing, including normalization and outlier removal, enhances model robustness. Diverse ML models (Logistic Regression, Random Forest, Support Vector Machine, K-Nearest Neighbor, Decision Tree, and Gradient Boosting) are compared with a Long Short-Term Memory (LSTM) neural network for DL. Evaluation metrics include accuracy, ROC AUC, computation time, and memory usage. Results identify the Gradient Boosting Classifier and LSTM as top performers, demonstrating high accuracy and ROC AUC scores. Comparative analyses highlight model strengths and limitations, contributing valuable insights for optimizing predictive strategies. This study advances predictive analytics for cardiovascular health, with implications for personalized medicine. The findings underscore the versatility of intelligent systems in addressing health challenges, emphasizing the broader applications of ML and DL in disease identification beyond cardiovascular health.
文摘This article reflects on the process of transcribing spoken interaction and makes a comparative analysis of two different varieties of spoken interaction(casual conver- sation and institutional talk). By doing so, it reveals how the different purposes of speech result in their distinctive characteristics, and shows how language is struc- tured to construct ideational meanings(Field) and interpersonal meanings(Tenor) that define each context.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(No.2017R1A5A1014883).
文摘This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.
基金This work is supported by the National Nature Science Foundation of China(QFSL2018004,2017YFC1702100,and 81741060)the Fundamental Research Funds for the Central Public Welfare Research Institutes(ZXKT17004).
文摘Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it into wider usage within the field of medicine.Salvia Linn.(S.Linn.)is a large genus of Labiatae that includes important medicinal plants.In this herbgenomics study,the complete chloroplast(cp)genomes of two Salvia spp.—namely,S.przewalskii and S.bulleyana,which are used as a surrogate for S.miltiorrhiza—were sequenced and compared with those of two other reported Salvia spp.—namely,S.miltiorrhiza and S.japonica.The genome organization,gene number,type,and repeat sequences were compared.The annotation results showed that both Salvia plants contain 114 unique genes,including 80 protein-coding,30 transfer RNA(tRNA),and four ribosomal RNA(rRNA)genes.Repeat sequence analysis revealed 21 forward and 22 palindromic sequences in both Salvia cp genomes,and 17 and 21 tandem repeats in S.przewalskii and S.bulleyana,respectively.A synteny comparison of the Salvia spp.cp genomes showed a high degree of sequence similarity in the coding regions and a relatively high divergence of the intergenic spacers.Pairwise alignment and single-nucleotide polymorphism(SNP)analyses found some candidate fragments to identify Salvia spp.,such as the intergenic region of the trnV–ndhC,trnQ–rps16,atpI–atpH,psbA–ycf3,ycf1,rpoC2,ndhF,matK,rpoB,rpoA,and accD genes.All of the results—including the repeat sequences and SNP sites,the inverted repeat(IR)region border,and the phylogenetic analysis—showed that S.przewalskii and S.bulleyana are extremely similar from a genetic standpoint.The cp genome sequences of the two Salvia spp.reported here will pave the way for breeding,species identification,phylogenetic evolution,and cp genetic engineering studies of Salvia medicinal plants.
基金supported by the Basic Research and Operating Fund (K0903)the China Geological survey's project (1212011085524 12120113019100)
文摘The knowledge of Martian salts has gone through substantial changes during the past decades. In the 70th of last century, Viking landers have noticed the existence of salts on Mars. Several salt species have been suggested from then on, such as sulfates and chlorides. However, their origin was a mystery due to the lack of observations. The recent explorations and related studies at the beginning of this century revealed that the crustal composition of Mars is similar to that of Earth, and it was hypothesized that almost one third of Martian surface was covered by oceans and lakes in the early stage of Mars. The huge water bodies may have dissolved a large quantity of ions from Martian primary rocks during the whole Noachian and Hesperian epoch. After the enormous drought event happened during the late Hesperian and the early Amazonian, these dissolved ions have formed huge salts deposits and most of them were preserved on Mars until today. To date, carbonates, sulfates, chlorides have all been detected by orbital remote sensing and by landers and rovers. However, the salt mineral assemblages on Mars seems to have some differences from those on Earth, e.g., rich in sulfates and lack of massive carbonates. To explain this difference, we propose that most of the surface carbonates precipitated from the ancient oceans may have been dissolved by the later ubiquitous acidic fluids originated from the global volcanism in the Hesperian era, and formed the enormous sulfate deposits as detected, and this hypothesis seems to be supported by the evidence that most of the sulfate deposits distribute around the Tharsis volcanic province while the survived carbonates located far from it. This process can release most of the carbon on Mars to the atmosphere in the form of CO2 and then be erased by the late heavy bombardments, which might have profound influence on the climate change happened in the Hesperian age. The positive correlation between the GRS results of the potassium distributions and the distribution of chlorides on Mars, together with the high Br concentration measured from the evaporate sediments at two Mars exploration rover landing sites, indicate that the brines in the regions where the chlorides deposited may have reached the stage for potassium salts deposition, thus we propose for the first time that potassium salts deposits might be prevalent in these regions.
