Magnetic resonance imaging-based radiomics model for preoperative assessment of risk stratification in endometrial cancer

BACKGROUND Preoperative risk stratification is significant for the management of endometrial cancer(EC)patients.Radiomics based on magnetic resonance imaging(MRI)in combination with clinical features may be useful to predict the risk grade of EC.AIM To construct machine learning models to predict preoperative risk stratification of patients with EC based on radiomics features extracted from MRI.METHODS The study comprised 112 EC patients.The participants were randomly separated into training and validation groups with a 7:3 ratio.Logistic regression analysis was applied to uncover independent clinical predictors.These predictors were then used to create a clinical nomogram.Extracted radiomics features from the T2-weighted imaging and diffusion weighted imaging sequences of MRI images,the Mann-Whitney U test,Pearson test,and least absolute shrinkage and selection operator analysis were employed to evaluate the relevant radiomic features,which were subsequently utilized to generate a radiomic signature.Seven machine learning strategies were used to construct radiomic models that relied on the screening features.The logistic regression method was used to construct a composite nomogram that incorporated both the radiomic signature and clinical independent risk indicators.RESULTS Having an accuracy of 0.82 along with an area under the curve(AUC)of 0.915[95%confidence interval(CI):0.806-0.986],the random forest method trained on radiomics characteristics performed better than expected.The predictive accuracy of radiomics prediction models surpassed that of both the clinical nomogram(AUC:0.75,95%CI:0.611-0.899)and the combined nomogram(AUC:0.869,95%CI:0.702-0.986)that integrated clinical parameters and radiomic signature.CONCLUSION The MRI-based radiomics model may be an effective tool for preoperative risk grade prediction in EC patients.

Discovery and validation of prognostic markers in gastric cancer by genome-wide expression profiling

AIM: To develop a prognostic gene set that can predict patient overall survival status based on the whole genome expression analysis. METHODS: Using Illumina HumanWG-6 BeadChip followed by semi-supervised analysis, we analyzed the expression of 47 296 transcripts in two batches of gastric cancer patients who underwent surgical resection. Thirty-nine samples in the first batch were used as the training set to discover candidate markers correlated to overall survival, and thirty-three samples in the second batch were used for validation. RESULTS: A panel of ten genes were identified as prognostic marker in the first batch samples and classified patients into a lowand a high-risk group with significantly different survival times (P = 0.000047). This prognostic marker was then verified in an independent validation sample batch (P = 0.0009). By comparing with the traditional Tumor-node-metastasis (TNM) staging system, this ten-gene prognostic marker showed consistent prognosis results. It was the only independent prognostic value by multivariate Cox regression analysis (P = 0.007). Interestingly, six of these ten genes are ribosomal proteins, suggesting a possible association between the deregulation of ribosome related gene expression and the poor prognosis. CONCLUSION: A ten-gene marker correlated with overall prognosis, including 6 ribosomal proteins, was identified and verified, which may complement the predictive value of TNM staging system.

Characterization of prognosis and immune infiltration by a novel glutamine metabolism-related model in cutaneous melanoma

Glutamine metabolism(GM)plays an important role in tumor growth and proliferation.Skin cutaneous melanoma(SKCM)is a glutamine-dependent cancer.However,the molecular characteristics and action mechanism of GM on SKCM remain unclear.Therefore,we aimed to explore the effects of GM-related genes on survival,clinicopathological characteristics,and the tumor microenvironment in SKCM.In this study,682 SKCM samples were obtained from the Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases.Consensus clustering was used to classify SKCM samples into distinct subtypes based on 41 GM-related genes.Differences in survival,immune infiltration,clinical characteristics,and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways as well as differentially expressed genes(DEGs)between subgroups were evaluated.A prognostic model was constructed according to prognostic DEGs.Differential analyses in survival,immune infiltration,tumor microenvironment(TME),tumor mutation burden(TMB),stemness,and drug sensitivity between risk groups were conducted.We identified two distinct GM-related subtypes on SKCM and found that GM-related gene alterations were associated with survival probability,clinical features,biological function,and immune infiltration.Then a risk model based on six DEGs(IL18,SEMA6A,PAEP,TNFRSF17,AIM2,and CXCL10)was constructed and validated for predicting overall survival in SKCM patients.The results showed that the risk score was negatively correlated with CD8+T cells,activated CD4+memory T cells,M1 macrophages,andγδT cells.The group with a low-risk score was accompanied by a better survival rate with higher TME scores and lower stemness index.Moreover,the group with high-and low-risk score had a significant difference with the sensitivity of 75 drugs(p<0.001).Overall,distinct subtypes in SKCM patients based on GM-related genes were identified and the risk model was constructed,which might contribute to prognosis prediction,guide clinical therapy,and develop novel therapeutic strategies.

