Þórarinsson, Elfar; Yao, Zizhen; Wiklund, Eric D.;
Recent computational scans for non-coding RNAs (ncRNAs) in multiple organisms have relied on existing multiple sequence alignments. However, as sequence similarity drops, a key signal of RNA structure--frequent compensating base changes--is increasingly likely to cause sequence-based alignment me...
Lei, Xiu-Juan; Sun, Jing-Jing; Ma, Qian-Zhi
This paper introduces a new improved algorithm called chaotic PSO (CPSO) based on the thought of chaos optimization to solve multiple sequence alignment. For one thing, the chaotic variables are generated between 0 and 1 when initializing the population so that the particles are distributed uniformly in the solution space. For another thing, the chaotic sequences are generated using the Logistic mapping function in order to make chaotic search and strengthen the diversity of the population. The simulation results of several benchmark data sets of BAliBase show that the improved algorithm is effective and has good performances for the data sets with different similarity.
Gorbalenya Alexander E
Full Text Available Abstract Background A growing diversity of biological data is tagged with unique identifiers (UIDs associated with polynucleotides and proteins to ensure efficient computer-mediated data storage, maintenance, and processing. These identifiers, which are not informative for most people, are often substituted by biologically meaningful names in various presentations to facilitate utilization and dissemination of sequence-based knowledge. This substitution is commonly done manually that may be a tedious exercise prone to mistakes and omissions. Results Here we introduce SNAD (Sequence Name Annotation-based Designer that mediates automatic conversion of sequence UIDs (associated with multiple alignment or phylogenetic tree, or supplied as plain text list into biologically meaningful names and acronyms. This conversion is directed by precompiled or user-defined templates that exploit wealth of annotation available in cognate entries of external databases. Using examples, we demonstrate how this tool can be used to generate names for practical purposes, particularly in virology. Conclusion A tool for controllable annotation-based conversion of sequence UIDs into biologically meaningful names and acronyms has been developed and placed into service, fostering links between quality of sequence annotation, and efficiency of communication and knowledge dissemination among researchers.
Over the past 5 years, large-scale sequencing has been revolutionized by the development of several so-called next-generation sequencing (NGS) technologies. These have drastically increased the number of bases obtained per sequencing run while at the same time decreasing the costs per base. Compared to Sanger sequencing, NGS technologies yield shorter read lengths; however, despite this drawback, they have greatly facilitated genome sequencing, first for prokaryotic genomes and within the las...
Lian, S; Tu, Y; Wang, Y; Chen, X; Wang, L
Repetitive sequences of variable length are common in almost all eukaryotic genomes, and most of them are presumed to have important biomedical functions and can cause genomic instability. Next-generation sequencing (NGS) technologies provide the possibility of identifying capturing these repetitive sequences directly from the NGS data. In this study, we assessed the performances in identifying capturing repeats of leading assemblers, such as Velvet, SOAPdenovo, SGA, MSR-CA, Bambus2, ALLPATHS-LG, and AByss using three real NGS datasets. Our results indicated that most of them performed poorly in capturing the repeats. Consequently, we proposed a repetitive sequence assembler, named NGSReper, for capturing repeats from NGS data. Simulated datasets were used to validate the feasibility of NGSReper. The results indicate that the completeness of capturing repeat is up to 99%. Cross validation was performed in three real NGS datasets, and extensive comparisons indicate that NGSReper performed best in terms of completeness and accuracy in capturing repeats. In conclusion, NGSReper is an appropriate and suitable tool for capturing repeats directly from NGS data. PMID:27525861
Beer, Neil Reginald
A system for fast DNA sequencing by amplification of genetic material within microreactors, denaturing, demulsifying, and then sequencing the material, while retaining it in a PCR/sequencing zone by a magnetic field. One embodiment includes sequencing nucleic acids on a microchip that includes a microchannel flow channel in the microchip. The nucleic acids are isolated and hybridized to magnetic nanoparticles or to magnetic polystyrene-coated beads. Microreactor droplets are formed in the microchannel flow channel. The microreactor droplets containing the nucleic acids and the magnetic nanoparticles are retained in a magnetic trap in the microchannel flow channel and sequenced.
Xingqin Qi; Edgar Fuller; Qin Wu; Cun-Quan Zhang
Sequence comparison is a primary technique for the analysis of DNA sequences. In order to make quantitative comparisons, one devises mathematical descriptors that capture the essence of the base composition and distribution of the sequence. Alignment methods and graphical techniques (where each sequence is represented by a curve in high-dimension Euclidean space) have been used popularly for a long time. In this contribution we will introduce a new nongraphical and nonalignment approach based...
McEneaney, John E.
Instructional technologies critically depend on systematic design, and learning hierarchies are a commonly advocated tool for designing instructional sequences. But hierarchies routinely allow numerous sequences and choosing an optimal sequence remains an unsolved problem. This study explores a simulation-based approach to modeling learning…
Sequence diagrams are a widely used design notation for describing software behaviors. Many reusable software artifacts such as design patterns and design aspects make use of sequence diagrams to describe interaction behaviors. When a pattern or an aspect is reused in an application, it is important to ensure that the sequence diagrams for the application correctly refines the corresponding sequence diagrams for the pattern or aspect. Reasoning about refinement of sequence diagrams has not been addressed adequately in literature. In this paper, we focus on refinement of mandatory behavior specified by a UML sequence diagram. A novel trace semantics is given that captures precisely mandatory behavior specified by a sequence diagram and a refinement relation between sequence diagrams is formalized based on the semantics. Properties of the trace semantics and the refinement relation are studied.
The structure-based sequence motif of the distant proteins in evolution, protein tyrosine phosphatases (PTP) Ⅰ and Ⅱ superfamilies, as an example, has been defined by the structural comparison, structure-based sequence alignment and analyses on substitution patterns of residues in common sequence conserved regions. And the phosphatases Ⅰ and Ⅱ can be correctly identified together by the structure-based PTP sequence motif from SWISS-PROT and TrEBML databases. The results show that the correct rates of identification are over 98%. This is the first time to identify PTP Ⅰ and Ⅱ together by this motif.
Full Text Available Conventional schemes for DNA sequence representation, storage, and processing areusually developed based on the character-based formats.We propose the quaternion number system for numerical representation and further processing on DNA sequences.In the proposed method, the quaternion cross-correlation operation can be used to obtain both the global and local matching/mismatching information between two DNA sequences from the depicted one-dimensional curve and two-dimensional pattern, respectively.Simulation results on various DNA sequences and the comparison result with the wellknown BLAST method are obtained to verify the effectiveness of the proposed method.
Vens, Celine; Rosso, Marie-Noëlle; Danchin, Etienne
Motivation: Identification of conserved motifs in biological sequences is crucial to unveil common shared functions. Many tools exist for motif identification, including some that allow degenerate positions with multiple possible nucleotides or amino acids. Most efficient methods available today search conserved motifs in a set of sequences, but do not check for their specificity regarding to a set of negative sequences. Results: We present a tool to identify degenerate motifs, based on a giv...
Li, Andrew X; Qin, Jing; Reidys, Christian M
Recently, $O(N^6)$ time and $O(N^4)$ space dynamic programming algorithms have become available that compute the partition function of RNA-RNA interaction complexes for pairs of RNA sequences. These algorithms and the biological requirement of more reliable interactions motivate to utilize the additional information contained in multiple sequence alignments and to generalize the above framework to the partition function and base pairing probabilities for multiple sequence alignments.
Full Text Available For the problem of estimation sequence effect on channel estimation accuracy and echo cancellation effect, this paper, based on the basic principle of echo cancellation, analyses the effect of PN sequence mechanism and the correlation on the channel estimation parameters. Comparing with using the input signal itself as the estimation sequence. With the input signal OFDM, the results of simulation and actual operation show that the method can increase both the accuracy of channel estimation and echo cancellation effect effectively.
A novel compressing method for video teleconference applications is presented. Semantic-based coding based on human image feature is realized, where human features are adopted as parameters. Model-based coding and the concept of vector coding are combined with the work on image feature extraction to obtain the result.
Multiple sequence alignment is a key process in today's biology, and finding a relevant alignment of several sequences is much more challenging than just optimizing some improbable evaluation functions. Our approach for addressing multiple sequence alignment focuses on the building of structures in a new graph model: the factor graph model. This model relies on block-based formulation of the original problem, formulation that seems to be one of the most suitable ways for capturing evolutionary aspects of alignment. The structures are implicitly built by a colony of ants laying down pheromones in the factor graphs, according to relations between blocks belonging to the different sequences.
Seyed Hossein Chavoshi
Full Text Available Increased affordability and deployment of advanced tracking technologies have led researchers from various domains to analyze the resulting spatio-temporal movement data sets for the purpose of knowledge discovery. Two different approaches can be considered in the analysis of moving objects: quantitative analysis and qualitative analysis. This research focuses on the latter and uses the qualitative trajectory calculus (QTC, a type of calculus that represents qualitative data on moving point objects (MPOs, and establishes a framework to analyze the relative movement of multiple MPOs. A visualization technique called sequence signature (SESI is used, which enables to map QTC patterns in a 2D indexed rasterized space in order to evaluate the similarity of relative movement patterns of multiple MPOs. The applicability of the proposed methodology is illustrated by means of two practical examples of interacting MPOs: cars on a highway and body parts of a samba dancer. The results show that the proposed method can be effectively used to analyze interactions of multiple MPOs in different domains.
Morin, Trevor J; Shropshire, Tyler; Liu, Xu; Briggs, Kyle; Huynh, Cindy; Tabard-Cossa, Vincent; Wang, Hongyun; Dunbar, William B
The promise of portable diagnostic devices relies on three basic requirements: comparable sensitivity to established platforms, inexpensive manufacturing and cost of operations, and the ability to survive rugged field conditions. Solid state nanopores can meet all these requirements, but to achieve high manufacturing yields at low costs, assays must be tolerant to fabrication imperfections and to nanopore enlargement during operation. This paper presents a model for molecular engineering techniques that meets these goals with the aim of detecting target sequences within DNA. In contrast to methods that require precise geometries, we demonstrate detection using a range of pore geometries. As a result, our assay model tolerates any pore-forming method and in-situ pore enlargement. Using peptide nucleic acid (PNA) probes modified for conjugation with synthetic bulk-adding molecules, pores ranging 15-50 nm in diameter are shown to detect individual PNA-bound DNA. Detection of the CFTRΔF508 gene mutation, a codon deletion responsible for ∼66% of all cystic fibrosis chromosomes, is demonstrated with a 26-36 nm pore size range by using a size-enhanced PNA probe. A mathematical framework for assessing the statistical significance of detection is also presented. PMID:27149679
Morin, Trevor J.; Shropshire, Tyler; Liu, Xu; Briggs, Kyle; Huynh, Cindy; Tabard-Cossa, Vincent; Wang, Hongyun; Dunbar, William B.
The promise of portable diagnostic devices relies on three basic requirements: comparable sensitivity to established platforms, inexpensive manufacturing and cost of operations, and the ability to survive rugged field conditions. Solid state nanopores can meet all these requirements, but to achieve high manufacturing yields at low costs, assays must be tolerant to fabrication imperfections and to nanopore enlargement during operation. This paper presents a model for molecular engineering techniques that meets these goals with the aim of detecting target sequences within DNA. In contrast to methods that require precise geometries, we demonstrate detection using a range of pore geometries. As a result, our assay model tolerates any pore-forming method and in-situ pore enlargement. Using peptide nucleic acid (PNA) probes modified for conjugation with synthetic bulk-adding molecules, pores ranging 15-50 nm in diameter are shown to detect individual PNA-bound DNA. Detection of the CFTRΔF508 gene mutation, a codon deletion responsible for ∼66% of all cystic fibrosis chromosomes, is demonstrated with a 26-36 nm pore size range by using a size-enhanced PNA probe. A mathematical framework for assessing the statistical significance of detection is also presented. PMID:27149679
Donigan, Katherine; Sweasy, Joann B.
Base excision repair is critical for the maintenance of genome stability because it repairs at least 20,000 endogenously generated DNA lesions per cell per day. Several enzymes within the base excision repair pathway exhibit sequence context dependency during the excision and DNA synthesis steps of repair. New evidence is emerging that germ line and tumor-associated variants of enzymes in this repair pathway exhibit sequence context dependence that is different from their ancestral counterpar...
Edwards, Suzanne; Stucki, Heinz; Bader, Joëlle; Vidal, Vincent; Kaiser, Rolf; Battegay, Manuel; Klimkait, Thomas
Key clinical studies for HIV coreceptor antagonists have used the phenotyping-based Trofile test. Meanwhile various simpler-to-do genotypic tests have become available that are compatible with standard laboratory equipment and Web-based interpretation tools. However, these systems typically analyze only the most prominent virus sequence in a specimen. We present a new diagnostic HIV tropism test not needing DNA sequencing. The system, XTrack, uses physical properties of DNA duplexes after hyb...
YANG Jian-guo; LI Bei-zhi; YU Lei; JIN Yu-song
In this paper an assembly sequence planning model inspired by natural immune and genetic algorithm (ASPIG) based on the part degrees of freedom matrix (PDFM) is proposed, and a proto system - DSFAS based on the ASPIG is introduced to solve assembly sequence problem. The concept and generation of PDFM and DSFAS are also discussed. DSFAS can prevent premature convergence, and promote population diversity, and can accelerate the learning and convergence speed in behavior evolution problem.
Barbi, M; Place, C.; Popkov, V.; Salerno, M.
The possibility that the sliding motion of proteins on DNA is influenced by the base sequence through a base pair reading interaction, is considered. Referring to the case of the T7 RNA-polymerase, we show that the protein should follow a noise-influenced sequence-dependent motion which deviate from the standard random walk usually assumed. The general validity and the implications of the results are discussed.
Abate, Adam R.; Hung, Tony; Sperling, Ralph A.; Mary, Pascaline; Rotem, Assaf; Agresti, Jeremy J.; Weiner, Michael A.; Weitz, David A.
Droplet-based microfluidic techniques can form and process micrometer scale droplets at thousands per second. Each droplet can house an individual biochemical reaction, allowing millions of reactions to be performed in minutes with small amounts of total reagent. This versatile approach has been used for engineering enzymes, quantifying concentrations of DNA in solution, and screening protein crystallization conditions. Here, we use it to read the sequences of DNA molecules with a FRET-based assay. Using probes of different sequences, we interrogate a target DNA molecule for polymorphisms. With a larger probe set, additional polymorphisms can be interrogated as well as targets of arbitrary sequence. PMID:24185402
Yanxiao Feng; Yuechuan Zhang; Cuifeng Ying; Deqiang Wang; Chunlei Du
Nanopore-based sequencers, as the fourth-generation DNA sequencing technology, have the potential to quickly and reliably sequence the entire human genome for less than $1000, and possibly for even less than$100. The single-molecule techniques used by this technology allow us to further study the interaction between DNA and protein, as well as between protein and protein. Nanopore analysis opens a new door to molecular biology investigation at the single-molecule scale. In this article, we have reviewed academic achievements in nanopore technology from the past as well as the latest advances, including both biological and solid-state nanopores, and discussed their recent and potential applications.
Liu, Xiao-lei; En, De; Wang, Li-guo
In this paper, a coherent asynchronous optical code division multiple access (OCDMA) system is proposed, whose encoder/decoder is an all-optical generator. This all-optical generator can generate analog and bipolar chaotic sequences satisfying the logistic maps. The formula of bit error rate (BER) is derived, and the relationship of BER and the number of simultaneous transmissions is analyzed. Due to the good property of correlation, this coherent OCDMA system based on these bipolar chaotic sequences can support a large number of simultaneous users, which shows that these chaotic sequences are suitable for asynchronous OCDMA system.
Caswell, Jennifer L.; Richter, Daniel J.; Neubauer, Julie; Schirmer, Christine; Gnerre, Sante; Mallick, Swapan; Reich, David Emil
Population geneticists often study small numbers of carefully chosen loci, but it has become possible to obtain orders of magnitude for more data from overlaps of genome sequences. Here, we generate tens of millions of base pairs of multiple sequence alignments from combinations of three western chimpanzees, three central chimpanzees, an eastern chimpanzee, a bonobo, a human, an orangutan, and a macaque. Analysis provides a more precise understanding of demographic history than was previously...
In this paper, statistical analysis of watermarking schemes based on correlation detection is presented. Statistical properties of watermark sequences generated by piecewise-linear Markov maps are exploited, resulting in superior watermark detection reliability. Correlation/spectral properties of such sequences are easily controllable, a fact that affects the watermarking system performance. A family of chaotic maps, namely the skew tent map family, is proposed for use in watermarking schemes
LeBlanc, C.; Hruska, S.I. [Florida State Univ., Tallahassee, FL (United States); Katholi, C.R.; Unnasch, T.R. [Univ. of Alabama, Birmingham, AL (United States)
Adaptive resonance theory (ART) describes a class of artificial neural network architectures that act as classification tools which self-organize, work in real-time, and require no retraining to classify novel sequences. We have adapted ART networks to provide support to scientists attempting to categorize tandem repeat DNA fragments from Onchocerca volvulus. In this approach, sequences of DNA fragments are presented to multiple ART-based networks which are linked together into two (or more) tiers; the first provides coarse sequence classification while the sub- sequent tiers refine the classifications as needed. The overall rating of the resulting classification of fragments is measured using statistical techniques based on those introduced to validate results from traditional phylogenetic analysis. Tests of the Hierarchical ART-based Classification Network, or HABclass network, indicate its value as a fast, easy-to-use classification tool which adapts to new data without retraining on previously classified data.
Abstract Background Protein-protein interactions underlie many important biological processes. Computational prediction methods can nicely complement experimental approaches for identifying protein-protein interactions. Recently, a unique category of sequence-based prediction methods has been put forward - unique in the sense that it does not require homologous protein sequences. This enables it to be universally applicable to all protein sequences unlike many of previous sequence-based predi...
Neng-zhi Jin; Zi-xian Liu; Yan-jiao Qi; Wen-yuan Qiu
On the basis of information theory and statistical methods, we use mutual information, n-tuple entropy and conditional entropy, combined with biological characteristics, to analyze the long range correlation and short range correlation in human Y chromosome palindromes. The magnitude distribution of the long range correlation which can be reflected by the mutual information is P5>P5a>P5b (P5a and P5b are the sequences that replace solely Alu repeats and all interspersed repeats with random uncorrelated sequences in human Y chromosome palindrome 5, respectively); and the magnitude distribution of the short range correlation which can be reflected by the n-tuple entropy and the conditional entropy is P5>P5a>P5b>random uncorrelated sequence. In other words, when the Alu repeats and all interspersed repeats replace with random uncorrelated sequence, the long range and short range correlation decrease gradually. However, the random uncorrelated sequence has no correlation. This research indicates that more repeat sequences result in stronger correlation between bases in human Y chromosome. The analyses may be helpful to understand the special structures of human Y chromosome palindromes profoundly.
Smaili, Fatima Z.
The number of available protein sequences in public databases is increasing exponentially. However, a significant fraction of these sequences lack functional annotation which is essential to our understanding of how biological systems and processes operate. In this master thesis project, we worked on inferring protein functions based on the primary protein sequence. In the approach we follow, 3D models are first constructed using I-TASSER. Functions are then deduced by structurally matching these predicted models, using global and local similarities, through three independent enzyme commission (EC) and gene ontology (GO) function libraries. The method was tested on 250 “hard” proteins, which lack homologous templates in both structure and function libraries. The results show that this method outperforms the conventional prediction methods based on sequence similarity or threading. Additionally, our method could be improved even further by incorporating protein-protein interaction information. Overall, the method we use provides an efficient approach for automated functional annotation of non-homologous proteins, starting from their sequence.
Caffrey, Sean M.
The use of metagenomic methods that directly sequence environmental samples has revealed the extraordinary microbial diversity missed by traditional culture-based methodologies. Therefore, to develop a complete and representative model of an environment's microbial community and activities, metagenomic analysis is an essential tool.
Kowalczuk, M.; Mackiewicz, P.; Szczepanik, D.; Nowicka, A.; Dudkiewicz, M.; Dudek, M. R.; Cebrat, S.
We discuss the Jukes and Cantor's one-parameter model and Kimura's two-parameter model unability to describe evolution of asymmetric DNA molecules. The standard distance measure between two DNA sequences, which is the number of substitutions per site, should include the effect of multiple base substitutions separately for each type of the base. Otherwise, the respective tables of substitutions cannot reconstruct the asymmetric DNA molecule with respect to the composition. Basing on Kimura's neutral theory, we have derived a linear law for the correlation of the mean survival time of nucleotides under constant mutation pressure and their fraction in the genome. According to the law, the corrections to Kimura's theory have been discussed to describe evolution of genomes with asymmetric nucleotide composition. We consider the particular case of the strongly asymmetric Borrelia burgdorferi genome and we discuss in detail the corrections, which should be introduced into the distance measure between two DNA sequences to include multiple base substitutions.
Exactly capturing three dimensional (3D) motion information of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision system and a method for determining 3D motion parameters of an object from binocular sequence images are introduced. The main steps include camera calibration, the matching of motion and stereo images, 3D feature point correspondences and resolving the motion parameters. Finally, the experimental results of acquiring the motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned method are presented.
Abate, Adam R.; Hung, Tony; Sperling, Ralph A.; Mary, Pascaline; Rotem, Assaf; Agresti, Jeremy J.; Weiner, Michael A.; Weitz, David A.
Droplet-based microfluidic techniques can form and process micrometer scale droplets at thousands per second. Each droplet can house an individual biochemical reaction, allowing millions of reactions to be performed in minutes with small amounts of total reagent. This versatile approach has been used for engineering enzymes, quantifying concentrations of DNA in solution, and screening protein crystallization conditions. Here, we use it to read the sequences of DNA molecules with a FRET-based ...
Ding, Wenwen; Liu, Kai; Cheng, Fei; Zhang, Jin; Li, YunSong
Human action recognition and analysis is an active research topic in computer vision for many years. This paper presents a method to represent human actions based on trajectories consisting of 3D joint positions. This method first decompose action into a sequence of meaningful atomic actions (actionlets), and then label actionlets with English alphabets according to the Davies-Bouldin index value. Therefore, an action can be represented using a sequence of actionlet symbols, which will preserve the temporal order of occurrence of each of the actionlets. Finally, we employ sequence comparison to classify multiple actions through using string matching algorithms (Needleman-Wunsch). The effectiveness of the proposed method is evaluated on datasets captured by commodity depth cameras. Experiments of the proposed method on three challenging 3D action datasets show promising results.
Telomeres are protein-DNA complexes at the terminals of linear chromosomes, which protect chromosomal integrity and maintain cellular replicative capacity.From single-cell organisms to advanced animals and plants,structures and functions of telomeres are both very conservative. In cells of human and vertebral animals, telomeric DNA base sequences all are (TTAGGG)n. In the present work, we have obtained absorption and fluorescence spectra measured from seven synthesized oligonucleotides to simulate the telomeric DNA system and calculated their relative fluorescence quantum yields on which not only telomeric DNA characteristics are predicted but also possibly the shortened telomeric sequences during cell division are imrelative fluorescence quantum yield and remarkable excitation energy innerconversion, which tallies with the telomeric sequence of (TTAGGG)n. This result shows that telomeric DNA has a strong non-radiative or innerconvertible capability.``
WANG GuoXin; PING XiJian; XU ManKun; ZHANG Tao; BAO XiRui
According to the distribution characteristics of short and repeated sequence (SRS),a steganalytic method based on the correlation of image bit planes is proposed.Firstly,we provide the conception of SRS distance statistics and deduce its statistical distribution.Because the SRS distance statistics can effectively reflect the correlation of the sequence,SRS has statistical features when the image bit plane sequence equals the image width.Using this characteristic,the steganalytic method is fulfilled by the distinct test of Poisson distribution.Experimental results show a good performance for detecting LSB matching steganographic method in still images.By the way,the proposed method is not designed for specific steganographic algorithms and has good generality.
Li, Mingkun; Copeland, Alex; Han, James
A new tool, DUK, is developed to perform matching task. Matching is to find whether a query sequence partially or totally matches given reference sequences or not. Matching is similar to alignment. Indeed many traditional analysis tasks like contaminant removal use alignment tools. But for matching, there is no need to know which bases of a query sequence matches which position of a reference sequence, it only need know whether there exists a match or not. This subtle difference can make matching task much faster than alignment. DUK is accurate, versatile, fast, and has efficient memory usage. It uses Kmer hashing method to index reference sequences and Poisson model to calculate p-value. DUK is carefully implemented in C++ in object oriented design. The resulted classes can also be used to develop other tools quickly. DUK have been widely used in JGI for a wide range of applications such as contaminant removal, organelle genome separation, and assembly refinement. Many real applications and simulated dataset demonstrate its power.
Shima Ramesh Maniyath
Full Text Available The rapid growth of the Internet and digitized content made image and video distribution simpler. Hence the need for image and video data protection is on the rise. In this paper, we propose a secure and computationally feasible image and video encryption/decryption algorithm based on DNA sequences. The main purpose of this algorithm is to reduce the big image encryption time. This algorithm is implemented by using the natural DNA sequences as main keys. The first part is the process of pixel scrambling. The original image is confused in the light of the scrambling sequence which is generated by the DNA sequence. The second part is the process of pixel replacement. The pixel gray values of the new image and the one of the three encryption templates generated by the other DNA sequence are XORed bit-by-bit in turn. The main scope of this paper is to propose an extension of this algorithm to videos and making it secure using modern Biological technology. A security analysis for the proposed system is performed and presented.
Santosh Kumar Swain
Full Text Available We present a comprehensive test case generation technique from UML models. We use the features in UML 2.0 sequence diagram including conditions, iterations, asynchronous messages and concurrent components. In our approach, test cases are derived from analysis artifacts such as use cases, their corresponding sequence diagrams and constraints specified across all these artifacts. We construct Use case Dependency Graph (UDG from use case diagram and Concurrent Control Flow Graph (CCFG from corresponding sequence diagrams for test sequence generation. We focus testing on sequences of messages among objects of use case scenarios. Our testing strategy derives test cases using full predicate coverage criteria. Our proposed test case generation technique can be used for integration and system testing accommodating the object message and condition information associated with the use case scenarios. The test cases thus generated are suitable for detecting synchronization and dependency of use cases and messages, object interaction and operational faults. Finally, we have made an analysis and comparison of our approach with existing approaches, which are based on other coverage criterion through an example.