基金supported by the National Natural Science Foundation of China(No.31860450)the Marine and Fisheries Bureau of Haikou(No.HHCL201804)+2 种基金the Innovative Research Projects of Graduate Students of Hai-nan Province(No.Hys2018-197)the Key Science and Technology Program of Haikou City(No.2017051)the Scientific Research Foundation of Hainan University(No.kyqd1662)
文摘This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were determined and compared with those from Semporna(Malaysia),Sabah(Malaysia),Petchburi(Thailand),and two other species of seaweeds(Malaysia).The results showed that the polysaccharide and protein contents of C.lentillifera from Hainan(44.82%±0.98%and 12.5%±0.70%),Shandong(43.22%±1.42%and 14.7%±0.72%),Petchburi(59.27%±2.31%and 12.49%±0.30%),and Sabah(44.02%±2.01%and 19.38%±1.48%)were higher than those of Eucheuma cottonii(26.49%±3.01%and 9.76%±1.33%)and Sargassum polycystum(33.49%±1.70%and 5.40%±0.07%),respectively.The polyunsaturated fatty acid contents in C.lentillifera from Hainan(29.98%)and Shandong(22.11%)were higher than that in Semporna(16.76%±0.27%),Sabah(9.49%),and S.polycystum(20.34%±0.43%),but lower than that in E.cottonii(51.55%±0.57%).In Caulerpa lentillifera of Hainan and Shandong provinces,the essential amino acid(EAA)/total amino acid(TAA)ratios were 35.22%and 38.78%,respectively;and the EAA/ETAA ratios were 54.36%and 63.35%,respectively.The EAA composition of C.lentillifera was close to the ideal model of Food and Agriculture Organization/World Health Organization.C.lentillifera was rich in mineral elements,including calcium((3315.85±127.55)mg(100 g)^-1 and(3728.35±92.38)mg(100 g)^-1),magnesium((6715.74±82.58)mg(100 g)^-1 and(8128.59±242.72)mg(100 g)^-1),and trace elements,including iron((510.65±5.47)mg(100 g)^-1 and(1972.97±183.35)mg(100 g)^-1),selenium((1.04±0.08)mg(100 g)^-1 and(0.83±0.15)mg(100 g)^-1),and zinc((33.90±0.13)mg(100 g)^-1 and(11.75±2.05)mg(100 g)^-1).These results showed that C.lentillifera was more nutritious than S.polycystum or E.cottonii in terms of polysaccharide,protein,and fatty acid contents.Furthermore,both C.lentillifera species collected from Hainan and Shandong provinces show more basic nutrients.Therefore,C.lentillifera has important development and application prospects.
文摘To examine accuracy of body composition predicted by the Multi-Frequency Bioelectric Impedance Analysis (MF-BIA) compared with the Dual-energy X-ray Absorptiometry (DXA) in adults with obese. We measured body composition of 749 adults with obese both by the MF-BIA and DXA. The Lin's concordance correlation and the Bland-Altman plots were used to examine the consistency. The concordance correlation coefficient of %BF between the MF-BIA and DXA in men and women was 0.560, and 0.669, respectively. Compared with the DXA, the MF-BIA significantly underestimated %BF by 4.33% in men (P 〈 0.001), however overestimated %BF by 0.50% in women (P 〈 0.001). After corrected by the correction equations established in this study, the differences were significantly decreased. Therefore, the MF-BIA (TANITA MC-180) may need to be corrected in estimating body composition for adults with obese.