The apricot(Prunus armeniaca L.)genome elucidates Rosaceae evolution and beta-carotenoid synthesis

Apricots,scientifically known as Prunus armeniaca L,are drupes that resemble and are closely related to peaches or plums.As one of the top consumed fruits,apricots are widely grown worldwide except in Antarctica.A high-quality reference genome for apricot is still unavailable,which has become a handicap that has dramatically limited the elucidation of the associations of phenotypes with the genetic background,evolutionary diversity,and population diversity in apricot.DNA from P.armeniaca was used to generate a standard,size-selected library with an average DNA fragment size of~20 kb.The library was run on Sequel SMRT Cells,generating a total of 16.54 Gb of PacBio subreads(N50=13.55 kb).The high-quality P.armeniaca reference genome presented here was assembled using long-read single-molecule sequencing at approximately 70×coverage and 171×Illumina reads(40.46 Gb),combined with a genetic map for chromosome scaffolding.The assembled genome size was 221.9 Mb,with a contig NG50 size of 1.02 Mb.Scaffolds covering 92.88%of the assembled genome were anchored on eight chromosomes.Benchmarking Universal Single-Copy Orthologs analysis showed 98.0%complete genes.We predicted 30,436 protein-coding genes,and 38.28%of the genome was predicted to be repetitive.We found 981 contracted gene families,1324 expanded gene families and 2300 apricot-specific genes.The differentially expressed gene(DEG)analysis indicated that a change in the expression of the 9-cis-epoxycarotenoid dioxygenase(NCED)gene but not lycopene beta-cyclase(LcyB)gene results in a lowβ-carotenoid content in the white cultivar“Dabaixing”.This complete and highly contiguous P.armeniaca reference genome will be of help for future studies of resistance to plum pox virus(PPV)and the identification and characterization of important agronomic genes and breeding strategies in apricot.

Analysis of expressed sequence tags from the Ulva prolifera (Chlorophyta)

In 2008, a green tide broke out before the sailing competition of the 29th Olympic Games in Qingdao. The causative species was determined to be Enteromorpha prolifera （Ulva prolifera O. F. Miiller）, a familiar green macroalga along the coastline of China. Rapid accumulation of a large biomass of floating U. prolifera prompted research on different aspects of this species. In this study, we constructed a nonnormalized cDNA library from the thalli of U. prolifera and acquired 10072 high-quality expressed sequence tags （ESTs）. These ESTs were assembled into 3 519 nonredundant gene groups, including 1 446 clusters and 2 073 singletons. After annotation with the nr database, a large number of genes were found to be related with chloroplast and ribosomal protein, GO functional classification showed 1 418 ESTs participated in photosynthesis and 1 359 ESTs were responsible for the generation of precursor metabolites and energy. In addition, rather comprehensive carbon fixation pathways were found in U. prolifera using KEGG. Some stress-related and signal transduction-related genes were also found in this study. All the evidences displayed that U. prolifera had substance and energy foundation for the intense photosynthesis and the rapid proliferation. Phylogenetic analysis of cytochrome c oxidase subunit I revealed that this green-tide causative species is most closely affiliated to Pseudendoclonium akinetum （Ulvophyceae）.

Genome engineering using the CRISPR/Cas system

Recently, an epoch-making genome engineering technology using clustered regularly at interspaced short palindromic repeats(CRISPR) and CRISPR associated(Cas) nucleases, was developed. Previous technologies for genome manipulation require the time-consuming design and construction of genome-engineered nucleases for each target and have, therefore, not been widely used in mouse research where standard techniques based on homologous recombination are commonly used. The CRISPR/Cas system only requires the design of sequences complementary to a target locus, making this technology fast and straightforward. In addition, CRISPR/Cas can be used to generate mice carrying mutations in multiple genes in a single step, an achievement not possible using other methods. Here, we review the uses of this technology in genetic analysis and manipulation, including achievements made possible to date and the prospects for future therapeutic applications.

