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Sample records for accurate phylogenetic classification

  1. Accurate phylogenetic classification of variable-length DNA fragments.

    PubMed

    McHardy, Alice Carolyn; Martín, Héctor García; Tsirigos, Aristotelis; Hugenholtz, Philip; Rigoutsos, Isidore

    2007-01-01

    Metagenome studies have retrieved vast amounts of sequence data from a variety of environments leading to new discoveries and insights into the uncultured microbial world. Except for very simple communities, the encountered diversity has made fragment assembly and the subsequent analysis a challenging problem. A taxonomic characterization of metagenomic fragments is required for a deeper understanding of shotgun-sequenced microbial communities, but success has mostly been limited to sequences containing phylogenetic marker genes. Here we present PhyloPythia, a composition-based classifier that combines higher-level generic clades from a set of 340 completed genomes with sample-derived population models. Extensive analyses on synthetic and real metagenome data sets showed that PhyloPythia allows the accurate classification of most sequence fragments across all considered taxonomic ranks, even for unknown organisms. The method requires no more than 100 kb of training sequence for the creation of accurate models of sample-specific populations and can assign fragments >or=1 kb with high specificity.

  2. Accurate phylogenetic classification of DNA fragments based onsequence composition

    SciTech Connect

    McHardy, Alice C.; Garcia Martin, Hector; Tsirigos, Aristotelis; Hugenholtz, Philip; Rigoutsos, Isidore

    2006-05-01

    Metagenome studies have retrieved vast amounts of sequenceout of a variety of environments, leading to novel discoveries and greatinsights into the uncultured microbial world. Except for very simplecommunities, diversity makes sequence assembly and analysis a verychallenging problem. To understand the structure a 5 nd function ofmicrobial communities, a taxonomic characterization of the obtainedsequence fragments is highly desirable, yet currently limited mostly tothose sequences that contain phylogenetic marker genes. We show that forclades at the rank of domain down to genus, sequence composition allowsthe very accurate phylogenetic 10 characterization of genomic sequence.We developed a composition-based classifier, PhyloPythia, for de novophylogenetic sequence characterization and have trained it on adata setof 340 genomes. By extensive evaluation experiments we show that themethodis accurate across all taxonomic ranks considered, even forsequences that originate fromnovel organisms and are as short as 1kb.Application to two metagenome datasets 15 obtained from samples ofphosphorus-removing sludge showed that the method allows the accurateclassification at genus level of most sequence fragments from thedominant populations, while at the same time correctly characterizingeven larger parts of the samples at higher taxonomic levels.

  3. Concepts of Classification and Taxonomy Phylogenetic Classification

    NASA Astrophysics Data System (ADS)

    Fraix-Burnet, D.

    2016-05-01

    Phylogenetic approaches to classification have been heavily developed in biology by bioinformaticians. But these techniques have applications in other fields, in particular in linguistics. Their main characteristics is to search for relationships between the objects or species in study, instead of grouping them by similarity. They are thus rather well suited for any kind of evolutionary objects. For nearly fifteen years, astrocladistics has explored the use of Maximum Parsimony (or cladistics) for astronomical objects like galaxies or globular clusters. In this lesson we will learn how it works.

  4. Towards an integrated phylogenetic classification of the Tremellomycetes.

    PubMed

    Liu, X-Z; Wang, Q-M; Göker, M; Groenewald, M; Kachalkin, A V; Lumbsch, H T; Millanes, A M; Wedin, M; Yurkov, A M; Boekhout, T; Bai, F-Y

    2015-06-01

    Families and genera assigned to Tremellomycetes have been mainly circumscribed by morphology and for the yeasts also by biochemical and physiological characteristics. This phenotype-based classification is largely in conflict with molecular phylogenetic analyses. Here a phylogenetic classification framework for the Tremellomycetes is proposed based on the results of phylogenetic analyses from a seven-genes dataset covering the majority of tremellomycetous yeasts and closely related filamentous taxa. Circumscriptions of the taxonomic units at the order, family and genus levels recognised were quantitatively assessed using the phylogenetic rank boundary optimisation (PRBO) and modified general mixed Yule coalescent (GMYC) tests. In addition, a comprehensive phylogenetic analysis on an expanded LSU rRNA (D1/D2 domains) gene sequence dataset covering as many as available teleomorphic and filamentous taxa within Tremellomycetes was performed to investigate the relationships between yeasts and filamentous taxa and to examine the stability of undersampled clades. Based on the results inferred from molecular data and morphological and physiochemical features, we propose an updated classification for the Tremellomycetes. We accept five orders, 17 families and 54 genera, including seven new families and 18 new genera. In addition, seven families and 17 genera are emended and one new species name and 185 new combinations are proposed. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the species names that are temporarily maintained.

  5. Towards an integrated phylogenetic classification of the Tremellomycetes

    PubMed Central

    Liu, X.-Z.; Wang, Q.-M.; Göker, M.; Groenewald, M.; Kachalkin, A.V.; Lumbsch, H.T.; Millanes, A.M.; Wedin, M.; Yurkov, A.M.; Boekhout, T.; Bai, F.-Y.

    2016-01-01

    Families and genera assigned to Tremellomycetes have been mainly circumscribed by morphology and for the yeasts also by biochemical and physiological characteristics. This phenotype-based classification is largely in conflict with molecular phylogenetic analyses. Here a phylogenetic classification framework for the Tremellomycetes is proposed based on the results of phylogenetic analyses from a seven-genes dataset covering the majority of tremellomycetous yeasts and closely related filamentous taxa. Circumscriptions of the taxonomic units at the order, family and genus levels recognised were quantitatively assessed using the phylogenetic rank boundary optimisation (PRBO) and modified general mixed Yule coalescent (GMYC) tests. In addition, a comprehensive phylogenetic analysis on an expanded LSU rRNA (D1/D2 domains) gene sequence dataset covering as many as available teleomorphic and filamentous taxa within Tremellomycetes was performed to investigate the relationships between yeasts and filamentous taxa and to examine the stability of undersampled clades. Based on the results inferred from molecular data and morphological and physiochemical features, we propose an updated classification for the Tremellomycetes. We accept five orders, 17 families and 54 genera, including seven new families and 18 new genera. In addition, seven families and 17 genera are emended and one new species name and 185 new combinations are proposed. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the species names that are temporarily maintained. PMID:26955199

  6. A Functional-Phylogenetic Classification System for Transmembrane Solute Transporters

    PubMed Central

    Saier, Milton H.

    2000-01-01

    A comprehensive classification system for transmembrane molecular transporters has been developed and recently approved by the transport panel of the nomenclature committee of the International Union of Biochemistry and Molecular Biology. This system is based on (i) transporter class and subclass (mode of transport and energy coupling mechanism), (ii) protein phylogenetic family and subfamily, and (iii) substrate specificity. Almost all of the more than 250 identified families of transporters include members that function exclusively in transport. Channels (115 families), secondary active transporters (uniporters, symporters, and antiporters) (78 families), primary active transporters (23 families), group translocators (6 families), and transport proteins of ill-defined function or of unknown mechanism (51 families) constitute distinct categories. Transport mode and energy coupling prove to be relatively immutable characteristics and therefore provide primary bases for classification. Phylogenetic grouping reflects structure, function, mechanism, and often substrate specificity and therefore provides a reliable secondary basis for classification. Substrate specificity and polarity of transport prove to be more readily altered during evolutionary history and therefore provide a tertiary basis for classification. With very few exceptions, a phylogenetic family of transporters includes members that function by a single transport mode and energy coupling mechanism, although a variety of substrates may be transported, sometimes with either inwardly or outwardly directed polarity. In this review, I provide cross-referencing of well-characterized constituent transporters according to (i) transport mode, (ii) energy coupling mechanism, (iii) phylogenetic grouping, and (iv) substrates transported. The structural features and distribution of recognized family members throughout the living world are also evaluated. The tabulations should facilitate familial and functional

  7. Phylogenetic classification and identification of bacteria by mass spectrometry.

    PubMed

    Freiwald, Anja; Sauer, Sascha

    2009-01-01

    Bacteria are a convenient source of intrinsic marker proteins, which can be detected efficiently by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The patterns of protein masses observed can be used for accurate classification and identification of bacteria. Key to the reliability of the method is a robust and standardized procedure for sample preparations, including bacterial culturing, chemical treatment for bacterial cell wall disruption and for protein extraction, and mass spectrometry analysis. The protocol is an excellent alternative to classical microbiological classification and identification procedures, requiring minimal sample preparation efforts and costs. Without cell culturing, the protocol takes in general <1 h.

  8. Phylogenetic classification of Cordyceps and the clavicipitaceous fungi

    PubMed Central

    Sung, Gi-Ho; Hywel-Jones, Nigel L.; Sung, Jae-Mo; Luangsa-ard, J. Jennifer; Shrestha, Bhushan; Spatafora, Joseph W.

    2007-01-01

    Cordyceps, comprising over 400 species, was historically classified in the Clavicipitaceae, based on cylindrical asci, thickened ascus apices and filiform ascospores, which often disarticulate into part-spores. Cordyceps was characterized by the production of well-developed often stipitate stromata and an ecology as a pathogen of arthropods and Elaphomyces with infrageneric classifications emphasizing arrangement of perithecia, ascospore morphology and host affiliation. To refine the classification of Cordyceps and the Clavicipitaceae, the phylogenetic relationships of 162 taxa were estimated based on analyses consisting of five to seven loci, including the nuclear ribosomal small and large subunits (nrSSU and nrLSU), the elongation factor 1α (tef1), the largest and the second largest subunits of RNA polymerase II (rpb1 and rpb2), β-tubulin (tub), and mitochondrial ATP6 (atp6). Our results strongly support the existence of three clavicipitaceous clades and reject the monophyly of both Cordyceps and Clavicipitaceae. Most diagnostic characters used in current classifications of Cordyceps (e.g., arrangement of perithecia, ascospore fragmentation, etc.) were not supported as being phylogenetically informative; the characters that were most consistent with the phylogeny were texture, pigmentation and morphology of stromata. Therefore, we revise the taxonomy of Cordyceps and the Clavicipitaceae to be consistent with the multi-gene phylogeny. The family Cordycipitaceae is validated based on the type of Cordyceps, C. militaris, and includes most Cordyceps species that possess brightly coloured, fleshy stromata. The new family Ophiocordycipitaceae is proposed based on Ophiocordyceps Petch, which we emend. The majority of species in this family produce darkly pigmented, tough to pliant stromata that often possess aperithecial apices. The new genus Elaphocordyceps is proposed for a subclade of the Ophiocordycipitaceae, which includes all species of Cordyceps that parasitize

  9. Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa).

    PubMed

    Maronna, Maximiliano M; Miranda, Thaís P; Peña Cantero, Álvaro L; Barbeitos, Marcos S; Marques, Antonio C

    2016-01-29

    Leptothecata are hydrozoans whose hydranths are covered by perisarc and gonophores and whose medusae bear gonads on their radial canals. They develop complex polypoid colonies and exhibit considerable morphological variation among species with respect to growth, defensive structures and mode of development. For instance, several lineages within this order have lost the medusa stage. Depending on the author, traditional taxonomy in hydrozoans may be either polyp- or medusa-oriented. Therefore, the absence of the latter stage in some lineages may lead to very different classification schemes. Molecular data have proved useful in elucidating this taxonomic challenge. We analyzed a super matrix of new and published rRNA gene sequences (16S, 18S and 28S), employing newly proposed methods to measure branch support and improve phylogenetic signal. Our analysis recovered new clades not recognized by traditional taxonomy and corroborated some recently proposed taxa. We offer a thorough taxonomic revision of the Leptothecata, erecting new orders, suborders, infraorders and families. We also discuss the origination and diversification dynamics of the group from a macroevolutionary perspective.

  10. Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa)

    PubMed Central

    Maronna, Maximiliano M.; Miranda, Thaís P.; Peña Cantero, Álvaro L.; Barbeitos, Marcos S.; Marques, Antonio C.

    2016-01-01

    Leptothecata are hydrozoans whose hydranths are covered by perisarc and gonophores and whose medusae bear gonads on their radial canals. They develop complex polypoid colonies and exhibit considerable morphological variation among species with respect to growth, defensive structures and mode of development. For instance, several lineages within this order have lost the medusa stage. Depending on the author, traditional taxonomy in hydrozoans may be either polyp- or medusa-oriented. Therefore, the absence of the latter stage in some lineages may lead to very different classification schemes. Molecular data have proved useful in elucidating this taxonomic challenge. We analyzed a super matrix of new and published rRNA gene sequences (16S, 18S and 28S), employing newly proposed methods to measure branch support and improve phylogenetic signal. Our analysis recovered new clades not recognized by traditional taxonomy and corroborated some recently proposed taxa. We offer a thorough taxonomic revision of the Leptothecata, erecting new orders, suborders, infraorders and families. We also discuss the origination and diversification dynamics of the group from a macroevolutionary perspective. PMID:26821567

  11. Automatic classification and accurate size measurement of blank mask defects

    NASA Astrophysics Data System (ADS)

    Bhamidipati, Samir; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2015-07-01

    complexity of defects encountered. The variety arises due to factors such as defect nature, size, shape and composition; and the optical phenomena occurring around the defect. This paper focuses on preliminary characterization results, in terms of classification and size estimation, obtained by Calibre MDPAutoClassify tool on a variety of mask blank defects. It primarily highlights the challenges faced in achieving the results with reference to the variety of defects observed on blank mask substrates and the underlying complexities which make accurate defect size measurement an important and challenging task.

  12. What's in the mix: phylogenetic classification of metagenome sequence samples.

    PubMed

    McHardy, Alice C; Rigoutsos, Isidore

    2007-10-01

    Metagenomics is a novel field which deals with the sequencing and study of microbial organisms or viruses isolated directly from a particular environment. This has already provided a wealth of information and new insights for the inhabitants of various environmental niches. For a given sample, one would like to determine the phylogenetic provenance of the obtained fragments, the relative abundance of its different members, their metabolic capabilities, and the functional properties of the community as a whole. To this end, computational analyses are becoming increasingly indispensable tools. In this review, we focus on the problem of determining the phylogenetic identity of the sample fragments, a procedure known as 'binning'. This step is essential for the reconstruction of the metabolic capabilities of individual organisms or phylogenetic clades of a community, and the study of their interactions.

  13. How accurate are the European Union's classifications of chemical substances.

    PubMed

    Rudén, Christina; Hansson, Sven Ove

    2003-09-30

    The European Commission has decided on harmonized classifications for a large number of individual chemicals according to its own directive for classification and labeling of dangerous substances. We have compared the harmonized classifications for acute oral toxicity to the acute oral toxicity data available in the RTECS database. Of the 992 substances eligible for this comparison, 15% were assigned a too low danger class and 8% a too high danger class according to the RTECS data. Due to insufficient transparency-scientific documentations of the classification decisions are not available-the causes of this discrepancy can only be hypothesized. We propose that the scientific motivations of future classifications be published and that the apparent over- and underclassifications in the present system be either explained or rectified, according to what are the facts in the matter.

  14. Phylogenetic classification of yeasts and related taxa within Pucciniomycotina

    PubMed Central

    Wang, Q.-M.; Yurkov, A.M.; Göker, M.; Lumbsch, H.T.; Leavitt, S.D.; Groenewald, M.; Theelen, B.; Liu, X.-Z.; Boekhout, T.; Bai, F.-Y.