基金funded by Natural Science Foundation of Zhejiang(LQ14C010006)National Natural Science Foundation of China(81501363)Planned Science and Technology Project of Zhejiang(2014C33261)
文摘In the present study,the complete genomes of four common(4/EV71/Wenzhou/CHN/2014,15/EV71/Wenzhou/CHN/2014,116/EV71/Wenzhou/CHN/2014,and 120/EV71/Wenzhou/CHN/2014)and two virulent(11/EV71/Wenzhou/CHN/2014and 109/EV71/Wenzhou/CHN/2014)enterovirus 71(EV71)isolates were sequenced and described.They are 7405 bp in length and belong to EV71 sub-genotype C4 (C4a cluster).
基金This work was supported by China Agriculture Research System(Grant No.CARS-23-G29).
文摘The male-sterile line has been largely used in the hybrid seed production of pepper, which can effectively improve the efficiency of hybrid seed production. However, the formation mechanism of male sterility in pepper remains unclear. In the present study, we compared the gene expression patterns between pepper cytoplasmic male sterile line 9704 A and its maintainer 9704 B during floral bud development using RNA sequencing technology. A total of 547 976 and 2 416 Differentially Expressed Genes(DEGs) were identified in the stage S1, S2 and S3, respectively,and more than 70% of the DEGs were down-regulated in the sterile line. Gene Ontology(GO), and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were performed to further understand the functions of these identified DEGs. The results showed that the DEGs were mainly enriched in pathways of starch and sucrose metabolism, pentose and glucuronate interconversions. A number of genes, such as MS1, PME5, ATPB, and lots of transcription factors were found down-regulated in the sterile line, and we also identified a series of genes with large differences in expression patterns between sterile line and maintainer line. Collectively, our findings laid a foundation for further molecular breeding in pepper and provided new insights into its mechanism underlying the male sterility.
文摘Members of Veratrum are perennial herbs widely used in traditional Chinese medicine to induce vomiting,resolve blood stasis and relieve pain.However,the intrageneric classification and phylogenetic relationships within Veratrum have long been controversial due to the complexity of morphological variations and lack of high-resolution molecular markers.In this study,we reevaluated the infrageneric relationships with the genus Veratrum using complete chloroplast genome sequence data.Herein,the complete cp genomes of ten species of Veratrum were newly sequenced and characterized.The complete cp genomes of ten species of Veratrum had the typical quadripartite structure,ranging from 151,597 bp to 153,711 bp in size and comprising a total of 135 genes.The structure of Veratrum cp genomes(i.e.,gene order,content,and genome components)was highly similar across species.The number of simple sequence repeats(SSRs)ranged from 63 to 7&and of long repeats ranged from 31 to 35.Eight highly divergent regions(ndhF,psbC-psbZ,psbK-psbl,rpoB-tmCjGCA,tmK_UUU-tmQ_UUG,tmS_GCU-tmG_UCC,tmT_UGU-tmL_UAA and ycfl)were identified and are potentially useful for the DNA barcoding of Veratrum.Phylogenetic analysis among 29 taxa based on cp genomes,total genes,protein-coding genes and intergenic regions strongly supported the monophyly of Veratrum.The circumscription and relationships of the infrageneric taxa of Veratrum were well-presented with great resolution.These results will facilitate the identification,taxonomy,and utilization of Veratrum plants as well as the evolutionary studies of Melanthiaceae.
文摘Taking three typical farmers' specialized cooperatives in Jingyuan County of Gansu Province as example,this paper compared with the operating mode of three cooperatives and their position in the agricultural industry chain,and analyzed operating characteristics,problems,and similarities of three cooperatives and their functions in the agricultural industry chain.The study indicated that the farmers' specialized cooperatives can accurately find their position in the agricultural industry chain.This is helpful for raising their comprehensive competitiveness and it is very important to manage the survival and development of farmers' specialized cooperatives,which is of utmost importance to their effective operation.According to this study,the government should strengthen its support,speed up the cultivation of new-type professional farmers,while farmers' specialized cooperatives should grasp the operating characteristics,locate themselves and integrate multi-resources.These are effective measures for promoting healthy operation of farmers' specialized cooperatives.