Comparative analysis of four essential Gracilariaceae species in China based on whole transcriptomic sequencing

Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-cies which are important resources for the production of special proteins, phycobilisomes, special carbo-hydrates, and agar in China. In this study, de novo transcriptome sequencing on these four species using the next generation sequencing technology was performed for the first time. Functional annotations on assembled sequencing reads showed that the transcriptomic profiles were quite different between G. lema-neiformis and other three Gracilaria species. Comparative analysis of differential gene expression related to carbohydrate and phycobiliprotein metabolisms also showed that the expression profiles of these essential genes were different in four species. The genes encoding allophycocyanin, phycocyanin and phycoerythrin were further examined in four species and their deduced amino acid sequences were used for phylogenetic analysis to confirm that G. lemaneiformis had close relationship to genus Gracilaria, as well as that within genus Gracilaria, G. chouae had closer relationship to G. vermiculophylla rather than to G. blodgettii. The de novo transcriptome study on four species provided a valuable genomic resource for further understanding and analysis on biological and evolutionary study among marine algae.

Phylogenetic analyses of the genes involved in carotenoid biosynthesis in algae

Carotenoids play a crucial role in absorbing light energy for photosynthesis,as well as in protecting chlorophyll from photodamage.In contrast to the Streptophyta,few studies have examined carotenoid biosynthetic pathways in algae,owing to a shortage of datasets.As part of the 1000 Plants Project,we sequenced and assembled the transcriptomes of 41 marine macroalgal species,including 22 rhodophytes and 19 phaeophytes,and then combined the datasets with publicly available data from Gen Bank（National Center for Biotechnology Information） and the U.S.Department of Energy Joint Genome Institute.As a result,we identified 68 and 79 fulllength homologs in the Rhodophyta and Phaeophyceae,respectively,of seven inferred carotenoid biosynthetic genes,including the genes for phytoene synthase（PSY）,phytoene desaturase（PDS）,ζ-carotene desaturase（ZDS）,ζ-carotene isomerase（Z-ISO）,prolycopene isomerase（crt ISO）,lycopene β-cyclase（LCYB）,and lycopene ε-cyclase（LCYE）.We found that the evolutionary history of the algal carotenoid biosynthetic pathway was more complex than that of the same pathway in the Streptophyta and,more specifically,that the evolutionary history involved endosymbiotic gene transfer,gene duplication,and gene loss.Almost all of the eukaryotic algae that we examined had inherited the seven carotenoid biosynthesis genes via endosymbiotic gene transfer.Moreover,PSY,crt ISO,and the ancestral lycopene cyclase gene（LCY） underwent duplication events that resulted in multiple gene copies,and the duplication and subsequent divergence of LCYB and LCYE specialized and complicated the cyclization of lycopene.Our findings also verify that the loss of LCYE in both the microphytic rhodophytes and phaeophytes explains the differences in their carotenoid patterns,when compared to the macrophytic rhodophytes.These analyses provide a molecular basis for further biochemical and physiological validation in additional algal species and should help elucidate the origin and evolution of carotenoid biosynthetic pathways.

Incidence,predictors,and prognosis of thrombocytopenia among patients undergoing intra-aortic balloon pumping in the intensive care unit:a propensity score analysis

OBJECTIVE To explore the incidence,predictors,and prognosis of intra-aortic balloon pumping(IABP)-related thrombocytopenia in critically ill patients.METHODS This multi-center study used the eICU Collaborative Research Database V1.2,comprising data on>130,000 patients from multiple intensive care units(ICUs)in America between 2014 and 2015.A total of 710 patients undergoing IABP were included.Thrombocytopenia was defined as a drop in platelet count>50%from baseline.From the cohort,167 patients who developed thrombocytopenia were matched 1:1 with 167 patients who did not,after propensity score(PS)matching.The associations between IABP-related thrombocytopenia and clinical outcomes were examined by multivariable logistic regression.RESULTS Among 710 patients undergoing IABP,249 patients(35.07%)developed thrombocytopenia.The APACHE IVa score was a predictor of thrombocytopenia[adjusted odds ratio(OR)=1.09,95%confidence interval(CI):1.02−1.15].After 1:1 PS matching,in-hospital mortality(adjusted OR=0.76,95%CI:0.37−1.56)and in-ICU mortality(adjusted OR=0.74,95%CI:0.34−1.63)were similar between the thrombocytopenia and non-thrombocytopenia groups.However,major bleeding occurred more frequently in the thrombocytopenia group(adjusted OR=2.54,95%CI:1.54−4.17).In-hospital length of stay(LOS)and in-ICU LOS were significantly longer in patients who developed thrombocytopenia than in those who did not(9.71 vs.7.36,P<0.001;5.13 vs.2.83,P<0.001).CONCLUSIONS Among patients undergoing IABP in the ICUs,thrombocytopenia was not associated with a difference in inhospital mortality or in-ICU mortality;however,thrombocytopenia was significantly associated with a greater risk of major bleeding and increased in-ICU and in-hospital LOS.