    2016-01-01

    Most small genera containing yeast species in the Pucciniomycotina (Basidiomycota, Fungi) are monophyletic, whereas larger genera including Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces are polyphyletic. With the implementation of the “One Fungus = One Name” nomenclatural principle these polyphyletic genera were revised. Nine genera, namely Bannoa, Cystobasidiopsis, Colacogloea, Kondoa, Erythrobasidium, Rhodotorula, Sporobolomyces, Sakaguchia and Sterigmatomyces, were emended to include anamorphic and teleomorphic species based on the results obtained by a multi-gene phylogenetic analysis, phylogenetic network analyses, branch length-based methods, as well as morphological, physiological and biochemical comparisons. A new class Spiculogloeomycetes is proposed to accommodate the order Spiculogloeales. The new families Buckleyzymaceae with Buckleyzyma gen. nov., Chrysozymaceae with Chrysozyma gen. nov., Microsporomycetaceae with Microsporomyces gen. nov., Ruineniaceae with Ruinenia gen. nov., Symmetrosporaceae with Symmetrospora gen. nov., Colacogloeaceae and Sakaguchiaceae are proposed. The new genera Bannozyma, Buckleyzyma, Fellozyma, Hamamotoa, Hasegawazyma, Jianyunia, Rhodosporidiobolus, Oberwinklerozyma, Phenoliferia, Pseudobensingtonia, Pseudohyphozyma, Sampaiozyma, Slooffia, Spencerozyma, Trigonosporomyces, Udeniozyma, Vonarxula, Yamadamyces and Yunzhangia are proposed to accommodate species segregated from the genera Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Ballistosporomyces is emended and reintroduced to include three Sporobolomyces species of the sasicola clade. A total of 111 new combinations are proposed in this study. PMID:26951631

  15. Phylogenetic relationships and a new classification of the family Cyclopteridae (Perciformes: Cottoidei).

    PubMed

    Oku, Kanami; Imamura, Hisashi; Yabe, Mamoru

    2017-01-16

     Phylogenetic relationships of the family Cyclopteridae were reconstructed based on osteological and external characters.  The monophyly of the family was strongly supported by 47 commonly recognized synapomorphies, including six autapomorphies (plus one additional autapomorphy, presence of a dorsal process on the pelvis, recognized after the phylogenetic analysis) among the suborder Cottoidei.  As a result of the cladistic analysis, a single most parsimonious phylogeny was obtained, based on characters in 32 transformation series.  A new classification of Cyclopteridae based on reconstructed relationships, including three subfamilies [Liparopsinae, Cyclopterinae and Eumicrotreminae (newly established)] and four genera (Aptocyclus, Cyclopsis, Cyclopterus and Eumicrotremus), is proposed.

  16. Accurate Classification of RNA Structures Using Topological Fingerprints

    PubMed Central

    Li, Kejie; Gribskov, Michael

    2016-01-01

    While RNAs are well known to possess complex structures, functionally similar RNAs often have little sequence similarity. While the exact size and spacing of base-paired regions vary, functionally similar RNAs have pronounced similarity in the arrangement, or topology, of base-paired stems. Furthermore, predicted RNA structures often lack pseudoknots (a crucial aspect of biological activity), and are only partially correct, or incomplete. A topological approach addresses all of these difficulties. In this work we describe each RNA structure as a graph that can be converted to a topological spectrum (RNA fingerprint). The set of subgraphs in an RNA structure, its RNA fingerprint, can be compared with the fingerprints of other RNA structures to identify and correctly classify functionally related RNAs. Topologically similar RNAs can be identified even when a large fraction, up to 30%, of the stems are omitted, indicating that highly accurate structures are not necessary. We investigate the performance of the RNA fingerprint approach on a set of eight highly curated RNA families, with diverse sizes and functions, containing pseudoknots, and with little sequence similarity–an especially difficult test set. In spite of the difficult test set, the RNA fingerprint approach is very successful (ROC AUC > 0.95). Due to the inclusion of pseudoknots, the RNA fingerprint approach both covers a wider range of possible structures than methods based only on secondary structure, and its tolerance for incomplete structures suggests that it can be applied even to predicted structures. Source code is freely available at https://github.rcac.purdue.edu/mgribsko/XIOS_RNA_fingerprint. PMID:27755571

  17. The phagotrophic origin of eukaryotes and phylogenetic classification of Protozoa.

    PubMed

    Cavalier-Smith, T

    2002-03-01

    ancestrally biciliate clade, named 'bikonts'. The apparently conflicting rRNA and protein trees can be reconciled with each other and this ultrastructural interpretation if long-branch distortions, some mechanistically explicable, are allowed for. Bikonts comprise two groups: corticoflagellates, with a younger anterior cilium, no centrosomal cone and ancestrally a semi-rigid cell cortex with a microtubular band on either side of the posterior mature centriole; and Rhizaria [a new infrakingdom comprising Cercozoa (now including Ascetosporea classis nov.), Retaria phylum nov., Heliozoa and Apusozoa phylum nov.], having a centrosomal cone or radiating microtubules and two microtubular roots and a soft surface, frequently with reticulopodia. Corticoflagellates comprise photokaryotes (Plantae and chromalveolates, both ancestrally with cortical alveoli) and Excavata (a new protozoan infrakingdom comprising Loukozoa, Discicristata and Archezoa, ancestrally with three microtubular roots). All basal eukaryotic radiations were of mitochondrial aerobes; hydrogenosomes evolved polyphyletically from mitochondria long afterwards, the persistence of their double envelope long after their genomes disappeared being a striking instance of membrane heredity. I discuss the relationship between the 13 protozoan phyla recognized here and revise higher protozoan classification by updating as subkingdoms Lankester's 1878 division of Protozoa into Corticata (Excavata, Alveolata; with prominent cortical microtubules and ancestrally localized cytostome--the Parabasalia probably secondarily internalized the cytoskeleton) and Gymnomyxa [infrakingdoms Sarcomastigota (Choanozoa, Amoebozoa) and Rhizaria; both ancestrally with a non-cortical cytoskeleton of radiating singlet microtubules and a relatively soft cell surface with diffused feeding]. As the eukaryote root almost certainly lies within Gymnomyxa, probably among the Sarcomastigota, Corticata are derived. Following the single symbiogenetic origin of

  18. Phylogeny and phylogenetic classification of the antbirds, ovenbirds, woodcreepers, and allies (Aves: Passeriformes: Infraorder Furnariides)

    USGS Publications Warehouse

    Moyle, R.G.; Chesser, R.T.; Brumfield, R.T.; Tello, J.G.; Marchese, D.J.; Cracraft, J.

    2009-01-01

    The infraorder Furnariides is a diverse group of suboscine passerine birds comprising a substantial component of the Neotropical avifauna. The included species encompass a broad array of morphologies and behaviours, making them appealing for evolutionary studies, but the size of the group (ca. 600 species) has limited well-sampled higher-level phylogenetic studies. Using DNA sequence data from the nuclear RAG-1 and RAG-2 exons, we undertook a phylogenetic analysis of the Furnariides sampling 124 (more than 88%) of the genera. Basal relationships among family-level taxa differed depending on phylogenetic method, but all topologies had little nodal support, mirroring the results from earlier studies in which discerning relationships at the base of the radiation was also difficult. In contrast, branch support for family-rank taxa and for many relationships within those clades was generally high. Our results support the Melanopareidae and Grallariidae as distinct from the Rhinocryptidae and Formicariidae, respectively. Within the Furnariides our data contradict some recent phylogenetic hypotheses and suggest that further study is needed to resolve these discrepancies. Of the few genera represented by multiple species, several were not monophyletic, indicating that additional systematic work remains within furnariine families and must include dense taxon sampling. We use this study as a basis for proposing a new phylogenetic classification for the group and in the process erect new family-group names for clades having high branch support across methods. ?? 2009 The Willi Hennig Society.

  19. Molecular phylogenetic perspectives for character classification and convergence: Framing some issues with nematode vulval appendages and telotylenchid tail termini

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characters flagged as convergent based on newer molecular phylogenetic trees inform both practical identification and more esoteric classification. Nematode morphological characters such as lateral lines, bullae and laciniae are quite independent structures from those similarly named in other organi...

  20. Classification of Phylogenetic Profiles for Protein Function Prediction: An SVM Approach

    NASA Astrophysics Data System (ADS)

    Kotaru, Appala Raju; Joshi, Ramesh C.

    Predicting the function of an uncharacterized protein is a major challenge in post-genomic era due to problems complexity and scale. Having knowledge of protein function is a crucial link in the development of new drugs, better crops, and even the development of biochemicals such as biofuels. Recently numerous high-throughput experimental procedures have been invented to investigate the mechanisms leading to the accomplishment of a protein’s function and Phylogenetic profile is one of them. Phylogenetic profile is a way of representing a protein which encodes evolutionary history of proteins. In this paper we proposed a method for classification of phylogenetic profiles using supervised machine learning method, support vector machine classification along with radial basis function as kernel for identifying functionally linked proteins. We experimentally evaluated the performance of the classifier with the linear kernel, polynomial kernel and compared the results with the existing tree kernel. In our study we have used proteins of the budding yeast saccharomyces cerevisiae genome. We generated the phylogenetic profiles of 2465 yeast genes and for our study we used the functional annotations that are available in the MIPS database. Our experiments show that the performance of the radial basis kernel is similar to polynomial kernel is some functional classes together are better than linear, tree kernel and over all radial basis kernel outperformed the polynomial kernel, linear kernel and tree kernel. In analyzing these results we show that it will be feasible to make use of SVM classifier with radial basis function as kernel to predict the gene functionality using phylogenetic profiles.

  1. How Accurate and Robust Are the Phylogenetic Estimates of Austronesian Language Relationships?

    PubMed Central

    Greenhill, Simon J.; Drummond, Alexei J.; Gray, Russell D.

    2010-01-01

    We recently used computational phylogenetic methods on lexical data to test between two scenarios for the peopling of the Pacific. Our analyses of lexical data supported a pulse-pause scenario of Pacific settlement in which the Austronesian speakers originated in Taiwan around 5,200 years ago and rapidly spread through the Pacific in a series of expansion pulses and settlement pauses. We claimed that there was high congruence between traditional language subgroups and those observed in the language phylogenies, and that the estimated age of the Austronesian expansion at 5,200 years ago was consistent with the archaeological evidence. However, the congruence between the language phylogenies and the evidence from historical linguistics was not quantitatively assessed using tree comparison metrics. The robustness of the divergence time estimates to different calibration points was also not investigated exhaustively. Here we address these limitations by using a systematic tree comparison metric to calculate the similarity between the Bayesian phylogenetic trees and the subgroups proposed by historical linguistics, and by re-estimating the age of the Austronesian expansion using only the most robust calibrations. The results show that the Austronesian language phylogenies are highly congruent with the traditional subgroupings, and the date estimates are robust even when calculated using a restricted set of historical calibrations. PMID:20224774

  2. Accurate and interpretable classification of microspectroscopy pixels using artificial neural networks.

    PubMed

    Manescu, Petru; Jong Lee, Young; Camp, Charles; Cicerone, Marcus; Brady, Mary; Bajcsy, Peter

    2017-04-01

    This paper addresses the problem of classifying materials from microspectroscopy at a pixel level. The challenges lie in identifying discriminatory spectral features and obtaining accurate and interpretable models relating spectra and class labels. We approach the problem by designing a supervised classifier from a tandem of Artificial Neural Network (ANN) models that identify relevant features in raw spectra and achieve high classification accuracy. The tandem of ANN models is meshed with classification rule extraction methods to lower the model complexity and to achieve interpretability of the resulting model. The contribution of the work is in designing each ANN model based on the microspectroscopy hypothesis about a discriminatory feature of a certain target class being composed of a linear combination of spectra. The novelty lies in meshing ANN and decision rule models into a tandem configuration to achieve accurate and interpretable classification results. The proposed method was evaluated using a set of broadband coherent anti-Stokes Raman scattering (BCARS) microscopy cell images (600 000  pixel-level spectra) and a reference four-class rule-based model previously created by biochemical experts. The generated classification rule-based model was on average 85% accurate measured by the DICE pixel label similarity metric, and on average 96% similar to the reference rules measured by the vector cosine metric.

  3. Accurate crop classification using hierarchical genetic fuzzy rule-based systems

    NASA Astrophysics Data System (ADS)

    Topaloglou, Charalampos A.; Mylonas, Stelios K.; Stavrakoudis, Dimitris G.; Mastorocostas, Paris A.; Theocharis, John B.

    2014-10-01

    This paper investigates the effectiveness of an advanced classification system for accurate crop classification using very high resolution (VHR) satellite imagery. Specifically, a recently proposed genetic fuzzy rule-based classification system (GFRBCS) is employed, namely, the Hierarchical Rule-based Linguistic Classifier (HiRLiC). HiRLiC's model comprises a small set of simple IF-THEN fuzzy rules, easily interpretable by humans. One of its most important attributes is that its learning algorithm requires minimum user interaction, since the most important learning parameters affecting the classification accuracy are determined by the learning algorithm automatically. HiRLiC is applied in a challenging crop classification task, using a SPOT5 satellite image over an intensively cultivated area in a lake-wetland ecosystem in northern Greece. A rich set of higher-order spectral and textural features is derived from the initial bands of the (pan-sharpened) image, resulting in an input space comprising 119 features. The experimental analysis proves that HiRLiC compares favorably to other interpretable classifiers of the literature, both in terms of structural complexity and classification accuracy. Its testing accuracy was very close to that obtained by complex state-of-the-art classification systems, such as the support vector machines (SVM) and random forest (RF) classifiers. Nevertheless, visual inspection of the derived classification maps shows that HiRLiC is characterized by higher generalization properties, providing more homogeneous classifications that the competitors. Moreover, the runtime requirements for producing the thematic map was orders of magnitude lower than the respective for the competitors.

  4. Molecular phylogenetic evaluation of classification and scenarios of character evolution in calcareous sponges (Porifera, Class Calcarea).

    PubMed

    Voigt, Oliver; Wülfing, Eilika; Wörheide, Gert

    2012-01-01

    Calcareous sponges (Phylum Porifera, Class Calcarea) are known to be taxonomically difficult. Previous molecular studies have revealed many discrepancies between classically recognized taxa and the observed relationships at the order, family and genus levels; these inconsistencies question underlying hypotheses regarding the evolution of certain morphological characters. Therefore, we extended the available taxa and character set by sequencing the complete small subunit (SSU) rDNA and the almost complete large subunit (LSU) rDNA of additional key species and complemented this dataset by substantially increasing the length of available LSU sequences. Phylogenetic analyses provided new hypotheses about the relationships of Calcarea and about the evolution of certain morphological characters. We tested our phylogeny against competing phylogenetic hypotheses presented by previous classification systems. Our data reject the current order-level classification by again finding non-monophyletic Leucosolenida, Clathrinida and Murrayonida. In the subclass Calcinea, we recovered a clade that includes all species with a cortex, which is largely consistent with the previously proposed order Leucettida. Other orders that had been rejected in the current system were not found, but could not be rejected in our tests either. We found several additional families and genera polyphyletic: the families Leucascidae and Leucaltidae and the genus Leucetta in Calcinea, and in Calcaronea the family Amphoriscidae and the genus Ute. Our phylogeny also provided support for the vaguely suspected close relationship of several members of Grantiidae with giantortical diactines to members of Heteropiidae. Similarly, our analyses revealed several unexpected affinities, such as a sister group relationship between Leucettusa (Leucaltidae) and Leucettidae and between Leucascandra (Jenkinidae) and Sycon carteri (Sycettidae). According to our results, the taxonomy of Calcarea is in desperate need of a

  5. Rapid phylogenetic and functional classification of short genomic fragments with signature peptides

    PubMed Central

    2012-01-01

    Background Classification is difficult for shotgun metagenomics data from environments such as soils, where the diversity of sequences is high and where reference sequences from close relatives may not exist. Approaches based on sequence-similarity scores must deal with the confounding effects that inheritance and functional pressures exert on the relation between scores and phylogenetic distance, while approaches based on sequence alignment and tree-building are typically limited to a small fraction of gene families. We describe an approach based on finding one or more exact matches between a read and a precomputed set of peptide 10-mers. Results At even the largest phylogenetic distances, thousands of 10-mer peptide exact matches can be found between pairs of bacterial genomes. Genes that share one or more peptide 10-mers typically have high reciprocal BLAST scores. Among a set of 403 representative bacterial genomes, some 20 million 10-mer peptides were found to be shared. We assign each of these peptides as a signature of a particular node in a phylogenetic reference tree based on the RNA polymerase genes. We classify the phylogeny of a genomic fragment (e.g., read) at the most specific node on the reference tree that is consistent with the phylogeny of observed signature peptides it contains. Using both synthetic data from four newly-sequenced soil-bacterium genomes and ten real soil metagenomics data sets, we demonstrate a sensitivity and specificity comparable to that of the MEGAN metagenomics analysis package using BLASTX against the NR database. Phylogenetic and functional similarity metrics applied to real metagenomics data indicates a signal-to-noise ratio of approximately 400 for distinguishing among environments. Our method assigns ~6.6 Gbp/hr on a single CPU, compared with 25 kbp/hr for methods based on BLASTX against the NR database. Conclusions Classification by exact matching against a precomputed list of signature peptides provides comparable

  6. Cloning, in Vitro expression, and novel phylogenetic classification of a channel catfish estrogen receptor

    USGS Publications Warehouse

    Xia, Z.; Patino, R.; Gale, W.L.; Maule, A.G.; Densmore, L.D.