Full Text Available The solid-state nanopore-based DNA sequencing technology is becoming more and more attractive for its brand new future in gene detection field. The challenges that need to be addressed are diverse: the effective methods to detect base-specific signatures, the control of the nanopore’s size and surface properties, and the modulation of translocation velocity and behavior of the DNA molecules. Among these challenges, the realization of the high-quality nanopores with the help of modern micro/nanofabrication technologies is a crucial one. In this paper, typical technologies applied in the field of solid-state nanopore-based DNA sequencing have been reviewed.
Silva, J. F. C.; Lemes Neto, M. C.; Blasechi, V.
The photogrammetric bridging or traverse is a special bundle block adjustment (BBA) for connecting a sequence of stereo-pairs and of determining the exterior orientation parameters (EOP). An object point must be imaged in more than one stereo-pair. In each stereo-pair the distance ratio between an object and its corresponding image point varies significantly. We propose to automate the photogrammetric bridging based on a fully automatic extraction of homologous points in stereo-pairs and on an arbitrary Cartesian datum to refer the EOP and tie points. The technique uses SIFT algorithm and the keypoint matching is given by similarity descriptors of each keypoint based on the smallest distance. All the matched points are used as tie points. The technique was applied initially to two pairs. The block formed by four images was treated by BBA. The process follows up to the end of the sequence and it is semiautomatic because each block is processed independently and the transition from one block to the next depends on the operator. Besides four image blocks (two pairs), we experimented other arrangements with block sizes of six, eight, and up to twenty images (respectively, three, four, five and up to ten bases). After the whole image pairs sequence had sequentially been adjusted in each experiment, a simultaneous BBA was run so to estimate the EOP set of each image. The results for classical ("normal case") pairs were analyzed based on standard statistics regularly applied to phototriangulation, and they show figures to validate the process.
Brown, Judith K.
Viruses of the genus Begomovirus (family Geminiviridae) are emergent pathogens of crops throughout the tropical and subtropical regions of the world. By virtue of having a small DNA genome that is easily cloned, and due to the recent innovations in cloning and low-cost sequencing, there has been a dramatic increase in the number of available begomovirus genome sequences. Even so, most of the available sequences have been obtained from cultivated plants and are likely a small and phylogenetically unrepresentative sample of begomovirus diversity, a factor constraining taxonomic decisions such as the establishment of operationally useful species demarcation criteria. In addition, problems in assigning new viruses to established species have highlighted shortcomings in the previously recommended mechanism of species demarcation. Based on the analysis of 3,123 full-length begomovirus genome (or DNA-A component) sequences available in public databases as of December 2012, a set of revised guidelines for the classification and nomenclature of begomoviruses are proposed. The guidelines primarily consider a) genus-level biological characteristics and b) results obtained using a standardized classification tool, Sequence Demarcation Tool, which performs pairwise sequence alignments and identity calculations. These guidelines are consistent with the recently published recommendations for the genera Mastrevirus and Curtovirus of the family Geminiviridae. Genome-wide pairwise identities of 91 % and 94 % are proposed as the demarcation threshold for begomoviruses belonging to different species and strains, respectively. Procedures and guidelines are outlined for resolving conflicts that may arise when assigning species and strains to categories wherever the pairwise identity falls on or very near the demarcation threshold value.
SAHA, AMRITA; Khapra, Mitesh M.; Chandar, Sarath; Rajendran, Janarthanan; Cho, Kyunghyun
Interlingua based Machine Translation (MT) aims to encode multiple languages into a common linguistic representation and then decode sentences in multiple target languages from this representation. In this work we explore this idea in the context of neural encoder decoder architectures, albeit on a smaller scale and without MT as the end goal. Specifically, we consider the case of three languages or modalities X, Z and Y wherein we are interested in generating sequences in Y starting from inf...
Rice is one of the most important crops in the world. Although genetic improvement is a key technology for the acceleration of rice breeding, a lack of genome information had restricted efforts in molecular-based breeding until the completion of the high-quality rice genome sequence, which opened new opportunities for research in various areas of genomics. The syntenic relationship of the rice genome to other cereal genomes makes the rice genome invaluable for understanding how cereal genomes...
Aliprantis, C. D.; I. Topolyan
We propose an equilibrium refinement of strict perfect equilibrium for the finite normal form games, which is not known in the literature. Okada came up with the idea of strict perfect equilibrium by strengthening the main definition of a perfect equilibrium, due to Selten . We consider the alternative (and equivalent) definition of perfect equilibrium, based on the substitute sequences, as appeared in Selten . We show that by strengthening and modifiyng this definition slightly, one ...
Wyrzykiewicz, T K; Cole, D L
We described a solid-supported desulfurization procedure allowing easy access to the sequence analysis of oligonucleotide phosphorothioates. The described method is based upon selective removal of the 2-cyanoethyl phosphate protecting groups, followed by iodine-promoted desulfurization of the resulting phosphorothioate diesters. Automatic oxidation of oligonucleotide phosphorothioates, anchored via an ester linkage to a standard solid support (LCAA/CPG), is combined with Maxam-Gilbert solid-s...
Diekstra, A.; Bosgoed, E.A.J.; Rikken, A.; Lier, B. van; Kamsteeg, E.J.; Tychon, M.W.J.; Derks, R.C.; Soest, R.A.; Mensenkamp, A.R.; Scheffer, H.; Neveling, K.; Nelen, M.R.
BACKGROUND: Dideoxy-based chain termination sequencing developed by Sanger is the gold standard sequencing approach and allows clinical diagnostics of disorders with relatively low genetic heterogeneity. Recently, new next generation sequencing (NGS) technologies have found their way into diagnostic
LIU Nian-sheng; GUO Dong-hui
The proposed perceptual mask is based on the singularity of cover image and matches very well with the properties of the human visual system. The cover colour image is decomposed into several subbands by the wavelet transform. The water-mark composed of chaotic sequence and the covert image is embedded into the subband with the largest energy. The chaos system plays an important role in the security invisibility and robustness of the proposed scheme. The parameter and initial state of chaos system can directly influence the generation of watermark information as a key. Moreover, the watermark information has the property of spread spectrum signal by chaotic sequence to improve the invisibility and security of watermarked image. Experimental results and comparisons with other watermarking techniques prove that the proposed algorithm is effective and feasible, and improves the security, invisibility and robustness of watermarking information.
Anderson, Iain J.; Loftus, Brendan J.
The sequencing of the genome of Entamoeba histolytica has allowed a reconstruction of its metabolic pathways, many of which are unusual for a eukaryote. Based on the genome sequence, it appears that amino acids may play a larger role than previously thought in energy metabolism, with roles in both ATP synthesis and NAD regeneration. Arginine decarboxylase may be involved in survival of E. histolytica during its passage through the stomach. The usual pyrimidine synthesis pathway is absent, but a partial pyrimidine degradation pathway could be part of a novel pyrimidine synthesis pathway. Ribonucleotide reductase was not found in the E. histolytica genome, but it was found in the close relatives Entamoeba invadens and Entamoeba moshkovskii, suggesting a recent loss from E. histolytica. The usual eukaryotic glucose transporters are not present, but members of a prokaryotic monosaccharide transporter family are present.
Full Text Available Abstract Background During the past decades, research and development in drug discovery have attracted much attention and efforts. However, only 324 drug targets are known for clinical drugs up to now. Identifying potential drug targets is the first step in the process of modern drug discovery for developing novel therapeutic agents. Therefore, the identification and validation of new and effective drug targets are of great value for drug discovery in both academia and pharmaceutical industry. If a protein can be predicted in advance for its potential application as a drug target, the drug discovery process targeting this protein will be greatly speeded up. In the current study, based on the properties of known drug targets, we have developed a sequence-based drug target prediction method for fast identification of novel drug targets. Results Based on simple physicochemical properties extracted from protein sequences of known drug targets, several support vector machine models have been constructed in this study. The best model can distinguish currently known drug targets from non drug targets at an accuracy of 84%. Using this model, potential protein drug targets of human origin from Swiss-Prot were predicted, some of which have already attracted much attention as potential drug targets in pharmaceutical research. Conclusion We have developed a drug target prediction method based solely on protein sequence information without the knowledge of family/domain annotation, or the protein 3D structure. This method can be applied in novel drug target identification and validation, as well as genome scale drug target predictions.
Miguel A Ré
Full Text Available Entropy based measures have been frequently used in symbolic sequence analysis. A symmetrized and smoothed form of Kullback-Leibler divergence or relative entropy, the Jensen-Shannon divergence (JSD, is of particular interest because of its sharing properties with families of other divergence measures and its interpretability in different domains including statistical physics, information theory and mathematical statistics. The uniqueness and versatility of this measure arise because of a number of attributes including generalization to any number of probability distributions and association of weights to the distributions. Furthermore, its entropic formulation allows its generalization in different statistical frameworks, such as, non-extensive Tsallis statistics and higher order Markovian statistics. We revisit these generalizations and propose a new generalization of JSD in the integrated Tsallis and Markovian statistical framework. We show that this generalization can be interpreted in terms of mutual information. We also investigate the performance of different JSD generalizations in deconstructing chimeric DNA sequences assembled from bacterial genomes including that of E. coli, S. enterica typhi, Y. pestis and H. influenzae. Our results show that the JSD generalizations bring in more pronounced improvements when the sequences being compared are from phylogenetically proximal organisms, which are often difficult to distinguish because of their compositional similarity. While small but noticeable improvements were observed with the Tsallis statistical JSD generalization, relatively large improvements were observed with the Markovian generalization. In contrast, the proposed Tsallis-Markovian generalization yielded more pronounced improvements relative to the Tsallis and Markovian generalizations, specifically when the sequences being compared arose from phylogenetically proximal organisms.
S. Santhosh Kumar
Full Text Available Human immunodeficiency virus (HIV is a lent virus that causes acquired immunodeficiency syndrome (AIDS. The main drawback in HIV treatment process is its sub type prediction. The sub type and group classification of HIV is based on its genetic variability and location. HIV can be divided into two major types, HIV type 1 (HIV-1 and HIV type 2 (HIV-2. Many classifier approaches have been used to classify HIV subtypes based on their group, but some of cases are having two groups in one; in such cases the classification becomes more complex. The methodology used is this paper based on the HIV sequences. For this work several classifier approaches are used to classify the HIV1 and HIV2. For implementation of the work a real time patient database is taken and the patient records are experimented and the final best classifier is identified with quick response time and least error rate.
Full Text Available We screened patients with choroideremia using next-generation sequencing (NGS and identified a novel mutation and a known mutation in the CHM gene. One patient presented an atypical fundus appearance for choroideremia. Another patient presented macular hole retinal detachment in the left eye. The present case series shows the utility of NGS-based screening in patients with choroideremia. In addition, the presence of macular hole in 1 of the 2 patients, together with a previous report, indicated the susceptibility of patients with choroideremia to macular hole.
Analysis of DNA methylation patterns relies increasingly on sequencing-based profiling methods. The four most frequently used sequencing-based technologies are the bisulfite-based methods MethylC-seq and reduced representation bisulfite sequencing (RRBS), and the enrichment-based techniques methylat...
Full Text Available Serology-based conventional microlymphocytotoxicity HLA typing method, which has been regarded as the gold standard in organ and hematopoietic stem cell transplantation, has been replaced now by DNA-based typing. Many laboratories all over the world have already switched over to molecular methods. Microlymphocytotoxicity-based tissue typing was done using commercial sera, while the molecular typing by genomic DNA based. DNA quality and its quantity obtained using various DNA extraction protocols was found to be an important factor in the molecular method of tissue typing in transplant outcome. Many polymerase chain reaction-based molecular techniques have been adopted with far reaching clinical outcome. The sequence-based typing (SBT has been the ultimate technique, which has been of the highest reliability in defining the HLA alleles. The nonavailability of specific HLA antisera from native populations, large number of blank alleles yet to be defined and comparable low resolution of HLA alleles in SSP or SSOP technique, suggests that highly refined DNA-based methods like SBT should be used as an adjunct to HLA serology and/or low/intermediate/high resolution HLA typing in order to achieve a better transplant outcome.
Full Text Available Phalaenopsis is one of the most interesting genera of orchids due to the members are often used as parents to produce hybrids. The establishment and development of highly reliable and discriminatory methods for identifying species and cultivars has become increasingly more important to plant breeders and members of the nursery industry. The aim of this research was to develop sequence-based microsatellite (eSSR markers for the Phalaenopsis orchid designed from the sequence of GenBank NCBI. Seventeen primers were designed and thirteen primers pairs could amplify the DNA giving the expected PCR product with polymorphism. A total of 51 alleles, with an average of 3 alleles per locus and polymorphism information content (PIC values at 0.674, were detected at the 16 SSR loci. Therefore, these markers could be used for identification of the Phalaenopsis orchid used in this study. Genetic similarity and principle coordinate analysis identified five major groups of Phalaenopsis sp. the first group consisted of P. amabilis, P. fuscata, P. javanica, and P. zebrine. The second group consisted of P. amabilis, P. amboinensis, P. bellina, P. floresens, and P. mannii. The third group consisted of P. bellina, P. cornucervi, P. cornucervi, P. violaceae sumatra, P. modesta. The forth group consisted of P. cornucervi and P. lueddemanniana, and the fifth group was P. amboinensis.
Smialowski, Pawel; Schmidt, Thorsten; Cox, Jürgen; Kirschner, Andreas; Frishman, Dmitrij
We propose a machine-learning approach to sequence-based prediction of protein crystallizability in which we exploit subtle differences between proteins whose structures were solved by X-ray analysis [or by both X-ray and nuclear magnetic resonance (NMR) spectroscopy] and those proteins whose structures were solved by NMR spectroscopy alone. Because the NMR technique is usually applied on relatively small proteins, sequence length distributions of the X-ray and NMR datasets were adjusted to avoid predictions biased by protein size. As feature space for classification, we used frequencies of mono-, di-, and tripeptides represented by the original 20-letter amino acid alphabet as well as by several reduced alphabets in which amino acids were grouped by their physicochemical and structural properties. The classification algorithm was constructed as a two-layered structure in which the output of primary support vector machine classifiers operating on peptide frequencies was combined by a second-level Naive Bayes classifier. Due to the application of metamethods for cost sensitivity, our method is able to handle real datasets with unbalanced class representation. An overall prediction accuracy of 67% [65% on the positive (crystallizable) and 69% on the negative (noncrystallizable) class] was achieved in a 10-fold cross-validation experiment, indicating that the proposed algorithm may be a valuable tool for more efficient target selection in structural genomics. A Web server for protein crystallizability prediction called SECRET is available at http://webclu.bio.wzw.tum.de:8080/secret. PMID:16315316
LI Chaofeng; LU Yansheng
The task of clustering Web sessions is to group Web sessions based on similarity and consists of maximizing the intra-group similarity while minimizing the inter-group similarity.The first and foremost question needed to be considered in clustering Web sessions is how to measure the similarity between Web sessions. However, there are many shortcomings in traditional measurements. This paper introduces a new method for measuring similarities between Web pages that takes into account not only the URL but also the viewing time of the visited Web page. Then we give a new method to measure the similarity of Web sessions using sequence alignment and the similarity of Web page access in detail.Experiments have proved that our method is valid and efficient.
Zeinab A. Fareed
Full Text Available The alignment of two DNA sequences is a basic step in the analysis of biological data. Sequencing a long DNA sequence is one of the most interesting problems in bioinformatics. Several techniques have been developed to solve this sequence alignment problem like dynamic programming and heuristic algorithms. In this paper, we introduce (GPCodon alignment a pairwise DNA-DNA method for global sequence alignment that improves the accuracy of pairwise sequence alignment. We use a new scoring matrix to produce the final alignment called the empirical codon substitution matrix. Using this matrix in our technique enabled the discovery of new relationships between sequences that could not be discovered using traditional matrices. In addition, we present experimental results that show the performance of the proposed technique over eleven datasets of average length of 2967 bps. We compared the efficiency and accuracy of our techniques against a comparable tool called “Pairwise Align Codons” .
Fei Chen; Yuan-Ting Zhang
DNA sequence analysis is of great significance for increasing our understanding of genomic functions. An important task facing us is the exploration of hidden structural information stored in the DNA sequence. This paper introduces a DNA structure-based adaptive wavelet transform (WT) – the bionic wavelet transform (BWT) – for DNA sequence analysis. The symbolic DNA sequence can be separated into four channels of indicator sequences. An adaptive symbol-to-number mapping, determined from the s...
Kang, Jian; Huang, Kuan-Chieh; Xu, Zheng; Wang, Yunfei; Abecasis, Gonçalo R.; Li, Yun
Summary: Recent advances in sequencing technologies have revolutionized genetic studies. Although high-coverage sequencing can uncover most variants present in the sequenced sample, low-coverage sequencing is appealing for its cost effectiveness. Here, we present AbCD (arbitrary coverage design) to aid the design of sequencing-based studies. AbCD is a user-friendly interface providing pre-estimated effective sample sizes, specific to each minor allele frequency category, for designs with arbi...
Full Text Available The DNA sequences similarity analysis approaches have been based on the representation and the frequency of sequences components; however, the position inside sequence is important information for the sequence data. Whereas, insufficient information in sequences representations is important reason that causes poor similarity results. Based on three classifications of the DNA bases according to their chemical properties, the frequencies and average positions of group mutations have been grouped into two twelve-components vectors, the Euclidean distances among introduced vectors applied to compare the coding sequences of the first exon of beta globin gene of 11 species.
Full Text Available Automated video based surveillance monitoring is an essential and computationally challenging task to resolve issues in the secure access localities. This paper deals with some of the issues which are encountered in the integration surveillance monitoring in the real-life circumstances. We have employed video frames which are extorted from heterogeneous video formats. Each video frame is chosen to identify the anomalous events which are occurred in the sequence of time-driven process. Background subtraction is essentially required based on the optimal threshold and reference frame. Rest of the frames are ablated from reference image, hence all the foreground images paradigms are obtained. The co-ordinate existing in the deducted images is found by scanning the images horizontally until the occurrence of first black pixel. Obtained coordinate is twinned with existing co-ordinates in the primary images. The twinned co-ordinate in the primary image is considered as an active-region-of-interest. At the end, the starred images are converted to temporal video that scrutinizes the moving silhouettes of human behaviors in a static background. The proposed model is implemented in Java. Results and performance analysis are carried out in the real-life environments.
Li, Ying; Li, Qiushi; Li, Xiwen; Song, Jingyuan; Sun, Chao
Fritillaria unibracteata var. wabuensis is an important medicinal plant used for the treatment of cough symptoms related to the respiratory system. The chloroplast genome of F. unibracteata var. wabuensis (GenBank accession no. KF769142) was assembled using the PacBio RS platform (Pacific Biosciences, Beverly, MA) as a circle sequence with 151 009 bp. The assembled genome contains 133 genes, including 88 protein-coding, 37 tRNA, and eight rRNA genes. This genome sequence will provide important resource for further studies on the evolution of Fritillaria genus and molecular identification of Fritillaria herbs and their adulterants. This work suggests that PacBio RS is a powerful tool to sequence and assemble chloroplast genomes. PMID:26370383
Full Text Available Abstract Background 454 pyrosequencing is a commonly used massively parallel DNA sequencing technology with a wide variety of application fields such as epigenetics, metagenomics and transcriptomics. A well-known problem of this platform is its sensitivity to base-calling insertion and deletion errors, particularly in the presence of long homopolymers. In addition, the base-call quality scores are not informative with respect to whether an insertion or a deletion error is more likely. Surprisingly, not much effort has been devoted to the development of improved base-calling methods and more intuitive quality scores for this platform. Results We present HPCall, a 454 base-calling method based on a weighted Hurdle Poisson model. HPCall uses a probabilistic framework to call the homopolymer lengths in the sequence by modeling well-known 454 noise predictors. Base-calling quality is assessed based on estimated probabilities for each homopolymer length, which are easily transformed to useful quality scores. Conclusions Using a reference data set of the Escherichia coli K-12 strain, we show that HPCall produces superior quality scores that are very informative towards possible insertion and deletion errors, while maintaining a base-calling accuracy that is better than the current one. Given the generality of the framework, HPCall has the potential to also adapt to other homopolymer-sensitive sequencing technologies.
Alquezar-Planas, David E; Fordyce, Sarah Louise
Since the development of so-called "next generation" high-throughput sequencing in 2005, this technology has been applied to a variety of fields. Such applications include disease studies, evolutionary investigations, and ancient DNA. Each application requires a specialized protocol to ensure tha...
Shivaram, Gurusrasad; Seetharaman, Guna; Rao, T. R. N.
A dynamic programming based approach for data compression of a ID sequence is presented. The compression of an input sequence of size N to that of a smaller size k is achieved by dividing the input sequence into k subsequences and replacing the subsequences by their respective average values. The partitioning of the input sequence is carried with the intention of reducing the mean squared error in the reconstructed sequence. The complexity involved in finding the partitions which would result in such an optimal compressed sequence is reduced by using the dynamic programming approach, which is presented.
N. V. Shcherbakova
Full Text Available Aim. To study what cardiac drugs currently have any comments on biomarkers and what information can be obtained by pharmacogenetic testing using data exome sequencing in patients with cardiac diseases.Material and methods. Exome sequencing in random participant of the ATEROGEN IVANOVO study and bioinformatics analysis of the data were performed. Point mutations were annotated using ANNOVAR program, as well as comparison with a number of specialized databases was done on the basis of user protocols.Results. 11 cardiac drugs and 7 genes which variants can influence cardiac drug metabolism were analyzed. According to exome sequencing of the participant we did not reveal allelic variants that require dose regime correction and careful efficacy control.Conclusion. The exome sequencing application is the next step to a wide range of personalized therapy. Future opportunities for improvement of the risk-benefit ratio in each patient are the main purpose of the collection and analysis of pharmacogenetic data.
Christensen, H.; Nordentoft, Steen; Olsen, J.E.
To establish the phylogenetic relationships between the subspecies of Salmonella enterica (official name Salmonella choleraesuis), Salmonella bongori and related members of Enterobacteriaceae, sequence comparison of rRNA was performed by maximum-likelihood analysis. The two Salmonella species were...
Taylor, Peter N.; Porcu, Eleonora; Chew, Shelby;
Normal thyroid function is essential for health, but its genetic architecture remains poorly understood. Here, for the heritable thyroid traits thyrotropin (TSH) and free thyroxine (FT4), we analyse whole-genome sequence data from the UK10K project (N = 2,287). Using additional whole-genome...... association with FT4 in NRG1. Our results demonstrate that increased coverage in whole-genome sequence association studies identifies novel variants associated with thyroid function....
Santosh Kumar Swain; Durga Prasad Mohapatra; Rajib Mall
We present a comprehensive test case generation technique from UML models. We use the features in UML 2.0 sequence diagram including conditions, iterations, asynchronous messages and concurrent components. In our approach, test cases are derived from analysis artifacts such as use cases, their corresponding sequence diagrams and constraints specified across all these artifacts. We construct Use case Dependency Graph (UDG) from use case diagram and Concurrent Control Flow Graph (CCFG) from cor...
Will, Sebastian; Otto, Christina; Miladi, Milad; Möhl, Mathias; Backofen, Rolf
Motivation: RNA-Seq experiments have revealed a multitude of novel ncRNAs. The gold standard for their analysis based on simultaneous alignment and folding suffers from extreme time complexity of O ( n 6 ) . Subsequently, numerous faster ‘Sankoff-style’ approaches have been suggested. Commonly, the performance of such methods relies on sequence-based heuristics that restrict the search space to optimal or near-optimal sequence alignments; however, the accuracy of sequence-based methods breaks...
Gravenor, M B; Schulz, M A; Schmalbach, B; Brugger, P; Witt, K.
In a random number generation task, participants are asked to generate a random sequence of numbers, most typically the digits 1 to 9. Such number sequences are not mathematically random, and both extent and type of bias allow one to characterize the brain's “internal random number generator”. We assume that certain patterns and their variations will frequently occur in humanly generated random number sequences. Thus, we introduce a pattern-based analysis of random number sequences. Twenty he...
Schulz, Marc-André; Schmalbach, Barbara; Brugger, Peter; Witt, Karsten
In a random number generation task, participants are asked to generate a random sequence of numbers, most typically the digits 1 to 9. Such number sequences are not mathematically random, and both extent and type of bias allow one to characterize the brain's “internal random number generator”. We assume that certain patterns and their variations will frequently occur in humanly generated random number sequences. Thus, we introduce a pattern-based analysis of random number sequences. Twenty he...
Sherwood, Rob; Mishkin, Andrew; Estlin, Tara; Chien, Steve; Backes, Paul; Cooper, Brian; Maxwell, Scott; Rabideau, Gregg
This paper discusses a proof-of-concept prototype for ground-based automatic generation of validated rover command sequences from highlevel science and engineering activities. This prototype is based on ASPEN, the Automated Scheduling and Planning Environment. This Artificial Intelligence (AI) based planning and scheduling system will automatically generate a command sequence that will execute within resource constraints and satisfy flight rules.
Full Text Available This paper is devoted to the generation and evaluation of the Chaos-based M-ary spreading sequences on communications systems. Sequences obtained by repeating a truncated and multi-ary quantized chaotic series are compared with classical m-sequences by means of the autocorrelation and cross-correlation properties and power-spectral features. Anti-noise performance of binary sequences and chaotic-based M-ary spreading sequences has been compared in the case of the same single-frequency interferences. Studies have shown that spectral features and anti-noise performance of chaotic-based M-ary spreading sequences which have great researching value are better than binary sequences.
Rajeev Singh; Teek Parval Sharma
Authentication per frame is an implicit necessity for security in wireless local area networks (WLANs). We propose a novel per frame secure authentication scheme which provides authentication to data frames in WLANs. The scheme involves no cryptographic overheads for authentication of frames. It utilizes the sequence number of the frame along with the authentication stream generators for authentication. Hence, it requires no extra bits or messages for the authentication purpose and also no change in the existing frame format is required. The scheme provides authentication by modifying the sequence number of the frame at the sender, and that the modification is verified at the receiver. The modified sequence number is protected by using the XOR operation with a random number selected from the random stream. The authentication is lightweight due to the fact that it requires only trivial arithmetic operations like the subtraction and XOR operation.
