Journal Articles, Hindawi Press
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Browsing Journal Articles, Hindawi Press by Department "Computer Science"
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- BSML: A Binding Schema Markup Language for Data Interchange in Problem Solving EnvironmentsVerstak, Alex; Ramakrishnan, Naren; Watson, Layne T.; He, Jian; Shaffer, Clifford A.; Bae, Kyung Kyoon; Jiang, Jing; Tranter, William H.; Rappaport, Theodore S. (Hindawi, 2003-01-01)We describe a binding schema markup language (BSML) for describing data interchange between scientific codes. Such a facility is an important constituent of scientific problem solving environments (PSEs). BSML is designed to integrate with a PSE or application composition system that views model specification and execution as a problem of managing semistructured data. The data interchange problem is addressed by three techniques for processing semistructured data: validation, binding, and conversion. We present BSML and describe its application to a PSE for wireless communications system design.
- Elucidating the Evolutionary Relationships among Bos taurus Digestive Organs Using Unigene Expression DataBeck, D. C.; Jiang, Honglin; Zhang, Liqing (Hindawi, 2010-02-08)Although the nature of ruminant evolution is still disputed, current theory based on physiology and genetic analysis suggests that the abomasum is the evolutionarily oldest stomach compartment, the rumen evolved some time after the abomasum, and the omasum is the evolutionarily youngest stomach compartment. In addition, there is some evidence of relaxed selective constraint in the stomach-like organ and the foregut shortly after the foregut formation event. Along with the assumption of a mean, stochastic rate of evolution, analysis of differences in genetic profiles among digestive body organs can give clues to the relationships among these organs. The presence of large numbers of uniquely expressed entries in the abomasum and rumen indicates either a period of relaxed selective constraint or greater evolutionary age. Additionally, differences in expression profiles indicate that the abomasum, rumen, and intestine are more closely related to each other, while the reticulum and omasum are more closely related to the rumen. Functional analysis using Gene Ontology (GO) categories also supports the proposed evolutionary relationships by identifying shared functions, such as muscle activity and development, lipid transport, and urea metabolism, between all sections of the digestive tract investigated.
- Expression Divergence of Tandemly Arrayed Genes in Human and MouseShoja, Valia; Murali, T. M.; Zhang, Liqing (Hindawi, 2007-10-30)Tandemly arrayed genes (TAGs) account for about one third of the duplicated genes in eukaryotic genomes, yet there has not been any systematic study of their gene expression patterns. Taking advantage of recently published large-scale microarray data sets, we studied the expression divergence of 361 two-member TAGs in human and 212 two-member TAGs in mouse and examined the effect of sequence divergence, gene orientation, and chromosomal proximity on the divergence of TAG expression patterns. Our results show that there is a weak negative correlation between sequence divergence of TAG members and their expression similarity. There is also a weak negative correlation between chromosomal proximity of TAG members and their expression similarity. We did not detect any significant relationship between gene orientation and expression similarity. We also found that downstream TAG members do not show significantly narrower expression breadth than upstream members, contrary to what we predict based on TAG expression divergence hypothesis that we propose. Finally, we show that both chromosomal proximity and expression correlation in TAGs do not differ significantly from their neighboring non-TAG gene pairs, suggesting that tandem duplication is unlikely to be the cause for the higher-than-random expression association between neighboring genes on a chromosome in human and mouse.
- HMEC: A Heuristic Algorithm for Individual Haplotyping with Minimum Error CorrectionBayzid, Md. Shamsuzzoha; Alam, Md. Maksudul; Mueen, Abdullah; Rahman, Md. Saidur (Hindawi, 2013-01-28)Haplotype is a pattern of single nucleotide polymorphisms (SNPs) on a single chromosome. Constructing a pair of haplotypes from aligned and overlapping but intermixed and erroneous fragments of the chromosomal sequences is a nontrivial problem. Minimum error correction approach aims to minimize the number of errors to be corrected so that the pair of haplotypes can be constructed through consensus of the fragments. We give a heuristic algorithm (HMEC) that searches through alternative solutions using a gain measure and stops whenever no better solution can be achieved. Time complexity of each iteration is for an SNP matrix where and are the number of fragments (number of rows) and number of SNP sites (number of columns), respectively, in an SNP matrix. Alternative gain measure is also given to reduce running time. We have compared our algorithm with other methods in terms of accuracy and running time on both simulated and real data, and our extensive experimental results indicate the superiority of our algorithm over others.