    1999-01-01

    We obtained two channel catfish estrogen receptor (ccER) cDNA from liver of female fish using RT–PCR. The two fragments were identical in sequence except that the smaller one had an out-of-frame deletion in the E domain, suggesting the existence of ccER splice variants. The larger fragment was used to screen a cDNA library from liver of a prepubescent female. A cDNA was obtained that encoded a 581-amino-acid ER with a deduced molecular weight of 63.8 kDa. Extracts of COS-7 cells transfected with ccER cDNA bound estrogen with high affinity (Kd = 4.7 nM) and specificity. Maximum parsimony and Neighbor Joining analyses were used to generate a phylogenetic classification of ccER on the basis of 18 full-length ER sequences. The tree suggested the existence of two major ER branches. One branch contained two clearly divergent clades which included all piscine ER (except Japanese eel ER) and all tetrapod ERα, respectively. The second major branch contained the eel ER and the mammalian ERβ. The high degree of divergence between the eel ER and mammalian ERβ suggested that they also represent distinct piscine and tetrapod ER. These data suggest that ERα and ERβ are present throughout vertebrates and that these two major ER types evolved by duplication of an ancestral ER gene. Sequence alignments with other members of the nuclear hormone receptor superfamily indicated the presence of 8 amino acids in the E domain that align exclusively among ER. Four of these amino acids have not received prior research attention and their function is unknown. The novel finding of putative ER splice variants in a nonmammalian vertebrate and the novel phylogenetic classification of ER offer new perspectives in understanding the diversification and function of ER.

  7. A phylum-level phylogenetic classification of zygomycete fungi based on genome-scale data.

    PubMed

    Spatafora, Joseph W; Chang, Ying; Benny, Gerald L; Lazarus, Katy; Smith, Matthew E; Berbee, Mary L; Bonito, Gregory; Corradi, Nicolas; Grigoriev, Igor; Gryganskyi, Andrii; James, Timothy Y; O'Donnell, Kerry; Roberson, Robert W; Taylor, Thomas N; Uehling, Jessie; Vilgalys, Rytas; White, Merlin M; Stajich, Jason E

    2016-09-01

    Zygomycete fungi were classified as a single phylum, Zygomycota, based on sexual reproduction by zygospores, frequent asexual reproduction by sporangia, absence of multicellular sporocarps, and production of coenocytic hyphae, all with some exceptions. Molecular phylogenies based on one or a few genes did not support the monophyly of the phylum, however, and the phylum was subsequently abandoned. Here we present phylogenetic analyses of a genome-scale data set for 46 taxa, including 25 zygomycetes and 192 proteins, and we demonstrate that zygomycetes comprise two major clades that form a paraphyletic grade. A formal phylogenetic classification is proposed herein and includes two phyla, six subphyla, four classes and 16 orders. On the basis of these results, the phyla Mucoromycota and Zoopagomycota are circumscribed. Zoopagomycota comprises Entomophtoromycotina, Kickxellomycotina and Zoopagomycotina; it constitutes the earliest diverging lineage of zygomycetes and contains species that are primarily parasites and pathogens of small animals (e.g. amoeba, insects, etc.) and other fungi, i.e. mycoparasites. Mucoromycota comprises Glomeromycotina, Mortierellomycotina, and Mucoromycotina and is sister to Dikarya. It is the more derived clade of zygomycetes and mainly consists of mycorrhizal fungi, root endophytes, and decomposers of plant material. Evolution of trophic modes, morphology, and analysis of genome-scale data are discussed.

  8. Phylogenetic Classification at Generic Level in the Absence of Distinct Phylogenetic Patterns of Phenotypical Variation: A Case Study in Graphidaceae (Ascomycota)

    PubMed Central

    Parnmen, Sittiporn; Lücking, Robert; Lumbsch, H. Thorsten

    2012-01-01

    Molecular phylogenies often reveal that taxa circumscribed by phenotypical characters are not monophyletic. While re-examination of phenotypical characters often identifies the presence of characters characterizing clades, there is a growing number of studies that fail to identify diagnostic characters, especially in organismal groups lacking complex morphologies. Taxonomists then can either merge the groups or split taxa into smaller entities. Due to the nature of binomial nomenclature, this decision is of special importance at the generic level. Here we propose a new approach to choose among classification alternatives using a combination of morphology-based phylogenetic binning and a multiresponse permutation procedure to test for morphological differences among clades. We illustrate the use of this method in the tribe Thelotremateae focusing on the genus Chapsa, a group of lichenized fungi in which our phylogenetic estimate is in conflict with traditional classification and the morphological and chemical characters do not show a clear phylogenetic pattern. We generated 75 new DNA sequences of mitochondrial SSU rDNA, nuclear LSU rDNA and the protein-coding RPB2. This data set was used to infer phylogenetic estimates using maximum likelihood and Bayesian approaches. The genus Chapsa was found to be polyphyletic, forming four well-supported clades, three of which clustering into one unsupported clade, and the other, supported clade forming two supported subclades. While these clades cannot be readily separated morphologically, the combined binning/multiresponse permutation procedure showed that accepting the four clades as different genera each reflects the phenotypical pattern significantly better than accepting two genera (or five genera if splitting the first clade). Another species within the Thelotremateae, Thelotrema petractoides, a unique taxon with carbonized excipulum resembling Schizotrema, was shown to fall outside Thelotrema. Consequently, the new

  9. Toward a stable classification of genera within the Entolomataceae: a phylogenetic re-evaluation of the Rhodocybe-Clitopilus clade.

    PubMed

    Kluting, Kerri L; Baroni, Timothy J; Bergemann, Sarah E

    2014-01-01

    Despite the recent molecular systematic analyses of the Entolomataceae (Agaricales, Basidiomycota), a robust classification of genera supported by morphological and phylogenetic evidence remains unresolved for this cosmopolitan family of pink-spored fungi. Here, a phylogenetic analysis for one of the two major clades (Rhodocybe-Clitopilus) was conducted using three nuclear protein-coding gene regions, the mitochondrial ATP synthase subunit 6 (atp6), the nuclear RNA polymerase subunit II (rpb2) and the nuclear translation elongation factor subunit 1-α (tef1). Five monophyletic groups are resolved with strong statistical support and a set of morphological features for delineation of genera is presented. In the revised classification proposed here, Clitopilus is retained, Rhodocybe is emended, two genera previously accepted as synonyms of Rhodocybe (Clitopilopsis and Rhodophana) are resurrected and Clitocella is described as new.

  10. Accurate Detection of Dysmorphic Nuclei Using Dynamic Programming and Supervised Classification.

    PubMed

    Verschuuren, Marlies; De Vylder, Jonas; Catrysse, Hannes; Robijns, Joke; Philips, Wilfried; De Vos, Winnok H

    2017-01-01

    A vast array of pathologies is typified by the presence of nuclei with an abnormal morphology. Dysmorphic nuclear phenotypes feature dramatic size changes or foldings, but also entail much subtler deviations such as nuclear protrusions called blebs. Due to their unpredictable size, shape and intensity, dysmorphic nuclei are often not accurately detected in standard image analysis routines. To enable accurate detection of dysmorphic nuclei in confocal and widefield fluorescence microscopy images, we have developed an automated segmentation algorithm, called Blebbed Nuclei Detector (BleND), which relies on two-pass thresholding for initial nuclear contour detection, and an optimal path finding algorithm, based on dynamic programming, for refining these contours. Using a robust error metric, we show that our method matches manual segmentation in terms of precision and outperforms state-of-the-art nuclear segmentation methods. Its high performance allowed for building and integrating a robust classifier that recognizes dysmorphic nuclei with an accuracy above 95%. The combined segmentation-classification routine is bound to facilitate nucleus-based diagnostics and enable real-time recognition of dysmorphic nuclei in intelligent microscopy workflows.

  11. GPD: a graph pattern diffusion kernel for accurate graph classification with applications in cheminformatics.

    PubMed

    Smalter, Aaron; Huan, Jun Luke; Jia, Yi; Lushington, Gerald

    2010-01-01

    Graph data mining is an active research area. Graphs are general modeling tools to organize information from heterogeneous sources and have been applied in many scientific, engineering, and business fields. With the fast accumulation of graph data, building highly accurate predictive models for graph data emerges as a new challenge that has not been fully explored in the data mining community. In this paper, we demonstrate a novel technique called graph pattern diffusion (GPD) kernel. Our idea is to leverage existing frequent pattern discovery methods and to explore the application of kernel classifier (e.g., support vector machine) in building highly accurate graph classification. In our method, we first identify all frequent patterns from a graph database. We then map subgraphs to graphs in the graph database and use a process we call "pattern diffusion" to label nodes in the graphs. Finally, we designed a graph alignment algorithm to compute the inner product of two graphs. We have tested our algorithm using a number of chemical structure data. The experimental results demonstrate that our method is significantly better than competing methods such as those kernel functions based on paths, cycles, and subgraphs.

  12. Accurate Detection of Dysmorphic Nuclei Using Dynamic Programming and Supervised Classification

    PubMed Central

    Verschuuren, Marlies; De Vylder, Jonas; Catrysse, Hannes; Robijns, Joke; Philips, Wilfried

    2017-01-01

    A vast array of pathologies is typified by the presence of nuclei with an abnormal morphology. Dysmorphic nuclear phenotypes feature dramatic size changes or foldings, but also entail much subtler deviations such as nuclear protrusions called blebs. Due to their unpredictable size, shape and intensity, dysmorphic nuclei are often not accurately detected in standard image analysis routines. To enable accurate detection of dysmorphic nuclei in confocal and widefield fluorescence microscopy images, we have developed an automated segmentation algorithm, called Blebbed Nuclei Detector (BleND), which relies on two-pass thresholding for initial nuclear contour detection, and an optimal path finding algorithm, based on dynamic programming, for refining these contours. Using a robust error metric, we show that our method matches manual segmentation in terms of precision and outperforms state-of-the-art nuclear segmentation methods. Its high performance allowed for building and integrating a robust classifier that recognizes dysmorphic nuclei with an accuracy above 95%. The combined segmentation-classification routine is bound to facilitate nucleus-based diagnostics and enable real-time recognition of dysmorphic nuclei in intelligent microscopy workflows. PMID:28125723

  13. Phylogenetic classification of Aureobasidium pullulans strains for production of feruloyl esterase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to phylogenetically classify diverse strains of A. pullulans and determine their production of feruloyl esterase. Seventeen strains from the A. pullulans literature were phylogenetically classified. Phenotypic traits of color variation and endo-ß-1,4-xylanase overproduction were as...

  14. Molecular and morphological data supporting phylogenetic reconstruction of the genus Goniothalamus (Annonaceae), including a reassessment of previous infrageneric classifications

    PubMed Central

    Tang, Chin Cheung; Thomas, Daniel C.; Saunders, Richard M.K.

    2015-01-01

    Data is presented in support of a phylogenetic reconstruction of the species-rich early-divergent angiosperm genus Goniothalamus (Annonaceae) (Tang et al., Mol. Phylogenetic Evol., 2015) [1], inferred using chloroplast DNA (cpDNA) sequences. The data includes a list of primers for amplification and sequencing for nine cpDNA regions: atpB-rbcL, matK, ndhF, psbA-trnH, psbM-trnD, rbcL, trnL-F, trnS-G, and ycf1, the voucher information and molecular data (GenBank accession numbers) of 67 ingroup Goniothalamus accessions and 14 outgroup accessions selected from across the tribe Annoneae, and aligned data matrices for each gene region. We also present our Bayesian phylogenetic reconstructions for Goniothalamus, with information on previous infrageneric classifications superimposed to enable an evaluation of monophyly, together with a taxon-character data matrix (with 15 morphological characters scored for 66 Goniothalamus species and seven other species from the tribe Annoneae that are shown to be phylogenetically correlated). PMID:26286044

  15. Molecular and morphological data supporting phylogenetic reconstruction of the genus Goniothalamus (Annonaceae), including a reassessment of previous infrageneric classifications.

    PubMed

    Tang, Chin Cheung; Thomas, Daniel C; Saunders, Richard M K

    2015-09-01

    Data is presented in support of a phylogenetic reconstruction of the species-rich early-divergent angiosperm genus Goniothalamus (Annonaceae) (Tang et al., Mol. Phylogenetic Evol., 2015) [1], inferred using chloroplast DNA (cpDNA) sequences. The data includes a list of primers for amplification and sequencing for nine cpDNA regions: atpB-rbcL, matK, ndhF, psbA-trnH, psbM-trnD, rbcL, trnL-F, trnS-G, and ycf1, the voucher information and molecular data (GenBank accession numbers) of 67 ingroup Goniothalamus accessions and 14 outgroup accessions selected from across the tribe Annoneae, and aligned data matrices for each gene region. We also present our Bayesian phylogenetic reconstructions for Goniothalamus, with information on previous infrageneric classifications superimposed to enable an evaluation of monophyly, together with a taxon-character data matrix (with 15 morphological characters scored for 66 Goniothalamus species and seven other species from the tribe Annoneae that are shown to be phylogenetically correlated).

  16. Photometric brown-dwarf classification. I. A method to identify and accurately classify large samples of brown dwarfs without spectroscopy

    NASA Astrophysics Data System (ADS)

    Skrzypek, N.; Warren, S. J.; Faherty, J. K.; Mortlock, D. J.; Burgasser, A. J.; Hewett, P. C.

    2015-02-01

    Aims: We present a method, named photo-type, to identify and accurately classify L and T dwarfs onto the standard spectral classification system using photometry alone. This enables the creation of large and deep homogeneous samples of these objects efficiently, without the need for spectroscopy. Methods: We created a catalogue of point sources with photometry in 8 bands, ranging from 0.75 to 4.6 μm, selected from an area of 3344 deg2, by combining SDSS, UKIDSS LAS, and WISE data. Sources with 13.0 0.8, were then classified by comparison against template colours of quasars, stars, and brown dwarfs. The L and T templates, spectral types L0 to T8, were created by identifying previously known sources with spectroscopic classifications, and fitting polynomial relations between colour and spectral type. Results: Of the 192 known L and T dwarfs with reliable photometry in the surveyed area and magnitude range, 189 are recovered by our selection and classification method. We have quantified the accuracy of the classification method both externally, with spectroscopy, and internally, by creating synthetic catalogues and accounting for the uncertainties. We find that, brighter than J = 17.5, photo-type classifications are accurate to one spectral sub-type, and are therefore competitive with spectroscopic classifications. The resultant catalogue of 1157 L and T dwarfs will be presented in a companion paper.

  17. Phylogenetic systematics and a revised generic classification of anthidiine bees (Hymenoptera: Megachile)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bee tribe Anthidiini (Hymenoptera: Megachilidae) is a large, cosmopolitan group of solitary bees that exhibit intriguing nesting behavior. We present the first molecular-based phylogenetic analysis of relationships within Anthidiini using model based methods and a large, multi-locus dataset (fiv...

  18. Impact of recent molecular phylogenetic studies on classification of ascomycete yeasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analyses of concatenated gene sequences as well as whole genome sequences are resolving relationships among the ascomycete yeasts (Saccharomycotina), thus allowing classification of members of this subphylum to be based on phylogeny. In addition, changes implemented in the new Botanical Code [Intern...

  19. Phylogenetic classification of the frog pathogen Amphibiothecum (Dermosporidium) penneri based on small ribosomal subunit sequencing

    USGS Publications Warehouse

    Feldman, S.H.; Wimsatt, J.H.; Green, D.E.