In multicellular organisms, including humans, understanding expression specificity at the tissue level is essential for interpreting protein function, such as tissue differentiation. We developed a prediction approach via generated sequence features from overrepresented patterns in housekeeping (HK) and tissue-specific (TS) genes to classify TS expression in humans. Using TS domains and transcriptional factor binding sites (TFBSs), sequence characteristics were used as indices of expressed tissues in a Random Forest algorithm by scoring exclusive patterns considering the biological intuition; TFBSs regulate gene expression, and the domains reflect the functional specificity of a TS gene. Our proposed approach displayed better performance than previous attempts and was validated using computational and experimental methods.
Full Text Available DNA sequence analysis is of great significance for increasing our understanding of genomic functions. An important task facing us is the exploration of hidden structural information stored in the DNA sequence. This paper introduces a DNA structure-based adaptive wavelet transform (WT – the bionic wavelet transform (BWT – for DNA sequence analysis. The symbolic DNA sequence can be separated into four channels of indicator sequences. An adaptive symbol-to-number mapping, determined from the structural feature of the DNA sequence, was introduced into WT. It can adjust the weight value of each channel to maximise the useful energy distribution of the whole BWT output. The performance of the proposed BWT was examined by analysing synthetic and real DNA sequences. Results show that BWT performs better than traditional WT in presenting greater energy distribution. This new BWT method should be useful for the detection of the latent structural features in future DNA sequence analysis.
We show a theoretical framework, based on triple-mode Floquet theory, to analyze recoupling sequences derived from symmetry-based pulse sequences, which have a non-vanishing effective field and are not rotor synchronized. We analyze the properties of one such sequence, a homonuclear double-quantum recoupling sequence derived from the C721 sequence. The new asynchronous sequence outperforms the rotor-synchronized version for spin pairs with small dipolar couplings in the presence of large chemical-shift anisotropy. The resonance condition of the new sequence is analyzed using triple-mode Floquet theory. Analytical calculations of second-order effective Hamiltonian are performed to compare the efficiency in suppressing second-order cross terms. Experiments and numerical simulations are shown to corroborate the results of the theoretical analysis
Robin Sequence (RS) is characterized by micrognathia and upper airway obstruction (UAO) caused by glossoptosis resulting in respiratory and feeding problems of varying severity. According to the original RS definition a cleft palate is associated with RS, but not part of the definition. Reported inc
Christensen, H.; Nordentoft, Steen; Olsen, J.E.
separated by 16S rRNA analysis and found to be closely related to the Escherichia coli and Shigella complex by both 16S and 23S rRNA analyses. The diphasic serotypes S. enterica subspp. I and VI were separated from the monophasic serotypes subspp. IIIa and IV, including S. bongori, by 23S rRNA sequence...
Full Text Available In this paper, the central limit theorems for the density estimator and for the integrated square error are proved for the case when the underlying sequence of random variables is nonstationary. Applications to Markov processes and ARMA processes are provided.
Liang, Peifeng; Zhang, Yancong; Lin, Kui; Hu, Jinglu
Assembling a large genome using next generation sequencing reads requires large computer memory and a long execution time. To reduce these requirements, a memory and time efficient assembler is presented from applying FM-index in JR-Assembler, called FMJ-Assembler, where FM stand for FMR-index derived from the FM-index and BWT and J for jumping extension. The FMJ-Assembler uses expanded FM-index and BWT to compress data of reads to save memory and jumping extension method make it faster in CPU time. An extensive comparison of the FMJ-Assembler with current assemblers shows that the FMJ-Assembler achieves a better or comparable overall assembly quality and requires lower memory use and less CPU time. All these advantages of the FMJ-Assembler indicate that the FMJ-Assembler will be an efficient assembly method in next generation sequencing technology. PMID:25569963
Stine, O. Colin; Sozhamannan, Shanmuga; Gou, Qing; Zheng, Siqen; Morris, J. Glenn; Johnson, Judith A.
We sequenced a 705-bp fragment of the recA gene from 113 Vibrio cholerae strains and closely related species. One hundred eighty-seven nucleotides were phylogenetically informative, 55 were phylogenetically uninformative, and 463 were invariant. Not unexpectedly, Vibrio parahaemolyticus and Vibrio vulnificus strains formed out-groups; we also identified isolates which resembled V. cholerae biochemically but which did not cluster with V. cholerae. In many instances, V. cholerae serogroup desig...
Anindya Poddar; Nagasuma Chandra; Madhavi Ganapathiraju; K Sekar; Judith Klein-Seetharaman; Raj Reddy; N Balakrishnan
Gene and protein sequence analyses, central components of studies in modern biology are easily amenable to string matching and pattern recognition algorithms. The growing need of analysing whole genome sequences more efficiently and thoroughly, has led to the emergence of new computational methods. Suffix trees and suffix arrays are data structures, well known in many other areas and are highly suited for sequence analysis too. Here we report an improvement to the design of construction of suffix arrays. Enhancement in versatility and scalability, enabled by this approach, is demonstrated through the use of real-life examples. The scalability of the algorithm to whole genomes renders it suitable to address many biologically interesting problems. One example is the evolutionary insight gained by analysing unigrams, bi-grams and higher n-grams, indicating that the genetic code has a direct influence on the overall composition of the genome. Further, different proteomes have been analysed for the coverage of the possible peptide space, which indicate that as much as a quarter of the total space at the tetra-peptide level is left un-sampled in prokaryotic organisms, although almost all tri-peptides can be seen in one protein or another in a proteome. Besides, distinct patterns begin to emerge for the counts of particular tetra and higher peptides, indicative of a ‘meaning’ for tetra and higher n-grams. The toolkit has also been used to demonstrate the usefulness of identifying repeats in whole proteomes efficiently. As an example, 16 members of one COG, coded by the genome of Mycobacterium tuberculosis H37Rv have been found to contain a repeating sequence of 300 amino acids.
Mohammed, Monzoorul Haque; Ghosh, Tarini Shankar; Reddy, Rachamalla Maheedhar; Reddy, Chennareddy Venkata Siva Kumar; Singh, Nitin Kumar; Sharmila S Mande
Background Taxonomic classification of metagenomic sequences is the first step in metagenomic analysis. Existing taxonomic classification approaches are of two types, similarity-based and composition-based. Similarity-based approaches, though accurate and specific, are extremely slow. Since, metagenomic projects generate millions of sequences, adopting similarity-based approaches becomes virtually infeasible for research groups having modest computational resources. In this study, we present ...
S Balaji; N Srinivasan
Several studies based on the known three-dimensional (3-D) structures of proteins show that two homologous proteins with insignificant sequence similarity could adopt a common fold and may perform same or similar biochemical functions. Hence, it is appropriate to use similarities in 3-D structure of proteins rather than the amino acid sequence similarities in modelling evolution of distantly related proteins. Here we present an assessment of using 3-D structures in modelling evolution of homologous proteins. Using a dataset of 108 protein domain families of known structures with at least 10 members per family we present a comparison of extent of structural and sequence dissimilarities among pairs of proteins which are inputs into the construction of phylogenetic trees. We find that correlation between the structure-based dissimilarity measures and the sequence-based dissimilarity measures is usually good if the sequence similarity among the homologues is about 30% or more. For protein families with low sequence similarity among the members, the correlation coefficient between the sequence-based and the structure-based dissimilarities are poor. In these cases the structure-based dendrogram clusters proteins with most similar biochemical functional properties better than the sequence-similarity based dendrogram. In multi-domain protein families and disulphide-rich protein families the correlation coefficient for the match of sequence-based and structure-based dissimilarity (SDM) measures can be poor though the sequence identity could be higher than 30%. Hence it is suggested that protein evolution is best modelled using 3-D structures if the sequence similarities (SSM) of the homologues are very low.
Afify, Heba; Wahed, Manal Abdel
Modern biological science produces vast amounts of genomic sequence data. This is fuelling the need for efficient algorithms for sequence compression and analysis. Data compression and the associated techniques coming from information theory are often perceived as being of interest for data communication and storage. In recent years, a substantial effort has been made for the application of textual data compression techniques to various computational biology tasks, ranging from storage and indexing of large datasets to comparison of genomic databases. This paper presents a differential compression algorithm that is based on production of difference sequences according to op-code table in order to optimize the compression of homologous sequences in dataset. Therefore, the stored data are composed of reference sequence, the set of differences, and differences locations, instead of storing each sequence individually. This algorithm does not require a priori knowledge about the statistics of the sequence set. The...
Bhowmick, S.; Shafiullah, M.; Rai, H.; Bastola, D.
Biological sequence comparison programs have revolutionized the practice of biochemistry, and molecular and evolutionary biology. Pairwise comparison of genomic sequences is a popular method of choice for analyzing genetic sequence data. However the quality of results from most sequence comparison methods are significantly affected by small perturbations in the data and furthermore, there is a dearth of computational tools to compare sequences beyond a certain length. In this paper, we describe a parallel algorithm for comparing genetic sequences using an alignment free-method based on computing the Longest Common Subsequence (LCS) between genetic sequences. We validate the quality of our results by comparing the phylogenetic tress obtained from ClustalW and LCS. We also show through complexity analysis of the isoefficiency and by empirical measurement of the running time that our algorithm is very scalable.
Drmanac, Radoje; Sparks, Andrew B; Callow, Matthew J; Halpern, Aaron L; Burns, Norman L; Kermani, Bahram G; Carnevali, Paolo; Nazarenko, Igor; Nilsen, Geoffrey B; Yeung, George; Dahl, Fredrik; Fernandez, Andres; Staker, Bryan; Pant, Krishna P; Baccash, Jonathan; Borcherding, Adam P; Brownley, Anushka; Cedeno, Ryan; Chen, Linsu; Chernikoff, Dan; Cheung, Alex; Chirita, Razvan; Curson, Benjamin; Ebert, Jessica C; Hacker, Coleen R; Hartlage, Robert; Hauser, Brian; Huang, Steve; Jiang, Yuan; Karpinchyk, Vitali; Koenig, Mark; Kong, Calvin; Landers, Tom; Le, Catherine; Liu, Jia; McBride, Celeste E; Morenzoni, Matt; Morey, Robert E; Mutch, Karl; Perazich, Helena; Perry, Kimberly; Peters, Brock A; Peterson, Joe; Pethiyagoda, Charit L; Pothuraju, Kaliprasad; Richter, Claudia; Rosenbaum, Abraham M; Roy, Shaunak; Shafto, Jay; Sharanhovich, Uladzislau; Shannon, Karen W; Sheppy, Conrad G; Sun, Michel; Thakuria, Joseph V; Tran, Anne; Vu, Dylan; Zaranek, Alexander Wait; Wu, Xiaodi; Drmanac, Snezana; Oliphant, Arnold R; Banyai, William C; Martin, Bruce; Ballinger, Dennis G; Church, George M; Reid, Clifford A
Genome sequencing of large numbers of individuals promises to advance the understanding, treatment, and prevention of human diseases, among other applications. We describe a genome sequencing platform that achieves efficient imaging and low reagent consumption with combinatorial probe anchor ligation chemistry to independently assay each base from patterned nanoarrays of self-assembling DNA nanoballs. We sequenced three human genomes with this platform, generating an average of 45- to 87-fold coverage per genome and identifying 3.2 to 4.5 million sequence variants per genome. Validation of one genome data set demonstrates a sequence accuracy of about 1 false variant per 100 kilobases. The high accuracy, affordable cost of $4400 for sequencing consumables, and scalability of this platform enable complete human genome sequencing for the detection of rare variants in large-scale genetic studies. PMID:19892942
Choi, Woo-Yong; Chatterjee, Mainak
With the growing use of RFID (Radio Frequency Identification), it is becoming important to devise ways to read RFID tags in real time. Access points (APs) of IEEE 802.11-based wireless Local Area Networks (LANs) are being integrated with RFID networks that can efficiently collect real-time RFID data. Several schemes, such as multipolling methods based on the dynamic search algorithm and random sequencing, have been proposed. However, as the number of RFID readers associated with an AP increases, it becomes difficult for the dynamic search algorithm to derive the multipolling sequence in real time. Though multipolling methods can eliminate the polling overhead, we still need to enhance the performance of the multipolling methods based on random sequencing. To that extent, we propose a real-time cluster-based multipolling sequencing algorithm that drastically eliminates more than 90% of the polling overhead, particularly so when the dynamic search algorithm fails to derive the multipolling sequence in real time.
Nagamani, Selvaraman; Singh, Kh Dhanachandra; Muthusamy, Karthikeyan
FGF23, CYP24A1 and VDR altogether play a significant role in genetic susceptibility to chronic kidney disease (CKD). Identification of possible causative mutations may serve as therapeutic targets and diagnostic markers for CKD. Thus, we adopted both sequence and sequence-structure based SNP analysis algorithm in order to overcome the limitations of both methods. We explore the functional significance towards the prediction of risky SNPs associated with CKD. We assessed the performance of four widely used pathogenicity prediction methods. We compared the performances of the programs using Mathews correlation Coefficient ranged from poor (MCC = 0.39) to reasonably good (MCC = 0.42). However, we got the best results for the combined sequence and structure based analysis method (MCC = 0.45). 4 SNPs from FGF23 gene, 8 SNPs from VDR gene and 13 SNPs from CYP24A1 gene were predicted to be the causative agents for human diseases. This study will be helpful in selecting potential SNPs for experimental study from the SNP pool and also will reduce the cost for identification of potential SNPs as a genetic marker. PMID:27114920
Xu, Shengzhi; Cheng, Xiang; Li, Zhengyi; Xiong, Li
In this paper, we study the problem of mining frequent sequences under the rigorous differential privacy model. We explore the possibility of designing a differentially private frequent sequence mining (FSM) algorithm which can achieve both high data utility and a high degree of privacy. We found, in differentially private FSM, the amount of required noise is proportionate to the number of candidate sequences. If we could effectively reduce the number of unpromising candidate sequences, the utility and privacy tradeoff can be significantly improved. To this end, by leveraging a sampling-based candidate pruning technique, we propose a novel differentially private FSM algorithm, which is referred to as PFS2. The core of our algorithm is to utilize sample databases to further prune the candidate sequences generated based on the downward closure property. In particular, we use the noisy local support of candidate sequences in the sample databases to estimate which sequences are potentially frequent. To improve the accuracy of such private estimations, a sequence shrinking method is proposed to enforce the length constraint on the sample databases. Moreover, to decrease the probability of misestimating frequent sequences as infrequent, a threshold relaxation method is proposed to relax the user-specified threshold for the sample databases. Through formal privacy analysis, we show that our PFS2 algorithm is ε-differentially private. Extensive experiments on real datasets illustrate that our PFS2 algorithm can privately find frequent sequences with high accuracy. PMID:26973430
ZHANG Fa; QIAO Xiangzhen; LIU Zhiyong
Tools for pair-wise bio-sequence alignment have for long played a central role in computation biology. Several algorithms for bio-sequence alignment have been developed. The Smith-Waterman algorithm, based on dynamic programming, is considered the most fundamental alignment algorithm in bioinformatics. However the existing parallel Smith-Waterman algorithm needs large memory space, and this disadvantage limits the size of a sequence to be handled. As the data of biological sequences expand rapidly, the memory requirement of the existing parallel SmithWaterman algorithm has become a critical problem. For solving this problem, we develop a new parallel bio-sequence alignment algorithm, using the strategy of divide and conquer, named PSW-DC algorithm. In our algorithm, first, we partition the query sequence into several subsequences and distribute them to every processor respectively,then compare each subsequence with the whole subject sequence in parallel, using the Smith-Waterman algorithm, and get an interim result, finally obtain the optimal alignment between the query sequence and subject sequence, through the special combination and extension method. Memory space required in our algorithm is reduced significantly in comparison with existing ones. We also develop a key technique of combination and extension, named the C&E method, to manipulate the interim results and obtain the final sequences alignment. We implement the new parallel bio-sequences alignment algorithm,the PSW-DC, in a cluster parallel system.
Gonnella Giorgio; Kurtz Stefan
Abstract Background Ongoing improvements in throughput of the next-generation sequencing technologies challenge the current generation of de novo sequence assemblers. Most recent sequence assemblers are based on the construction of a de Bruijn graph. An alternative framework of growing interest is the assembly string graph, not necessitating a division of the reads into k-mers, but requiring fast algorithms for the computation of suffix-prefix matches among all pairs of reads. Results Here we...
Manske, Heinrich Magnus; Dominic P Kwiatkowski
Sequencing a genome to great depth can be highly informative about heterogeneity within an individual or a population. Here we address the problem of how to visualize the multiple layers of information contained in deep sequencing data. We propose an interactive AJAX-based web viewer for browsing large data sets of aligned sequence reads. By enabling seamless browsing and fast zooming, the LookSeq program assists the user to assimilate information at different levels of resolution, from an ov...
Liu, Ming; Crussière, Matthieu; Hélard, Jean-François
An accurate channel estimation is crucial for the novel time domain synchronous orthogonal frequency-division multiplexing (TDS-OFDM) scheme in which pseudo noise (PN) sequences serve as both guard intervals (GI) for OFDM data symbols and training sequences for synchronization/channel estimation. This paper studies the channel estimation method based on the cross-correlation of PN sequences. A theoretical analysis of this estimator is conducted and several improved estimators are then propose...
Chen, Chunxian; Gmitter Jr, Fred G
Background Single nucleotide polymorphisms (SNPs), the most abundant variations in a genome, have been widely used in various studies. Detection and characterization of citrus haplotype-based expressed sequence tag (EST) SNPs will greatly facilitate further utilization of these gene-based resources. Results In this paper, haplotype-based SNPs were mined out of publicly available citrus expressed sequence tags (ESTs) from different citrus cultivars (genotypes) individually and collectively for...
We introduce a new distance-based phylogeny reconstruction technique which provably achieves, at sufficiently short branch lengths, a polylogarithmic sequence-length requirement -- improving significantly over previous polynomial bounds for distance-based methods. The technique is based on an averaging procedure that implicitly reconstructs ancestral sequences. In the same token, we extend previous results on phase transitions in phylogeny reconstruction to general time-reversible models. More precisely, we show that in the so-called Kesten-Stigum zone (roughly, a region of the parameter space where ancestral sequences are well approximated by ``linear combinations'' of the observed sequences) sequences of length $\\poly(\\log n)$ suffice for reconstruction when branch lengths are discretized. Here $n$ is the number of extant species. Our results challenge, to some extent, the conventional wisdom that estimates of evolutionary distances alone carry significantly less information about phylogenies than full sequ...
Kielpinski, Lukasz Jan
In this thesis we describe the development of four related methods for RNA structure probing that utilize massive parallel sequencing. Using them, we were able to gather structural data for multiple, long molecules simultaneously. First, we have established an easy to follow experimental and...... RTTS-Seq to detect antisense oligonucleotide binding sites within a transcriptome. In this case, we applied an enrichment strategy to greatly reduce the background. Finally, we have modified the RTTS-Seq to study the secondary structure of 3’ untranslated regions. In the course of this thesis we...... computational protocol for detecting the reverse transcription termination sites (RTTS-Seq). This protocol was subsequently applied to hydroxyl radical footprinting of three dimensional RNA structures to give a probing signal that correlates well with the RNA backbone solvent accessibility. Moreover, we applied...
Gao, Song; He, Dan; Li, Guangquan; Zhang, Yanhua; Lv, Huiying; Wang, Li
Thermal asymmetric staggered PCR is the most widely used technique to obtain the flanking sequences. However, it has some limitations, including a low rate of positivity, and complex operation. In this study, a improved method of it was made based on suppression-PCR and touchdown PCR. The PCR fragment obtained by the amplification was used directly for sequencing after gel purification. Using this improved method, the positive rate of amplified flanking sequences of the ATMT mutants reached 99%. In addition, the time from DNA extraction to flanking sequence analysis was shortened to 2 days with about 6 dollars each sample. PMID:27393656
Niu Xinwen; Ding Han; Xiong Youlun
Using group and subassembly cluster methods, the hierarchical structure of a product is.generated automatically, which largely reduces the complexity of planning. Based on genetic algofithn the optimal of assembly sequence of each stracture level can be obtained by sequence-bysequence search. As a result, a better assembly sequence of the product can be generated by combining the assembly sequences of all hierarchical structures, which provides more parallelism and flexibility for assembly operations. An industrial example is solved by this new approach.
Peng Xiuping; Xu Chengqian
In this paper,a new class of almost binary sequence pair with a single zero element is presented.The almost binary sequence pairs with three-level correlation are constructed based on cyclotomic numbers of order 2,4,and 6.Most of them have good correlation and balance property,whose maximum nontrivial correlation magnitudes are 2 and the difference between the numbers of occurrence of +1's and -1's are 0 or 1.In addition,the corresponding binary sequence pairs are investigated as well and we can also get some kinds of binary sequence pairs with optimum balance and good correlation.
Motivation. The third generation sequencing (3GS) technology generates long sequences of thousands of bases. However, its current error rates are estimated in the range of 15–40%, significantly higher than those of the prevalent next generation sequencing (NGS) technologies (less than 1%). Fundamental bioinformatics tasks such as de novo genome assembly and variant calling require high-quality sequences that need to be extracted from these long but erroneous 3GS sequences. Results. We describe a versatile and efficient linear complexity consensus algorithm Sparc to facilitate de novo genome assembly. Sparc builds a sparse k-mer graph using a collection of sequences from a targeted genomic region. The heaviest path which approximates the most likely genome sequence is searched through a sparsity-induced reweighted graph as the consensus sequence. Sparc supports using NGS and 3GS data together, which leads to significant improvements in both cost efficiency and computational efficiency. Experiments with Sparc show that our algorithm can efficiently provide high-quality consensus sequences using both PacBio and Oxford Nanopore sequencing technologies. With only 30× PacBio data, Sparc can reach a consensus with error rate NGS data. Compared with the existing approaches, Sparc calculates the consensus with higher accuracy, and uses approximately 80% less memory and time. Availability. The source code is available for download at https://github.com/yechengxi/Sparc. PMID:27330851
During 2012, five isolates of pycnidial fungi were recovered from roots of tomato (Solanum lycopersicum) plants in Iran. Based on morphological characteristics the presence of Ampelomyces was documented. To confirm morphological identification and clarify the placement of endophytic isolates of Ampelomyces, DNA was extracted from isolates using a genomic DNA purification Kit. Region of internal transcribed spacers 1, 2 and 5.8S genes of rDNA were amplified using ITS4 and ITS1 universal primer set. Amplicons were purified, sequenced and submitted to the GenBank. The resulting sequence (600 bp) was submitted to a BLAST search to find most similar sequences in GenBank. The ITS sequences of isolates obtained in Iran were compared to those of other related authentic sequences obtained from GenBank. Iranian endophytic isolates had 100 % similarity of among themselves, while all isolates of Ampelomyces sequences analyzed had an average of 95.2 % (range 87-100 %) similarity. When Ampelomyces ITS sequences were analyzed by both distance-based and maximum parsimony methods, the Ampelomyces isolates were segregate into 11 distinct clades. The ITS sequences of endophytic isolates obtained in Iran were identical with endophytic isolates from other country including USA, Australia, Hungary and Spain. Our analyses of phylogenetic data showed that endophytic isolates from Iran and other countries are distinct group. The high ITS sequence-divergence values and the phylogenetic analysis suggested the isolates of Ampelomyces in the clades are not closely related and indeed a problematic species complex. PMID:25245955
Chiumenti, Michela; Mohorianu, Irina; Roseti, Vincenzo; Saldarelli, Pasquale; Dalmay, Tamas; Minafra, Angelantonio
A new satellite RNA (satRNA) of grapevine fanleaf virus (GFLV) was identified by high-throughput sequencing of high-definition (HD) adapter libraries from grapevine plants of the cultivar Panse precoce (PPE) affected by enation disease. The complete nucleotide sequence was obtained by automatic sequencing using primers designed based on next-generation sequencing (NGS) data. The full-length sequence, named satGFLV-PPE, consisted of 1119 nucleotides with a single open reading frame from position 15 to 1034. This satRNA showed maximum nucleotide sequence identity of 87 % to satArMV-86 and satGFLV-R6. Symptomatic grapevines were surveyed for the presence of the satRNA, and no correlation was found between detection of the satRNA and enation symptom expression. PMID:26873812
LEI LiHua; SHI HuLi; MA GuanYi
Multiple Path Interference (MPI) and Multiple Access Interference (MAI) are Important factors that affect the performance of Chinese Area Positioning System (CAPS),These problems can be solved by using spreading sequences with ideal properties and multi-user detectors.Chaotic sequences based on Chebyshev map are studied and the satellite communication system model is set up to investigate the application of chaotic sequences for CAPS in this paper,Simulation results show that chaotic sequences have desirable correlation properties and it is easy to generate a large number of chaotic sequences with good security.It has great practical value to apply chaotic sequences to CAPS together with multi-user detecting technology and the system performance can be improved greatly.
For an advanced aircraft, the amount of its effectors is much more than that for a traditional one, the functions of effectors are more complex and the coupling between each other is more severe. Based on the current control allocation research, this paper puts forward the concept and framework of the control allocation and management system for aircrafts with redundancy con-trol effectors. A new optimal control allocation method, bases sequenced optimal (BSO) method, is then presented. By analyz-ing the physical meaning of the allocation process of BSO method, four types of management strategies are adopted by the system, which act on the control allocation process under different flight conditions, mission requirements and effectors work-ing conditions. Simulation results show that functions of the control allocation system are extended and the system adaptability to flight status, mission requirements and effector failure conditions is improved.