Phylogenomic analysis of transcriptomic sequences of mitochondria and chloroplasts of essential brown algae(Phaeophyceae)in China

The chloroplast and mitochondrion of brown algae （Class Phaeophyceae of Phylum Ochrophyta） may have originated from different endosymbiosis. In this study, we carried out phylogenomic analysis to distinguish their evolutionary lineages by using algal RNA-seq datasets of the 1 000 Plants （1KP） Project and publicly available complete genomes of mitochondria and chloroplasts of Kingdom Chromista. We have found that there is a split between Class Phaeophyceae of Phylum Ochrophyta and the others （Phylum Cryptophyta and Haptophyta） in Kingdom Chromista, and identified more diversity in chloroplast genes than mitochondrial ones in their phylogenetic trees. Taxonomy resolution for Class Phaeophyceae showed that it was divided into Laminariales-Ectocarpales clade and Fucales clade, and phylogenetic positions of Kjellmaniella crassi-folia, Hizikia fusifrome and Ishige okamurai were confirmed. Our analysis provided the basic phylogenetic relationships of Chromista algae, and demonstrated their potential ability to study endosymbiotic events.

De novo sequencing and comparative analysis of three red algal species of Family Solieriaceae to discover putative genes associated with carrageenan biosysthesis

Betaphycus gelatinus, Kappaphycus alvarezii and Eucheuma denticulatum of Family Solieriaceae, Order Gi-gartinales, Class Rhodophyceae are three important carrageenan-producing red algal species, which pro-duce different types of carrageenans, beta （β）-carrageenan, kappa （κ）-carrageenan and iota （ι）-carrageenan. So far the carrageenan biosynthesis pathway is not fully understood and few information is about the So-lieriaceae genome and transcriptome sequence. Here, we performed the de novo transcriptome sequencing, assembly, functional annotation and comparative analysis of these three commercial-valuable species using an Illumina short-sequencing platform Hiseq 2000 and bioinformatic software. Furthermore, we compared the different expression of some unigenes involved in some pathways relevant to carrageenan biosynthe-sis. We finally found 861 different expressed KEGG orthologs which contained a glycolysis/gluconeogenesis pathway （21 orthologs）, carbon fixation in photosynthetic organisms （16 orthologs）, galactose metabolism （5 orthologs）, and fructose and mannose metabolism （9 orthologs） which are parts of the carbohydrate me-tabolism. We also found 8 different expressed KEGG orthologs for sulfur metabolism which might be impor-tantly related to biosynthesis of different types of carrageenans. The results presented in this study provided valuable resources for functional genomics annotation and investigation of mechanisms underlying the biosynthesis of carrageenan in Family Solieriaceae.

Phylogenomic analysis of transcriptomic sequences of mitochondria and chloroplasts for marine red algae(Rhodophyta)in China

The chloroplast and mitochondrion of red algae （Phylum Rhodophyta） may have originated from different endosymbiosis. In this study, we carried out phylogenomic analysis to distinguish their evolutionary lin-eages by using red algal RNA-seq datasets of the 1 000 Plants （1KP） Project and publicly available complete genomes of mitochondria and chloroplasts of Rhodophyta. We have found that red algae were divided into three clades of orders, Florideophyceae, Bangiophyceae and Cyanidiophyceae. Taxonomy resolution for Class Florideophyceae showed that Order Gigartinales was close to Order Halymeniales, while Order Graci-lariales was in a clade of Order Ceramials. We confirmed Prionitis divaricata （Family Halymeniaceae） was closely related to the clade of Order Gracilariales, rather than to genus Grateloupia of Order Halymeniales as reported before. Furthermore, we found both mitochondrial and chloroplastic genes in Rhodophyta under negative selection （Ka/Ks〈1）, suggesting that red algae, as one primitive group of eukaryotic algae, might share joint evolutionary history with these two organelles for a long time, although we identified some dif-ferences in their phylogenetic trees. Our analysis provided the basic phylogenetic relationships of red algae, and demonstrated their potential ability to study endosymbiotic events.