    2005-01-01

    We determined 1,600 base pairs of DNA sequence in the 18S small ribosomal subunit from two geographically distinct isolates of Dermosporidium penneri. Maximum likelihood and parsimony analysis of these sequences place D. penneri in the order Dermocystida of the class Mesomycetozoea. The 18S rRNA sequences from these two isolates only differ within a single region of 16 contiguous nucleotides. Based on the distant phylogenetic relationship of these organisms to Amphibiocystidium ranae and similarity to Sphaerothecum destruens we propose the organism be renamed Amphibiothecum penneri.

  20. Chemical classification of cattle. 2. Phylogenetic tree and specific status of the Zebu.

    PubMed

    Manwell, C; Baker, C M

    1980-01-01

    Phylogenetic trees for the ten major breed groups of cattle were constructed by Farris's (1972) maximum parsimony method, or Fitch & Margoliash's (1967) method, which averages ou the deviation over the entire assemblage. Both techniques yield essentially identical trees. The phylogenetic tree for the ten major cattle breed groups can be superimposed on a map of Europe and western Asia, the root of the tree being close to the 'fertile crescent' in Asia Minor, believed to be a primary centre of bovine domestication. For some but not all protein variants there is a cline of gene frequencies as one proceeds from the British Isles and northwest Europe towards southeast Europe and Asia Minor, with the most extreme gene frequencies in the Zebu breeds of India. It is not clear to what extent the observed clines are primary or secondary, i.e., consequent to the initial migrations of cattle towards the end of the Pleistocene or consequent to the many migrations of man with his domesticated cattle. Such clines as exist are not in themselves sufficient to prove either selection versus genetic drift or to establish taxonomic ranking. Contrary to some suggestions in the literature, the biochemical evidence supports Linnaeus's original conclusions: Bos taurus and Bos indicus are distinct species.

  1. Archaeal-eubacterial mergers in the origin of Eukarya: phylogenetic classification of life.

    PubMed Central

    Margulis, L

    1996-01-01

    A symbiosis-based phylogeny leads to a consistent, useful classification system for all life. "Kingdoms" and "Domains" are replaced by biological names for the most inclusive taxa: Prokarya (bacteria) and Eukarya (symbiosis-derived nucleated organisms). The earliest Eukarya, anaerobic mastigotes, hypothetically originated from permanent whole-cell fusion between members of Archaea (e.g., Thermoplasma-like organisms) and of Eubacteria (e.g., Spirochaeta-like organisms). Molecular biology, life-history, and fossil record evidence support the reunification of bacteria as Prokarya while subdividing Eukarya into uniquely defined subtaxa: Protoctista, Animalia, Fungi, and Plantae. Images Fig. 1 PMID:8577716

  2. Archaeal-eubacterial mergers in the origin of Eukarya: phylogenetic classification of life.

    PubMed

    Margulis, L

    1996-02-06

    A symbiosis-based phylogeny leads to a consistent, useful classification system for all life. "Kingdoms" and "Domains" are replaced by biological names for the most inclusive taxa: Prokarya (bacteria) and Eukarya (symbiosis-derived nucleated organisms). The earliest Eukarya, anaerobic mastigotes, hypothetically originated from permanent whole-cell fusion between members of Archaea (e.g., Thermoplasma-like organisms) and of Eubacteria (e.g., Spirochaeta-like organisms). Molecular biology, life-history, and fossil record evidence support the reunification of bacteria as Prokarya while subdividing Eukarya into uniquely defined subtaxa: Protoctista, Animalia, Fungi, and Plantae.

  3. Archaeal-eubacterial mergers in the origin of Eukarya: phylogenetic classification of life

    NASA Technical Reports Server (NTRS)

    Margulis, L.

    1996-01-01

    A symbiosis-based phylogeny leads to a consistent, useful classification system for all life. "Kingdoms" and "Domains" are replaced by biological names for the most inclusive taxa: Prokarya (bacteria) and Eukarya (symbiosis-derived nucleated organisms). The earliest Eukarya, anaerobic mastigotes, hypothetically originated from permanent whole-cell fusion between members of Archaea (e.g., Thermoplasma-like organisms) and of Eubacteria (e.g., Spirochaeta-like organisms). Molecular biology, life-history, and fossil record evidence support the reunification of bacteria as Prokarya while subdividing Eukarya into uniquely defined subtaxa: Protoctista, Animalia, Fungi, and Plantae.

  4. Classification algorithms with multi-modal data fusion could accurately distinguish neuromyelitis optica from multiple sclerosis.

    PubMed

    Eshaghi, Arman; Riyahi-Alam, Sadjad; Saeedi, Roghayyeh; Roostaei, Tina; Nazeri, Arash; Aghsaei, Aida; Doosti, Rozita; Ganjgahi, Habib; Bodini, Benedetta; Shakourirad, Ali; Pakravan, Manijeh; Ghana'ati, Hossein; Firouznia, Kavous; Zarei, Mojtaba; Azimi, Amir Reza; Sahraian, Mohammad Ali

    2015-01-01

    Neuromyelitis optica (NMO) exhibits substantial similarities to multiple sclerosis (MS) in clinical manifestations and imaging results and has long been considered a variant of MS. With the advent of a specific biomarker in NMO, known as anti-aquaporin 4, this assumption has changed; however, the differential diagnosis remains challenging and it is still not clear whether a combination of neuroimaging and clinical data could be used to aid clinical decision-making. Computer-aided diagnosis is a rapidly evolving process that holds great promise to facilitate objective differential diagnoses of disorders that show similar presentations. In this study, we aimed to use a powerful method for multi-modal data fusion, known as a multi-kernel learning and performed automatic diagnosis of subjects. We included 30 patients with NMO, 25 patients with MS and 35 healthy volunteers and performed multi-modal imaging with T1-weighted high resolution scans, diffusion tensor imaging (DTI) and resting-state functional MRI (fMRI). In addition, subjects underwent clinical examinations and cognitive assessments. We included 18 a priori predictors from neuroimaging, clinical and cognitive measures in the initial model. We used 10-fold cross-validation to learn the importance of each modality, train and finally test the model performance. The mean accuracy in differentiating between MS and NMO was 88%, where visible white matter lesion load, normal appearing white matter (DTI) and functional connectivity had the most important contributions to the final classification. In a multi-class classification problem we distinguished between all of 3 groups (MS, NMO and healthy controls) with an average accuracy of 84%. In this classification, visible white matter lesion load, functional connectivity, and cognitive scores were the 3 most important modalities. Our work provides preliminary evidence that computational tools can be used to help make an objective differential diagnosis of NMO and MS.

  5. Automatic phylogenetic classification of bacterial beta-lactamase sequences including structural and antibiotic substrate preference information.

    PubMed

    Ma, Jianmin; Eisenhaber, Frank; Maurer-Stroh, Sebastian

    2013-12-01

    Beta lactams comprise the largest and still most effective group of antibiotics, but bacteria can gain resistance through different beta lactamases that can degrade these antibiotics. We developed a user friendly tree building web server that allows users to assign beta lactamase sequences to their respective molecular classes and subclasses. Further clinically relevant information includes if the gene is typically chromosomal or transferable through plasmids as well as listing the antibiotics which the most closely related reference sequences are known to target and cause resistance against. This web server can automatically build three phylogenetic trees: the first tree with closely related sequences from a Tachyon search against the NCBI nr database, the second tree with curated reference beta lactamase sequences, and the third tree built specifically from substrate binding pocket residues of the curated reference beta lactamase sequences. We show that the latter is better suited to recover antibiotic substrate assignments through nearest neighbor annotation transfer. The users can also choose to build a structural model for the query sequence and view the binding pocket residues of their query relative to other beta lactamases in the sequence alignment as well as in the 3D structure relative to bound antibiotics. This web server is freely available at http://blac.bii.a-star.edu.sg/.

  6. Number of signatures necessary for accurate classification. [for multispectral scanner data

    NASA Technical Reports Server (NTRS)

    Richardson, W.; Pentland, A.; Crane, R.; Horwitz, H.

    1976-01-01

    This paper presents a procedure for determining the number of signatures to use in classifying multispectral scanner data. A large initial set of signatures is obtained by clustering the training points within each category (such as 'wheat' or 'other') to be recognized. These clusters are then combined into broader signatures by a program that considers each pair of signatures within a category, combines the best pair in the light of certain criteria, saves the combined signature and repeats the procedure until there is one signature for each category. The result is a collection of sets of signatures, one set for each number between the number of initial clusters and the number of categories. With the aid of statistics such as an estimate of the probability of misclassification between categories, the user can choose the smallest set satisfying his requirements for classification accuracy.

  7. Expression analysis of LIM gene family in poplar, toward an updated phylogenetic classification

    PubMed Central

    2012-01-01

    Background Plant LIM domain proteins may act as transcriptional activators of lignin biosynthesis and/or as actin binding and bundling proteins. Plant LIM genes have evolved in phylogenetic subgroups differing in their expression profiles: in the whole plant or specifically in pollen. However, several poplar PtLIM genes belong to uncharacterized monophyletic subgroups and the expression patterns of the LIM gene family in a woody plant have not been studied. Findings In this work, the expression pattern of the twelve duplicated poplar PtLIM genes has been investigated by semi quantitative RT-PCR in different vegetative and reproductive tissues. As in other plant species, poplar PtLIM genes were widely expressed in the tree or in particular tissues. Especially, PtXLIM1a, PtXLIM1b and PtWLIM1b genes were preferentially expressed in the secondary xylem, suggesting a specific function in wood formation. Moreover, the expression of these genes and of the PtPLIM2a gene was increased in tension wood. Western-blot analysis confirmed the preferential expression of PtXLIM1a protein during xylem differentiation and tension wood formation. Genes classified within the pollen specific PLIM2 and PLIM2-like subgroups were all strongly expressed in pollen but also in cottony hairs. Interestingly, pairs of duplicated PtLIM genes exhibited different expression patterns indicating subfunctionalisations in specific tissues. Conclusions The strong expression of several LIM genes in cottony hairs and germinating pollen, as well as in xylem fibers suggests an involvement of plant LIM domain proteins in the control of cell expansion. Comparisons of expression profiles of poplar LIM genes with the published functions of closely related plant LIM genes suggest conserved functions in the areas of lignin biosynthesis, pollen tube growth and mechanical stress response. Based on these results, we propose a novel nomenclature of poplar LIM domain proteins. PMID:22339987

  8. Deceptive Desmas: Molecular Phylogenetics Suggests a New Classification and Uncovers Convergent Evolution of Lithistid Demosponges

    PubMed Central

    Schuster, Astrid; Erpenbeck, Dirk; Pisera, Andrzej; Hooper, John; Bryce, Monika; Fromont, Jane; Wörheide, Gert

    2015-01-01

    Reconciling the fossil record with molecular phylogenies to enhance the understanding of animal evolution is a challenging task, especially for taxa with a mostly poor fossil record, such as sponges (Porifera). ‘Lithistida’, a polyphyletic group of recent and fossil sponges, are an exception as they provide the richest fossil record among demosponges. Lithistids, currently encompassing 13 families, 41 genera and >300 recent species, are defined by the common possession of peculiar siliceous spicules (desmas) that characteristically form rigid articulated skeletons. Their phylogenetic relationships are to a large extent unresolved and there has been no (taxonomically) comprehensive analysis to formally reallocate lithistid taxa to their closest relatives. This study, based on the most comprehensive molecular and morphological investigation of ‘lithistid’ demosponges to date, corroborates some previous weakly-supported hypotheses, and provides novel insights into the evolutionary relationships of the previous ‘order Lithistida’. Based on molecular data (partial mtDNA CO1 and 28S rDNA sequences), we show that 8 out of 13 ‘Lithistida’ families belong to the order Astrophorida, whereas Scleritodermidae and Siphonidiidae form a separate monophyletic clade within Tetractinellida. Most lithistid astrophorids are dispersed between different clades of the Astrophorida and we propose to formally reallocate them, respectively. Corallistidae, Theonellidae and Phymatellidae are monophyletic, whereas the families Pleromidae and Scleritodermidae are polyphyletic. Family Desmanthidae is polyphyletic and groups within Halichondriidae – we formally propose a reallocation. The sister group relationship of the family Vetulinidae to Spongillida is confirmed and we propose here for the first time to include Vetulina into a new Order Sphaerocladina. Megascleres and microscleres possibly evolved and/or were lost several times independently in different

  9. The International Classification of Headache Disorders: accurate diagnosis of orofacial pain?

    PubMed

    Benoliel, R; Birman, N; Eliav, E; Sharav, Y

    2008-07-01

    The aim was to apply diagnostic criteria, as published by the International Headache Society (IHS), to the diagnosis of orofacial pain. A total of 328 consecutive patients with orofacial pain were collected over a period of 2 years. The orofacial pain clinic routinely employs criteria published by the IHS, the American Academy of Orofacial Pain (AAOP) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDCTMD). Employing IHS criteria, 184 patients were successfully diagnosed (56%), including 34 with persistent idiopathic facial pain. In the remaining 144 we applied AAOP/RDCTMD criteria and diagnosed 120 as masticatory myofascial pain (MMP) resulting in a diagnostic efficiency of 92.7% (304/328) when applying the three classifications (IHS, AAOP, RDCTMD). Employing further published criteria, 23 patients were diagnosed as neurovascular orofacial pain (NVOP, facial migraine) and one as a neuropathy secondary to connective tissue disease. All the patients were therefore allocated to predefined diagnoses. MMP is clearly defined by AAOP and the RDCTMD. However, NVOP is not defined by any of the above classification systems. The features of MMP and NVOP are presented and analysed with calculations for positive (PPV) and negative predictive values (NPV). In MMP the combination of facial pain aggravated by jaw movement, and the presence of three or more tender muscles resulted in a PPV = 0.82 and a NPV = 0.86. For NVOP the combination of facial pain, throbbing quality, autonomic and/or systemic features and attack duration of > 60 min gave a PPV = 0.71 and a NPV = 0.95. Expansion of the IHS system is needed so as to integrate more orofacial pain syndromes.

  10. Comparative Analysis of Phylogenetic Assignment of Human and Avian ExPEC and Fecal Commensal Escherichia coli Using the (Previous and Revised) Clermont Phylogenetic Typing Methods and its Impact on Avian Pathogenic Escherichia coli (APEC) Classification.

    PubMed

    Logue, Catherine M; Wannemuehler, Yvonne; Nicholson, Bryon A; Doetkott, Curt; Barbieri, Nicolle L; Nolan, Lisa K

    2017-01-01

    The Clermont scheme has been used for subtyping of Escherichia coli since it was initially described in early 2000. Since then, researchers have used the scheme to type and sub-type commensal E. coli and pathogenic E. coli, such as extraintestinal pathogenic E. coli (ExPEC), and compare their phylogenetic assignment by pathogenicity, serogroup, distribution among ExPEC of different host species and complement of virulence and resistance traits. Here, we compare assignments of human and avian ExPEC and commensal E. coli using the old and revised Clermont schemes to determine if the new scheme provides a refined snapshot of isolate classification. 1,996 E. coli from human hosts and poultry, including 84 human neonatal meningitis E. coli isolates, 88 human vaginal E. coli, 696 human uropathogenic E. coli, 197 healthy human fecal E. coli, 452 avian pathogenic E. coli (APEC), 200 retail poultry E. coli, 80 crop and gizzard E. coli from healthy poultry at slaughter and 199 fecal E. coli from healthy birds at slaughter. All isolates were subject to phylogenetic analysis using the Clermont et al. (2000, 2013) schemes and compared to determine the effect of the new classification on strain designation. Most of the isolates' strain designation remained where they were originally assigned. Greatest designation change occurred in APEC where 53.8% of isolates were reclassified; while classification rates among human strains ranged from 8 to 14%. However, some significant changes were observed for UPEC associated strains with significant (P < 0.05) designation changes observed from A to C and D to E or F phylogenetic types; a similar designation change was noted among NMEC for D to F designation change. Among the APEC significant designation changes were observed from A to C and D to E and F. These studies suggest that the new scheme provides a tighter and more meaningful definition of some ExPEC; while the new typing scheme has a significant impact on APEC classification. A

  11. Comparative Analysis of Phylogenetic Assignment of Human and Avian ExPEC and Fecal Commensal Escherichia coli Using the (Previous and Revised) Clermont Phylogenetic Typing Methods and its Impact on Avian Pathogenic Escherichia coli (APEC) Classification

    PubMed Central

    Logue, Catherine M.; Wannemuehler, Yvonne; Nicholson, Bryon A.; Doetkott, Curt; Barbieri, Nicolle L.; Nolan, Lisa K.