Lee T Sam
Full Text Available The second wave of next generation sequencing technologies, referred to as single-molecule sequencing (SMS, carries the promise of profiling samples directly without employing polymerase chain reaction steps used by amplification-based sequencing (AS methods. To examine the merits of both technologies, we examine mRNA sequencing results from single-molecule and amplification-based sequencing in a set of human cancer cell lines and tissues. We observe a characteristic coverage bias towards high abundance transcripts in amplification-based sequencing. A larger fraction of AS reads cover highly expressed genes, such as those associated with translational processes and housekeeping genes, resulting in relatively lower coverage of genes at low and mid-level abundance. In contrast, the coverage of high abundance transcripts plateaus off using SMS. Consequently, SMS is able to sequence lower- abundance transcripts more thoroughly, including some that are undetected by AS methods; however, these include many more mapping artifacts. A better understanding of the technical and analytical factors introducing platform specific biases in high throughput transcriptome sequencing applications will be critical in cross platform meta-analytic studies.
Samorodnitsky, Eric; Jewell, Benjamin M.; Hagopian, Raffi; Miya, Jharna; Wing, Michele R.; Lyon, Ezra; Damodaran, Senthilkumar; Bhatt, Darshna; Reeser, Julie W.; Datta, Jharna
ABSTRACT Next‐generation sequencing has aided characterization of genomic variation. While whole‐genome sequencing may capture all possible mutations, whole‐exome sequencing remains cost‐effective and captures most phenotype‐altering mutations. Initial strategies for exome enrichment utilized a hybridization‐based capture approach. Recently, amplicon‐based methods were designed to simplify preparation and utilize smaller DNA inputs. We evaluated two hybridization capture‐based and two amplicon‐based whole‐exome sequencing approaches, utilizing both Illumina and Ion Torrent sequencers, comparing on‐target alignment, uniformity, and variant calling. While the amplicon methods had higher on‐target rates, the hybridization capture‐based approaches demonstrated better uniformity. All methods identified many of the same single‐nucleotide variants, but each amplicon‐based method missed variants detected by the other three methods and reported additional variants discordant with all three other technologies. Many of these potential false positives or negatives appear to result from limited coverage, low variant frequency, vicinity to read starts/ends, or the need for platform‐specific variant calling algorithms. All methods demonstrated effective copy‐number variant calling when evaluated against a single‐nucleotide polymorphism array. This study illustrates some differences between whole‐exome sequencing approaches, highlights the need for selecting appropriate variant calling based on capture method, and will aid laboratories in selecting their preferred approach. PMID:26110913
Samorodnitsky, Eric; Jewell, Benjamin M; Hagopian, Raffi; Miya, Jharna; Wing, Michele R; Lyon, Ezra; Damodaran, Senthilkumar; Bhatt, Darshna; Reeser, Julie W; Datta, Jharna; Roychowdhury, Sameek
Next-generation sequencing has aided characterization of genomic variation. While whole-genome sequencing may capture all possible mutations, whole-exome sequencing remains cost-effective and captures most phenotype-altering mutations. Initial strategies for exome enrichment utilized a hybridization-based capture approach. Recently, amplicon-based methods were designed to simplify preparation and utilize smaller DNA inputs. We evaluated two hybridization capture-based and two amplicon-based whole-exome sequencing approaches, utilizing both Illumina and Ion Torrent sequencers, comparing on-target alignment, uniformity, and variant calling. While the amplicon methods had higher on-target rates, the hybridization capture-based approaches demonstrated better uniformity. All methods identified many of the same single-nucleotide variants, but each amplicon-based method missed variants detected by the other three methods and reported additional variants discordant with all three other technologies. Many of these potential false positives or negatives appear to result from limited coverage, low variant frequency, vicinity to read starts/ends, or the need for platform-specific variant calling algorithms. All methods demonstrated effective copy-number variant calling when evaluated against a single-nucleotide polymorphism array. This study illustrates some differences between whole-exome sequencing approaches, highlights the need for selecting appropriate variant calling based on capture method, and will aid laboratories in selecting their preferred approach. PMID:26110913
Srinivas Behara; Shiv Datt Kumar
This paper deals with the study of behaviour of -associated ideals and strong Krull -associated ideals with flat base change of rings and behaviour of -associated ideals with short exact sequences over rings graded by finitely generated abelian group .
Viennot, L.; Rainson, S.
Illustrates an approach to research-based teaching strategies and their evaluation. Addresses a teaching sequence on the superposition of electric fields implemented at the college level in an institutional framework subject to severe constraints. Contains 28 references. (DDR)
Bullard, Whitney; Cliffe, Laura; Wang, Pengcheng; Wang, Yinsheng; Sabatini, Robert
Telomeric DNA of trypanosomatids possesses a modified thymine base, called base J, that is synthesized in a two-step process; the base is hydroxylated by a thymidine hydroxylase forming hydroxymethyluracil (hmU) and a glucose moiety is then attached by the J-associated glucosyltransferase (JGT). To examine the importance of JGT in modifiying specific thymine in DNA, we used a Leishmania episome system to demonstrate that the telomeric repeat (GGGTTA) stimulates J synthesis in vivo while mutant telomeric sequences (GGGTTT, GGGATT, and GGGAAA) do not. Utilizing an in vitro GT assay we find that JGT can glycosylate hmU within any sequence with no significant change in Km or kcat, even mutant telomeric sequences that are unable to be J-modified in vivo. The data suggests that JGT possesses no DNA sequence specificity in vitro, lending support to the hypothesis that the specificity of base J synthesis is not at the level of the JGT reaction. PMID:26815240
Eiter, T.; Fink, M; Sabbatini, G; Tompits, H.
We consider an approach to update nonmonotonic knowledge bases represented as extended logic programs under answer set semantics. New information is incorporated into the current knowledge base subject to a causal rejection principle enforcing that, in case of conflicts, more recent rules are preferred and older rules are overridden. Such a rejection principle is also exploited in other approaches to update logic programs, e.g., in dynamic logic programming by Alferes et al. We give a thoroug...
Tardif, Keith D.; Simmon, Keith E.; Kommedal, Øyvind; Pyne, Michael T.; Schlaberg, Robert
Sequencing-based pathogen identification directly from clinical specimens requires time-consuming interpretation, especially with mixed chromatograms when multiple microorganisms are detected. We assessed RipSeq Mixed software for human papillomavirus (HPV) genotyping by comparison to the linear array HPV genotyping assay. RipSeq Mixed provided rapid, sequencing-based HPV typing for single-type infections and coinfections with 2 types.
Comin, Matteo; Schimd, Michele
Background With the advent of Next-Generation Sequencing technologies (NGS), a large amount of short read data has been generated. If a reference genome is not available, the assembly of a template sequence is usually challenging because of repeats and the short length of reads. When NGS reads cannot be mapped onto a reference genome alignment-based methods are not applicable. However it is still possible to study the evolutionary relationship of unassembled genomes based on NGS data. Results...
Yoder, Garett; Cook, Jerry
The Department of Physics at EKU [Eastern Kentucky University] with support from the National Science Foundations Course Curriculum and Laboratory Improvement Program has successfully converted our entire introductory physics sequence, both algebra-based and calculus-based courses, to an activity-based format where laboratory activities,…
T. J. Vogl
Full Text Available Background/Objective: To evaluate T1 and PRF thermometry methods utilizing fast MR sequences and fluoroptic thermometer."nMaterials and Methods: The MR-guided LITT (Laser-Induced Interstitial Thermotherapy with a laser wavelength/power of 1064nm/30W was applied to pig liver and a gel phantom. During the ablation process, the temperature was measured using a fluoroptic thermometer and MR imaging was performed applying a 1.5-Tesla tomograph with an EPI (Echo Planar Imaging sequence for PRF (Proton Resonance Frequency method and FLASH, IRTF, SRTF and TRUFI sequences for T1 method. Plotting MR signal intensity against measured temperature determined the temperature constant for each of the T1 sequences. To determine the PRF temperature constant, phase values were recorded from phase images and then plotted against temperature. The PRF temperature constant was verified comparing the MR temperature with the measured one obtained from a second LITT experiment on gel phantom."nResults: The experiments determining the temperature constant for T1 method showed that the IRTF and FLASH sequences have the highest temperature sensitivity and the most linear relationship between MR signal intensity and measured temperature. SRTF sequence presented relatively good linearity but inferior temperature sensitivity compared to IRTF and FLASH sequences. Conversely, TRUFI sequence exhibited the lowest temperature sensitivity and linearity of data points. Concerning the PRF method, the measured and the MR-based temperatures agreed up to approximately 70 C."nConclusion: To demonstrate and control temperature in target tissue during the LITT process, the PRF method with an EPI sequence is preferred for temperatures below 70 C due to its acceptable accuracy. Among the T1 sequences, FLASH is preferable as the most robust, though not the most accurate T1 sequence.
Diaz, G.; Arboleya, P.; Gomez-Aleixandre, J. [University of Oviedo (Spain). Dept. of Electrical Engineering
Two relaying techniques for protecting power transformers are presented and discussed. Very often, differential relaying is used for this purpose. A comparison between the two proposed techniques and conventional differential relaying is thus presented. The first technique, based on the measurements of zero sequence current within a delta winding, performs best in multiwinding transformers, since only measurement of the coil currents is needed. Thus, great simplicity is achieved. The second one is based on the differential procedure, but its analysis of asymmetries in the plot in Park's plane avoids problems related to spectral analysis in conventional differential relaying. The technique is justified from the analysis of symmetrical components. Misoperation in conventional differential relaying has been observed in some cases as a function of switching instant and fault location. This issue is discussed in the paper, and a statistical analysis of a large number of laboratory tests, in which both factors were controlled, is presented. As a conclusion, both relaying techniques proposed succeed in protecting the transformer. Additionally, the Park-based relay exhibits three characteristics of most importance: fastest performance, robustness and simplicity in its formulation. (author)
Gao, Chunsheng; Xin, Pengfei; Cheng, Chaohua; Tang, Qing; Ping CHEN; Wang, Changbiao; Zang, Gonggu; Zhao, Lining
Cannabis sativa L. is an important economic plant for the production of food, fiber, oils, and intoxicants. However, lack of sufficient simple sequence repeat (SSR) markers has limited the development of cannabis genetic research. Here, large-scale development of expressed sequence tag simple sequence repeat (EST-SSR) markers was performed to obtain more informative genetic markers, and to assess genetic diversity in cannabis (Cannabis sativa L.). Based on the cannabis transcriptome, 4,577 SS...
Full Text Available Abstract Background The size and repetitive nature of the Rhipicephalus microplus genome makes obtaining a full genome sequence fiscally and technically problematic. To selectively obtain gene-enriched regions of this tick's genome, Cot filtration was performed, and Cot-filtered DNA was sequenced via 454 FLX pyrosequencing. Results The sequenced Cot-filtered genomic DNA was assembled with an EST-based gene index of 14,586 unique entries where each EST served as a potential "seed" for scaffold formation. The new sequence assembly extended the lengths of 3,913 of the 14,586 gene index entries. Over half of the extensions corresponded to extensions of over 30 amino acids. To survey the repetitive elements in the tick genome, the complete sequences of five BAC clones were determined. Both Class I and II transposable elements were found. Comparison of the BAC and Cot filtration data indicates that Cot filtration was highly successful in filtering repetitive DNA out of the genomic DNA used in 454 sequencing. Conclusion Cot filtration is a very useful strategy to incorporate into genome sequencing projects on organisms with large genome sizes and which contain high percentages of repetitive, difficult to assemble, genomic DNA. Combining the Cot selection approach with 454 sequencing and assembly with a pre-existing EST database as seeds resulted in extensions of 27% of the members of the EST database.
Klette, Reinhard; Krüger, Norbert; Vaudrey, Tobi;
This paper discusses options for testing correspondence algorithms in stereo or motion analysis that are designed or considered for vision-based driver assistance. It introduces a globally available database, with a main focus on testing on video sequences of real-world data. We suggest the......) for demonstrating ideas, difficulties, and possible ways in this future field of extensive performance tests in vision-based driver assistance, particularly for cases where the ground truth is not available. This paper shows that the complexity of real-world data does not support the identification of...... report on hours of driving, and multiple hours of long video data may be segmented into basic sequences and classified into situations. This paper prepares for this expected development. This paper uses three different evaluation approaches (prediction error, synthesized sequences, and labeled sequences...
Full Text Available The system propose a video retargeting algorithmto resize images based on the extracted saliency informationfrom the compressed domain. The system utilizes DCTcoefficients in JP2 bit stream to perform saliency detectionwith the consideration of the human visual sensitivity.Valuable retargeting requires emphasize the main satisfiedwhile retain immediate context with minimal visualdeformation. A number of algorithms have been proposedfor image retargeting with image substance taken as muchas potential. But, they usually suffer from deformationresults, such as edge or structure twists. A structure andcontent preserving image retargeting technique is used thatpreserves the content and image structure. The imagecontent saliency is estimated from the structure of thecontent using probability map. A block structure energy isuse for structure conservation along both directions. Blockstructure energy uses top down strategy to constrict theimage structure consistently. However, the flexibilities ofretargeting are altered for different images. To defeat thisproblem, the patch transform is introduced, where an imageis broken into non-overlapping patches, and modificationsor constraints are applied in the “patch domain”.. Thus, theresized image is produced to preserve the structure andimage content quality.
Full Text Available The rapid development of next-generation sequencing platforms has enabled the use of sequencing for routine genotyping across a range of genetics studies and breeding applications. Genotyping-by-sequencing (GBS, a low-cost, reduced representation sequencing method, is becoming a common approach for whole-genome marker profiling in many species. With quickly developing sequencing technologies, adapting current GBS methodologies to new platforms will leverage these advancements for future studies. To test new semiconductor sequencing platforms for GBS, we genotyped a barley recombinant inbred line (RIL population. Based on a previous GBS approach, we designed bar code and adapter sets for the Ion Torrent platforms. Four sets of 24-plex libraries were constructed consisting of 94 RILs and the two parents and sequenced on two Ion platforms. In parallel, a 96-plex library of the same RILs was sequenced on the Illumina HiSeq 2000. We applied two different computational pipelines to analyze sequencing data; the reference-independent TASSEL pipeline and a reference-based pipeline using SAMtools. Sequence contigs positioned on the integrated physical and genetic map were used for read mapping and variant calling. We found high agreement in genotype calls between the different platforms and high concordance between genetic and reference-based marker order. There was, however, paucity in the number of SNP that were jointly discovered by the different pipelines indicating a strong effect of alignment and filtering parameters on SNP discovery. We show the utility of the current barley genome assembly as a framework for developing very low-cost genetic maps, facilitating high resolution genetic mapping and negating the need for developing de novo genetic maps for future studies in barley. Through demonstration of GBS on semiconductor sequencing platforms, we conclude that the GBS approach is amenable to a range of platforms and can easily be modified as new
Willems, Sander; Fraiture, Marie-Alice; Deforce, Dieter; De Keersmaecker, Sigrid; Herman, Philippe; De Loose, Marc; Ruttink, Tom; Van Nieuwerburgh, Filip; Roosens, Nancy
Because the number and diversity of genetically modified (GM) crops has significantly increased, their analysis based on real-time PCR (qPCR) methods is becoming increasingly complex and laborious. While several pioneers already investigated Next Generation Sequencing (NGS) as an alternative to qPCR, its practical use has not been assessed for routine analysis. In this study a statistical framework was developed to predict the number of NGS reads needed to detect transgene sequences, to prove...
Zhao, Di; Narayanan, G.; Ayyanar, Raja
This paper analyzes the switching loss characteristics of sequences involving division of active state duration in space vector based PWM. This analysis, together with the THD performance of the different sequences, reported recently, is used to design new hybrid PWM techniques for induction motor drives, which result in simultaneous reduction in both THD as well as inverter switching losses. Experimental results are presented to demonstrate the feasibility and advantages of the proposed PWM ...
Francisco Alexandre P; Vaz Ctia; Monteiro Pedro T; Melo-Cristino José; Ramirez Mário; Carrio Joo A
Abstract Background With the decrease of DNA sequencing costs, sequence-based typing methods are rapidly becoming the gold standard for epidemiological surveillance. These methods provide reproducible and comparable results needed for a global scale bacterial population analysis, while retaining their usefulness for local epidemiological surveys. Online databases that collect the generated allelic profiles and associated epidemiological data are available but this wealth of data remains under...
Minevich, Gregory; Park, Danny S.; Blankenberg, Daniel; Richard J Poole; Hobert, Oliver
Whole genome sequencing (WGS) allows researchers to pinpoint genetic differences between individuals and significantly shortcuts the costly and time-consuming part of forward genetic analysis in model organism systems. Currently, the most effort-intensive part of WGS is the bioinformatic analysis of the relatively short reads generated by second generation sequencing platforms. We describe here a novel, easily accessible and cloud-based pipeline, called CloudMap, which greatly simplifies the ...
Tewolde, Rediat; Dallman, Timothy; Schaefer, Ulf; Sheppard, Carmen L; Ashton, Philip; Pichon, Bruno; Ellington, Matthew; Swift, Craig; Green, Jonathan; Underwood, Anthony
Multilocus sequence typing (MLST) is an effective method to describe bacterial populations. Conventionally, MLST involves Polymerase Chain Reaction (PCR) amplification of housekeeping genes followed by Sanger DNA sequencing. Public Health England (PHE) is in the process of replacing the conventional MLST methodology with a method based on short read sequence data derived from Whole Genome Sequencing (WGS). This paper reports the comparison of the reliability of MLST results derived from WGS data, comparing mapping and assembly-based approaches to conventional methods using 323 bacterial genomes of diverse species. The sensitivity of the two WGS based methods were further investigated with 26 mixed and 29 low coverage genomic data sets from Salmonella enteridis and Streptococcus pneumoniae. Of the 323 samples, 92.9% (n = 300), 97.5% (n = 315) and 99.7% (n = 322) full MLST profiles were derived by the conventional method, assembly- and mapping-based approaches, respectively. The concordance between samples that were typed by conventional (92.9%) and both WGS methods was 100%. From the 55 mixed and low coverage genomes, 89.1% (n = 49) and 67.3% (n = 37) full MLST profiles were derived from the mapping and assembly based approaches, respectively. In conclusion, deriving MLST from WGS data is more sensitive than the conventional method. When comparing WGS based methods, the mapping based approach was the most sensitive. In addition, the mapping based approach described here derives quality metrics, which are difficult to determine quantitatively using conventional and WGS-assembly based approaches. PMID:27602279
Brejnev Muhizi Muhire
Full Text Available The perpetually increasing rate at which viral full-genome sequences are being determined is creating a pressing demand for computational tools that will aid the objective classification of these genome sequences. Taxonomic classification approaches that are based on pairwise genetic identity measures are potentially highly automatable and are progressively gaining favour with the International Committee on Taxonomy of Viruses (ICTV. There are, however, various issues with the calculation of such measures that could potentially undermine the accuracy and consistency with which they can be applied to virus classification. Firstly, pairwise sequence identities computed based on multiple sequence alignments rather than on multiple independent pairwise alignments can lead to the deflation of identity scores with increasing dataset sizes. Also, when gap-characters need to be introduced during sequence alignments to account for insertions and deletions, methodological variations in the way that these characters are introduced and handled during pairwise genetic identity calculations can cause high degrees of inconsistency in the way that different methods classify the same sets of sequences. Here we present Sequence Demarcation Tool (SDT, a free user-friendly computer program that aims to provide a robust and highly reproducible means of objectively using pairwise genetic identity calculations to classify any set of nucleotide or amino acid sequences. SDT can produce publication quality pairwise identity plots and colour-coded distance matrices to further aid the classification of sequences according to ICTV approved taxonomic demarcation criteria. Besides a graphical interface version of the program for Windows computers, command-line versions of the program are available for a variety of different operating systems (including a parallel version for cluster computing platforms.
Full Text Available Phylogenetic trees have been constructed for a wide range of organisms using gene sequence information, especially through the identification of orthologous genes that have been vertically inherited. The number of available complete genome sequences is rapidly increasing, and many tools for construction of genome trees based on whole genome sequences have been proposed. However, development of a reasonable method of using complete genome sequences for construction of phylogenetic trees has not been established. We have developed a method for construction of phylogenetic trees based on the average sequence similarities of whole genome sequences. We used this method to examine the phylogeny of 115 photosynthetic prokaryotes, i.e., cyanobacteria, Chlorobi, proteobacteria, Chloroflexi, Firmicutes and nonphotosynthetic organisms including Archaea. Although the bootstrap values for the branching order of phyla were low, probably due to lateral gene transfer and saturated mutation, the obtained tree was largely consistent with the previously reported phylogenetic trees, indicating that this method is a robust alternative to traditional phylogenetic methods.
Mer, Arvind Singh; Klevebring, Daniel; Grönberg, Henrik; Rantalainen, Mattias
Sequencing-based molecular characterization of tumors provides information required for individualized cancer treatment. There are well-defined molecular subtypes of breast cancer that provide improved prognostication compared to routine biomarkers. However, molecular subtyping is not yet implemented in routine breast cancer care. Clinical translation is dependent on subtype prediction models providing high sensitivity and specificity. In this study we evaluate sample size and RNA-sequencing read requirements for breast cancer subtyping to facilitate rational design of translational studies. We applied subsampling to ascertain the effect of training sample size and the number of RNA sequencing reads on classification accuracy of molecular subtype and routine biomarker prediction models (unsupervised and supervised). Subtype classification accuracy improved with increasing sample size up to N = 750 (accuracy = 0.93), although with a modest improvement beyond N = 350 (accuracy = 0.92). Prediction of routine biomarkers achieved accuracy of 0.94 (ER) and 0.92 (Her2) at N = 200. Subtype classification improved with RNA-sequencing library size up to 5 million reads. Development of molecular subtyping models for cancer diagnostics requires well-designed studies. Sample size and the number of RNA sequencing reads directly influence accuracy of molecular subtyping. Results in this study provide key information for rational design of translational studies aiming to bring sequencing-based diagnostics to the clinic. PMID:26830453
Chuan Sheng∗,Yongshun Zhang; Wenlong Lu
The study of phased array radar ( PAR) pulse amplitude sequence characteristics is the key to understand the radar’s working state and its beam’s scanning manner. According to the principle of antenna pattern formation and the searching and tracking modes of beams, this paper analyzes the characteristics and differences of pulse amplitude sequence when the radar beams work in searching and tracking modes respectively. Then an optimal sorting model of pulse amplitude sequence is established based on least⁃squares and curve⁃fitting methods. This method is helpful for acquiring the current working state of the radar and recognizing its instantaneous beam pointing by sorting the pulse amplitude sequence without the necessity to estimate the antenna pattern.
Tian Chunna; Gao Xinbo
A fast interactive segmentation algorithm of image-sequences based on relative fuzzy connectedness is presented. In comparison with the original algorithm, the proposed one, with the same accuracy, accelerates the segmentation speed by three times for single image. Meanwhile, this fast segmentation algorithm is extended from single object to multiple objects and from single-image to image-sequences. Thus the segmentation of multiple objects from complex background and batch segmentation of image-sequences can be achieved. In addition, a post-processing scheme is incorporated in this algorithm, which extracts smooth edge with one-pixel-width for each segmented object. The experimental results illustrate that the proposed algorithm can obtain the object regions of interest from medical image or image-sequences as well as man-made images quickly and reliably with only a little interaction.
David, Mathieu; Garde, Francois; Boyer, Harry
In building studies dealing about energy efficiency and comfort, simulation software need relevant weather files with optimal time steps. Few tools generate extreme and mean values of simultaneous hourly data including correlation between the climatic parameters. This paper presents the C++ Runeole software based on typical weather sequences analysis. It runs an analysis process of a stochastic continuous multivariable phenomenon with frequencies properties applied to a climatic database. The database analysis associates basic statistics, PCA (Principal Component Analysis) and automatic classifications. Different ways of applying these methods will be presented. All the results are stored in the Runeole internal database that allows an easy selection of weather sequences. The extreme sequences are used for system and building sizing and the mean sequences are used for the determination of the annual cooling loads as proposed by Audrier-Cros (Audrier-Cros, 1984). This weather analysis was tested with the datab...
Tai, N.L.; Ai, Q. [Shanghai Jiao Tong University (China). Dept. of Power Electrical Engineering
A mathematical model on a coil basis is used to study the characteristics of the zero sequence voltage of a generator The proposed technique for the stator groundfault detection simultaneously takes into account the fault contributed zero sequence fundamental voltage and the fault contributed third-harmonic voltage (Delta-zero sequence voltage). The effect of the start-up component based on the wavelet transform is also highlighted. As information both on the fault contributed zero sequence fundamental voltage and the third-harmonic voltage is used simultaneously, the scheme can obtain higher sensitivity. Results from the experiment and in the field show that the proposed technique can detect the ground fault with high sensitivity and reliability during all operating conditions. (author)
G. N. Dash
Full Text Available Discrimination of protein coding regions called exons from noncoding regions called introns or junk DNA in eukaryotic cell is a computationally intensive task. But the dimension of the DNA string is huge; hence it requires large computation time. Further the DNA sequences are inherently random and have vast redundancy, hidden regularities, long repeats and complementary palindromes and therefore cannot be compressed efficiently. The objective of this study is to present an integrated signal processing algorithm that considerably reduces the computational load by compressing the DNA sequence effectively and aids the problem of searching for coding regions in DNA sequences. The presented algorithm is based on the Discrete Wavelet Transform (DWT, a very fast and effective method used for data compression and followed by comb filter for effective prediction of protein coding period-3 regions in DNA sequences. This algorithm is validated using standard dataset such as HMR195, Burset and Guigo and KEGG.
An inquiry-based site visit teaching sequence for school science was designed in co-operation with researchers and science teachers, according to the principles of Design Based Research (DBR). Out-of-school industry site visits were central in the design. Theory-based conjectures arising from the literature on motivation, interest and inquiry-based science teaching (IBST) were embodied in the design solution, and these embodied conjectures were studied in order to uncover the aspects of the d...
Forbin, G.; Besserer, B.; Boldyš, Jiří; Tschumperlé, D.
Anaheim: ACTA Press, 2005, s. 1-5. ISBN 0-88986-528-0. [Visualization, Imaging, and Image Processing (VIIP 2005). Benidorm (ES), 07.09.2005-09.09.2005] R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : image sequences * digital restoration * exemplar-based inpainting method Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2009/ZOI/boldys-temporal extension to exemplar-based inpainting applied to scratch correction in damaged image sequences.pdf
Negative selection against protein instability is a central influence on evolution of proteins. Protein stability is maintained over evolution despite changes in underlying sequences. An empirical all-site stability-based model of evolution was developed to focus on the selection of residues arising from their contributions to protein stability. In this model, site rates could vary. A structure-based method was used to predict stationary frequencies of hemoglobin residues based on their prope...