Identification of Estrogen-associated Intrinsic Aging Genes in Chinese Han Female Skin by cDNA Microarray Technology

Objective Estrogens play an important role in intrinsic skin aging.The associated changes in global gene expression are poorly understood.Methods We used the Illumina microarray platform to obtain comprehensive gene expression profiles in female Chinese Han skin,and confirmed the data by quantitative real-time PCR （Q-RT-PCR）.Results We found 244 genes significantly related to estrogen-associated intrinsic skin aging,and some of these genes were confirmed by Q-RT-PCR.We also performed functional analysis by both Gene Ontology annotation and enrichment of the Kyoto Encyclopedia of Genes and Genomes （KEGG） pathways database.The functional analysis revealed 11 biological pathways （including the KEGG pathways,the mitogen-activated protein kinase signaling pathway and metabolic pathways）,that were associated with multiple cellular functions which may be involved in intrinsic skin aging.Conclusion This study suggests that estrogen-associated intrinsic skin aging is a complicated biological process involving many genes and pathways.

Origin and evolution of alginate-c5-mannuronan-epimerase gene based on transcriptomic analysis of brown algae

The coding product of alginate-c5-mannuronan-epimerase gene （algG gene） can catalyze the conversion of mannuronate to guluronate and determine the M/G ratio of alginate. Most of the current knowledge about genes involved in the alginate biosynthesis comes from bacterial systems. In this article, based on some algal and bacterial algG genes registered on GenBank and EMBL databases, we predicted 94 algG genes open reading frame （ORF） sequences of brown algae from the 1 000 Plant Transcriptome Sequencing Project （OneKP）. By method of transcriptomic sequence analysis, gene structure and gene localization analysis, multiple sequence alignment and phylogenetic tree construction, we studied the algal algG gene family characteristics, the structure modeling and conserved motifs of AlgG protein, the origin of alginate biosyn-thesis and the variation incidents that might have happened during evolution in algae. Although there are different members in the algal algG gene family, almost all of them harbor the conserved epimerase region. Based on the phylogenetic analysis of algG genes, we proposed that brown algae acquired the alginate bio-synthesis pathway from an ancient bacterium by horizontal gene transfer （HGT）. Afterwards, followed by duplications, chromosome disorder, mutation or recombination during evolution, brown algal algG genes were divided into different types.

The discovery of archaea origin phosphomannomutase in algae based on the algal transcriptome

Phosphomannomutase （PMM;EC 5.4.2.8） is an enzyme that catalyzes the interconversion reaction between mannose-6-phosphate and mannose-1-phosphate. However, its systematic molecular and functional in-vestigations in algae have not hitherto been reported. In this work, with the accomplishment of the 1 000 Plant Project （OneKP） in which more than 218 species of Chromista, including 19 marine phaeophytes, 22 marine rhodophytes, 171 chlorophytes, 5 cryptophytes, 4 haptophytes, and 5 glaucophytes were sequenced, we used a gene analysis method to analyze the PMM gene sequences in algae and confirm the existence of the PMM gene in the transcriptomic sequencing data of Rhodophyta and Ochrophyta. Our results showed that only one type of PMM with four conserved motifs exists in Chromista which is similar to human PMM. Moreover, the phylogenetic tree revealed that algae PMM possibly originated from archaea.

Endogenous viral elements in algal genomes

Endogenous viral elements （EVEs） are host-genomic fragments originated from viral genomes. They have been found universally in animal and plant genomes. Here we carried out a systematic screening and analy-sis of EVEs in algal genomes and found that EVEs commonly exist in algal genomes. We classified the EVE fragments into three categories according to the length of EVE fragments. Due to the probability of sequence similarity by chance, we ignored the potential function of medium-length EVE fragments. However, long-length EVE fragments probably had capability to encode protein domains or even entire proteins, and some short-length EVE fragments had high similarity with host＇s siRNA sequences and possibly served functions of small RNAs. Therefore, short and long EVE fragments might provide regulomic and proteomic novelty to the host＇s metabolism and adaptation. We also found several EVE fragments shared by more than 3 algal genomes. By phylogenetic analysis of the shared EVEs and their corresponding species, we found that the integration of viral fragments into host genomes was an ancient event, possibly before the divergence of Chlorophytes and Ochrophytes. Our findings show that there is a frequent genetic flow from viruses to algal genomes. Moreover, study on algal EVEs shed light on the virus-host interaction in large timescale and could also help us understand the balance of marine ecosystems.