    2017-01-01

    The Clermont scheme has been used for subtyping of Escherichia coli since it was initially described in early 2000. Since then, researchers have used the scheme to type and sub-type commensal E. coli and pathogenic E. coli, such as extraintestinal pathogenic E. coli (ExPEC), and compare their phylogenetic assignment by pathogenicity, serogroup, distribution among ExPEC of different host species and complement of virulence and resistance traits. Here, we compare assignments of human and avian ExPEC and commensal E. coli using the old and revised Clermont schemes to determine if the new scheme provides a refined snapshot of isolate classification. 1,996 E. coli from human hosts and poultry, including 84 human neonatal meningitis E. coli isolates, 88 human vaginal E. coli, 696 human uropathogenic E. coli, 197 healthy human fecal E. coli, 452 avian pathogenic E. coli (APEC), 200 retail poultry E. coli, 80 crop and gizzard E. coli from healthy poultry at slaughter and 199 fecal E. coli from healthy birds at slaughter. All isolates were subject to phylogenetic analysis using the Clermont et al. (2000, 2013) schemes and compared to determine the effect of the new classification on strain designation. Most of the isolates’ strain designation remained where they were originally assigned. Greatest designation change occurred in APEC where 53.8% of isolates were reclassified; while classification rates among human strains ranged from 8 to 14%. However, some significant changes were observed for UPEC associated strains with significant (P < 0.05) designation changes observed from A to C and D to E or F phylogenetic types; a similar designation change was noted among NMEC for D to F designation change. Among the APEC significant designation changes were observed from A to C and D to E and F. These studies suggest that the new scheme provides a tighter and more meaningful definition of some ExPEC; while the new typing scheme has a significant impact on APEC classification. A

  12. Towards a phylogenetic generic classification of Thelypteridaceae: Additional sampling suggests alterations of neotropical taxa and further study of paleotropical genera.

    PubMed

    Almeida, Thaís Elias; Hennequin, Sabine; Schneider, Harald; Smith, Alan R; Batista, João Aguiar Nogueira; Ramalho, Aline Joseph; Proite, Karina; Salino, Alexandre

    2016-01-01

    Thelypteridaceae is one of the largest fern families, having about 950 species and a cosmopolitan distribution but with most species occurring in tropical and subtropical regions. Its generic classification remains controversial, with different authors recognizing from one up to 32 genera. Phylogenetic relationships within the family have not been exhaustively studied, but previous studies have confirmed the monophyly of the lineage. Thus far, sampling has been inadequate for establishing a robust hypothesis of infrafamilial relationships within the family. In order to understand phylogenetic relationships within Thelypteridaceae and thus to improve generic reclassification, we expand the molecular sampling, including new samples of Old World taxa and, especially, many additional neotropical representatives. We also explore the monophyly of exclusively or mostly neotropical genera Amauropelta, Goniopteris, Meniscium, and Steiropteris. Our sampling includes 68 taxa and 134 newly generated sequences from two plastid genomic regions (rps4-trnS and trnL-trnF), plus 73 rps4 and 72 trnL-trnF sequences from GenBank. These data resulted in a concatenated matrix of 1980 molecular characters for 149 taxa. The combined data set was analyzed using maximum parsimony and bayesian inference of phylogeny. Our results are consistent with the general topological structure found in previous studies, including two main lineages within the family: phegopteroid and thelypteroid. The thelypteroid lineage comprises two clades; one of these included the segregates Metathelypteris, Coryphopteris, and Amauropelta (including part of Parathelypteris), whereas the other comprises all segregates of Cyclosorus s.l., such as Goniopteris, Meniscium, and Steiropteris (including Thelypteris polypodioides, previously incertae sedis). The three mainly neotropical segregates were found to be monophyletic but nested in a broadly defined Cyclosorus. The fourth mainly neotropical segregate, Amauropelta

  13. Phylogenetic analysis of the main neutralization and hemagglutination determinants of all human adenovirus prototypes as a basis for molecular classification and taxonomy.

    PubMed

    Madisch, Ijad; Harste, Gabi; Pommer, Heidi; Heim, Albert

    2005-12-01

    Human adenoviruses (HAdV) are responsible for a wide spectrum of diseases. The neutralization epsilon determinant (loops 1 and 2) and the hemagglutination gamma determinant are relevant for the taxonomy of HAdV. Precise type identification of HAdV prototypes is crucial for detection of infection chains and epidemiology. epsilon and gamma determinant sequences of all 51 HAdV were generated to propose molecular classification criteria. Phylogenetic analysis of epsilon determinant sequences demonstrated sufficient genetic divergence for molecular classification, with the exception of HAdV-15 and HAdV-29, which also cannot be differentiated by classical cross-neutralization. Precise sequence divergence criteria for typing (<2.5% from loop 2 prototype sequence and <2.4% from loop 1 sequence) were deduced from phylogenetic analysis. These criteria may also facilitate identification of new HAdV prototypes. Fiber knob (gamma determinant) phylogeny indicated a two-step model of species evolution and multiple intraspecies recombination events in the origin of HAdV prototypes. HAdV-29 was identified as a recombination variant of HAdV-15 (epsilon determinant) and a speculative, not-yet-isolated HAdV prototype (gamma determinant). Subanalysis of molecular evolution in hypervariable regions 1 to 6 of the epsilon determinant indicated different selective pressures in subclusters of species HAdV-D. Additionally, gamma determinant phylogenetic analysis demonstrated that HAdV-8 did not cluster with -19 and -37 in spite of their having the same tissue tropism. The phylogeny of HAdV-E4 suggested origination by interspecies recombination between HAdV-B (hexon) and HAdV-C (fiber), as in simian adenovirus 25, indicating additional zoonotic transfer. In conclusion, molecular classification by systematic sequence analysis of immunogenic determinants yields new insights into HAdV phylogeny and evolution.

  14. A comprehensive multilocus phylogeny of the Neotropical cotingas (Cotingidae, Aves) with a comparative evolutionary analysis of breeding system and plumage dimorphism and a revised phylogenetic classification.

    PubMed

    Berv, Jacob S; Prum, Richard O

    2014-12-01

    The Neotropical cotingas (Cotingidae: Aves) are a group of passerine birds that are characterized by extreme diversity in morphology, ecology, breeding system, and behavior. Here, we present a comprehensive phylogeny of the Neotropical cotingas based on six nuclear and mitochondrial loci (∼7500 bp) for a sample of 61 cotinga species in all 25 genera, and 22 species of suboscine outgroups. Our taxon sample more than doubles the number of cotinga species studied in previous analyses, and allows us to test the monophyly of the cotingas as well as their intrageneric relationships with high resolution. We analyze our genetic data using a Bayesian species tree method, and concatenated Bayesian and maximum likelihood methods, and present a highly supported phylogenetic hypothesis. We confirm the monophyly of the cotingas, and present the first phylogenetic evidence for the relationships of Phibalura flavirostris as the sister group to Ampelion and Doliornis, and the paraphyly of Lipaugus with respect to Tijuca. In addition, we resolve the diverse radiations within the Cotinga, Lipaugus, Pipreola, and Procnias genera. We find no support for Darwin's (1871) hypothesis that the increase in sexual selection associated with polygynous breeding systems drives the evolution of color dimorphism in the cotingas, at least when analyzed at a broad categorical scale. Finally, we present a new comprehensive phylogenetic classification of all cotinga species.

  15. Analysis of genetic diversity in banana cultivars (Musa cvs.) from the South of Oman using AFLP markers and classification by phylogenetic, hierarchical clustering and principal component analyses.

    PubMed

    Opara, Umezuruike Linus; Jacobson, Dan; Al-Saady, Nadiya Abubakar

    2010-05-01

    Banana is an important crop grown in Oman and there is a dearth of information on its genetic diversity to assist in crop breeding and improvement programs. This study employed amplified fragment length polymorphism (AFLP) to investigate the genetic variation in local banana cultivars from the southern region of Oman. Using 12 primer combinations, a total of 1094 bands were scored, of which 1012 were polymorphic. Eighty-two unique markers were identified, which revealed the distinct separation of the seven cultivars. The results obtained show that AFLP can be used to differentiate the banana cultivars. Further classification by phylogenetic, hierarchical clustering and principal component analyses showed significant differences between the clusters found with molecular markers and those clusters created by previous studies using morphological analysis. Based on the analytical results, a consensus dendrogram of the banana cultivars is presented.

  16. Classification

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2013-01-01

    In this article, Renee Clary and James Wandersee describe the beginnings of "Classification," which lies at the very heart of science and depends upon pattern recognition. Clary and Wandersee approach patterns by first telling the story of the "Linnaean classification system," introduced by Carl Linnacus (1707-1778), who is…

  17. Phylogenetic inference rejects sporophyte based classification of the Funariaceae (Bryophyta): rapid radiation suggests rampant homoplasy in sporophyte evolution.

    PubMed

    Liu, Yang; Budke, Jessica M; Goffinet, Bernard

    2012-01-01

    The moss family Funariaceae, which includes the model systems Funaria hygrometrica and Physcomitrella patens, comprises 15 genera, of which three accommodate approximately 95% of the 250-400 species. Generic concepts are drawn primarily from patterns in the diversity of morphological complexity of the sporophyte. Phylogenetic inferences from ten loci sampled across the three genomic compartments yield a hypothesis that is incompatible with the current circumscription of two of the speciose genera of the Funariaceae. The single clade, comprising exemplars of Funaria with a compound annulus, is congruent with the systematic concept proposed by Fife (1985). By contrast, Entosthodon and Physcomitrium are resolved as polyphyletic entities, and even the three species of Physcomitrella are confirmed to have diverged from distinct ancestors. Although the backbone relationships within the core clade of the Funariaceae remain unresolved, the polyphyly of these genera withstands alternative hypothesis testing. Consequently, the sporophytic characters that define these lineages are clearly homoplasious suggesting that selective pressures (or their relaxation) are in fact driving the diversification rather than the conservation of sporophytic architecture in the Funariaceae.

  18. A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection.

    PubMed

    Bechet, P; Mitran, R; Munteanu, M

    2013-08-01

    Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

  19. A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection

    NASA Astrophysics Data System (ADS)

    Bechet, P.; Mitran, R.; Munteanu, M.

    2013-08-01

    Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

  20. MetaShot: an accurate workflow for taxon classification of host-associated microbiome from shotgun metagenomic data.

    PubMed

    Fosso, B; Santamaria, M; D'Antonio, M; Lovero, D; Corrado, G; Vizza, E; Passaro, N; Garbuglia, A R; Capobianchi, M R; Crescenzi, M; Valiente, G; Pesole, G

    2017-01-27

    Shotgun metagenomics by high-throughput sequencing may allow deep and accurate characterization of host-associated total microbiomes, including bacteria, viruses, protists and fungi. However, the analysis of such sequencing data is still extremely challenging in terms of both overall accuracy and computational efficiency, and current methodologies show substantial variability in misclassification rate and resolution at lower taxonomic ranks or are limited to specific life domains (e.g. only bacteria). We present here MetaShot, a workflow for assessing the total microbiome composition from host-associated shotgun sequence data, and show its overall optimal accuracy performance by analyzing both simulated and real datasets.

  1. Fast, Simple and Accurate Handwritten Digit Classification by Training Shallow Neural Network Classifiers with the 'Extreme Learning Machine' Algorithm.

    PubMed

    McDonnell, Mark D; Tissera, Migel D; Vladusich, Tony; van Schaik, André; Tapson, Jonathan

    2015-01-01

    Recent advances in training deep (multi-layer) architectures have inspired a renaissance in neural network use. For example, deep convolutional networks are becoming the default option for difficult tasks on large datasets, such as image and speech recognition. However, here we show that error rates below 1% on the MNIST handwritten digit benchmark can be replicated with shallow non-convolutional neural networks. This is achieved by training such networks using the 'Extreme Learning Machine' (ELM) approach, which also enables a very rapid training time (∼ 10 minutes). Adding distortions, as is common practise for MNIST, reduces error rates even further. Our methods are also shown to be capable of achieving less than 5.5% error rates on the NORB image database. To achieve these results, we introduce several enhancements to the standard ELM algorithm, which individually and in combination can significantly improve performance. The main innovation is to ensure each hidden-unit operates only on a randomly sized and positioned patch of each image. This form of random 'receptive field' sampling of the input ensures the input weight matrix is sparse, with about 90% of weights equal to zero. Furthermore, combining our methods with a small number of iterations of a single-batch backpropagation method can significantly reduce the number of hidden-units required to achieve a particular performance. Our close to state-of-the-art results for MNIST and NORB suggest that the ease of use and accuracy of the ELM algorithm for designing a single-hidden-layer neural network classifier should cause it to be given greater consideration either as a standalone method for simpler problems, or as the final classification stage in deep neural networks applied to more difficult problems.

  2. Classification.

    PubMed

    Tuxhorn, Ingrid; Kotagal, Prakash

    2008-07-01

    In this article, we review the practical approach and diagnostic relevance of current seizure and epilepsy classification concepts and principles as a basic framework for good management of patients with epileptic seizures and epilepsy. Inaccurate generalizations about terminology, diagnosis, and treatment may be the single most important factor, next to an inadequately obtained history, that determines the misdiagnosis and mismanagement of patients with epilepsy. A stepwise signs and symptoms approach for diagnosis, evaluation, and management along the guidelines of the International League Against Epilepsy and definitions of epileptic seizures and epilepsy syndromes offers a state-of-the-art clinical approach to managing patients with epilepsy.

  3. Classification

    NASA Technical Reports Server (NTRS)

    Oza, Nikunj C.

    2011-01-01

    A supervised learning task involves constructing a mapping from input data (normally described by several features) to the appropriate outputs. Within supervised learning, one type of task is a classification learning task, in which each output is one or more classes to which the input belongs. In supervised learning, a set of training examples---examples with known output values---is used by a learning algorithm to generate a model. This model is intended to approximate the mapping between the inputs and outputs. This model can be used to generate predicted outputs for inputs that have not been seen before. For example, we may have data consisting of observations of sunspots. In a classification learning task, our goal may be to learn to classify sunspots into one of several types. Each example may correspond to one candidate sunspot with various measurements or just an image. A learning algorithm would use the supplied examples to generate a model that approximates the mapping between each supplied set of measurements and the type of sunspot. This model can then be used to classify previously unseen sunspots based on the candidate's measurements. This chapter discusses methods to perform machine learning, with examples involving astronomy.

  4. A High Resolution/Accurate Mass (HRAM) Data-Dependent MS3 Neutral Loss Screening, Classification, and Relative Quantitation Methodology for Carbonyl Compounds in Saliva

    NASA Astrophysics Data System (ADS)

    Dator, Romel; Carrà, Andrea; Maertens, Laura; Guidolin, Valeria; Villalta, Peter W.; Balbo, Silvia

    2016-10-01

    Reactive carbonyl compounds (RCCs) are ubiquitous in the environment and are generated endogenously as a result of various physiological and pathological processes. These compounds can react with biological molecules inducing deleterious processes believed to be at the basis of their toxic effects. Several of these compounds are implicated in neurotoxic processes, aging disorders, and cancer. Therefore, a method characterizing exposures to these chemicals will provide insights into how they may influence overall health and contribute to disease pathogenesis. Here, we have developed a high resolution accurate mass (HRAM) screening strategy allowing simultaneous identification and relative quantitation of DNPH-derivatized carbonyls in human biological fluids. The screening strategy involves the diagnostic neutral loss of hydroxyl radical triggering MS3 fragmentation, which is only observed in positive ionization mode of DNPH-derivatized carbonyls. Unique fragmentation pathways were used to develop a classification scheme for characterizing known and unanticipated/unknown carbonyl compounds present in saliva. Furthermore, a relative quantitation strategy was implemented to assess variations in the levels of carbonyl compounds before and after exposure using deuterated d 3 -DNPH. This relative quantitation method was tested on human samples before and after exposure to specific amounts of alcohol. The nano-electrospray ionization (nano-ESI) in positive mode afforded excellent sensitivity with detection limits on-column in the high-attomole levels. To the best of our knowledge, this is the first report of a method using HRAM neutral loss screening of carbonyl compounds. In addition, the method allows simultaneous characterization and relative quantitation of DNPH-derivatized compounds using nano-ESI in positive mode.