Solis, A D; Rackovsky, S
We examine the informatic characteristics of amino acid representations based on physical properties. We demonstrate that sequences rewritten using contracted alphabets based on physical properties do not encode local folding information well. The best four-character alphabet can only encode approximately 57% of the maximum possible amount of structural information. This result suggests that property-based representations that operate on a local length scale are not likely to be useful in homology searches and fold-recognition exercises. PMID:17387739
Li-Xia LIU; Meng-Long LI; Fu-Yuan TAN; Min-Chun LU; Ke-Long WANG; Yan-Zhi GUO; Zhi-Ning WEN; Lin JIANG
In our previous work, we developed a computational tool, PreK-ClassK-ClassKv, to predict and classify potassium (K+) channels. For K+ channel prediction (PreK) and classification at family level (ClassK), this method performs well. However, it does not perform so well in classifying voltage-gated potassium (Kv) channels (ClassKv). In this paper, a new method based on the local sequence information of Kv channels is introduced to classify Kv channels. Six transmembrane domains of a Kv channel protein are used to define a protein, and the dipeptide composition technique is used to transform an amino acid sequence to a numerical sequence. A Kv channel protein is represented by a vector with 2000 elements, and a support vector machine algorithm is applied to classify Kv channels. This method shows good performance with averages of total accuracy (Acc), sensitivity (SE), specificity (SP); reliability (R) and Matthews correlation coefficient (MCC) of 98.0%, 89.9%, 100%, 0.95 and 0.94 respectively. The results indicate that the local sequence information-based method is better than the global sequence information-based method to classify Kv channels.
Wu, Yu-Wei; Ye, Yuzhen
Metagenomics is the study of microbial communities sampled directly from their natural environment, without prior culturing. Among the computational tools recently developed for metagenomic sequence analysis, binning tools attempt to classify all (or most) of the sequences in a metagenomic dataset into different bins (i.e., species), based on various DNA composition patterns (e.g., the tetramer frequencies) of various genomes. Composition-based binning methods, however, cannot be used to classify very short fragments, because of the substantial variation of DNA composition patterns within a single genome. We developed a novel approach (AbundanceBin) for metagenomics binning by utilizing the different abundances of species living in the same environment. AbundanceBin is an application of the Lander-Waterman model to metagenomics, which is based on the l-tuple content of the reads. AbundanceBin achieved accurate, unsupervised, clustering of metagenomic sequences into different bins, such that the reads classified in a bin belong to species of identical or very similar abundances in the sample. In addition, AbundanceBin gave accurate estimations of species abundances, as well as their genome sizes - two important parameters for characterizing a microbial community. We also show that AbundanceBin performed well when the sequence lengths are very short (e.g. 75 bp) or have sequencing errors.
N. K. Khalid
Full Text Available Problem statement: In DNA based computation and DNA nanotechnology, the design of good DNA sequences has turned out to be an essential problem and one of the most practical and important research topics. Basically, the DNA sequence design problem is a multi-objective problem and it can be evaluated using four objective functions, namely, Hmeasure, similarity, continuity and hairpin. Approach: There are several ways to solve multi-objective problem, however, in order to evaluate the correctness of PSO algorithm in DNA sequence design, this problem is converted into single objective problem. Particle Swarm Optimization (PSO is proposed to minimize the objective in the problem, subjected to two constraints: melting temperature and GCcontent. A model is developed to present the DNA sequence design based on PSO computation. Results: Based on experiments and researches done, 20 particles are used in the implementation of the optimization process, where the average values and the standard deviation for 100 runs are shown along with comparison to other existing methods. Conclusion: The results achieve verified that PSO can suitably solves the DNA sequence design problem using the proposed method and model, comparatively better than other approaches.
Neelam Bajpai; Raghav Ram Tewari
The phylogenetic relationships among flesh flies of the family Sarcophagidae has been based mainly on the morphology of male genitalia. However, the male genitalic character-based relationships are far from satisfactory. Therefore, in the present study mitochondrial DNA has been used as marker to unravel genetic relatedness and to construct phylogeny among five sympatric species of the genus Sarcophaga. Two mitochondrial genes viz., cytochrome oxidase subunit 1 (COI) and NAD dehydrogenase subunit 5 (ND5) were sequenced and genetic distance values were calculated on the basis of sequence differences in both the mitochondrial genes. The data revealed very few genetic difference among the five species for the COI and ND5 gene sequences.
Guo, Y C; Wang, H; Wu, H P; Zhang, M Q
Aimed to address the defects of the large mean square error (MSE), and the slow convergence speed in equalizing the multi-modulus signals of the constant modulus algorithm (CMA), a multi-modulus algorithm (MMA) based on global artificial fish swarm (GAFS) intelligent optimization of DNA encoding sequences (GAFS-DNA-MMA) was proposed. To improve the convergence rate and reduce the MSE, this proposed algorithm adopted an encoding method based on DNA nucleotide chains to provide a possible solution to the problem. Furthermore, the GAFS algorithm, with its fast convergence and global search ability, was used to find the best sequence. The real and imaginary parts of the initial optimal weight vector of MMA were obtained through DNA coding of the best sequence. The simulation results show that the proposed algorithm has a faster convergence speed and smaller MSE in comparison with the CMA, the MMA, and the AFS-DNA-MMA. PMID:26782395
The genus Citrus (Aurantioideae, Rutaceae) is the sole source of the citrus fruits of commerce showing high economic values. In this study, the taxonomy and phylogeny of Citrus species is evaluated using sequence analysis of the ITS region of nrDNA. This study is based on 26 plants materials belonging to 22 Citrus species having wild, domesticated, and cultivated species. Through DNA alignment of the ITS sequence, ITS1 and ITS2 regions showed relatively high variations of sequence length and nucleotide among these Citrus species. According to previous six-tribe discrimination theory by Swingle and Reece, the grouping in our ITS phylogenetic tree reconstructed by ITS sequences was not related to tribe discrimination but species discrimination. However, the molecular analysis could provide more information on citrus taxonomy. Combined with ITS sequences of other subgenera in then true citrus fruit tree group, the ITS phylogenetic tree indicated subgenera Citrus was monophyletic and nearer to Fortunella, Poncirus, and Clymenia compared to Microcitrus and Eremocitrus. Abundant sequence variations of the ITS region shown in this study would help species identification and tribe differentiation of the genus Citrus. (author)
Chaos game representation (CGR) is proposed as a scale-independent representation for DNA sequences and provides information about the statistical distribution of oligonucleotides in a DNA sequence. CGR images of DNA sequences represent some kinds of fractal patterns, but the common multifractal analysis based on the box counting method cannot deal with CGR images perfectly. Here, the wavelet transform modulus maxima (WTMM) method is applied to the multifractal analysis of CGR images. The results show that the scale-invariance range of CGR edge images can be extended to three orders of magnitude, and complete singularity spectra can be calculated. Spectrum parameters such as the singularity spectrum span are extracted to describe the statistical character of DNA sequences. Compared with the singularity spectrum span, exon sequences with a minimal spectrum span have the most uniform fractal structure. Also, the singularity spectrum parameters are related to oligonucleotide length, sequence component and species, thereby providing a method of studying the length polymorphism of repeat oligonucleotides. (general)
Full Text Available Modern biological science produces vast amounts of genomic sequence data. This is fuelling the need forefficient algorithms for sequence compression and analysis. Data compression and the associatedtechniques coming from information theory are often perceived as being of interest for datacommunication and storage. In recent years, a substantial effort has been made for the application oftextual data compression techniques to various computational biology tasks, ranging from storage andindexing of large datasets to comparison of genomic databases. This paper presents a differentialcompression algorithm that is based on production of difference sequences according to op-code table inorder to optimize the compression of homologous sequences in dataset. Therefore, the stored data arecomposed of reference sequence, the set of differences, and differences locations, instead of storing eachsequence individually. This algorithm does not require a priori knowledge about the statistics of thesequence set. The algorithm was applied to three different datasets of genomic sequences, it achieved upto 195-fold compression rate corresponding to 99.4% space saving.
Full Text Available The vast majority of methods available for sequence comparison rely on a first sequence alignment step, which requires a number of assumptions on evolutionary history and is sometimes very difficult or impossible to perform due to the abundance of gaps (insertions/deletions. In such cases, an alternative alignment-free method would prove valuable. Our method starts by a computation of a generalized suffix tree of all sequences, which is completed in linear time. Using this tree, the frequency of all possible words with a preset length L—L-words—in each sequence is rapidly calculated. Based on the L-words frequency profile of each sequence, a pairwise standard Euclidean distance is then computed producing a symmetric genetic distance matrix, which can be used to generate a neighbor joining dendrogram or a multidimensional scaling graph. We present an improvement to word counting alignment-free approaches for sequence comparison, by determining a single optimal word length and combining suffix tree structures to the word counting tasks. Our approach is, thus, a fast and simple application that proved to be efficient and powerful when applied to mitochondrial genomes. The algorithm was implemented in Python language and is freely available on the web.
Milius, Robert P; Heuer, Michael; Valiga, Daniel; Doroschak, Kathryn J; Kennedy, Caleb J; Bolon, Yung-Tsi; Schneider, Joel; Pollack, Jane; Kim, Hwa Ran; Cereb, Nezih; Hollenbach, Jill A; Mack, Steven J; Maiers, Martin
We present an electronic format for exchanging data for HLA and KIR genotyping with extensions for next-generation sequencing (NGS). This format addresses NGS data exchange by refining the Histoimmunogenetics Markup Language (HML) to conform to the proposed Minimum Information for Reporting Immunogenomic NGS Genotyping (MIRING) reporting guidelines (miring.immunogenomics.org). Our refinements of HML include two major additions. First, NGS is supported by new XML structures to capture additional NGS data and metadata required to produce a genotyping result, including analysis-dependent (dynamic) and method-dependent (static) components. A full genotype, consensus sequence, and the surrounding metadata are included directly, while the raw sequence reads and platform documentation are externally referenced. Second, genotype ambiguity is fully represented by integrating Genotype List Strings, which use a hierarchical set of delimiters to represent allele and genotype ambiguity in a complete and accurate fashion. HML also continues to enable the transmission of legacy methods (e.g. site-specific oligonucleotide, sequence-specific priming, and Sequence Based Typing (SBT)), adding features such as allowing multiple group-specific sequencing primers, and fully leveraging techniques that combine multiple methods to obtain a single result, such as SBT integrated with NGS. PMID:26319908
Full Text Available High-throughput sequencing technology, also called next-generation sequencing (NGS, has the potential to revolutionize the whole process of genome sequencing, transcriptomics, and epigenetics. Sequencing data is captured in a public primary data archive, the Sequence Read Archive (SRA. As of January 2013, data from more than 14,000 projects have been submitted to SRA, which is double that of the previous year. Researchers can download raw sequence data from SRA website to perform further analyses and to compare with their own data. However, it is extremely difficult to search entries and download raw sequences of interests with SRA because the data structure is complicated, and experimental conditions along with raw sequences are partly described in natural language. Additionally, some sequences are of inconsistent quality because anyone can submit sequencing data to SRA with no quality check. Therefore, as a criterion of data quality, we focused on SRA entries that were cited in journal articles. We extracted SRA IDs and PubMed IDs (PMIDs from SRA and full-text versions of journal articles and retrieved 2748 SRA ID-PMID pairs. We constructed a publication list referring to SRA entries. Since, one of the main themes of -omics analyses is clarification of disease mechanisms, we also characterized SRA entries by disease keywords, according to the Medical Subject Headings (MeSH extracted from articles assigned to each SRA entry. We obtained 989 SRA ID-MeSH disease term pairs, and constructed a disease list referring to SRA data. We previously developed feature profiles of diseases in a system called "Gendoo". We generated hyperlinks between diseases extracted from SRA and the feature profiles of it. The developed project, publication and disease lists resulting from this study are available at our web service, called "DBCLS SRA" (http://sra.dbcls.jp/. This service will improve accessibility to high-quality data from SRA.
Singh, Vinod Kumar; Krishnamachari, Annangarachari
Genome-wide experimental studies in Saccharomyces cerevisiae reveal that autonomous replicating sequence (ARS) requires an essential consensus sequence (ACS) for replication activity. Computational studies identified thousands of ACS like patterns in the genome. However, only a few hundreds of these sites act as replicating sites and the rest are considered as dormant or evolving sites. In a bid to understand the sequence makeup of replication sites, a content and context-based analysis was performed on a set of replicating ACS sequences that binds to origin-recognition complex (ORC) denoted as ORC-ACS and non-replicating ACS sequences (nrACS), that are not bound by ORC. In this study, DNA properties such as base composition, correlation, sequence dependent thermodynamic and DNA structural profiles, and their positions have been considered for characterizing ORC-ACS and nrACS. Analysis reveals that ORC-ACS depict marked differences in nucleotide composition and context features in its vicinity compared to nrACS. Interestingly, an A-rich motif was also discovered in ORC-ACS sequences within its nucleosome-free region. Profound changes in the conformational features, such as DNA helical twist, inclination angle and stacking energy between ORC-ACS and nrACS were observed. Distribution of ACS motifs in the non-coding segments points to the locations of ORC-ACS which are found far away from the adjacent gene start position compared to nrACS thereby enabling an accessible environment for ORC-proteins. Our attempt is novel in considering the contextual view of ACS and its flanking region along with nucleosome positioning in the S. cerevisiae genome and may be useful for any computational prediction scheme. PMID:27508123
Full Text Available Combining single-cell methods and next-generation sequencing should provide a powerful means to understand single-cell biology and obviate the effects of sample heterogeneity. Here we report a single-cell identification method and seamless cancer gene profiling using semiconductor-based massively parallel sequencing. A549 cells (adenocarcinomic human alveolar basal epithelial cell line were used as a model. Single-cell capture was performed using laser capture microdissection (LCM with an Arcturus® XT system, and a captured single cell and a bulk population of A549 cells (≈106 cells were subjected to whole genome amplification (WGA. For cell identification, a multiplex PCR method (AmpliSeq™ SNP HID panel was used to enrich 136 highly discriminatory SNPs with a genotype concordance probability of 1031–35. For cancer gene profiling, we used mutation profiling that was performed in parallel using a hotspot panel for 50 cancer-related genes. Sequencing was performed using a semiconductor-based bench top sequencer. The distribution of sequence reads for both HID and Cancer panel amplicons was consistent across these samples. For the bulk population of cells, the percentages of sequence covered at coverage of more than 100× were 99.04% for the HID panel and 98.83% for the Cancer panel, while for the single cell percentages of sequence covered at coverage of more than 100× were 55.93% for the HID panel and 65.96% for the Cancer panel. Partial amplification failure or randomly distributed non-amplified regions across samples from single cells during the WGA procedures or random allele drop out probably caused these differences. However, comparative analyses showed that this method successfully discriminated a single A549 cancer cell from a bulk population of A549 cells. Thus, our approach provides a powerful means to overcome tumor sample heterogeneity when searching for somatic mutations.
Dong, Qiwen; Zhou, Shuigeng; Deng, Lei; Guan, Jihong
The prediction of protein function is a difficult and important problem in computational biology. In this study, an efficient method is presented to predict protein function with sequence composition information. Four kinds of basic building blocks of protein sequences are investigated, including N-grams, binary profiles, PFAM domains and InterPro domains. The protein sequences are mapped into high-dimensional vectors by using the occurrence frequencies of each kind of building blocks. The resulting vectors are then taken as input to support vector machine to predict their function based on gene ontology. Experiments are conducted over the subset of GOA database. The experimental results show that the protein function can be predicted from primary sequence information. The method based on InterPro domains outperforms the other building blocks, and gets an overall accuracy of 0.87 and ROC score is 0.93. We also demonstrate that the use of feature extraction algorithms such as latent semantic analysis and nonnegative matrix factorization, can efficiently remove noise and improve the prediction efficiency without significantly degrading the performance. The results obtained here are helpful for the prediction of protein function by using only sequence information. PMID:19995340
Maggioni, R; Rogers, A D; Maclean, N; D'Incao, F
Partial sequences for the 16S rRNA mitochondrial gene were obtained from 10 penaeid shrimp species: Farfantepenaeus paulensis, F. brasiliensis, F. subtilis, F. duorarum, F. aztecus, Litopenaeus schmitti, L. setiferus, and Xiphopenaeus kroyeri from the western Atlantic and L. vannamei and L. stylirostris from the eastern Pacific. Sequences were also obtained from an undescribed morphotype of pink shrimp (morphotype II) usually identified as F. subtilis. The phylogeny resulting from the 16S partial sequences showed that these species form two well-supported monophyletic clades consistent with the two genera proposed in a recent systematic review of the suborder Dendrobranchiata. This contrasted with conclusions drawn from recent molecular phylogenetic work on penaeid shrimps based on partial sequences of the mitochondrial COI region that failed to support recent revisions of the Dendrobranchiata based on morphological analysis. Consistent differences observed in the sequences for morphotype II, coupled with previous allozyme data, support the conclusion that this is a previously undescribed species of Farfantepenaeus. PMID:11161743
Full Text Available Abstract Background We present a complete re-implementation of the segment-based approach to multiple protein alignment that contains a number of improvements compared to the previous version 2.2 of DIALIGN. This previous version is superior to Needleman-Wunsch-based multi-alignment programs on locally related sequence sets. However, it is often outperformed by these methods on data sets with global but weak similarity at the primary-sequence level. Results In the present paper, we discuss strengths and weaknesses of DIALIGN in view of the underlying objective function. Based on these results, we propose several heuristics to improve the segment-based alignment approach. For pairwise alignment, we implemented a fragment-chaining algorithm that favours chains of low-scoring local alignments over isolated high-scoring fragments. For multiple alignment, we use an improved greedy procedure that is less sensitive to spurious local sequence similarities. To evaluate our method on globally related protein families, we used the well-known database BAliBASE. For benchmarking tests on locally related sequences, we created a new reference database called IRMBASE which consists of simulated conserved motifs implanted into non-related random sequences. Conclusion On BAliBASE, our new program performs significantly better than the previous version of DIALIGN and is comparable to the standard global aligner CLUSTAL W, though it is outperformed by some newly developed programs that focus on global alignment. On the locally related test sets in IRMBASE, our method outperforms all other programs that we evaluated.
Kielpinski, Lukasz Jan; Sidiropoulos, Nikos; Vinther, Jeppe
time also made analysis of the data challenging for scientists without formal training in computational biology. Here, we discuss different strategies for data analysis of massive parallel sequencing-based structure-probing data. To facilitate reproducible and standardized analysis of this type of data...
Braguglia, Kay H.; Jackson, Kanata A.
This article presents a reflective analysis of teaching research methodology through a three course sequence using a project-based approach. The authors reflect critically on their experiences in teaching research methods courses in an undergraduate business management program. The introduction of a range of specific techniques including student…
Narjaikaew, Pattawan; Emarat, Narumon; Arayathanitkul, Kwan; Cowie, Bronwen
The study investigated the impact on student motivation and understanding of magnetism of teaching sequences based on an inductive approach. The study was conducted in large lecture classes. A pre- and post-Conceptual Survey of Electricity and Magnetism was conducted with just fewer than 700 Thai undergraduate science students, before and after…
Spicker, J.S.; Wikman, F.; Lu, M.L.;
We have trained an artificial neural network to predict the sequence of the human TP53 tumor suppressor gene based on a p53 GeneChip. The trained neural network uses as input the fluorescence intensities of DNA hybridized to oligonucleotides on the surface of the chip and makes between zero and...
Spraggins Thomas A
Full Text Available Abstract Background Cowpea [Vigna unguiculata (L. Walp.] is one of the most important food and forage legumes in the semi-arid tropics because of its ability to tolerate drought and grow on poor soils. It is cultivated mostly by poor farmers in developing countries, with 80% of production taking place in the dry savannah of tropical West and Central Africa. Cowpea is largely an underexploited crop with relatively little genomic information available for use in applied plant breeding. The goal of the Cowpea Genomics Initiative (CGI, funded by the Kirkhouse Trust, a UK-based charitable organization, is to leverage modern molecular genetic tools for gene discovery and cowpea improvement. One aspect of the initiative is the sequencing of the gene-rich region of the cowpea genome (termed the genespace recovered using methylation filtration technology and providing annotation and analysis of the sequence data. Description CGKB, Cowpea Genespace/Genomics Knowledge Base, is an annotation knowledge base developed under the CGI. The database is based on information derived from 298,848 cowpea genespace sequences (GSS isolated by methylation filtering of genomic DNA. The CGKB consists of three knowledge bases: GSS annotation and comparative genomics knowledge base, GSS enzyme and metabolic pathway knowledge base, and GSS simple sequence repeats (SSRs knowledge base for molecular marker discovery. A homology-based approach was applied for annotations of the GSS, mainly using BLASTX against four public FASTA formatted protein databases (NCBI GenBank Proteins, UniProtKB-Swiss-Prot, UniprotKB-PIR (Protein Information Resource, and UniProtKB-TrEMBL. Comparative genome analysis was done by BLASTX searches of the cowpea GSS against four plant proteomes from Arabidopsis thaliana, Oryza sativa, Medicago truncatula, and Populus trichocarpa. The possible exons and introns on each cowpea GSS were predicted using the HMM-based Genscan gene predication program and the
Nakayama, S.; Kretsinger, R. H.
In the first report in this series we presented dendrograms based on 152 individual proteins of the EF-hand family. In the second we used sequences from 228 proteins, containing 835 domains, and showed that eight of the 29 subfamilies are congruent and that the EF-hand domains of the remaining 21 subfamilies have diverse evolutionary histories. In this study we have computed dendrograms within and among the EF-hand subfamilies using the encoding DNA sequences. In most instances the dendrograms based on protein and on DNA sequences are very similar. Significant differences between protein and DNA trees for calmodulin remain unexplained. In our fourth report we evaluate the sequences and the distribution of introns within the EF-hand family and conclude that exon shuffling did not play a significant role in its evolution.
Tseitlin, Mark; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R
Polyphase continuous excitation based on the Frank sequence is suggested as an alternative to single pulse excitation in EPR. The method allows reduction of the source power, while preserving the excitation bandwidth of a single pulse. For practical EPR implementation the use of a cross-loop resonator is essential to provide isolation between the spin system and the resonator responses to the excitation. Provided that a line broadening of about 5% is acceptable, the cumulative turning angle of the magnetization vector generated by the excitation sequence can be quite large and can produce signal amplitudes that are comparable to that achieved with a higher power 90° pulse. PMID:21737326
Laustsen, Christoffer; Greferath, Marcus; Ringgaard, Steffen;
Radio frequency (RF) spectrally selective multiband pulses or tagging pulses, are applicable in a broad range of magnetic resonance methods. We demonstrate through simulations and experiments a new phase-modulation-only RF pulse for RF tagging based on the Frank poly-phase perfect sequence. In...... addition, we introduce an extended version with a WURST modulation (Frank-WURST). The new pulses exhibit interesting and flexible spin tagging properties and are easily implemented in existing MR sequences, where they can substitute slice-selective pulses with no additional alterations....
DU Mao-Kang; HE Bo; WANG Yong
Recently, the cryptosystem based on chaos has attracted much attention. Wang and Yu (Commun. Nonlin. Sci. Numer. Simulat. 14(2009)574) proposed a block encryption algorithm based on dynamic sequences of multiple chaotic systems. We analyze the potential Saws in the algorithm. Then, a chosen-plaintext attack is presented. Some remedial measures are suggested to avoid the flaws effectively. Furthermore, an improved encryption algorithm is proposed to resist the attacks and to keep all the merits of the original cryptosystem.
Reiner, Joseph E.; Balijepalli, Arvind; Robertson, Joseph W. F.; Drown, Bryon S.; Burden, Daniel L.; Kasianowicz, John J.
Over 15 years ago, the ability to electrically detect and characterize individual polynucleotides as they are driven through a single protein ion channel was suggested as a potential method for rapidly sequencing DNA, base-by-base, in a ticker tape-like fashion. More recently, a variation of this method was proposed in which a nanopore would instead detect single nucleotides cleaved sequentially by an exonuclease enzyme in close proximity to one pore entrance. We analyze the exonuclease/nanop...
Ruppitsch, Werner; Pietzka, Ariane; Prior, Karola; Bletz, Stefan; Fernandez, Haizpea Lasa; Allerberger, Franz; Harmsen, Dag; Mellmann, Alexander
Whole-genome sequencing (WGS) has emerged today as an ultimate typing tool to characterize Listeria monocytogenes outbreaks. However, data analysis and interlaboratory comparability of WGS data are still challenging for most public health laboratories. Therefore, we have developed and evaluated a new L. monocytogenes typing scheme based on genome-wide gene-by-gene comparisons (core genome multilocus the sequence typing [cgMLST]) to allow for a unique typing nomenclature. Initially, we determi...
Sherwood, R.; Mutz, D.; Estlin, T.; Chien, S.; Backes, P.; Norris, J.; Tran, D.; Cooper, B.; Rabideau, G.; Mishkin, A.; Maxwell, S.
This article discusses a proof-of-concept prototype for ground-based automatic generation of validated rover command sequences from high-level science and engineering activities. This prototype is based on ASPEN, the Automated Scheduling and Planning Environment. This artificial intelligence (AI)-based planning and scheduling system will automatically generate a command sequence that will execute within resource constraints and satisfy flight rules. An automated planning and scheduling system encodes rover design knowledge and uses search and reasoning techniques to automatically generate low-level command sequences while respecting rover operability constraints, science and engineering preferences, environmental predictions, and also adhering to hard temporal constraints. This prototype planning system has been field-tested using the Rocky 7 rover at JPL and will be field-tested on more complex rovers to prove its effectiveness before transferring the technology to flight operations for an upcoming NASA mission. Enabling goal-driven commanding of planetary rovers greatly reduces the requirements for highly skilled rover engineering personnel. This in turn greatly reduces mission operations costs. In addition, goal-driven commanding permits a faster response to changes in rover state (e.g., faults) or science discoveries by removing the time-consuming manual sequence validation process, allowing rapid "what-if" analyses, and thus reducing overall cycle times.