- Large Display Interaction via Multiple Acceleration Curves and Multifinger Pointer ControlEsakia, Andrey; Endert, Alex; North, Christopher L. (Hindawi, 2014-11-25)Large high-resolution displays combine high pixel density with ample physical dimensions. The combination of these factors creates a multiscale workspace where interactive targeting of on-screen objects requires both high speed for distant targets and high accuracy for small targets. Modern operating systems support implicit dynamic control-display gain adjustment (i.e., a pointer acceleration curve) that helps to maintain both speed and accuracy. However, large high-resolution displays require a broader range of control-display gains than a single acceleration curve can usably enable. Some interaction techniques attempt to solve the problem by utilizing multiple explicit modes of interaction, where different modes provide different levels of pointer precision. Here, we investigate the alternative hypothesis of using a single mode of interaction for continuous pointing that enables both (1) standard implicit granularity control via an acceleration curve and (2) explicit switching between multiple acceleration curves in an efficient and dynamic way. We evaluate a sample solution that augments standard touchpad accelerated pointer manipulation with multitouch capability, where the choice of acceleration curve dynamically changes depending on the number of fingers in contact with the touchpad. Specifically, users can dynamically switch among three different acceleration curves by using one, two, or three fingers on the touchpad.
- Objective and Comprehensive Evaluation of Bisulfite Short Read Mapping ToolsTran, Hong T.; Porter, Jacob; Sun, Ming-an; Xie, Hehuang David; Zhang, Liqing (Hindawi, 2014-04-15)Background. Large-scale bisulfite treatment and short reads sequencing technology allow comprehensive estimation of methylation states of Cs in the genomes of different tissues, cell types, and developmental stages. Accurate characterization of DNA methylation is essential for understanding genotype phenotype association, gene and environment interaction, diseases, and cancer. Aligning bisulfite short reads to a reference genome has been a challenging task. We compared five bisulfite short read mapping tools, BSMAP, Bismark, BS-Seeker, BiSS, and BRAT-BW, representing two classes of mapping algorithms (hash table and suffix/prefix tries). We examined their mapping efficiency (i.e., the percentage of reads that can be mapped to the genomes), usability, running time, and effects of changing default parameter settings using both real and simulated reads. We also investigated how preprocessing data might affect mapping efficiency. Conclusion. Among the five programs compared, in terms of mapping efficiency, Bismark performs the best on the real data, followed by BiSS, BSMAP, and finally BRAT-BW and BS-Seeker with very similar performance. If CPU time is not a constraint, Bismark is a good choice of program for mapping bisulfite treated short reads. Data quality impacts a great deal mapping efficiency. Although increasing the number of mismatches allowed can increase mapping efficiency, it not only significantly slows down the program, but also runs the risk of having increased false positives. Therefore, users should carefully set the related parameters depending on the quality of their sequencing data.
- A Pattern Analysis of Gene Conversion LiteratureLawson, Mark J.; Jiao, Jian; Fan, Weiguo; Zhang, Liqing (Hindawi, 2009-11-15)Gene conversion is an important biological process that involves the transfer of genetic (sequence) information from one gene to another. This can have a variety of effects on an organism, both short-term and long-term and both positive and detrimental. In an effort to better understand this process, we searched through over 3,000 abstracts that contain research on gene conversions, tagging the important data and performing an analysis on what we extract. Through this we established trends that give a better insight into gene conversion research and genetic research in general. Our results show the importance of the process and the importance of continuing gene conversion research.