  5. Evolutionary Phylogenetic Networks: Models and Issues

    NASA Astrophysics Data System (ADS)

    Nakhleh, Luay

    Phylogenetic networks are special graphs that generalize phylogenetic trees to allow for modeling of non-treelike evolutionary histories. The ability to sequence multiple genetic markers from a set of organisms and the conflicting evolutionary signals that these markers provide in many cases, have propelled research and interest in phylogenetic networks to the forefront in computational phylogenetics. Nonetheless, the term 'phylogenetic network' has been generically used to refer to a class of models whose core shared property is tree generalization. Several excellent surveys of the different flavors of phylogenetic networks and methods for their reconstruction have been written recently. However, unlike these surveys, this chapte focuses specifically on one type of phylogenetic networks, namely evolutionary phylogenetic networks, which explicitly model reticulate evolutionary events. Further, this chapter focuses less on surveying existing tools, and addresses in more detail issues that are central to the accurate reconstruction of phylogenetic networks.

  6. GB Virus C/Hepatitis G Virus Groups and Subgroups: Classification by a Restriction Fragment Length Polymorphism Method Based on Phylogenetic Analysis of the 5′ Untranslated Region

    PubMed Central

    Quarleri, J. F.; Mathet, V. L.; Feld, M.; Ferrario, D.; della Latta, M. P.; Verdun, R.; Sánchez, D. O.; Oubiña, J. R.

    1999-01-01

    A phylogenetic tree based on 150 5′ untranslated region sequences deposited in GenBank database allowed segregation of the sequences into three major groups, including two subgroups, i.e., 1, 2a, 2b, and 3, supported by bootstrap analysis. Restriction site analysis of these sequences predicted that HinfI and either AatII or AciI could be used for genomic typing with 99.4% accuracy. cDNA sequencing and subsequent alignment of 21 Argentine GB virus C/hepatitis G virus strains confirmed restriction fragment length polymorphism patterns theoretically predicted. This method may be useful for a rapid screening of samples when either epidemiological or transmission studies of this agent are carried out. PMID:10203483

  7. Molecular phylogenetics of Alchemilla, Aphanes and Lachemilla (Rosaceae) inferred from plastid and nuclear intron and spacer DNA sequences, with comments on generic classification.

    PubMed

    Gehrke, B; Bräuchler, C; Romoleroux, K; Lundberg, M; Heubl, G; Eriksson, T

    2008-06-01

    Alchemilla (the lady's mantles) is a well known but inconspicuous group in the Rosaceae, notable for its ornamental leaves and pharmaceutical properties. The systematics of Alchemilla has remained poorly understood, most likely due to confusion resulting from apomixis, polyploidisation and hybridisation, which are frequently observed in the group, and which have led to the description of a large number of (micro-) species. A molecular phylogeny of the genus, including all sections of Alchemilla and Lachemilla as well as five representatives of Aphanes, based on the analysis of the chloroplast trnL-trnF and the nuclear ITS regions is presented here. Gene phylogenies reconstructed from the nuclear and chloroplast sequence data were largely congruent. Limited conflict between the data partitions was observed with respect to a small number of taxa. This is likely to be the result of hybridisation/introgression or incomplete lineage sorting. Four distinct clades were resolved, corresponding to major geographical division and life forms: Eurasian Alchemilla, annual Aphanes, South American Lachemilla and African Alchemilla. We argue for a wider circumscription of the genus Alchemilla, including Lachemilla and Aphanes, based on the morphology and the phylogenetic relationships between the different clades.

  8. Suitability of Root and Rhizome Anatomy for Taxonomic Classification and Reconstruction of Phylogenetic Relationships in the Tribes Cardueae and Cichorieae (Asteraceae)

    PubMed Central

    Ginko, Elisabeth; Dobeš, Christoph; Saukel, Johannes

    2016-01-01

    The value of root and rhizome anatomy for the taxonomic characterisation of 59 species classified into 34 genera and 12 subtribes from the Asteraceae tribes Cardueae and Cichorieae was assessed. In addition, the evolutionary history of anatomical characters was reconstructed using a nuclear ribosomal DNA sequence-based phylogeny of the Cichorieae. Taxa were selected with a focus on pharmaceutically relevant species. A binary decision tree was constructed and discriminant function analyses were performed to extract taxonomically relevant anatomical characters and to infer the separability of infratribal taxa, respectively. The binary decision tree distinguished 33 species and two subspecies, but only five of the genera (sampled for at least two species) by a unique combination of hierarchically arranged characters. Accessions were discriminated—except for one sample worthy of discussion—according to their subtribal affiliation in the discriminant function analyses (DFA). However, constantly expressed subtribe-specific characters were almost missing and even in combination, did not discriminate the subtribes. Most anatomical characters showed at least some degree of homoplasious evolution limiting their suitability as phylogenetically informative characters.

  9. Large-Scale Phylogenetic Classification of Fungal Chitin Synthases and Identification of a Putative Cell-Wall Metabolism Gene Cluster in Aspergillus Genomes

    PubMed Central

    Pacheco-Arjona, Jose Ramon; Ramirez-Prado, Jorge Humberto

    2014-01-01

    The cell wall is a protective and versatile structure distributed in all fungi. The component responsible for its rigidity is chitin, a product of chitin synthase (Chsp) enzymes. There are seven classes of chitin synthase genes (CHS) and the amount and type encoded in fungal genomes varies considerably from one species to another. Previous Chsp sequence analyses focused on their study as individual units, regardless of genomic context. The identification of blocks of conserved genes between genomes can provide important clues about the interactions and localization of chitin synthases. On the present study, we carried out an in silico search of all putative Chsp encoded in 54 full fungal genomes, encompassing 21 orders from five phyla. Phylogenetic studies of these Chsp were able to confidently classify 347 out of the 369 Chsp identified (94%). Patterns in the distribution of Chsp related to taxonomy were identified, the most prominent being related to the type of fungal growth. More importantly, a synteny analysis for genomic blocks centered on class IV Chsp (the most abundant and widely distributed Chsp class) identified a putative cell wall metabolism gene cluster in members of the genus Aspergillus, the first such association reported for any fungal genome. PMID:25148134

  10. Geometric morphometric character suites as phylogenetic data: extracting phylogenetic signal from gastropod shells.

    PubMed

    Smith, Ursula E; Hendricks, Jonathan R

    2013-05-01

    Despite being the objects of numerous macroevolutionary studies, many of the best represented constituents of the fossil record-including diverse examples such as foraminifera, brachiopods, and mollusks-have mineralized skeletons with limited discrete characteristics, making morphological phylogenies difficult to construct. In contrast to their paucity of phylogenetic characters, the mineralized structures (tests and shells) of these fossil groups frequently have distinctive shapes that have long proved useful for their classification. The recent introduction of methodologies for including continuous data directly in a phylogenetic analysis has increased the number of available characters, making it possible to produce phylogenies based, in whole or part, on continuous character data collected from such taxa. Geometric morphometric methods provide tools for accurately characterizing shape variation and can produce quantitative data that can therefore now be included in a phylogenetic matrix in a nonarbitrary manner. Here, the marine gastropod genus Conus is used to evaluate the ability of continuous characters-generated from a geometric morphometric analysis of shell shape-to contribute to a total evidence phylogenetic hypothesis constructed using molecular and morphological data. Furthermore, the ability of continuous characters derived from geometric morphometric analyses to place fossil taxa with limited discrete characters into a phylogeny with their extant relatives was tested by simulating the inclusion of fossil taxa. This was done by removing the molecular partition of individual extant species to produce a "cladistic pseudofossil" with only the geometric morphometric derived characters coded. The phylogenetic position of each cladistic pseudofossil taxon was then compared with its placement in the total evidence tree and a symmetric resampling tree to evaluate the degree to which morphometric characters alone can correctly place simulated fossil species

  11. High-resolution phylogenetic microbial community profiling

    PubMed Central

    Singer, Esther; Bushnell, Brian; Coleman-Derr, Devin; Bowman, Brett; Bowers, Robert M; Levy, Asaf; Gies, Esther A; Cheng, Jan-Fang; Copeland, Alex; Klenk, Hans-Peter; Hallam, Steven J; Hugenholtz, Philip; Tringe, Susannah G; Woyke, Tanja

    2016-01-01

    Over the past decade, high-throughput short-read 16S rRNA gene amplicon sequencing has eclipsed clone-dependent long-read Sanger sequencing for microbial community profiling. The transition to new technologies has provided more quantitative information at the expense of taxonomic resolution with implications for inferring metabolic traits in various ecosystems. We applied single-molecule real-time sequencing for microbial community profiling, generating full-length 16S rRNA gene sequences at high throughput, which we propose to name PhyloTags. We benchmarked and validated this approach using a defined microbial community. When further applied to samples from the water column of meromictic Sakinaw Lake, we show that while community structures at the phylum level are comparable between PhyloTags and Illumina V4 16S rRNA gene sequences (iTags), variance increases with community complexity at greater water depths. PhyloTags moreover allowed less ambiguous classification. Last, a platform-independent comparison of PhyloTags and in silico generated partial 16S rRNA gene sequences demonstrated significant differences in community structure and phylogenetic resolution across multiple taxonomic levels, including a severe underestimation in the abundance of specific microbial genera involved in nitrogen and methane cycling across the Lake's water column. Thus, PhyloTags provide a reliable adjunct or alternative to cost-effective iTags, enabling more accurate phylogenetic resolution of microbial communities and predictions on their metabolic potential. PMID:26859772

  12. Phylogenetic classification of Escherichia coli O157:H7 strains of human and bovine origin using a novel set of nucleotide polymorphisms

    PubMed Central

    Clawson, Michael L; Keen, James E; Smith, Timothy PL; Durso, Lisa M; McDaneld, Tara G; Mandrell, Robert E; Davis, Margaret A; Bono, James L

    2009-01-01

    Background Cattle are a reservoir of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157), and are known to harbor subtypes not typically found in clinically ill humans. Consequently, nucleotide polymorphisms previously discovered via strains originating from human outbreaks may be restricted in their ability to distinguish STEC O157 genetic subtypes present in cattle. The objectives of this study were firstly to identify nucleotide polymorphisms in a diverse sampling of human and bovine STEC O157 strains, secondly to classify strains of either bovine or human origin by polymorphism-derived genotypes, and finally to compare the genotype diversity with pulsed-field gel electrophoresis (PFGE), a method currently used for assessing STEC O157 diversity. Results High-throughput 454 sequencing of pooled STEC O157 strain DNAs from human clinical cases (n = 91) and cattle (n = 102) identified 16,218 putative polymorphisms. From those, 178 were selected primarily within genomic regions conserved across E. coli serotypes and genotyped in 261 STEC O157 strains. Forty-two unique genotypes were observed that are tagged by a minimal set of 32 polymorphisms. Phylogenetic trees of the genotypes are divided into clades that represent strains of cattle origin, or cattle and human origin. Although PFGE diversity surpassed genotype diversity overall, ten PFGE patterns each occurred with multiple strains having different genotypes. Conclusions Deep sequencing of pooled STEC O157 DNAs proved highly effective in polymorphism discovery. A polymorphism set has been identified that characterizes genetic diversity within STEC O157 strains of bovine origin, and a subset observed in human strains. The set may complement current techniques used to classify strains implicated in disease outbreaks. PMID:19463166

  13. Redescription and phylogenetic position of Myxobolus aeglefini and Myxobolus platessae n. comb. (Myxosporea), parasites in the cartilage of some North Atlantic marine fishes, with notes on the phylogeny and classification of the Platysporina.

    PubMed

    Karlsbakk, Egil; Kristmundsson, Árni; Albano, Marco; Brown, Paul; Freeman, Mark A

    2017-02-01

    Myxobolus 'aeglefini' Auerbach, 1906 was originally described from cranial cartilage of North sea haddock (Melanogrammus aeglefinus), but has subsequently been recorded from cartilaginous tissues of a range of other gadoid hosts, from pleuronectids and from lumpsucker (Cyclopterus lumpus) in the North Atlantic and from a zoarcid fish in the Japan Sea (Pacific). We obtained partial small-subunit rDNA sequences of Myxobolus 'aeglefini' from gadoids and pleuronectids from Norway and Iceland. The sequences from gadoids and pleuronectids represented two different genotypes, showing 98.2% identity. Morphometric studies on the spores from selected gadids and pleuronectids revealed slight but statistically significant differences in spore dimensions associated with the genotypes, the spores from pleuronectids were thicker and with larger polar capsules. We identify the morpho- and genotype from gadoids with Myxobolus 'aeglefini' sensu Auerbach, and the one from pleuronectids with Sphaerospora platessae Woodcock, 1904 as Myxobolus platessae n. comb. The latter species was originally described from Irish Sea plaice (Pleuronectes platessa). Myxobolus albi Picon et al., 2009 described from the common goby Pomatoschistus microps in Scotland is a synonym of M. 'aeglefini'. The Pacific Myxobolus 'aeglefini' represents a separate species, showing only 97.4-97.6% identity to the Atlantic species. In phylogenetic analyses based on SSU rDNA sequences, these and some related marine chondrotropic Myxobolus spp. form a distinct well supported group. This clusters with freshwater and marine myxobolids and Triangula and Cardimyxobolus species, in a basal clade in the phylogeny of the Platysporina. Members of family Myxobilatidae, Ortholinea spp. (currently Ortholineidae) and sequences of some other urinary system infecting myxosporeans form a well supported clade among members of the suborder Platysporina. Based on phylogenetic analyses, we propose the following changes to the

  14. Phylogenetic analysis of Escherichia coli isolated from broilers with colibacillosis based on gyrA gene sequences.

    PubMed

    Shamsi, Hamid; Mardani, Karim; Ownagh, Abdolghaffar

    2017-01-01

    Escherichia coli isolates from chickens with colibacillosis were assigned to phylogenetic groups based on multiplex polymerase chain reaction (PCR) and antibacterial resistance of E. coli belonging to these groups was examined. Furthermore, the gyrA gene of isolates was sequenced and a phylogenetic tree was generated. A total of 84 E. coli isolates were grouped using multiplex PCR of TSPE4.C2, chuA, yjaA, and gadA molecular markers. Four phylogenetic groups were identified with strains divided as follows: 16 in group A (19.05%), 17 in group B1 (20.24%), 23 in group B2 (27.38%), and 28 in group D (33.33%). Escherichia coli isolates belonging to phylogenetic groups B2 and D were resistant to Soltrim and Flumequine unlike the majority of E. coli isolates that belonged to groups A and B1, and which were susceptible to these antibiotics. The phylogenetic results based on gyrA gene sequences from multiplex PCR revealed that E. coli phylogenetic grouping was in accordance with the clusters obtained in the phylogenetic tree. In conclusion, the comparative sequence analysis of gyrA sequences provides a firm framework for an accurate classification of E. coli and related taxa and may constitute a pertinent phylogenetic marker for E. coli.

  15. ICGA-PSO-ELM approach for accurate multiclass cancer classification resulting in reduced gene sets in which genes encoding secreted proteins are highly represented.