Xiang-RuMA; Shao-BoXIAO; Ai-ZhenGUO; Jian-QiangLUE; Huan-ChunCHEN
Sueoka and Lobry declared respectively that, in the absence of bias between the two DNA strands for mutation and selection, the base composition within each strand should be A=T and C=G (this state is called Parity Rule type 2, PR2). However, the genome sequences of many bacteria, vertebrates and viruses showed asymmetries in base composition and gene direction. To determine the relationship of base composition skews with replication orientation, gene function, codon usage biases and phylogenetic evolution,in this paper a program called DNAskew was developed for the statistical analysis of strand asymmetry and codon composition bias in the DNA sequence. In addition, the program can also be used to predict the replication boundaries of genome sequences. The method builds on the fact that there are compositional asymmetries between the leading and the lagging strand for replication. DNAskew was written in Perl script language and implemented on the LINUX operating system. It works quickly with annotated or unannotated sequences in GBFF (GenBank flatfile) or fasta format. The source code is freely available for academic use at http://www.epizooty.com/pub/stat/DNAskew.
Tinker, Nicholas A.; Bekele, Wubishet A.; Hattori, Jiro
Genotyping-by-sequencing (GBS), and related methods, are based on high-throughput short-read sequencing of genomic complexity reductions followed by discovery of single nucleotide polymorphisms (SNPs) within sequence tags. This provides a powerful and economical approach to whole-genome genotyping, facilitating applications in genomics, diversity analysis, and molecular breeding. However, due to the complexity of analyzing large data sets, applications of GBS may require substantial time, expertise, and computational resources. Haplotag, the novel GBS software described here, is freely available, and operates with minimal user-investment on widely available computer platforms. Haplotag is unique in fulfilling the following set of criteria: (1) operates without a reference genome; (2) can be used in a polyploid species; (3) provides a discovery mode, and a production mode; (4) discovers polymorphisms based on a model of tag-level haplotypes within sequenced tags; (5) reports SNPs as well as haplotype-based genotypes; and (6) provides an intuitive visual “passport” for each inferred locus. Haplotag is optimized for use in a self-pollinating plant species. PMID:26818073
Bowling, A T; Del Valle, A; Bowling, M
Through DNA sequence comparisons of a mitochondrial D-loop hypervariable region, we investigated matrilineal diversity for Arabian horses in the United States. Sixty-two horses were tested. From published pedigrees they traced in the maternal line to 34 mares acquired primarily in the mid to late 19th century from nomadic Bedouin tribes. Compared with the reference sequence (GenBank X79547), these samples showed 27 haplotypes with altogether 31 base substitution sites within 397 bp of sequence. Based on examination of pedigrees from a random sampling of 200 horses in current studbooks of the Arabian Horse Registry of America, we estimated that this study defined the expected mtDNA haplotypes for at least 89% of Arabian horses registered in the US. The reliability of the studbook recorded maternal lineages of Arabian pedigrees was demonstrated by haplotype concordance among multiple samplings in 14 lines. Single base differences observed within two maternal lines were interpreted as representing alternative fixations of past heteroplasmy. The study also demonstrated the utility of mtDNA sequence studies to resolve historical maternity questions without access to biological material from the horses whose relationship was in question, provided that representatives of the relevant female lines were available for comparison. The data call into question the traditional assumption that Arabian horses of the same strain necessarily share a common maternal ancestry. PMID:10690354
Full Text Available Chlorophyceae are important constituents of marine phytoplankton. The taxonomy of Chlorophyceae was traditionally based solely on morphological characteristics. In the present research project, genetic diversity was investigated to analyze five species of Chlorophyceae from waters of the Persian Gulf.A clone library of the ribosomal small subunit RNA gene (18S rDNA in the nuclear genome was constructed by PCR, and then, after examining the clones, selected clones were sequenced. The determined clone sequences were analyzed by a similarity search of the NCBI GenBank database using BLAST.Eleven sequences were identified correctly and used for phylogenetic analysis. We identified species of Chlorophyta (Chlorella sorokiniana, Chlamydomonas sp., Neochloris aquatic, Picochlorum sp. and Nannochloris atomus without the need to conduct extensive colony isolation techniques. Therefore, this improved molecular method can be used to generate a robust database describing the species diversity of environmental samples.
Full Text Available We applied whole-genome sequencing to reconstruct the spatial and temporal dynamics underpinning the expansion of Clostridium difficile ribotype 027 in Germany. Based on re-sequencing of genomes from 57 clinical C. difficile isolates, which had been collected from hospitalized patients at 36 locations throughout Germany between 1990 and 2012, we demonstrate that C. difficile genomes have accumulated sequence variation sufficiently fast to document the pathogen's spread at a regional scale. We detected both previously described lineages of fluoroquinolone-resistant C. difficile ribotype 027, FQR1 and FQR2. Using Bayesian phylogeographic analyses, we show that fluoroquinolone-resistant C. difficile 027 was imported into Germany at least four times, that it had been widely disseminated across multiple federal states even before the first outbreak was noted in 2007, and that it has continued to spread since.
Full Text Available Abstract Background Although homology-based methods are among the most widely used methods for predicting the structure and function of proteins, the question as to whether interface sequence conservation can be effectively exploited in predicting protein-protein interfaces has been a subject of debate. Results We studied more than 300,000 pair-wise alignments of protein sequences from structurally characterized protein complexes, including both obligate and transient complexes. We identified sequence similarity criteria required for accurate homology-based inference of interface residues in a query protein sequence. Based on these analyses, we developed HomPPI, a class of sequence homology-based methods for predicting protein-protein interface residues. We present two variants of HomPPI: (i NPS-HomPPI (Non partner-specific HomPPI, which can be used to predict interface residues of a query protein in the absence of knowledge of the interaction partner; and (ii PS-HomPPI (Partner-specific HomPPI, which can be used to predict the interface residues of a query protein with a specific target protein. Our experiments on a benchmark dataset of obligate homodimeric complexes show that NPS-HomPPI can reliably predict protein-protein interface residues in a given protein, with an average correlation coefficient (CC of 0.76, sensitivity of 0.83, and specificity of 0.78, when sequence homologs of the query protein can be reliably identified. NPS-HomPPI also reliably predicts the interface residues of intrinsically disordered proteins. Our experiments suggest that NPS-HomPPI is competitive with several state-of-the-art interface prediction servers including those that exploit the structure of the query proteins. The partner-specific classifier, PS-HomPPI can, on a large dataset of transient complexes, predict the interface residues of a query protein with a specific target, with a CC of 0.65, sensitivity of 0.69, and specificity of 0.70, when homologs of
Green, Robert C; Goddard, Katrina A B; Jarvik, Gail P; Amendola, Laura M; Appelbaum, Paul S; Berg, Jonathan S; Bernhardt, Barbara A; Biesecker, Leslie G; Biswas, Sawona; Blout, Carrie L; Bowling, Kevin M; Brothers, Kyle B; Burke, Wylie; Caga-Anan, Charlisse F; Chinnaiyan, Arul M; Chung, Wendy K; Clayton, Ellen W; Cooper, Gregory M; East, Kelly; Evans, James P; Fullerton, Stephanie M; Garraway, Levi A; Garrett, Jeremy R; Gray, Stacy W; Henderson, Gail E; Hindorff, Lucia A; Holm, Ingrid A; Lewis, Michelle Huckaby; Hutter, Carolyn M; Janne, Pasi A; Joffe, Steven; Kaufman, David; Knoppers, Bartha M; Koenig, Barbara A; Krantz, Ian D; Manolio, Teri A; McCullough, Laurence; McEwen, Jean; McGuire, Amy; Muzny, Donna; Myers, Richard M; Nickerson, Deborah A; Ou, Jeffrey; Parsons, Donald W; Petersen, Gloria M; Plon, Sharon E; Rehm, Heidi L; Roberts, J Scott; Robinson, Dan; Salama, Joseph S; Scollon, Sarah; Sharp, Richard R; Shirts, Brian; Spinner, Nancy B; Tabor, Holly K; Tarczy-Hornoch, Peter; Veenstra, David L; Wagle, Nikhil; Weck, Karen; Wilfond, Benjamin S; Wilhelmsen, Kirk; Wolf, Susan M; Wynn, Julia; Yu, Joon-Ho
Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine. PMID:27181682
Background The detection and exploitation of genetic variation underpins crop improvement. However, the polyploid nature of the genomes of many of our most important crops represents a barrier, particularly for the analysis of variation within genes. To overcome this, we aimed to develop methodologies based on amplicon sequencing that involve the incorporation of barcoded amplification tags (BATs) into PCR products. Results A protocol was developed to tag PCR products with 5’ 6-base oligonucleotide barcode extensions before pooling for sequencing library production using standard Illumina adapters. A computational method was developed for the de-convolution of products and the robust detection and scoring of sequence variants. Using this methodology, amplicons targeted to gene sequences were screened across a B. napus mapping population and the resulting allele scoring strings for 24 markers linkage mapped to the expected regions of the genome. Furthermore, using one-dimensional 8-fold pooling, 4608 lines of a B. napus mutation population were screened for induced mutations in a locus-specific amplicon (an orthologue of GL2.b) and mixed product of three co-amplified loci (orthologues of FAD2), identifying 10 and 41 mutants respectively. Conclusions The utilisation of barcode tags to de-convolute pooled PCR products in multiplexed, variation screening via Illumina sequencing provides a cost effective method for SNP genotyping and mutation detection and, potentially, markers for causative changes, even in polyploid species. Combining this approach with existing Illumina multiplexing workflows allows the analysis of thousands of lines cheaply and efficiently in a single sequencing run with minimal library production costs. PMID:23915099
Lesk Arthur M
Full Text Available Abstract Background The relationship between divergence of amino-acid sequence and divergence of function among homologous proteins is complex. The assumption that homologs share function – the basis of transfer of annotations in databases – must therefore be regarded with caution. Here, we present a quantitative study of sequence and function divergence, based on the Gene Ontology classification of function. We determined the relationship between sequence divergence and function divergence in 6828 protein families from the PFAM database. Within families there is a broad range of sequence similarity from very closely related proteins – for instance, orthologs in different mammals – to very distantly-related proteins at the limit of reliable recognition of homology. Results We correlated the divergence in sequences determined from pairwise alignments, and the divergence in function determined by path lengths in the Gene Ontology graph, taking into account the fact that many proteins have multiple functions. Our results show that, among homologous proteins, the proportion of divergent functions decreases dramatically above a threshold of sequence similarity at about 50% residue identity. For proteins with more than 50% residue identity, transfer of annotation between homologs will lead to an erroneous attribution with a totally dissimilar function in fewer than 6% of cases. This means that for very similar proteins (about 50 % identical residues the chance of completely incorrect annotation is low; however, because of the phenomenon of recruitment, it is still non-zero. Conclusion Our results describe general features of the evolution of protein function, and serve as a guide to the reliability of annotation transfer, based on the closeness of the relationship between a new protein and its nearest annotated relative.
My project focuses on characterizing different cyanobacteria in thrombolitic mats found on the island of Highborn Cay, Bahamas. Thrombolites are interesting ecosystems because of the ability of bacteria in these mats to remove carbon dioxide from the atmosphere and mineralize it as calcium carbonate. In the future they may be used as models to develop carbon sequestration technologies, which could be used as part of regenerative life systems in space. These thrombolitic communities are also significant because of their similarities to early communities of life on Earth. I targeted two cyanobacteria in my research, Dichothrix spp. and whatever black is, since they are believed to be important to carbon sequestration in these thrombolitic mats. The goal of my summer research project was to molecularly identify these two cyanobacteria. DNA was isolated from each organism through mat dissections and DNA extractions. I ran Polymerase Chain Reactions (PCR) to amplify the 16S ribosomal RNA (rRNA) gene in each cyanobacteria. This specific gene is found in almost all bacteria and is highly conserved, meaning any changes in the sequence are most likely due to evolution. As a result, the 16S rRNA gene can be used for bacterial identification of different species based on the sequence of their 16S rRNA gene. Since the exact sequence of the Dichothrix gene was unknown, I designed different primers that flanked the gene based on the known sequences from other taxonomically similar cyanobacteria. Once the 16S rRNA gene was amplified, I cloned the gene into specialized Escherichia coli cells and sent the gene products for sequencing. Once the sequence is obtained, it will be added to a genetic database for future reference to and classification of other Dichothrix sp.
Hu, Yuanqi; Georgiou, Pantelis
This paper presents an FPGA based DNA comparison platform which can be run concurrently with the sensing phase of DNA sequencing and shortens the overall time needed for de novo DNA assembly. A hybrid overlap searching algorithm is applied which is scalable and can deal with incremental detection of new bases. To handle the incomplete data set which gradually increases during sequencing time, all-against-all comparisons are broken down into successive window-against-window comparison phases and executed using a novel dynamic suffix comparison algorithm combined with a partitioned dynamic programming method. The complete system has been designed to facilitate parallel processing in hardware, which allows real-time comparison and full scalability as well as a decrease in the number of computations required. A base pair comparison rate of 51.2 G/s is achieved when implemented on an FPGA with successful DNA comparison when using data sets from real genomes. PMID:27045828
Surjit B Dixit; Mihaly Mezei; David L Beveridge
Detailed analyses of the sequence-dependent solvation and ion atmosphere of DNA are presented based on molecular dynamics (MD) simulations on all the 136 unique tetranucleotide steps obtained by the ABC consortium using the AMBER suite of programs. Significant sequence effects on solvation and ion localization were observed in these simulations. The results were compared to essentially all known experimental data on the subject. Proximity analysis was employed to highlight the sequence dependent differences in solvation and ion localization properties in the grooves of DNA. Comparison of the MD-calculated DNA structure with canonical A- and B-forms supports the idea that the G/C-rich sequences are closer to canonical A- than B-form structures, while the reverse is true for the poly A sequences, with the exception of the alternating ATAT sequence. Analysis of hydration density maps reveals that the flexibility of solute molecule has a significant effect on the nature of observed hydration. Energetic analysis of solute–solvent interactions based on proximity analysis of solvent reveals that the GC or CG base pairs interactmore strongly with watermolecules in the minor groove of DNA that the AT or TA base pairs, while the interactions of the AT or TA pairs in the major groove are stronger than those of the GC or CG pairs. Computation of solvent-accessible surface area of the nucleotide units in the simulated trajectories reveals that the similarity with results derived from analysis of a database of crystallographic structures is excellent. The MD trajectories tend to follow Manning’s counterion condensation theory, presenting a region of condensed counterions within a radius of about 17 Å from the DNA surface independent of sequence. The GC and CG pairs tend to associate with cations in the major groove of the DNA structure to a greater extent than the AT and TA pairs. Cation association is more frequent in the minor groove of AT than the GC pairs. In general
Full Text Available Abstract Background Ongoing improvements in throughput of the next-generation sequencing technologies challenge the current generation of de novo sequence assemblers. Most recent sequence assemblers are based on the construction of a de Bruijn graph. An alternative framework of growing interest is the assembly string graph, not necessitating a division of the reads into k-mers, but requiring fast algorithms for the computation of suffix-prefix matches among all pairs of reads. Results Here we present efficient methods for the construction of a string graph from a set of sequencing reads. Our approach employs suffix sorting and scanning methods to compute suffix-prefix matches. Transitive edges are recognized and eliminated early in the process and the graph is efficiently constructed including irreducible edges only. Conclusions Our suffix-prefix match determination and string graph construction algorithms have been implemented in the software package Readjoiner. Comparison with existing string graph-based assemblers shows that Readjoiner is faster and more space efficient. Readjoiner is available at http://www.zbh.uni-hamburg.de/readjoiner.
Armanhi, Jaderson Silveira Leite; de Souza, Rafael Soares Correa; de Araújo, Laura Migliorini; Okura, Vagner Katsumi; Mieczkowski, Piotr; Imperial, Juan; Arruda, Paulo
Microbiome analysis using metagenomic sequencing has revealed a vast microbial diversity associated with plants. Identifying the molecular functions associated with microbiome-plant interaction is a significant challenge concerning the development of microbiome-derived technologies applied to agriculture. An alternative to accelerate the discovery of the microbiome benefits to plants is to construct microbial culture collections concomitant with accessing microbial community structure and abundance. However, traditional methods of isolation, cultivation, and identification of microbes are time-consuming and expensive. Here we describe a method for identification of microbes in culture collections constructed by picking colonies from primary platings that may contain single or multiple microorganisms, which we named community-based culture collections (CBC). A multiplexing 16S rRNA gene amplicon sequencing based on two-step PCR amplifications with tagged primers for plates, rows, and columns allowed the identification of the microbial composition regardless if the well contains single or multiple microorganisms. The multiplexing system enables pooling amplicons into a single tube. The sequencing performed on the PacBio platform led to recovery near-full-length 16S rRNA gene sequences allowing accurate identification of microorganism composition in each plate well. Cross-referencing with plant microbiome structure and abundance allowed the estimation of diversity and abundance representation of microorganism in the CBC. PMID:27404280
Francisco Alexandre P
Full Text Available Abstract Background With the decrease of DNA sequencing costs, sequence-based typing methods are rapidly becoming the gold standard for epidemiological surveillance. These methods provide reproducible and comparable results needed for a global scale bacterial population analysis, while retaining their usefulness for local epidemiological surveys. Online databases that collect the generated allelic profiles and associated epidemiological data are available but this wealth of data remains underused and are frequently poorly annotated since no user-friendly tool exists to analyze and explore it. Results PHYLOViZ is platform independent Java software that allows the integrated analysis of sequence-based typing methods, including SNP data generated from whole genome sequence approaches, and associated epidemiological data. goeBURST and its Minimum Spanning Tree expansion are used for visualizing the possible evolutionary relationships between isolates. The results can be displayed as an annotated graph overlaying the query results of any other epidemiological data available. Conclusions PHYLOViZ is a user-friendly software that allows the combined analysis of multiple data sources for microbial epidemiological and population studies. It is freely available at http://www.phyloviz.net.
Drory Retwitzer, Matan; Reinharz, Vladimir; Ponty, Yann; Waldispühl, Jérôme; Barash, Danny
In recent years, new methods for computational RNA design have been developed and applied to various problems in synthetic biology and nanotechnology. Lately, there is considerable interest in incorporating essential biological information when solving the inverse RNA folding problem. Correspondingly, RNAfbinv aims at including biologically meaningful constraints and is the only program to-date that performs a fragment-based design of RNA sequences. In doing so it allows the design of sequences that do not necessarily exactly fold into the target, as long as the overall coarse-grained tree graph shape is preserved. Augmented by the weighted sampling algorithm of incaRNAtion, our web server called incaRNAfbinv implements the method devised in RNAfbinv and offers an interactive environment for the inverse folding of RNA using a fragment-based design approach. It takes as input: a target RNA secondary structure; optional sequence and motif constraints; optional target minimum free energy, neutrality and GC content. In addition to the design of synthetic regulatory sequences, it can be used as a pre-processing step for the detection of novel natural occurring RNAs. The two complementary methodologies RNAfbinv and incaRNAtion are merged together and fully implemented in our web server incaRNAfbinv, available at http://www.cs.bgu.ac.il/incaRNAfbinv. PMID:27185893
Full Text Available Abstract Background The rapid burgeoning of available protein data makes the use of clustering within families of proteins increasingly important. The challenge is to identify subfamilies of evolutionarily related sequences. This identification reveals phylogenetic relationships, which provide prior knowledge to help researchers understand biological phenomena. A good evolutionary model is essential to achieve a clustering that reflects the biological reality, and an accurate estimate of protein sequence similarity is crucial to the building of such a model. Most existing algorithms estimate this similarity using techniques that are not necessarily biologically plausible, especially for hard-to-align sequences such as proteins with different domain structures, which cause many difficulties for the alignment-dependent algorithms. In this paper, we propose a novel similarity measure based on matching amino acid subsequences. This measure, named SMS for Substitution Matching Similarity, is especially designed for application to non-aligned protein sequences. It allows us to develop a new alignment-free algorithm, named CLUSS, for clustering protein families. To the best of our knowledge, this is the first alignment-free algorithm for clustering protein sequences. Unlike other clustering algorithms, CLUSS is effective on both alignable and non-alignable protein families. In the rest of the paper, we use the term "phylogenetic" in the sense of "relatedness of biological functions". Results To show the effectiveness of CLUSS, we performed an extensive clustering on COG database. To demonstrate its ability to deal with hard-to-align sequences, we tested it on the GH2 family. In addition, we carried out experimental comparisons of CLUSS with a variety of mainstream algorithms. These comparisons were made on hard-to-align and easy-to-align protein sequences. The results of these experiments show the superiority of CLUSS in yielding clusters of proteins
Truong, Hoa T; Ramos, A Marcos; Yalcin, Feyruz; de Ruiter, Marjo; van der Poel, Hein J A; Huvenaars, Koen H J; Hogers, René C J; van Enckevort, Leonora J G; Janssen, Antoine; van Orsouw, Nathalie J; van Eijk, Michiel J T
Conventional marker-based genotyping platforms are widely available, but not without their limitations. In this context, we developed Sequence-Based Genotyping (SBG), a technology for simultaneous marker discovery and co-dominant scoring, using next-generation sequencing. SBG offers users several advantages including a generic sample preparation method, a highly robust genome complexity reduction strategy to facilitate de novo marker discovery across entire genomes, and a uniform bioinformatics workflow strategy to achieve genotyping goals tailored to individual species, regardless of the availability of a reference sequence. The most distinguishing features of this technology are the ability to genotype any population structure, regardless whether parental data is included, and the ability to co-dominantly score SNP markers segregating in populations. To demonstrate the capabilities of SBG, we performed marker discovery and genotyping in Arabidopsis thaliana and lettuce, two plant species of diverse genetic complexity and backgrounds. Initially we obtained 1,409 SNPs for arabidopsis, and 5,583 SNPs for lettuce. Further filtering of the SNP dataset produced over 1,000 high quality SNP markers for each species. We obtained a genotyping rate of 201.2 genotypes/SNP and 58.3 genotypes/SNP for arabidopsis (n = 222 samples) and lettuce (n = 87 samples), respectively. Linkage mapping using these SNPs resulted in stable map configurations. We have therefore shown that the SBG approach presented provides users with the utmost flexibility in garnering high quality markers that can be directly used for genotyping and downstream applications. Until advances and costs will allow for routine whole-genome sequencing of populations, we expect that sequence-based genotyping technologies such as SBG will be essential for genotyping of model and non-model genomes alike. PMID:22662172
Full Text Available Abstract Background We present two melting curve analysis (MCA-based semiquantitative real time PCR techniques to detect the promoter methylation status of genes. The first, MCA-MSP, follows the same principle as standard MSP but it is performed in a real time thermalcycler with results being visualized in a melting curve. The second, MCA-Meth, uses a single pair of primers designed with no CpGs in its sequence. These primers amplify both unmethylated and methylated sequences. In clinical applications the MSP technique has revolutionized methylation detection by simplifying the analysis to a PCR-based protocol. MCA-analysis based techniques may be able to further improve and simplify methylation analyses by reducing starting DNA amounts, by introducing an all-in-one tube reaction and by eliminating a final gel stage for visualization of the result. The current study aimed at investigating the feasibility of both MCA-MSP and MCA-Meth in the analysis of promoter methylation, and at defining potential advantages and shortcomings in comparison to currently implemented techniques, i.e. bisulfite sequencing and standard MSP. Methods The promoters of the RASSF1A (3p21.3, BLU (3p21.3 and MGMT (10q26 genes were analyzed by MCA-MSP and MCA-Meth in 13 astrocytoma samples, 6 high grade glioma cell lines and 4 neuroblastoma cell lines. The data were compared with standard MSP and validated by bisulfite sequencing. Results Both, MCA-MSP and MCA-Meth, successfully determined promoter methylation. MCA-MSP provided information similar to standard MSP analyses. However the analysis was possible in a single tube and avoided the gel stage. MCA-Meth proved to be useful in samples with intermediate methylation status, reflected by a melting curve position shift in dependence on methylation extent. Conclusion We propose MCA-MSP and MCA-Meth as alternative or supplementary techniques to MSP or bisulfite sequencing.
Steyaert, Sandra; Van Criekinge, Wim; De Paepe, Ayla; Denil, Simon; Mensaert, Klaas; Vandepitte, Katrien; Vanden Berghe, Wim; Trooskens, Geert; De Meyer, Tim
Monoallelic gene expression is typically initiated early in the development of an organism. Dysregulation of monoallelic gene expression has already been linked to several non-Mendelian inherited genetic disorders. In humans, DNA-methylation is deemed to be an important regulator of monoallelic gene expression, but only few examples are known. One important reason is that current, cost-affordable truly genome-wide methods to assess DNA-methylation are based on sequencing post-enrichment. Here, we present a new methodology based on classical population genetic theory, i.e. the Hardy-Weinberg theorem, that combines methylomic data from MethylCap-seq with associated SNP profiles to identify monoallelically methylated loci. Applied on 334 MethylCap-seq samples of very diverse origin, this resulted in the identification of 80 genomic regions featured by monoallelic DNA-methylation. Of these 80 loci, 49 are located in genic regions of which 25 have already been linked to imprinting. Further analysis revealed statistically significant enrichment of these loci in promoter regions, further establishing the relevance and usefulness of the method. Additional validation was done using both 14 whole-genome bisulfite sequencing data sets and 16 mRNA-seq data sets. Importantly, the developed approach can be easily applied to other enrichment-based sequencing technologies, like the ChIP-seq-based identification of monoallelic histone modifications. PMID:25237057
Wang Simin; Liu Zhaojun; Liu Kui
Base - level is a kind of surface which controls sedimentation and erosion. So, it can be concluded that it is baselevel change that controls the formation and internal structure of a sequence. A single cycle of base- level change can generate four sets of different stacking patterns. They are two sets of aggradation, one progradation and one retrogradation, which affects the features of the internal structure of a sequence. Lishu fault subsidence of Songliao basin is a typical half - graben lacustrine basin. Comprehensive base - level change analysis indicates that six base - level cycles and their related six sequences can be recognized between T4 and T5 seismic reflection surface. The contemporaneous fault is the main controlling factor of the fault lacustrine basin. There are obvious differences exist in the composition of sedimentary systems and all systems tracts between its steep slope (the side that basin control fault existed) and flat slope. Except highstand systems tract is composed of fan delta - lacustrine system, lowstand systems tract, transgressive systems tract and regressive systems tract are all made up of fan delta - underwater fan- lacustrine sedimentary systems in the side of steep slope.