基金supported by the Key Forestry Public Welfare Project of China(201504105)the National Key Research and Development Program of China(2017YFD0600700)the Agricultural Science and Technology Independent Innovation Funds of Jiangsu Province[CX(16)1005].
文摘Ginkgo biloba is a famous living“fossil”and has played an important role in the evolution of the Plant Kingdom.Here,the complete chloroplast genome of G.biloba was sequenced and analysed.The chloroplast genome was 156,990 bp long and predicted to encode 134 genes including 85 protein-coding genes,41 tRNA genes and 8 rRNA genes.The chloroplast genome has a typical quadripartite structure with a pair of inverted repeat regions(IRa and IRb,17,732 bp),a large(LSC,99,259 bp)and small single(SSC,22,267 bp)copy region.After an extensive comparison to previously published gymnosperm plastomes,the gene content and organisation of G.biloba showed high divergence,although part was relatively conserved.The two typical IR regions in the G.biloba chloroplast genome were relatively shorter because it the ycf2 gene.In addition,it was obvious that the IR regions and gene loss were responsible for changes in chloroplast genome size and structure stability,which influenced plastome evolution in different gymnosperms.Phylogenetic analysis revealed that G.biloba is sister to cycads rather than to gnetophytes,cupressophytes,and Pinaceae.Overall,the study showed that the genomic characteristics of G.biloba would be of great help in the further research on the taxonomy,species identification and evolutionary history of gymnosperms,especially for their position in plant systematics and evolution.
基金supported by grants from the National Natural Science Foundation of China(31372079)the National High Technology Research and Development Program of China(863 Program,2012AA101903)+1 种基金the Natural Science Foundation of Shanghai Science and Technology Committee,China(13ZR1422400)Shanghi Graduate Education and Innovation Program(Horticulture),China
文摘Salinity is one of the most important abiotic stresses that adversely affects crop growth and productivity. A subtractive suppression hybridization (SSH) library were constructed from the roots of salt-sensitive Yulu cultivar melon seedlings under salt stress; 557 high-quality expressed sequence tags (ESTs) were randomly sequenced, with an average size of 428 bp, which assembled into 68 contigs and 315 singletons. Compared with our previous SSH library generated from the salt-tolerant Bingxuecui cultivar, the proportion of transcripts involved in metabolism, protein fate, cellular communication/signal transduction mechanisms, and cell rescue/defense were 4, 1.46, 0.94, and 0.4% higher, respectively, in the salt-tolerant cultivar than the in salt-sensitive cultivar. Quantitative real-time PCR analysis of eleven transcripts revealed temporal variations in their expression in the two cultivars under salt stress. One NAC gene (JZ477011) was heterologously expressed in yeast for functional characterization, and enhanced the sensitivity of yeast cells to high-salinity to salt stress and inhibited their growth. Information regards to their functions would aid in the understanding of response mechanisms to saline stress and in the development of molecular markers for selecting salt-tolerant melon cultivars.
基金supported by the NSFC project (Grant Nos. 40905037, 40775055,40705016, and 40828004)the NSFC key program(Grant No. 40830956)
文摘In this study, the Palmer Drought Severity Index (PDSI) was used to analyze the average and extreme dry/wet states of Asia and North America from 1953 to 2003. The results indicate that the two continents underwent drying trends during this period. Compared with North America, Asia showed more severe drought trends. However, more significant and regular seasonal variation for drought was found in North America. The driest regions in Asia were located in the northern region of China, Mongolia, and eastern mid-Siberian plateau. Most regions in central North America were relatively wetter than other regions. The northern and southwestern regions of North America, as well as the Atlantic and Pacific coastal areas, experienced the most drought during this period. A sharp increase of the drought area and the number of extreme drought events took place from 1997 to 2003 in both Asia and North America. Severe drought events were more likely to occur during the summer on both continents. Asia had the most extreme drought events during July, but North America reached its highest drought frequency from June to September. In Asia, a persistent increasing trend of extreme drought emerged throughout the studied period. However, a more complex evolution of drought emerged in North America: a decreasing trend appeared before the mid-1960s and an increasing trend appeared after the late 1970s. A relatively steady dry/wet status was observed between the mid-1960s and the late 1970s. The role of exceptional, extreme drought events with respect to the La Nin?a event was considered during 1997–2003.