    PubMed

    Saraswathi, Saras; Sundaram, Suresh; Sundararajan, Narasimhan; Zimmermann, Michael; Nilsen-Hamilton, Marit

    2011-01-01

    A combination of Integer-Coded Genetic Algorithm (ICGA) and Particle Swarm Optimization (PSO), coupled with the neural-network-based Extreme Learning Machine (ELM), is used for gene selection and cancer classification. ICGA is used with PSO-ELM to select an optimal set of genes, which is then used to build a classifier to develop an algorithm (ICGA_PSO_ELM) that can handle sparse data and sample imbalance. We evaluate the performance of ICGA-PSO-ELM and compare our results with existing methods in the literature. An investigation into the functions of the selected genes, using a systems biology approach, revealed that many of the identified genes are involved in cell signaling and proliferation. An analysis of these gene sets shows a larger representation of genes that encode secreted proteins than found in randomly selected gene sets. Secreted proteins constitute a major means by which cells interact with their surroundings. Mounting biological evidence has identified the tumor microenvironment as a critical factor that determines tumor survival and growth. Thus, the genes identified by this study that encode secreted proteins might provide important insights to the nature of the critical biological features in the microenvironment of each tumor type that allow these cells to thrive and proliferate.

  16. A preliminary phylogenetic analysis of the New World Helopini (Coleoptera, Tenebrionidae, Tenebrioninae) indicates the need for profound rearrangements of the classification

    PubMed Central

    Cifuentes-Ruiz, Paulina; Zaragoza-Caballero, Santiago; Ochoterena-Booth, Helga; Morón, Miguel Ángel

    2014-01-01

    Abstract Helopini is a diverse tribe in the subfamily Tenebrioninae with a worldwide distribution. The New World helopine species have not been reviewed recently and several doubts emerge regarding their generic assignment as well as the naturalness of the tribe and subordinate taxa. To assess these questions, a preliminary cladistic analysis was conducted with emphasis on sampling the genera distributed in the New World, but including representatives from other regions. The parsimony analysis includes 30 ingroup species from America, Europe and Asia of the subtribes Helopina and Cylindrinotina, plus three outgroups, and 67 morphological characters. Construction of the matrix resulted in the discovery of morphological character states not previously reported for the tribe, particularly from the genitalia of New World species. A consensus of the 12 most parsimonious trees supports the monophyly of the tribe based on a unique combination of characters, including one synapomorphy. None of the subtribes or the genera of the New World represented by more than one species (Helops Fabricius, Nautes Pascoe and Tarpela Bates) were recovered as monophyletic. Helopina was recovered as paraphyletic in relation to Cylindrinotina. One Nearctic species of Helops and one Palearctic species of Tarpela (subtribe Helopina) were more closely related to species of Cylindrinotina. A relatively derived clade, mainly composed by Neotropical species, was found; it includes seven species of Tarpela, seven species of Nautes, and three species of Helops, two Nearctic and one Neotropical. Our results reveal the need to deeply re-evaluate the current classification of the tribe and subordinated taxa, but a broader taxon sampling and further character exploration is needed in order to fully recognize monophyletic groups at different taxonomic levels (from subtribes to genera). PMID:25009428

  17. A preliminary phylogenetic analysis of the New World Helopini (Coleoptera, Tenebrionidae, Tenebrioninae) indicates the need for profound rearrangements of the classification.

    PubMed

    Cifuentes-Ruiz, Paulina; Zaragoza-Caballero, Santiago; Ochoterena-Booth, Helga; Morón, Miguel Ángel

    2014-01-01

    Helopini is a diverse tribe in the subfamily Tenebrioninae with a worldwide distribution. The New World helopine species have not been reviewed recently and several doubts emerge regarding their generic assignment as well as the naturalness of the tribe and subordinate taxa. To assess these questions, a preliminary cladistic analysis was conducted with emphasis on sampling the genera distributed in the New World, but including representatives from other regions. The parsimony analysis includes 30 ingroup species from America, Europe and Asia of the subtribes Helopina and Cylindrinotina, plus three outgroups, and 67 morphological characters. Construction of the matrix resulted in the discovery of morphological character states not previously reported for the tribe, particularly from the genitalia of New World species. A consensus of the 12 most parsimonious trees supports the monophyly of the tribe based on a unique combination of characters, including one synapomorphy. None of the subtribes or the genera of the New World represented by more than one species (Helops Fabricius, Nautes Pascoe and Tarpela Bates) were recovered as monophyletic. Helopina was recovered as paraphyletic in relation to Cylindrinotina. One Nearctic species of Helops and one Palearctic species of Tarpela (subtribe Helopina) were more closely related to species of Cylindrinotina. A relatively derived clade, mainly composed by Neotropical species, was found; it includes seven species of Tarpela, seven species of Nautes, and three species of Helops, two Nearctic and one Neotropical. Our results reveal the need to deeply re-evaluate the current classification of the tribe and subordinated taxa, but a broader taxon sampling and further character exploration is needed in order to fully recognize monophyletic groups at different taxonomic levels (from subtribes to genera).

  18. Fast, Simple and Accurate Handwritten Digit Classification by Training Shallow Neural Network Classifiers with the ‘Extreme Learning Machine’ Algorithm

    PubMed Central

    McDonnell, Mark D.; Tissera, Migel D.; Vladusich, Tony; van Schaik, André; Tapson, Jonathan

    2015-01-01

    Recent advances in training deep (multi-layer) architectures have inspired a renaissance in neural network use. For example, deep convolutional networks are becoming the default option for difficult tasks on large datasets, such as image and speech recognition. However, here we show that error rates below 1% on the MNIST handwritten digit benchmark can be replicated with shallow non-convolutional neural networks. This is achieved by training such networks using the ‘Extreme Learning Machine’ (ELM) approach, which also enables a very rapid training time (∼ 10 minutes). Adding distortions, as is common practise for MNIST, reduces error rates even further. Our methods are also shown to be capable of achieving less than 5.5% error rates on the NORB image database. To achieve these results, we introduce several enhancements to the standard ELM algorithm, which individually and in combination can significantly improve performance. The main innovation is to ensure each hidden-unit operates only on a randomly sized and positioned patch of each image. This form of random ‘receptive field’ sampling of the input ensures the input weight matrix is sparse, with about 90% of weights equal to zero. Furthermore, combining our methods with a small number of iterations of a single-batch backpropagation method can significantly reduce the number of hidden-units required to achieve a particular performance. Our close to state-of-the-art results for MNIST and NORB suggest that the ease of use and accuracy of the ELM algorithm for designing a single-hidden-layer neural network classifier should cause it to be given greater consideration either as a standalone method for simpler problems, or as the final classification stage in deep neural networks applied to more difficult problems. PMID:26262687

  19. Accurate Arabic Script Language/Dialect Classification

    DTIC Science & Technology

    2014-01-01

    language processing ( NLP ) tools and models only function well when applied to the language for which they were designed or trained. Thus, it is...and MSA, NLP tools trained using MSA data collections tend to perform poorly on dialectal text (Rambow et al., 2005). Thus, it is important to

  20. Taxonomic update on proposed nomenclature and classification changes for bacteria of medical importance, 2016.

    PubMed

    Janda, J Michael

    2017-02-13

    A key aspect of medical, public health, and diagnostic microbiology laboratories is the accurate identification and rapid reporting and communication to medical staff regarding patients with infectious agents of clinical importance. Microbial taxonomy in the age of molecular diagnostics and phylogenetics creates changes in taxonomy at a logarithmic rate further complicating this process. This update focuses on the description of new species and classification changes proposed in 2016.

  1. Phylogenetic molecular function annotation

    NASA Astrophysics Data System (ADS)

    Engelhardt, Barbara E.; Jordan, Michael I.; Repo, Susanna T.; Brenner, Steven E.

    2009-07-01

    It is now easier to discover thousands of protein sequences in a new microbial genome than it is to biochemically characterize the specific activity of a single protein of unknown function. The molecular functions of protein sequences have typically been predicted using homology-based computational methods, which rely on the principle that homologous proteins share a similar function. However, some protein families include groups of proteins with different molecular functions. A phylogenetic approach for predicting molecular function (sometimes called "phylogenomics") is an effective means to predict protein molecular function. These methods incorporate functional evidence from all members of a family that have functional characterizations using the evolutionary history of the protein family to make robust predictions for the uncharacterized proteins. However, they are often difficult to apply on a genome-wide scale because of the time-consuming step of reconstructing the phylogenies of each protein to be annotated. Our automated approach for function annotation using phylogeny, the SIFTER (Statistical Inference of Function Through Evolutionary Relationships) methodology, uses a statistical graphical model to compute the probabilities of molecular functions for unannotated proteins. Our benchmark tests showed that SIFTER provides accurate functional predictions on various protein families, outperforming other available methods.

  2. Phylogenetic molecular function annotation

    PubMed Central

    Engelhardt, Barbara E; Jordan, Michael I; Repo, Susanna T; Brenner, Steven E

    2010-01-01

    It is now easier to discover thousands of protein sequences in a new microbial genome than it is to biochemically characterize the specific activity of a single protein of unknown function. The molecular functions of protein sequences have typically been predicted using homology-based computational methods, which rely on the principle that homologous proteins share a similar function. However, some protein families include groups of proteins with different molecular functions. A phylogenetic approach for predicting molecular function (sometimes called “phylogenomics”) is an effective means to predict protein molecular function. These methods incorporate functional evidence from all members of a family that have functional characterizations using the evolutionary history of the protein family to make robust predictions for the uncharacterized proteins. However, they are often difficult to apply on a genome-wide scale because of the time-consuming step of reconstructing the phylogenies of each protein to be annotated. Our automated approach for function annotation using phylogeny, the SIFTER (Statistical Inference of Function Through Evolutionary Relationships) methodology, uses a statistical graphical model to compute the probabilities of molecular functions for unannotated proteins. Our benchmark tests showed that SIFTER provides accurate functional predictions on various protein families, outperforming other available methods. PMID:20664722

  3. [Analysis phylogenetic relationship of Gynostemma (Cucurbitaceae)].

    PubMed

    Qin, Shuang-shuang; Li, Hai-tao; Wang, Zhou-yong; Cui, Zhan-hu; Yu, Li-ying

    2015-05-01

    The sequences of ITS, matK, rbcL and psbA-trnH of 9 Gynostemma species or variety including 38 samples were compared and analyzed by molecular phylogeny method. Hemsleya macrosperma was designated as outgroup. The MP and NJ phylogenetic tree of Gynostemma was built based on ITS sequence, the results of PAUP phylogenetic analysis showed the following results: (1) The eight individuals of G. pentaphyllum var. pentaphyllum were not supported as monophyletic in the strict consensus trees and NJ trees. (2) It is suspected whether G. longipes and G. laxum should be classified as the independent species. (3)The classification of subgenus units of Gynostemma plants is supported.

  4. A genus-level classification of the family Thraupidae (Class Aves: Order Passeriformes).

    PubMed

    Burns, Kevin J; Unitt, Philip; Mason, Nicholas A

    2016-03-09

    The tanagers (Thraupidae) are a major component of the Neotropical avifauna, and vary in plumage colors, behaviors, morphologies, and ecologies. Globally, they represent nearly 4% of all avian species and are the largest family of songbirds. However, many currently used tanager genera are not monophyletic, based on analyses of molecular data that have accumulated over the past 25 years. Current genus-level classifications of tanagers have not been revised according to newly documented relationships of tanagers for various reasons: 1) the lack of a comprehensive phylogeny, 2) reluctance to lump existing genera into larger groups, and 3) the lack of available names for newly defined smaller groups. Here, we present two alternative classifications based on a newly published comprehensive phylogeny of tanagers. One of these classifications uses existing generic names, but defines them broadly. The other, which we advocate and follow here, provides new generic names for more narrowly defined groups. Under the latter, we propose eleven new genera (Asemospiza, Islerothraupis, Maschalethraupis, Chrysocorypha, Kleinothraupis, Castanozoster, Ephippiospingus, Chionodacryon, Pseudosaltator, Poecilostreptus, Stilpnia), and resurrect several generic names to form monophyletic taxa. Either of these classifications would allow taxonomic authorities to reconcile classification with current understanding of tanager phylogenetic relationships. Having a more phylogenetically accurate classification for tanagers will facilitate the study and conservation of this important Neotropical radiation of songbirds.

  5. Directional biases in phylogenetic structure quantification: a Mediterranean case study

    PubMed Central

    Molina-Venegas, Rafael; Roquet, Cristina

    2014-01-01

    Recent years have seen an increasing effort to incorporate phylogenetic hypotheses to the study of community assembly processes. The incorporation of such evolutionary information has been eased by the emergence of specialized software for the automatic estimation of partially resolved supertrees based on published phylogenies. Despite this growing interest in the use of phylogenies in ecological research, very few studies have attempted to quantify the potential biases related to the use of partially resolved phylogenies and to branch length accuracy, and no work has examined how tree shape may affect inference of community phylogenetic metrics. In this study, using a large plant community and elevational dataset, we tested the influence of phylogenetic resolution and branch length information on the quantification of phylogenetic structure; and also explored the impact of tree shape (stemminess) on the loss of accuracy in phylogenetic structure quantification due to phylogenetic resolution. For this purpose, we used 9 sets of phylogenetic hypotheses of varying resolution and branch lengths to calculate three indices of phylogenetic structure: the mean phylogenetic distance (NRI), the mean nearest taxon distance (NTI) and phylogenetic diversity (stdPD) metrics. The NRI metric was the less sensitive to phylogenetic resolution, stdPD showed an intermediate sensitivity, and NTI was the most sensitive one; NRI was also less sensitive to branch length accuracy than NTI and stdPD, the degree of sensitivity being strongly dependent on the dating method and the sample size. Directional biases were generally towards type II errors. Interestingly, we detected that tree shape influenced the accuracy loss derived from the lack of phylogenetic resolution, particularly for NRI and stdPD. We conclude that well-resolved molecular phylogenies with accurate branch length information are needed to identify the underlying phylogenetic structure of communities, and also that

  6. Profiling phylogenetic informativeness.

    PubMed

    Townsend, Jeffrey P

    2007-04-01

    The resolution of four controversial topics in phylogenetic experimental design hinges upon the informativeness of characters about the historical relationships among taxa. These controversies regard the power of different classes of phylogenetic character, the relative utility of increased taxonomic versus character sampling, the differentiation between lack of phylogenetic signal and a historical rapid radiation, and the design of taxonomically broad phylogenetic studies optimized by taxonomically sparse genome-scale data. Quantification of the informativeness of characters for resolution of phylogenetic hypotheses during specified historical epochs is key to the resolution of these controversies. Here, such a measure of phylogenetic informativeness is formulated. The optimal rate of evolution of a character to resolve a dated four-taxon polytomy is derived. By scaling the asymptotic informativeness of a character evolving at a nonoptimal rate by the derived asymptotic optimum, and by normalizing so that net phylogenetic informativeness is equivalent for all rates when integrated across all of history, an informativeness profile across history is derived. Calculation of the informativeness per base pair allows estimation of the cost-effectiveness of character sampling. Calculation of the informativeness per million years allows comparison across historical radiations of the utility of a gene for the inference of rapid adaptive radiation. The theory is applied to profile the phylogenetic informativeness of the genes BRCA1, RAG1, GHR, and c-myc from a muroid rodent sequence data set. Bounded integrations of the phylogenetic profile of these genes over four epochs comprising the diversifications of the muroid rodents, the mammals, the lobe-limbed vertebrates, and the early metazoans demonstrate the differential power of these genes to resolve the branching order among ancestral lineages. This measure of phylogenetic informativeness yields a new kind of information

  7. Phylogenetic Inference From Conserved sites Alignments

    SciTech Connect

    grundy, W.N.; Naylor, G.J.P.

    1999-08-15

    Molecular sequences provide a rich source of data for inferring the phylogenetic relationships among species. However, recent work indicates that even an accurate multiple alignment of a large sequence set may yield an incorrect phylogeny and that the quality of the phylogenetic tree improves when the input consists only of the highly conserved, motif regions of the alignment. This work introduces two methods of producing multiple alignments that include only the conserved regions of the initial alignment. The first method retains conserved motifs, whereas the second retains individual conserved sites in the initial alignment. Using parsimony analysis on a mitochondrial data set containing 19 species among which the phylogenetic relationships are widely accepted, both conserved alignment methods produce better phylogenetic trees than the complete alignment. Unlike any of the 19 inference methods used before to analyze this data, both methods produce trees that are completely consistent with the known phylogeny. The motif-based method employs far fewer alignment sites for comparable error rates. For a larger data set containing mitochondrial sequences from 39 species, the site-based method produces a phylogenetic tree that is largely consistent with known phylogenetic relationships and suggests several novel placements.