Taherzadeh, Ghazaleh; Yang, Yuedong; Zhang, Tuo; Liew, Alan Wee-Chung; Zhou, Yaoqi
Protein-peptide interactions are essential for all cellular processes including DNA repair, replication, gene-expression, and metabolism. As most protein-peptide interactions are uncharacterized, it is cost effective to investigate them computationally as the first step. All existing approaches for predicting protein-peptide binding sites, however, are based on protein structures despite the fact that the structures for most proteins are not yet solved. This article proposes the first machine-learning method called SPRINT to make Sequence-based prediction of Protein-peptide Residue-level Interactions. SPRINT yields a robust and consistent performance for 10-fold cross validations and independent test. The most important feature is evolution-generated sequence profiles. For the test set (1056 binding and non-binding residues), it yields a Matthews' Correlation Coefficient of 0.326 with a sensitivity of 64% and a specificity of 68%. This sequence-based technique shows comparable or more accurate than structure-based methods for peptide-binding site prediction. SPRINT is available as an online server at: http://sparks-lab.org/. © 2016 Wiley Periodicals, Inc. PMID:26833816
Kim, Han; Kim, Yong-Hoon
The DNA sequencing approach based on the combination of nanopores and electron tunnelling has seen considerable advances in recent years, and particularly carbon nanomaterials have emerged as promising candidates to replace metal electrodes. Carrying out extensive first-principles calculations, we here show that two distinct DNA sequencing mechanisms can be achieved with different configurations of a single-type nitrogen-doped capped carbon nanotube (CNT) that has significantly enhanced transmission and chemical sensitivity over its pristine counterpart. With a small CNT-CNT gap size that induces face-on nucleobase configurations, we obtain a typical conductance ordering where the largest signal is induced from guanine due to its highest occupied molecular orbital energetic position higher than those of other bases. On the other hand, for a large CNT-CNT gap size that accommodates edge-on nucleobase configurations, we extract a completely different conductance ordering in which thymine results in the largest signal. We find that the latter novel nucleobase sensing mechanism originates from the nature of chemical connectivity between nitrogen-doped CNT caps and nucleobase functional groups that include the thymine methyl group. This work thus demonstrates the feasibility of a tunnelling-based dual-mode approach toward whole genome sequencing applications, detection of DNA base modifications, and single-molecule sensing in general.
Hashimoto, Masahiko; He, Yan; Yeung, Edward S.
A fully integrated system has been developed for genetic analysis based on direct sequencing of polymerase chain reaction (PCR) products. The instrument is based on a serially connected fused-silica capillary assembly. The technique involves the use of microreactors for small-volume PCR and for dye-terminator cycle-sequencing reaction, purification of the sequencing fragments, and separation of the purified DNA ladder. Four modifications to the normal PCR protocol allow the elimination of pos...
Lees Jonathan G; Janes Robert W
Abstract Background A number of sequence-based methods exist for protein secondary structure prediction. Protein secondary structures can also be determined experimentally from circular dichroism, and infrared spectroscopic data using empirical analysis methods. It has been proposed that comparable accuracy can be obtained from sequence-based predictions as from these biophysical measurements. Here we have examined the secondary structure determination accuracies of sequence prediction method...
Wernersson, R; Schierup, Mikkel Heide; Jørgensen, Frank Grønlund;
to the structure in human. Conclusion The addition of the pig to the set of species sequenced at low coverage adds to the understanding of selective pressures that have acted on the human genome by bisecting the evolutionary branch between human and mouse with the mouse branch being approximately 3 times as long...
Wang, Ligang; Ma, Tianxing
We investigate electronic band structure and transport properties in aperiodic graphene-based superlattices of Thue-Morse (TM) sequence. The robust properties of zero- k gap are demonstrated in both mono-layer and bi-layer graphene TM sequence. The Extra Dirac points may emerge at ky ≠ 0, and the electronic transport behaviors such as the conductance and the Fano factor are discussed in detail. Our results provide a flexible and effective way to control the transport properties in graphene-based superlattices. This work is supported by NSFCs (Nos. 11274275, 11104014 and 61078021), Research Fund for the Doctoral Program of Higher Education 20110003120007, SRF for ROCS (SEM), and the National Basic Research Program of China (No. 2011CBA00108, and 2012CB921602).
Lundegaard, Claus; Hoof, Ilka; Lund, Ole;
field has evolved significantly. Methods have now been developed that produce highly accurate binding predictions for many alleles and integrate both proteasomal cleavage and transport events. Moreover have so-called pan-specific methods been developed, which allow for prediction of peptide binding to......Sequence based T-cell epitope predictions have improved immensely in the last decade. From predictions of peptide binding to major histocompatibility complex molecules with moderate accuracy, limited allele coverage, and no good estimates of the other events in the antigen-processing pathway, the...... MHC alleles characterized by limited or no peptide binding data. Most of the developed methods are publicly available, and have proven to be very useful as a shortcut in epitope discovery. Here, we will go through some of the history of sequence-based predictions of helper as well as cytotoxic T cell...
Yoon-Ho Kim; Alla Kim; Hwa-Young Jeong
Since the fire causes serious disasters, fire detection has been an important study to protect human life. Based on the deficiencies of existing fire detection on real-time and monitoring accuracy, the wireless sensor network technique for fire detection was introduced and needed. In this paper, we proposed the fire detection algorithm in video sequences on wireless sensor network. The proposed fire detection algorithm processes visual information acquired through static camera that lets us i...
Yanan Liu; Lian Kun Jia; Wen Yu Yu
Human motion capturing is of great importance in video information retrieval, hence, in this paper, we propose a novel approach to effectively capturing human motions based on modified hidden markov model from multi-view image sequences. Firstly, the structure of the human skeleton model is illustrated, which is extended from skeleton root and spine root, and this skeleton consists of right leg, left leg and spine. Secondly, our proposed human motion capturing system is made up of data traini...
Pei-Xiang Ni; Xin Ding; Yin-Xin Zhang; Xue Yao; Rui-Xue Sun; Peng Wang; Yan-Ping Gong; Jia-Li Zhou; Dong-Fang Li; Hong-Long Wu; Xin Yi; Ling Yang; Yun Long
Background: The dilemma of pathogens identification in patients with unidentified clinical symptoms such as fever of unknown origin exists, which not only poses a challenge to both the diagnostic and therapeutic process by itself, but also to expert physicians. Methods: In this report, we have attempted to increase the awareness of unidentified pathogens by developing a method to investigate hitherto unidentified infectious pathogens based on unbiased high-throughput sequencing. Resul...
Tseitlin, Mark; Quine, Richard W.; Eaton, Sandra S.; Eaton, Gareth R.
Polyphase continuous excitation based on the Frank sequence is suggested as an alternative to single pulse excitation in EPR. The method allows reduction of the source power, while preserving the excitation bandwidth of a single pulse. For practical EPR implementation the use of a cross-loop resonator is essential to provide isolation between the spin system and the resonator responses to the excitation. Provided that a line broadening of about 5% is acceptable, the cumulative turning angle o...
Keeling, J W; Kjaer, I
The axial skeletal development of eight second trimester aborted fetuses, clinically diagnosed as amnion rupture sequence with cranial involvement, was examined radiographically and histologically. Three of the eight fetuses showed axial skeletal malformation in the spine and the craniofacial skeleton corresponding to the malformations seen in anencephaly. These are vertebral body malformations, consisting of double corpora and of osseous malformations in the components of the cranial base, t...
Ogilvie, Lesley A.; Bowler, Lucas D.; Caplin, Jonathan; Dedi, Cinzia; Diston, David; Cheek, Elizabeth; Taylor, Huw; Ebdon, James E.; Jones, Brian V.
Bacterial viruses (bacteriophages) have a key role in shaping the development and functional outputs of host microbiomes. Although metagenomic approaches have greatly expanded our understanding of the prokaryotic virosphere, additional tools are required for the phage-oriented dissection of metagenomic data sets, and host-range affiliation of recovered sequences. Here we demonstrate the application of a genome signature-based approach to interrogate conventional whole-community metagenomes an...
Spigaglia, Patrizia; Mastrantonio, Paola
Repetitive element sequence-based PCR (rep-PCR) is a typing method that enables the generation of DNA fingerprinting that discriminates bacterial strains. In this study, we evaluated the applicability of rep-PCR in typing Clostridium difficile clinical isolates. The results obtained by rep-PCR were compared with those obtained by pulsed-field gel electrophoresis (PFGE) and PCR ribotyping. A high correspondence between pattern differentiations produced by rep-PCR and PFGE was observed, whereas...
Steyaert, Sandra; Van Criekinge, Wim; De Paepe, Ayla; Denil, Simon; Mensaert, Klaas; Vandepitte, Katrien; Vanden Berghe, Wim; Trooskens, Geert; de Meyer, Tim
Monoallelic gene expression is typically initiated early in the development of an organism. Dysregulation of monoallelic gene expression has already been linked to several non-Mendelian inherited genetic disorders. In humans, DNA-methylation is deemed to be an important regulator of monoallelic gene expression, but only few examples are known. One important reason is that current, cost-affordable truly genome-wide methods to assess DNA-methylation are based on sequencing post-enrichment. Here...
Michelle Klein Sercundes; Samantha Yuri Oshiro Branco Valadas; Lara Borges Keid; Tricia Maria Ferreira Souza Oliveira; Helena Lage Ferreira; Ricardo Wagner Almeida Vitor; Fábio Gregori; Rodrigo Martins Soares
Abstract Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC) and beta subunit of RNA polymerase (rpoB), and mitochondrial gene coding for cytochrome B (cytB) were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula ...
Davesne, Frédéric; Barret, Claude
National audience Within the contest of learning sequences of basic tasks to build a complex behavior, a method is proposed to coordinate a hierarchical set of tasks. Each one possesses a set of sub-tasks lower in the hierarchy, which must be coordinated to respect a binary perceptive constraint. For each task, the coordination is achieved by a reinforcement learning inspired algorithm based on the heuristic which does not need internal parameters. A validation of the method is given, usin...
Kurgan, Lukasz; Disfani, Fatemeh Miri
The last few decades observed an increasing interest in development and application of 1-dimensional (1D) descriptors of protein structure. These descriptors project 3D structural features onto 1D strings of residue-wise structural assignments. They cover a wide-range of structural aspects including conformation of the backbone, burying depth/solvent exposure and flexibility of residues, and inter-chain residue-residue contacts. We perform first-of-its-kind comprehensive comparative review of the existing 1D structural descriptors. We define, review and categorize ten structural descriptors and we also describe, summarize and contrast over eighty computational models that are used to predict these descriptors from the protein sequences. We show that the majority of the recent sequence-based predictors utilize machine learning models, with the most popular being neural networks, support vector machines, hidden Markov models, and support vector and linear regressions. These methods provide high-throughput predictions and most of them are accessible to a non-expert user via web servers and/or stand-alone software packages. We empirically evaluate several recent sequence-based predictors of secondary structure, disorder, and solvent accessibility descriptors using a benchmark set based on CASP8 targets. Our analysis shows that the secondary structure can be predicted with over 80% accuracy and segment overlap (SOV), disorder with over 0.9 AUC, 0.6 Matthews Correlation Coefficient (MCC), and 75% SOV, and relative solvent accessibility with PCC of 0.7 and MCC of 0.6 (0.86 when homology is used). We demonstrate that the secondary structure predicted from sequence without the use of homology modeling is as good as the structure extracted from the 3D folds predicted by top-performing template-based methods. PMID:21787299
Background: Ion mobility-mass spectrometry (IMMS), an analytical technique which combines the features of ion mobility spectrometry (IMS) and mass spectrometry (MS), can rapidly separates ions on a millisecond time-scale. IMMS becomes a powerful tool to analyzing complex mixtures, especially for the analysis of peptides in proteomics. The high-throughput nature of this technique provides a challenge for the identification of peptides in complex biological samples. As an important parameter, peptide drift time can be used for enhancing downstream data analysis in IMMS-based proteomics.Results: In this paper, a model is presented based on least square support vectors regression (LS-SVR) method to predict peptide ion drift time in IMMS from the sequence-based features of peptide. Four descriptors were extracted from peptide sequence to represent peptide ions by a 34-component vector. The parameters of LS-SVR were selected by a grid searching strategy, and a 10-fold cross-validation approach was employed for the model training and testing. Our proposed method was tested on three datasets with different charge states. The high prediction performance achieve demonstrate the effectiveness and efficiency of the prediction model.Conclusions: Our proposed LS-SVR model can predict peptide drift time from sequence information in relative high prediction accuracy by a test on a dataset of 595 peptides. This work can enhance the confidence of protein identification by combining with current protein searching techniques. 2013 Wang et al.; licensee BioMed Central Ltd.
In targeted mutagenesis of lambda phage by ultraviolet light, the mutations are caused by radiation-induced lesions in the phage DNA. Of 62 mutations in the lambda cI gene that were sequenced, 41 of the targeted mutations were transitions, with similar numbers of C.G to T.A and T.A to C.G base changes. The remaining 21 mutations were about equally divided among eight transversions, seven frameshifts (5 additions and 2 deletions), and six double events with either two nearby base changes or a base change and a nearby frameshift. Of the 62 mutations, 60 could be associated with -Pyr-Pyr- sequences in the DNA, sites of likely photoproducts. For more information on this point, lambda phage were irradiated with 313 nm light in the presence of acetophenone for which the major photoproduct is reported to be the thymine-thymine cyclobutyl dimer, with no measurable Pyr(6-4)Pyo photoproducts. Of 22 mutations sequenced, 19 were transversions and only one was a transition, permitting the conclusion that thymine-thymine cyclobutyl dimers are not the primary cause of ultraviolet light-induced transitions. A consideration of all the data strongly suggests that Pyr(6-4)Pyo photoproducts are mutagenic lesions. (author)
Kaanan P Shah
Full Text Available Owing to recent advances in DNA sequencing, it is now technically feasible to evaluate the contribution of rare variation to complex traits and diseases. However, it is still cost prohibitive to sequence the whole genome (or exome of all individuals in each study. For quantitative traits, one strategy to reduce cost is to sequence individuals in the tails of the trait distribution. However, the next challenge becomes how to prioritize traits and individuals for sequencing since individuals are often characterized for dozens of medically relevant traits. In this article, we describe a new method, the Rare Variant Kinship Test (RVKT, which leverages relationship information in family-based studies to identify quantitative traits that are likely influenced by rare variants. Conditional on nuclear families and extended pedigrees, we evaluate the power of the RVKT via simulation. Not unexpectedly, the power of our method depends strongly on effect size, and to a lesser extent, on the frequency of the rare variant and the number and type of relationships in the sample. As an illustration, we also apply our method to data from two genetic studies in the Old Order Amish, a founder population with extensive genealogical records. Remarkably, we implicate the presence of a rare variant that lowers fasting triglyceride levels in the Heredity and Phenotype Intervention (HAPI Heart study (p = 0.044, consistent with the presence of a previously identified null mutation in the APOC3 gene that lowers fasting triglyceride levels in HAPI Heart study participants.
Full Text Available Abstract Background Detecting groups of functionally related proteins from their amino acid sequence alone has been a long-standing challenge in computational genome research. Several clustering approaches, following different strategies, have been published to attack this problem. Today, new sequencing technologies provide huge amounts of sequence data that has to be efficiently clustered with constant or increased accuracy, at increased speed. Results We advocate that the model of weighted cluster editing, also known as transitive graph projection is well-suited to protein clustering. We present the FORCE heuristic that is based on transitive graph projection and clusters arbitrary sets of objects, given pairwise similarity measures. In particular, we apply FORCE to the problem of protein clustering and show that it outperforms the most popular existing clustering tools (Spectral clustering, TribeMCL, GeneRAGE, Hierarchical clustering, and Affinity Propagation. Furthermore, we show that FORCE is able to handle huge datasets by calculating clusters for all 192 187 prokaryotic protein sequences (66 organisms obtained from the COG database. Finally, FORCE is integrated into the corynebacterial reference database CoryneRegNet. Conclusion FORCE is an applicable alternative to existing clustering algorithms. Its theoretical foundation, weighted cluster editing, can outperform other clustering paradigms on protein homology clustering. FORCE is open source and implemented in Java. The software, including the source code, the clustering results for COG and CoryneRegNet, and all evaluation datasets are available at http://gi.cebitec.uni-bielefeld.de/comet/force/.
Lee, Wan-Ping; Stromberg, Michael P; Ward, Alistair; Stewart, Chip; Garrison, Erik P; Marth, Gabor T
MOSAIK is a stable, sensitive and open-source program for mapping second and third-generation sequencing reads to a reference genome. Uniquely among current mapping tools, MOSAIK can align reads generated by all the major sequencing technologies, including Illumina, Applied Biosystems SOLiD, Roche 454, Ion Torrent and Pacific BioSciences SMRT. Indeed, MOSAIK was the only aligner to provide consistent mappings for all the generated data (sequencing technologies, low-coverage and exome) in the 1000 Genomes Project. To provide highly accurate alignments, MOSAIK employs a hash clustering strategy coupled with the Smith-Waterman algorithm. This method is well-suited to capture mismatches as well as short insertions and deletions. To support the growing interest in larger structural variant (SV) discovery, MOSAIK provides explicit support for handling known-sequence SVs, e.g. mobile element insertions (MEIs) as well as generating outputs tailored to aid in SV discovery. All variant discovery benefits from an accurate description of the read placement confidence. To this end, MOSAIK uses a neural-network based training scheme to provide well-calibrated mapping quality scores, demonstrated by a correlation coefficient between MOSAIK assigned and actual mapping qualities greater than 0.98. In order to ensure that studies of any genome are supported, a training pipeline is provided to ensure optimal mapping quality scores for the genome under investigation. MOSAIK is multi-threaded, open source, and incorporated into our command and pipeline launcher system GKNO (http://gkno.me). PMID:24599324
Xiang-Chu Yin; Xin-Jiang Li; Wen-Qiang Wang; Hong Yin; Cheng-Quan Cao; Bao-Hua Ye; Zhan Yin
Based on the 16S mitochondrial partial gene sequences of 29 genera, containing 26 from Oedipodidae and one each from Tanaoceridae, Pyrgomorphidae and Tetrigidae (as outgroups), the homologus sequences were compared and phylogenetic analyses were performed. A phylogenetic tree was inferred by neighbor-joining (N J). The results of sequences compared show that: (i) in a total of 574 bp of Oedipodidae, the number of substituted nucleotides was 265 bp and the average percentages ofT, C, A and G were 38.3%,11.4%, 31.8% and 18.5%, respectively, and the content of A+T (70.1%) was distinctly richer than that of C+G (29.9%); and (ii) the average nucleotide divergence of 16S rDNA sequences among genera of Oedipodidae were 9.0%, among families of Acridoidea were 17.0%, and between superfamilies (Tetrigoidea and Acridoidea) were 23.9%, respectively. The phylogenetic tree indicated: (i) the Oedipodidae was a monophyletic group, which suggested that the taxonomic status of this family was confLrrned; (ii) the genus Heteropternis separated from the other Oedipodids first and had another unique sound-producing structure in morphology, which is the type-genus of subfamily Heteropterninae; and (iii) the relative intergeneric relationship within the same continent was closer than that of different continents, and between the Eurasian genera and the African genera, was closer than that between Eurasians and Americans.
Gaddis, Sara S; Wu, Qi; Thames, Howard D; DiGiovanni, John; Walborg, Earl F; MacLeod, Michael C; Vasquez, Karen M
Triplex technology offers a useful approach for site-specific modification of gene structure and function both in vitro and in vivo. Triplex-forming oligonucleotides (TFOs) bind to their target sites in duplex DNA, thereby forming triple-helical DNA structures via Hoogsteen hydrogen bonding. TFO binding has been demonstrated to site-specifically inhibit gene expression, enhance homologous recombination, induce mutation, inhibit protein binding, and direct DNA damage, thus providing a tool for gene-specific manipulation of DNA. We have developed a flexible web-based search engine to find and annotate TFO target sequences within the human and mouse genomes. Descriptive information about each site, including sequence context and gene region (intron, exon, or promoter), is provided. The engine assists the user in finding highly specific TFO target sequences by eliminating or flagging known repeat sequences and flagging overlapping genes. A convenient way to check for the uniqueness of a potential TFO binding site is provided via NCBI BLAST. The search engine may be accessed at spi.mdanderson.org/tfo. PMID:16764543
Hu, Han; Wang, Weitao; Zhu, Zhongxu; Zhu, Jianhua; Tan, Deyong; Zhou, Zhipeng; Mao, Chuanzao; Chen, Xin
The Gene Identification via Phenotype Sequencing (GIPS) software considers a range of experimental and analysis choices in sequencing-based forward genetics studies within an integrated probabilistic framework, which enables direct gene cloning from the sequencing of several unrelated mutants of the same phenotype without the need to create segregation populations. GIPS estimates four measurements to help optimize an analysis procedure as follows: (1) the chance of reporting the true phenotype-associated gene; (2) the expected number of random genes that may be reported; (3) the significance of each candidate gene's association with the phenotype; and (4) the significance of violating the Mendelian assumption if no gene is reported or if all candidate genes have failed validation. The usage of GIPS is illustrated with the identification of a rice (Oryza sativa) gene that epistatically suppresses the phenotype of the phosphate2 mutant from sequencing three unrelated ethyl methanesulfonate mutants. GIPS is available at https://github.com/synergy-zju/gips/wiki with the user manual and an analysis example. PMID:26842621
Full Text Available Few studies investigated the donkey (Equus asinus at the whole genome level so far. Here, we sequenced the genome of two male donkeys using a next generation semiconductor based sequencing platform (the Ion Proton sequencer and compared obtained sequence information with the available donkey draft genome (and its Illumina reads from which it was originated and with the EquCab2.0 assembly of the horse genome. Moreover, the Ion Torrent Personal Genome Analyzer was used to sequence reduced representation libraries (RRL obtained from a DNA pool including donkeys of different breeds (Grigio Siciliano, Ragusano and Martina Franca. The number of next generation sequencing reads aligned with the EquCab2.0 horse genome was larger than those aligned with the draft donkey genome. This was due to the larger N50 for contigs and scaffolds of the horse genome. Nucleotide divergence between E. caballus and E. asinus was estimated to be ~ 0.52-0.57%. Regions with low nucleotide divergence were identified in several autosomal chromosomes and in the whole chromosome X. These regions might be evolutionally important in equids. Comparing Y-chromosome regions we identified variants that could be useful to track donkey paternal lineages. Moreover, about 4.8 million of single nucleotide polymorphisms (SNPs in the donkey genome were identified and annotated combining sequencing data from Ion Proton (whole genome sequencing and Ion Torrent (RRL runs with Illumina reads. A higher density of SNPs was present in regions homologous to horse chromosome 12, in which several studies reported a high frequency of copy number variants. The SNPs we identified constitute a first resource useful to describe variability at the population genomic level in E. asinus and to establish monitoring systems for the conservation of donkey genetic resources.
Bertolini, Francesca; Scimone, Concetta; Geraci, Claudia; Schiavo, Giuseppina; Utzeri, Valerio Joe; Chiofalo, Vincenzo; Fontanesi, Luca
Few studies investigated the donkey (Equus asinus) at the whole genome level so far. Here, we sequenced the genome of two male donkeys using a next generation semiconductor based sequencing platform (the Ion Proton sequencer) and compared obtained sequence information with the available donkey draft genome (and its Illumina reads from which it was originated) and with the EquCab2.0 assembly of the horse genome. Moreover, the Ion Torrent Personal Genome Analyzer was used to sequence reduced representation libraries (RRL) obtained from a DNA pool including donkeys of different breeds (Grigio Siciliano, Ragusano and Martina Franca). The number of next generation sequencing reads aligned with the EquCab2.0 horse genome was larger than those aligned with the draft donkey genome. This was due to the larger N50 for contigs and scaffolds of the horse genome. Nucleotide divergence between E. caballus and E. asinus was estimated to be ~ 0.52-0.57%. Regions with low nucleotide divergence were identified in several autosomal chromosomes and in the whole chromosome X. These regions might be evolutionally important in equids. Comparing Y-chromosome regions we identified variants that could be useful to track donkey paternal lineages. Moreover, about 4.8 million of single nucleotide polymorphisms (SNPs) in the donkey genome were identified and annotated combining sequencing data from Ion Proton (whole genome sequencing) and Ion Torrent (RRL) runs with Illumina reads. A higher density of SNPs was present in regions homologous to horse chromosome 12, in which several studies reported a high frequency of copy number variants. The SNPs we identified constitute a first resource useful to describe variability at the population genomic level in E. asinus and to establish monitoring systems for the conservation of donkey genetic resources. PMID:26151450
Sato, Shusei; Andersen, Stig Uggerhøj
The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based on transcr......The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based...
Mizianty, Marcin J.; Stach, Wojciech; Chen, Ke; Kedarisetti, Kanaka Durga; Disfani, Fatemeh Miri; Kurgan, Lukasz
Motivation: Intrinsically disordered proteins play a crucial role in numerous regulatory processes. Their abundance and ubiquity combined with a relatively low quantity of their annotations motivate research toward the development of computational models that predict disordered regions from protein sequences. Although the prediction quality of these methods continues to rise, novel and improved predictors are urgently needed. Results: We propose a novel method, named MFDp (Multilayered Fusion-based Disorder predictor), that aims to improve over the current disorder predictors. MFDp is as an ensemble of 3 Support Vector Machines specialized for the prediction of short, long and generic disordered regions. It combines three complementary disorder predictors, sequence, sequence profiles, predicted secondary structure, solvent accessibility, backbone dihedral torsion angles, residue flexibility and B-factors. Our method utilizes a custom-designed set of features that are based on raw predictions and aggregated raw values and recognizes various types of disorder. The MFDp is compared at the residue level on two datasets against eight recent disorder predictors and top-performing methods from the most recent CASP8 experiment. In spite of using training chains with ≤25% similarity to the test sequences, our method consistently and significantly outperforms the other methods based on the MCC index. The MFDp outperforms modern disorder predictors for the binary disorder assignment and provides competitive real-valued predictions. The MFDp's outputs are also shown to outperform the other methods in the identification of proteins with long disordered regions. Availability: http://biomine.ece.ualberta.ca/MFDp.html Supplementary information: Supplementary data are available at Bioinformatics online. Contact: email@example.com PMID:20823312
Wernersson, Rasmus; Schierup, M.H.; Jorgensen, F.G.;
sequences (0.66X coverage) from the pig genome. The data are hereby released (NCBI Trace repository with center name "SDJVP", and project name "Sino-Danish Pig Genome Project") together with an initial evolutionary analysis. The non-repetitive fraction of the sequences was aligned to the UCSC human......Background: Comparative whole genome analysis of Mammalia can benefit from the addition of more species. The pig is an obvious choice due to its economic and medical importance as well as its evolutionary position in the artiodactyls. Results: We have generated similar to 3.84 million shotgun......-mouse alignment and the resulting three-species alignments were annotated using the human genome annotation. Ultra-conserved elements and miRNAs were identified. The results show that for each of these types of orthologous data, pig is much closer to human than mouse is. Purifying selection has been more...