Transcriptome characterization of Ishige okamurae(Phaeophyceae)shows strong environmental acclimation

Ishige okamurae, with leathery branched narrow fronds consisting of cylindrical hairs, is the typical species of the genus Ishige, which is considered as one of the most basal genera in the phylogeny of the Phaeophy-ceae. Apart from great public interest from the evolutionary respect, more attention has been brought on the abundant bioactive compounds in I. okamurae for therapeutic or economic considerations, such as di-phlorethohydroxycarmalol and ishigoside. Yet little is known about related key genes or metabolic pathways involved in I. okamurae, which calls upon us to carry out global analyses of transcriptome by next generation sequencing. Altogether, we obtained 78 583 assembled scaffolds with N50 of 1 709 nucleotides, and 25 357 unigenes with significant BLAST matches （E-value cutoff of 10-5）. In terms of characterization of the tran-scriptome of I. okamurae, we focused on anti-stress metabolic pathways and synthetic routes of bioactive compounds in an attempt to obtain a better understanding of the interactive organism-environment regula-tory networks. Pathway-based analysis helped us to deepen our comprehension of the interaction between I. okamurae and its surroundings, with MAPK signal pathway as an example. Furthermore, we discovered a wide range of novel putative functional proteins that could be of wide application, such as Rab family, using sequence-based transcriptome. In conclusion, transcriptome characterization of I. okamurae （Phaeophy-ceae） shows strong environmental acclimation.

Analysis of Saccharina japonica transcriptome using the high-throughput DNA sequencing technique and its vanadium-dependent haloperoxidase gene

Saccharina is one of the most important cold-water living marine brown algal genera. In this study we ana-lyzed the transcriptome of S. japonica, which belongs to the 1 000 Plants （OneKP） Project, by using a next-generation high-throughput DNA sequencing technique. About 5.16 GB of raw data were generated, and 65 536 scaffolds with an average length of 454 bp were assembled with SOAP de novo assembly method. In total, 19 040 unigenes were identified by BLAST;25 734 scaffolds were clustered into 37 Gene ontology functional groups;6 760 scaffolds were classified into 25 COG categories, as well as 2 665 scaffolds that were assigned to 306 KEGG pathways. Majority of the unigenes exhibited more similarities to algae including brown algae and diatom than other cyanobacteria, marine diatom, and plant. Saccharina japonica has the outstanding capability to accumulate halogen such as Br and I via halogenation processes from seawater. We acquired 42 different vanadium-dependent haloperoxidases （vHPO） in S. japonica transcriptome data, including 5 segments of vanadium-dependent iodoperoxidase （vIPO） and 37 segments of vanadium-de-pendent bromoperoxidase （vBPO）. Complicated analyses of identified fulllength S. japonica vBPO1 and S. japonica vBPO2 revealed the importance of vBPO among species of brown algae and the strong relationship between marine algal vBPOs and vIPOs. This study will enhance our understanding of the biological charac-teristics and economic values of S. japonica species.

A New Definition of Modularity for Community Detection in Complex Networks

We propose a new definition of modularity,i.e.the Qd function,for network analysis,which takes the edge density and topological structure of modules into account and is different from the original strategy of simply calculating the number of edges(the definition of modularity Q introduced by Newman and Girvan).Armed with this novel quality function Qd,we implement an adaptive clustering algorithm for process optimization,and apply our strategy to several synthetic and real-world networks.The results of our exercises demonstrate a better performance in extracting accurate community ingredients from complex networks.

Comparative gene expression analysis in stems of <i>Dolichos purpureus</i>and <i>Arabidopsis thaliana</i>

The outermost layer epidermis of a plant stem plays an important role in protection and environment-sensing. The mechanisms of sensing and response to the environment through the stem epidermis remain unclear. Here we report enriched expression of genes involved in stress resistance and signal transduction functions in the stem epidermis of both D. purpureus and A. thaliana by cDNA cloning and QPCR in D. purpureus and by analysis using dataset from a genome-wide comparison with cDNAs differentially expressed between the epidermis and inner parts of top and base stem in A. thaliana. Among 188 cDNAs from the stem epidermis of D. purpureus, 13% and 17% were related to signal transduction and defense respectively. Most of them were up-regulated more in the stem epidermis than the inner stem, as well as in A. thaliana. Also, the distribution of the numbers and specificities of up-regulated genes related to signal transduction and regulatory networks in the epidermis and inner stem revealed the possibility of positional differences in regulation. The results revealed the importance of the epidermis in signal transduction and plant defence.