- Strengthening MT6D Defenses with LXC-Based Honeypot CapabilitiesBasam, Dileep; Ransbottom, J. Scot; Marchany, Randolph C.; Tront, Joseph G. (Hindawi, 2016-04-20)Moving Target IPv6 Defense (MT6D) imparts radio-frequency hopping behavior to IPv6 networks by having participating nodes periodically hop onto new addresses while giving up old addresses. Our previous research efforts implemented a solution to identify and acquire these old addresses that are being discarded by MT6D hosts on a local network besides being able to monitor and visualize the incoming traffic on these addresses. This was essentially equivalent to forming a darknet out of the discarded MT6D addresses, but the solution presented in the previous research effort did not include database integration for it to scale and be extended. This paper presents a solution with a new architecture that not only extends the previous solution in terms of automation and database integration but also demonstrates the ability to deploy a honeypot on a virtual LXC (Linux Container) on-demand based on any interesting traffic pattern observed on a discarded address. The proposed architecture also allows an MT6D host to query the solution database for network activity on its relinquished addresses as a JavaScript Object Notation (JSON) object. This allows an MT6D host to identify suspicious activity on its discarded addresses and strengthen the MT6D scheme parameters accordingly. We have built a proof-of-concept for the proposed solution and analyzed the solution’s feasibility and scalability.
- Studying the Functional Genomics of Stress Responses in Loblolly Pine With the Expresso Microarray Experiment Management SystemHeath, Lenwood S.; Ramakrishnan, Naren; Sederoff, Ronald R.; Whetten, Ross W.; Chevone, Boris I.; Struble, Craig A.; Jouenne, Vincent Y.; Chen, Dawei; van Zyl, Leonel; Grene, Ruth (Hindawi, 2002-01-01)Conception, design, and implementation of cDNA microarray experiments present avariety of bioinformatics challenges for biologists and computational scientists. The multiplestages of data acquisition and analysis have motivated the design of Expresso, asystem for microarray experiment management. Salient aspects of Expresso includesupport for clone replication and randomized placement; automatic gridding, extraction ofexpression data from each spot, and quality monitoring; flexible methods of combiningdata from individual spots into information about clones and functional categories; and theuse of inductive logic programming for higher-level data analysis and mining. Thedevelopment of Expresso is occurring in parallel with several generations of microarrayexperiments aimed at elucidating genomic responses to drought stress in loblolly pineseedlings. The current experimental design incorporates 384 pine cDNAs replicated andrandomly placed in two specific microarray layouts. We describe the design of Expresso aswell as results of analysis with Expresso that suggest the importance of molecularchaperones and membrane transport proteins in mechanisms conferring successfuladaptation to long-term drought stress.
- Tandemly Arrayed Genes in Vertebrate GenomesPan, Deng; Zhang, Liqing (Hindawi, 2008-09-21)Tandemly arrayed genes (TAGs) are duplicated genes that are linked as neighbors on a chromosome, many of which have important physiological and biochemical functions. Here we performed a survey of these genes in 11 available vertebrate genomes. TAGs account for an average of about 14% of all genes in these vertebrate genomes, and about 25% of all duplications. The majority of TAGs (72–94%) have parallel transcription orientation (i.e., they are encoded on the same strand) in contrast to the genome, which has about 50% of its genes in parallel transcription orientation. The majority of tandem arrays have only two members. In all species, the proportion of genes that belong to TAGs tends to be higher in large gene families than in small ones; together with our recent finding that tandem duplication played a more important role than retroposition in large families, this fact suggests that among all types of duplication mechanisms, tandem duplication is the predominant mechanism of duplication, especially in large families. Finally, several species have a higher proportion of large tandem arrays that are species-specific than random expectation.
- A Transcriptome Post-Scaffolding Method for Assembling High Quality ContigsLiu, Mingming; Adelman, Zach N.; Myles, Kevin M.; Zhang, Liqing (Hindawi Publishing Corp, 2014-05-28)With the rapid development of high throughput sequencing technologies, new transcriptomes can be sequenced for little cost with high coverage. Sequence assembly approaches have been modified to meet the requirements for de novo transcriptomes, which have complications not found in traditional genome assemblies such as variation in coverage for each candidate mRNA and alternative splicing. As a consequence, de novo assembly strategies tend to generate a large number of redundant contigs due to sequence variations, which adversely affects downstream analysis and experiments. In this work we proposed TransPS, a transcriptome post-scaffolding method, to generate high quality, nonredundant de novo transcriptomes. TransPS shows promising results on the test transcriptome datasets, where redundancy is greatly reduced by more than 50% and, at the same time, coverage is improved considerably. The web server and source code are available.