Full Text Available Abstract Background Comparative whole genome analysis of Mammalia can benefit from the addition of more species. The pig is an obvious choice due to its economic and medical importance as well as its evolutionary position in the artiodactyls. Results We have generated ~3.84 million shotgun sequences (0.66X coverage from the pig genome. The data are hereby released (NCBI Trace repository with center name "SDJVP", and project name "Sino-Danish Pig Genome Project" together with an initial evolutionary analysis. The non-repetitive fraction of the sequences was aligned to the UCSC human-mouse alignment and the resulting three-species alignments were annotated using the human genome annotation. Ultra-conserved elements and miRNAs were identified. The results show that for each of these types of orthologous data, pig is much closer to human than mouse is. Purifying selection has been more efficient in pig compared to human, but not as efficient as in mouse, and pig seems to have an isochore structure most similar to the structure in human. Conclusion The addition of the pig to the set of species sequenced at low coverage adds to the understanding of selective pressures that have acted on the human genome by bisecting the evolutionary branch between human and mouse with the mouse branch being approximately 3 times as long as the human branch. Additionally, the joint alignment of the shot-gun sequences to the human-mouse alignment offers the investigator a rapid way to defining specific regions for analysis and resequencing.
Macas, Jiří; Neumann, Pavel; Novák, Petr; Jiang, J.
Roč. 26, č. 1797 (2010), s. 2101-2108. ISSN 1367-4803 R&D Projects: GA AV ČR KJB500960802; GA MŠk(CZ) OC10037; GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50510513 Keywords : next-generation sequencing * satellite repeats * K-mer analysis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.877, year: 2010
Gupta, Ankit; Tran, Viet Chi
We consider a stochastic individual based model for a population structured by a vector trait and with logistic interactions. We consider its limit in a context from adaptive dynamics: the population is large, the mutations are rare and we view the process in the timescale of mutations. Using averaging techniques due to Kurtz (1992), we give a new proof of the convergence of the individual based model to the Trait substitution sequence of Metz et al. (1992) and rigorously proved by Champagnat (2006): assuming that "invasion implies fixation", we obtain in the limit a process that jumps from one population equilibrum to another one when mutations occur and invade the population.
The authors have previously developed a knowledge-based method of factor analysis to analyze dynamic nuclear medicine image sequences. In this paper, the authors analyze dynamic PET cerebral glucose metabolism and neuroreceptor binding studies. These methods have shown the ability to reduce the dimensionality of the data, enhance the image quality of the sequence, and generate meaningful functional images and their corresponding physiological time functions. The new information produced by the factor analysis has now been used to improve the estimation of various physiological parameters. A principal component analysis (PCA) is first performed to identify statistically significant temporal variations and remove the uncorrelated variations (noise) due to Poisson counting statistics. The statistically significant principal components are then used to reconstruct a noise-reduced image sequence as well as provide an initial solution for the factor analysis. Prior knowledge such as the compartmental models or the requirement of positivity and simple structure can be used to constrain the analysis. These constraints are used to rotate the factors to the most physically and physiologically realistic solution. The final result is a small number of time functions (factors) representing the underlying physiological processes and their associated weighting images representing the spatial localization of these functions. Estimation of physiological parameters can then be performed using the noise-reduced image sequence generated from the statistically significant PCs and/or the final factor images and time functions. These results are compared to the parameter estimation using standard methods and the original raw image sequences. Graphical analysis was performed at the pixel level to generate comparable parametric images of the slope and intercept (influx constant and distribution volume)
Full Text Available Sweet potatoes (Ipomea batatas L. are grown extensively, in tropical and temperate regions, and are important food crops worldwide. In Korea, potyviruses, including Sweet potato feathery mottle virus (SPFMV, Sweet potato virus C (SPVC, Sweet potato virus G (SPVG, Sweet potato virus 2 (SPV2, and Sweet potato latent virus (SPLV, have been detected in sweet potato fields at a high (~95% incidence. In the present work, complete genome sequences of 18 isolates, representing the five potyviruses mentioned above, were compared with previously reported genome sequences. The complete genomes consisted of 10,081 to 10,830 nucleotides, excluding the poly-A tails. Their genomic organizations were typical of the Potyvirus genus, including one target open reading frame coding for a putative polyprotein. Based on phylogenetic analyses and sequence comparisons, the Korean SPFMV isolates belonged to the strains RC and O with >98% nucleotide sequence identity. Korean SPVC isolates had 99% identity to the Japanese isolate SPVC-Bungo and 70% identity to the SPFMV isolates. The Korean SPVG isolates showed 99% identity to the three previously reported SPVG isolates. Korean SPV2 isolates had 97% identity to the SPV2 GWB-2 isolate from the USA. Korean SPLV isolates had a relatively low (88% nucleotide sequence identity with the Taiwanese SPLV-TW isolates, and they were phylogenetically distantly related to SPFMV isolates. Recombination analysis revealed that possible recombination events occurred in the P1, HC-Pro and NIa-NIb regions of SPFMV and SPLV isolates and these regions were identified as hotspots for recombination in the sweet potato potyviruses.
Full Text Available Abstract Background DNA methylation plays important roles in gene regulation during both normal developmental and disease states. In the past decade, a number of methods have been developed and applied to characterize the genome-wide distribution of DNA methylation. Most of these methods endeavored to screen whole genome and turned to be enormously costly and time consuming for studies of the complex mammalian genome. Thus, they are not practical for researchers to study multiple clinical samples in biomarker research. Results Here, we display a novel strategy that relies on the selective capture of target regions by liquid hybridization followed by bisulfite conversion and deep sequencing, which is referred to as liquid hybridization capture-based bisulfite sequencing (LHC-BS. To estimate this method, we utilized about 2 μg of native genomic DNA from YanHuang (YH whole blood samples and a mature dendritic cell (mDC line, respectively, to evaluate their methylation statuses of target regions of exome. The results indicated that the LHC-BS system was able to cover more than 97% of the exome regions and detect their methylation statuses with acceptable allele dropouts. Most of the regions that couldn't provide accurate methylation information were distributed in chromosomes 6 and Y because of multiple mapping to those regions. The accuracy of this strategy was evaluated by pair-wise comparisons using the results from whole genome bisulfite sequencing and validated by bisulfite specific PCR sequencing. Conclusions In the present study, we employed a liquid hybridisation capture system to enrich for exon regions and then combined with bisulfite sequencing to examine the methylation statuses for the first time. This technique is highly sensitive and flexible and can be applied to identify differentially methylated regions (DMRs at specific genomic locations of interest, such as regulatory elements or promoters.
Full Text Available Abstract Background Brassica rapa is an economically important crop and a model plant for studies concerning polyploidization and the evolution of extreme morphology. The multinational B. rapa Genome Sequencing Project (BrGSP was launched in 2003. In 2008, next generation sequencing technology was used to sequence the B. rapa genome. Several maps concerning B. rapa pseudochromosome assembly have been published but their coverage of the genome is incomplete, anchoring approximately 73.6% of the scaffolds on to chromosomes. Therefore, a new genetic map to aid pseudochromosome assembly is required. Results This study concerns the construction of a reference genetic linkage map for Brassica rapa, forming the backbone for anchoring sequence scaffolds of the B. rapa genome resulting from recent sequencing efforts. One hundred and nineteen doubled haploid (DH lines derived from microspore cultures of an F1 cross between a Chinese cabbage (B. rapa ssp. pekinensis DH line (Z16 and a rapid cycling inbred line (L144 were used to construct the linkage map. PCR-based insertion/deletion (InDel markers were developed by re-sequencing the two parental lines. The map comprises a total of 507 markers including 415 InDels and 92 SSRs. Alignment and orientation using SSR markers in common with existing B. rapa linkage maps allowed ten linkage groups to be identified, designated A01-A10. The total length of the linkage map was 1234.2 cM, with an average distance of 2.43 cM between adjacent marker loci. The lengths of linkage groups ranged from 71.5 cM to 188.5 cM for A08 and A09, respectively. Using the developed linkage map, 152 scaffolds were anchored on to the chromosomes, encompassing more than 82.9% of the B. rapa genome. Taken together with the previously available linkage maps, 183 scaffolds were anchored on to the chromosomes and the total coverage of the genome was 88.9%. Conclusions The development of this linkage map is vital for the integration of genome
Full Text Available The biological implications of bioinformatics can already be seen in various implementations. Biological taxonomy may seem like a simple science in which the biologists merely observe similarities among organisms and construct classifications according to those similarities, but it is not so simple. By applying data mining techniques on gene sequence database we can cluster the data to find interesting similarities in the gene expression data. One of the applications of such kind of clustering is taxonomically clustering the organisms based on their gene sequential expressions. In this study we outlined a method for taxonomical clustering of species of the organisms based on the genetic profile using Principal Component Analysis and Self Organizing Neural Networks. We have implemented the idea using Matlab and tried to cluster the gene sequences taken from PAUP version of the ML5/ML6 database. The taxa used for some of the basidiomycetous fungi form the database. To study the scalability issues another large gene sequence database was used. The proposed method clustered the species of organisms correctly in almost all the cases. The obtained were more significant and promising. The proposed method clustered the species of organisms correctly in almost all the cases. The obtained results were more significant and promising.
Ercan Selçuk Ünlü
Full Text Available Small RNA molecules are short, non-coding RNAs identified for their crucial role in post-transcriptional regulation. A well-studied example includes miRNAs (microRNAs which have been identified in several model organisms including the freshwater flea and planktonic crustacean Daphnia. A model for epigenetic-based studies with an available genome database, the identification of miRNAs and their potential role in regulating Daphnia gene expression has only recently garnered interest. Computational-based work using Daphnia pulex, has indicated the existence of 45 miRNAs, 14 of which have been experimentally verified. To extend this study, we took a sequencing approach towards identifying miRNAs present in a small RNA library isolated from Daphnia magna. Using Perl codes designed for comparative genomic analysis, 815,699 reads were obtained from 4 million raw reads and run against a database file of known miRNA sequences. Using this approach, we have identified 205 putative mature miRNA sequences belonging to 188 distinct miRNA families. Data from this study provides critical information necessary to begin an investigation into a role for these transcripts in the epigenetic regulation of Daphnia magna.
Nguyen Xuan Quyen
Full Text Available This paper proposes a chaos-based secure direct-sequence/spread-spectrum (DS/SS communication system which is based on a novel combination of the conventional DS/SS and chaos techniques. In the proposed system, bit duration is varied according to a chaotic behavior but is always equal to a multiple of the fixed chip duration in the communication process. Data bits with variable duration are spectrum-spread by multiplying directly with a pseudonoise (PN sequence and then modulated onto a sinusoidal carrier by means of binary phase-shift keying (BPSK. To recover exactly the data bits, the receiver needs an identical regeneration of not only the PN sequence but also the chaotic behavior, and hence data security is improved significantly. Structure and operation of the proposed system are analyzed in detail. Theoretical evaluation of bit-error rate (BER performance in presence of additive white Gaussian noise (AWGN is provided. Parameter choice for different cases of simulation is also considered. Simulation and theoretical results are shown to verify the reliability and feasibility of the proposed system. Security of the proposed system is also discussed.
Joseph, Agnel Praveen; Srinivasan, Narayanaswamy; de Brevern, Alexandre G
Comparison of multiple protein structures has a broad range of applications in the analysis of protein structure, function and evolution. Multiple structure alignment tools (MSTAs) are necessary to obtain a simultaneous comparison of a family of related folds. In this study, we have developed a method for multiple structure comparison largely based on sequence alignment techniques. A widely used Structural Alphabet named Protein Blocks (PBs) was used to transform the information on 3D protein backbone conformation as a 1D sequence string. A progressive alignment strategy similar to CLUSTALW was adopted for multiple PB sequence alignment (mulPBA). Highly similar stretches identified by the pairwise alignments are given higher weights during the alignment. The residue equivalences from PB based alignments are used to obtain a three dimensional fit of the structures followed by an iterative refinement of the structural superposition. Systematic comparisons using benchmark datasets of MSTAs underlines that the alignment quality is better than MULTIPROT, MUSTANG and the alignments in HOMSTRAD, in more than 85% of the cases. Comparison with other rigid-body and flexible MSTAs also indicate that mulPBA alignments are superior to most of the rigid-body MSTAs and highly comparable to the flexible alignment methods. PMID:22676903
Ruppitsch, Werner; Pietzka, Ariane; Prior, Karola; Bletz, Stefan; Fernandez, Haizpea Lasa; Allerberger, Franz; Harmsen, Dag; Mellmann, Alexander
Whole-genome sequencing (WGS) has emerged today as an ultimate typing tool to characterize Listeria monocytogenes outbreaks. However, data analysis and interlaboratory comparability of WGS data are still challenging for most public health laboratories. Therefore, we have developed and evaluated a new L. monocytogenes typing scheme based on genome-wide gene-by-gene comparisons (core genome multilocus the sequence typing [cgMLST]) to allow for a unique typing nomenclature. Initially, we determined the breadth of the L. monocytogenes population based on MLST data with a Bayesian approach. Based on the genome sequence data of representative isolates for the whole population, cgMLST target genes were defined and reappraised with 67 L. monocytogenes isolates from two outbreaks and serotype reference strains. The Bayesian population analysis generated five L. monocytogenes groups. Using all available NCBI RefSeq genomes (n = 36) and six additionally sequenced strains, all genetic groups were covered. Pairwise comparisons of these 42 genome sequences resulted in 1,701 cgMLST targets present in all 42 genomes with 100% overlap and ≥90% sequence similarity. Overall, ≥99.1% of the cgMLST targets were present in 67 outbreak and serotype reference strains, underlining the representativeness of the cgMLST scheme. Moreover, cgMLST enabled clustering of outbreak isolates with ≤10 alleles difference and unambiguous separation from unrelated outgroup isolates. In conclusion, the novel cgMLST scheme not only improves outbreak investigations but also enables, due to the availability of the automatically curated cgMLST nomenclature, interlaboratory exchange of data that are crucial, especially for rapid responses during transsectorial outbreaks. PMID:26135865
Willems, Sander; Fraiture, Marie-Alice; Deforce, Dieter; De Keersmaecker, Sigrid C J; De Loose, Marc; Ruttink, Tom; Herman, Philippe; Van Nieuwerburgh, Filip; Roosens, Nancy
Because the number and diversity of genetically modified (GM) crops has significantly increased, their analysis based on real-time PCR (qPCR) methods is becoming increasingly complex and laborious. While several pioneers already investigated Next Generation Sequencing (NGS) as an alternative to qPCR, its practical use has not been assessed for routine analysis. In this study a statistical framework was developed to predict the number of NGS reads needed to detect transgene sequences, to prove their integration into the host genome and to identify the specific transgene event in a sample with known composition. This framework was validated by applying it to experimental data from food matrices composed of pure GM rice, processed GM rice (noodles) or a 10% GM/non-GM rice mixture, revealing some influential factors. Finally, feasibility of NGS for routine analysis of GM crops was investigated by applying the framework to samples commonly encountered in routine analysis of GM crops. PMID:26304412
Adalsteinsson, Viktor A; Love, J Christopher
Sequencing-based analysis of single circulating tumor cells (CTCs) has the potential to revolutionize our understanding of metastatic cancer and improve clinical care. Technologies exist to enrich, identify, recover, and sequence single cells, but to enable systematic routine analysis of single CTCs from a range of cancer patients, there is a need to establish processes that efficiently integrate these specific operations. Such engineered processes should address challenges associated with the yield and viability of enriched CTCs, the robust identification of candidate single CTCs with minimal degradation of DNA, the bias in whole-genome amplification, and the efficient handling of candidate single CTCs or their amplified DNA products. Advances in methods for single-cell analysis and nanoscale technologies suggest opportunities to overcome these challenges, and could create integrated platforms that perform several of the unit operations together. Ultimately, technologies should be selected or adapted for optimal performance and compatibility in an integrated process. PMID:24839591
Tian, Z Z; Zhang, F Q; Cai, Z Y; Chen, S L
Populus cathayana occupies a large area within the northern, central, and southwestern regions of China, and is considered to be an important reforestation species in western China. In order to investigate the population genetic structure of this species, 10 polymorphic microsatellite loci were identified based on expressed sequence tags from de novo sequencing on the Illumina HiSeq 2000 platform. All microsatellite primers were tested on 48 P. cathayana individuals from four locations on the Qinghai-Tibet Plateau. The observed heterozygosity ranged from 0.000 to 1.000, and the null-allele frequency ranged from 0.000 to 0.904. These microsatellite markers may be a useful tool in genetic studies on P. cathayana and closely related species. PMID:27525845
ZHANG Daoyuan; ZHANG Yuan; GASKIN J. F.; CHEN Zhiduan
Myrtama is a genus named from Myricaria elegans Royle in the 1970's in terms of its morphological peculiarities. The establishment of this genus and its systematic position have been disputed since its inception. ITS sequences from 10 species of Tamaricaceae are reported, and analyzed by PAUP 4.0b8 and Bayesian Inference to reconstruct the phylogenies. A single ITS tree is generated from maximum parsimony and MrBayes analyses, respectively. The molecular data set shows strong support for Tamarix and Myricaria as monophyletic genera,and Myrtama as a sister group to the genus Myricaria.Based on morphological differences, a single morphological tree is also generated, in which two major lineages existed but Myrtama is a sister group to Tamarix, rather than Myricaria. The evidence from DNA sequences and morphological characters supports that Myicaria elegans should be put into neither Myricaria nor Tamarix, but kept in its own monotypic genus.
Full Text Available One of the key mechanisms of transcriptional control are the specific connections between transcription factors (TF and cis-regulatory elements in gene promoters. The elucidation of these specific protein-DNA interactions is crucial to gain insights into the complex regulatory mechanisms and networks underlying the adaptation of organisms to dynamically changing environmental conditions. As experimental techniques for determining TF binding sites are expensive and mostly performed for selected TFs only, accurate computational approaches are needed to analyze transcriptional regulation in eukaryotes on a genome-wide level. We implemented a four-step classification workflow which for a given protein sequence (1 discriminates TFs from other proteins, (2 determines the structural superclass of TFs, (3 identifies the DNA-binding domains of TFs and (4 predicts their cis-acting DNA motif. While existing tools were extended and adapted for performing the latter two prediction steps, the first two steps are based on a novel numeric sequence representation which allows for combining existing knowledge from a BLAST scan with robust machine learning-based classification. By evaluation on a set of experimentally confirmed TFs and non-TFs, we demonstrate that our new protein sequence representation facilitates more reliable identification and structural classification of TFs than previously proposed sequence-derived features. The algorithms underlying our proposed methodology are implemented in the two complementary tools TFpredict and SABINE. The online and stand-alone versions of TFpredict and SABINE are freely available to academics at http://www.cogsys.cs.uni-tuebingen.de/software/TFpredict/ and http://www.cogsys.cs.uni-tuebingen.de/software/SABINE/.
Kakarala, Kavita Kumari; Jamil, Kaiser
Current methods of G protein coupled receptors (GPCRs) phylogenetic classification are sequence based and therefore inappropriate for highly divergent sequences, sharing low sequence identity. In this study, sequence structure profile based alignment generated by PROMALS3D was used to understand the GPCR Class A Rhodopsin superfamily evolution using the MEGA 5 software. Phylogenetic analysis included a combination of Neighbor-Joining method and Maximum Likelihood method, with 1000 bootstrap replicates. Our study was able to identify potential ligand association for Class A Orphans and putative/unclassified Class A receptors with no cognate ligand information: GPR21 and GPR52 with fatty acids; GPR75 with Neuropeptide Y; GPR82, GPR18, GPR141 with N-arachidonylglycine; GPR176 with Free fatty acids, GPR10 with Tachykinin & Neuropeptide Y; GPR85 with ATP, ADP & UDP glucose; GPR151 with Galanin; GPR153 and GPR162 with Adrenalin, Noradrenalin; GPR146, GPR139, GPR142 with Neuromedin, Ghrelin, Neuromedin U-25 & Thyrotropin-releasing hormone; GPR171 with ATP, ADP & UDP Glucose; GPR88, GPR135, GPR161, GPR101with 11-cis-retinal; GPR83 with Tackykinin; GPR148 with Prostanoids, GPR109b, GPR81, GPR31with ATP & UTP and GPR150 with GnRH I & GnRHII. Furthermore, we suggest that this study would prove useful in re-classification of receptors, selecting templates for homology modeling and identifying ligands which may show cross reactivity with other GPCRs as signaling via multiple ligands play a significant role in disease modulation. PMID:24503482
Salahuddin, Parveen; Khan, Asad U
The β-lactamases enzymes cleave the amide bond in β-lactam ring, rendering β-lactam antibiotics harmless to bacteria. In this communication we have studied structure-function relationship and phylogenies of class A, B and D beta-lactamases using structure-based sequence alignment and phylip programs respectively. The data of structure-based sequence alignment suggests that in different isolates of TEM-1, mutations did not occur at or near sequence motifs. Since deletions are reported to be lethal to structure and function of enzyme. Therefore, in these variants antibiotic hydrolysis profile and specificity will be affected. The alignment data of class A enzyme SHV-1, CTX-M-15, class D enzyme, OXA-10, and class B enzyme VIM-2 and SIM-1 show sequence motifs along with other part of polypeptide are essentially conserved. These results imply that conformations of betalactamases are close to native state and possess normal hydrolytic activities towards beta-lactam antibiotics. However, class B enzyme such as IMP-1 and NDM-1 are less conserved than other class A and D studied here because mutation and deletions occurred at critically important region such as active site. Therefore, the structure of these beta-lactamases will be altered and antibiotic hydrolysis profile will be affected. Phylogenetic studies suggest that class A and D beta-lactamases including TOHO-1 and OXA-10 respectively evolved by horizontal gene transfer (HGT) whereas other member of class A such as TEM-1 evolved by gene duplication mechanism. Taken together, these studies justify structure-function relationship of beta-lactamases and phylogenetic studies suggest these enzymes evolved by different mechanisms. PMID:24966539
Eisenhaber, Birgit; Kuchibhatla, Durga; Sherman, Westley; Sirota, Fernanda L; Berezovsky, Igor N; Wong, Wing-Cheong; Eisenhaber, Frank
As biomolecular sequencing is becoming the main technique in life sciences, functional interpretation of sequences in terms of biomolecular mechanisms with in silico approaches is getting increasingly significant. Function prediction tools are most powerful for protein-coding sequences; yet, the concepts and technologies used for this purpose are not well reflected in bioinformatics textbooks. Notably, protein sequences typically consist of globular domains and non-globular segments. The two types of regions require cardinally different approaches for function prediction. Whereas the former are classic targets for homology-inspired function transfer based on remnant, yet statistically significant sequence similarity to other, characterized sequences, the latter type of regions are characterized by compositional bias or simple, repetitive patterns and require lexical analysis and/or empirical sequence pattern-function correlations. The recipe for function prediction recommends first to find all types of non-globular segments and, then, to subject the remaining query sequence to sequence similarity searches. We provide an updated description of the ANNOTATOR software environment as an advanced example of a software platform that facilitates protein sequence-based function prediction. PMID:27115649
Gil-Jiménez, Víctor P.; Fernández-Getino García, María Julia; García-Armada, Ana; Sánchez-Fernández, Matilde
In this paper the use of complementary Golay sequences (CGS) for peak-to-average power ratio (PAR) reduction and forward error correction (FEC) in an orthogonal frequency division multiplexing (OFDM)-based wireless local area network (WLAN) system is explored; performance is examined and complexity issues are analyzed. We study their PAR reduction performance depending on sequence lengths and we have found that, for the case that the number of sub-carriers differs from the sequence length, so...
B.Subtilis expression plasmids generally require a stringent Shine-Dalgarno Sequence(SDS). Site-directed-mutagenesis was explored to change the Shine-Dalgarno Sequence from AAAAATGGGG (mutant type) to AAAAAGGGGG (wild type) in recombinant plasmid PSM604. The single base substitution made the plasmid with wild SDS unstable in structure and segregation. The interaction of SDS with subtilisin leader sequence of PSM604 might be responsible for the instability of plasmid.
Gao, Peng-fei; Zhao, Hui-ting; ZHANG, Chun-xiang; Jiang, Yu-suo
In order to provide the basic datum to protect and rationally develop the Apis cerana resources in china, phylogeny of different geographic populations Apis cerana in China was studied based on mtDNA Cytochrome b gene sequences. In this study, the partial sequences of mtDNA Cytochrome b gene of 21 colonies of Apis cerana collected from 10 provinces and the homologous sequences of Apis nigrocincta and Apis mellifera downloaded from GenBank were analyzed. Molecular phylogenetic trees were reco...
Bettotti, P; Mancinelli, M; Guider, R; Masi, M; Vanacharla, M Rao; Pavesi, L
A novel (to our knowledge) scheme of an optical router/switch element, composed of a tapered side-coupled integrated spaced sequence of optical resonators, is proposed. It is based on a modified design of the ring sequence in which the resonance conditions are set by the single ring resonance and by the coherent feedback of the sequence of rings. This double condition yields robustness against fabrication defects, dense routing capability, and high switching efficiency. PMID:21499394