  8. Phylogenetic Trees From Sequences

    NASA Astrophysics Data System (ADS)

    Ryvkin, Paul; Wang, Li-San

    In this chapter, we review important concepts and approaches for phylogeny reconstruction from sequence data.We first cover some basic definitions and properties of phylogenetics, and briefly explain how scientists model sequence evolution and measure sequence divergence. We then discuss three major approaches for phylogenetic reconstruction: distance-based phylogenetic reconstruction, maximum parsimony, and maximum likelihood. In the third part of the chapter, we review how multiple phylogenies are compared by consensus methods and how to assess confidence using bootstrapping. At the end of the chapter are two sections that list popular software packages and additional reading.

  9. Taxonomic Identity Resolution of Highly Phylogenetically Related Strains and Selection of Phylogenetic Markers by Using Genome-Scale Methods: The Bacillus pumilus Group Case

    PubMed Central

    Espariz, Martín; Zuljan, Federico A.; Esteban, Luis; Magni, Christian

    2016-01-01

    Bacillus pumilus group strains have been studied due their agronomic, biotechnological or pharmaceutical potential. Classifying strains of this taxonomic group at species level is a challenging procedure since it is composed of seven species that share among them over 99.5% of 16S rRNA gene identity. In this study, first, a whole-genome in silico approach was used to accurately demarcate B. pumilus group strains, as a case of highly phylogenetically related taxa, at the species level. In order to achieve that and consequently to validate or correct taxonomic identities of genomes in public databases, an average nucleotide identity correlation, a core-based phylogenomic and a gene function repertory analyses were performed. Eventually, more than 50% such genomes were found to be misclassified. Hierarchical clustering of gene functional repertoires was also used to infer ecotypes among B. pumilus group species. Furthermore, for the first time the machine-learning algorithm Random Forest was used to rank genes in order of their importance for species classification. We found that ybbP, a gene involved in the synthesis of cyclic di-AMP, was the most important gene for accurately predicting species identity among B. pumilus group strains. Finally, principal component analysis was used to classify strains based on the distances between their ybbP genes. The methodologies described could be utilized more broadly to identify other highly phylogenetically related species in metagenomic or epidemiological assessments. PMID:27658251

  10. Phylogenetic reconstruction of the wolf spiders (Araneae: Lycosidae) using sequences from the 12S rRNA, 28S rRNA, and NADH1 genes: implications for classification, biogeography, and the evolution of web building behavior.

    PubMed

    Murphy, Nicholas P; Framenau, Volker W; Donnellan, Stephen C; Harvey, Mark S; Park, Yung-Chul; Austin, Andrew D

    2006-03-01

    Current knowledge of the evolutionary relationships amongst the wolf spiders (Araneae: Lycosidae) is based on assessment of morphological similarity or phylogenetic analysis of a small number of taxa. In order to enhance the current understanding of lycosid relationships, phylogenies of 70 lycosid species were reconstructed by parsimony and Bayesian methods using three molecular markers; the mitochondrial genes 12S rRNA, NADH1, and the nuclear gene 28S rRNA. The resultant trees from the mitochondrial markers were used to assess the current taxonomic status of the Lycosidae and to assess the evolutionary history of sheet-web construction in the group. The results suggest that a number of genera are not monophyletic, including Lycosa, Arctosa, Alopecosa, and Artoria. At the subfamilial level, the status of Pardosinae needs to be re-assessed, and the position of a number of genera within their respective subfamilies is in doubt (e.g., Hippasa and Arctosa in Lycosinae and Xerolycosa, Aulonia and Hygrolycosa in Venoniinae). In addition, a major clade of strictly Australasian taxa may require the creation of a new subfamily. The analysis of sheet-web building in Lycosidae revealed that the interpretation of this trait as an ancestral state relies on two factors: (1) an asymmetrical model favoring the loss of sheet-webs and (2) that the suspended silken tube of Pirata is directly descended from sheet-web building. Paralogous copies of the nuclear 28S rRNA gene were sequenced, confounding the interpretation of the phylogenetic analysis and suggesting that a cautionary approach should be taken to the further use of this gene for lycosid phylogenetic analysis.

  11. Phylogenetic lineages in Entomophthoromycota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomophthoromycota Humber is one of five major phylogenetic lineages among the former phylum Zygomycota. These early terrestrial fungi share evolutionarily ancestral characters such as coenocytic mycelium and gametangiogamy as a sexual process resulting in zygospore formation. Previous molecular st...

  12. Phylogenetic analysis of Salmonella, Shigella, and Escherichia coli strains on the basis of the gyrB gene sequence.

    PubMed

    Fukushima, Masao; Kakinuma, Kenichi; Kawaguchi, Ryuji

    2002-08-01

    Phylogenetic analysis of about 200 strains of Salmonella, Shigella, and Escherichia coli was carried out using the nucleotide sequence of the gene for DNA gyrase B (gyrB), which was determined by directly sequencing PCR fragments. The results establish a new phylogenetic tree for the classification of Salmonella, Shigella, and Escherichia coli in which Salmonella forms a cluster separate from but closely related to Shigella and E. coli. In comparison with 16S rRNA analysis, the gyrB sequences indicated a greater evolutionary divergence for the bacteria. Thus, in screening for the presence of bacteria, the gyrB gene might be a useful tool for differentiating between closely related species of bacteria such as Shigella spp. and E. coli. At present, 16S rRNA sequence analysis is an accurate and rapid method for identifying most unknown bacteria to the genus level because the highly conserved 16S rRNA region is easy to amplify; however, analysis of the more variable gyrB sequence region can identify unknown bacteria to the species level. In summary, we have shown that gyrB sequence analysis is a useful alternative to 16S rRNA analysis for constructing the phylogenetic relationships of bacteria, in particular for the classification of closely related bacterial species.

  13. Identification of a Bacteria Using Phylogenetic Relationships Revealed by MS/MS Sequencing of Tryptic Peptides Derived From Cellular Proteins

    DTIC Science & Technology

    2004-12-01

    phylogenetic relationships between bacterial species as a part of a hierarchical decision tree process. 1. INTRODUCTION The detection and...1 IDENTIFICATION OF BACTERIA USING PHYLOGENETIC RELATIONSHIPS REVEALED BY MS/MS SEQUENCING OF TRYPTIC PEPTIDES DERIVED FROM CELLULAR PROTEINS...based on analysis of an electrospray ionization (ESI)-MS/MS data for the fast classification of analyzed bacteria, using phylogenetic relationships

  14. Phylogenetically resolving epidemiologic linkage

    PubMed Central

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-01-01

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results. PMID:26903617

  15. The phylogenetic likelihood library.

    PubMed

    Flouri, T; Izquierdo-Carrasco, F; Darriba, D; Aberer, A J; Nguyen, L-T; Minh, B Q; Von Haeseler, A; Stamatakis, A

    2015-03-01

    We introduce the Phylogenetic Likelihood Library (PLL), a highly optimized application programming interface for developing likelihood-based phylogenetic inference and postanalysis software. The PLL implements appropriate data structures and functions that allow users to quickly implement common, error-prone, and labor-intensive tasks, such as likelihood calculations, model parameter as well as branch length optimization, and tree space exploration. The highly optimized and parallelized implementation of the phylogenetic likelihood function and a thorough documentation provide a framework for rapid development of scalable parallel phylogenetic software. By example of two likelihood-based phylogenetic codes we show that the PLL improves the sequential performance of current software by a factor of 2-10 while requiring only 1 month of programming time for integration. We show that, when numerical scaling for preventing floating point underflow is enabled, the double precision likelihood calculations in the PLL are up to 1.9 times faster than those in BEAGLE. On an empirical DNA dataset with 2000 taxa the AVX version of PLL is 4 times faster than BEAGLE (scaling enabled and required). The PLL is available at http://www.libpll.org under the GNU General Public License (GPL).

  16. Phylogenetically resolving epidemiologic linkage

    SciTech Connect

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-02-22

    The use of phylogenetic trees in epidemiological investigations has become commonplace, but their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. Moreover, we confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results.

  17. Phylogenetically resolving epidemiologic linkage

    DOE PAGES

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-02-22

    The use of phylogenetic trees in epidemiological investigations has become commonplace, but their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the truemore » transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. Moreover, we confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results.« less

  18. A Universal Phylogenetic Tree.

    ERIC Educational Resources Information Center

    Offner, Susan

    2001-01-01

    Presents a universal phylogenetic tree suitable for use in high school and college-level biology classrooms. Illustrates the antiquity of life and that all life is related, even if it dates back 3.5 billion years. Reflects important evolutionary relationships and provides an exciting way to learn about the history of life. (SAH)

  19. Molecular phylogenetics before sequences

    PubMed Central

    Ragan, Mark A; Bernard, Guillaume; Chan, Cheong Xin

    2014-01-01

    From 1971 to 1985, Carl Woese and colleagues generated oligonucleotide catalogs of 16S/18S rRNAs from more than 400 organisms. Using these incomplete and imperfect data, Carl and his colleagues developed unprecedented insights into the structure, function, and evolution of the large RNA components of the translational apparatus. They recognized a third domain of life, revealed the phylogenetic backbone of bacteria (and its limitations), delineated taxa, and explored the tempo and mode of microbial evolution. For these discoveries to have stood the test of time, oligonucleotide catalogs must carry significant phylogenetic signal; they thus bear re-examination in view of the current interest in alignment-free phylogenetics based on k-mers. Here we consider the aims, successes, and limitations of this early phase of molecular phylogenetics. We computationally generate oligonucleotide sets (e-catalogs) from 16S/18S rRNA sequences, calculate pairwise distances between them based on D2 statistics, compute distance trees, and compare their performance against alignment-based and k-mer trees. Although the catalogs themselves were superseded by full-length sequences, this stage in the development of computational molecular biology remains instructive for us today. PMID:24572375

  20. Spatial predictions of phylogenetic diversity in conservation decision making.

    PubMed

    Pio, Dorothea V; Broennimann, Olivier; Barraclough, Timothy G; Reeves, Gail; Rebelo, Anthony G; Thuiller, Wilfried; Guisan, Antoine; Salamin, Nicolas

    2011-12-01

    Considering genetic relatedness among species has long been argued as an important step toward measuring biological diversity more accurately, rather than relying solely on species richness. Some researchers have correlated measures of phylogenetic diversity and species richness across a series of sites and suggest that values of phylogenetic diversity do not differ enough from those of species richness to justify their inclusion in conservation planning. We compared predictions of species richness and 10 measures of phylogenetic diversity by creating distribution models for 168 individual species of a species-rich plant family, the Cape Proteaceae. When we used average amounts of land set aside for conservation to compare areas selected on the basis of species richness with areas selected on the basis of phylogenetic diversity, correlations between species richness and different measures of phylogenetic diversity varied considerably. Correlations between species richness and measures that were based on the length of phylogenetic tree branches and tree shape were weaker than those that were based on tree shape alone. Elevation explained up to 31% of the segregation of species rich versus phylogenetically rich areas. Given these results, the increased availability of molecular data, and the known ecological effect of phylogenetically rich communities, consideration of phylogenetic diversity in conservation decision making may be feasible and informative.

  1. Challenges in prosthesis classification.

    PubMed

    Robertsson, Otto; Mendenhall, Stan; Paxton, Elizabeth W; Inacio, Maria C S; Graves, Stephen

    2011-12-21

    Accurate prosthesis classification is critical for total joint arthroplasty surveillance and assessment of comparative effectiveness. Historically, prosthesis classification was based solely on the names of the prosthesis manufacturers. As a result, prosthesis designs changed without corresponding name changes, and other prostheses' names changed over time without substantial design modifications. As the number of prostheses used in total joint arthroplasty on the market increased, catalog and lot numbers associated with prosthesis descriptions were introduced by manufacturers. Currently, these catalog and lot numbers are not standardized, and there is no consensus on categorization of these numbers into brands or subbrands. Classification of the attributes of a prosthesis also varies, limiting comparisons of prostheses across studies and reports. The development of a universal prosthesis classification system would standardize prosthesis classification and enhance total joint arthroplasty research collaboration worldwide. This is a current area of focus for the International Consortium of Orthopaedic Registries (ICOR).

  2. Host specificity and phylogenetic relationships of chicken and turkey parvoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous reports indicate that the newly discovered chicken parvoviruses (ChPV) and turkey parvoviruses (TuPV) are very similar to each other, yet they represent different species within a new genus of Parvoviridae. Currently, strain classification is based on the phylogenetic analysis of a 561 bas...

  3. Charles Darwin, beetles and phylogenetics.

    PubMed

    Beutel, Rolf G; Friedrich, Frank; Leschen, Richard A B

    2009-11-01

    Here, we review Charles Darwin's relation to beetles and developments in coleopteran systematics in the last two centuries. Darwin was an enthusiastic beetle collector. He used beetles to illustrate different evolutionary phenomena in his major works, and astonishingly, an entire sub-chapter is dedicated to beetles in "The Descent of Man". During his voyage on the Beagle, Darwin was impressed by the high diversity of beetles in the tropics, and he remarked that, to his surprise, the majority of species were small and inconspicuous. However, despite his obvious interest in the group, he did not get involved in beetle taxonomy, and his theoretical work had little immediate impact on beetle classification. The development of taxonomy and classification in the late nineteenth and earlier twentieth century was mainly characterised by the exploration of new character systems (e.g. larval features and wing venation). In the mid-twentieth century, Hennig's new methodology to group lineages by derived characters revolutionised systematics of Coleoptera and other organisms. As envisioned by Darwin and Ernst Haeckel, the new Hennigian approach enabled systematists to establish classifications truly reflecting evolution. Roy A. Crowson and Howard E. Hinton, who both made tremendous contributions to coleopterology, had an ambivalent attitude towards the Hennigian ideas. The Mickoleit school combined detailed anatomical work with a classical Hennigian character evaluation, with stepwise tree building, comparatively few characters and a priori polarity assessment without explicit use of the outgroup comparison method. The rise of cladistic methods in the 1970s had a strong impact on beetle systematics. Cladistic computer programs facilitated parsimony analyses of large data matrices, mostly morphological characters not requiring detailed anatomical investigations. Molecular studies on beetle phylogeny started in the 1990s with modest taxon sampling and limited DNA data. This has

  4. Charles Darwin, beetles and phylogenetics

    NASA Astrophysics Data System (ADS)

    Beutel, Rolf G.; Friedrich, Frank; Leschen, Richard A. B.

    2009-11-01

    Here, we review Charles Darwin’s relation to beetles and developments in coleopteran systematics in the last two centuries. Darwin was an enthusiastic beetle collector. He used beetles to illustrate different evolutionary phenomena in his major works, and astonishingly, an entire sub-chapter is dedicated to beetles in “The Descent of Man”. During his voyage on the Beagle, Darwin was impressed by the high diversity of beetles in the tropics, and he remarked that, to his surprise, the majority of species were small and inconspicuous. However, despite his obvious interest in the group, he did not get involved in beetle taxonomy, and his theoretical work had little immediate impact on beetle classification. The development of taxonomy and classification in the late nineteenth and earlier twentieth century was mainly characterised by the exploration of new character systems (e.g. larval features and wing venation). In the mid-twentieth century, Hennig’s new methodology to group lineages by derived characters revolutionised systematics of Coleoptera and other organisms. As envisioned by Darwin and Ernst Haeckel, the new Hennigian approach enabled systematists to establish classifications truly reflecting evolution. Roy A. Crowson and Howard E. Hinton, who both made tremendous contributions to coleopterology, had an ambivalent attitude towards the Hennigian ideas. The Mickoleit school combined detailed anatomical work with a classical Hennigian character evaluation, with stepwise tree building, comparatively few characters and a priori polarity assessment without explicit use of the outgroup comparison method. The rise of cladistic methods in the 1970s had a strong impact on beetle systematics. Cladistic computer programs facilitated parsimony analyses of large data matrices, mostly morphological characters not requiring detailed anatomical investigations. Molecular studies on beetle phylogeny started in the 1990s with modest taxon sampling and limited DNA data

  5. The revised classification of eukaryotes

    PubMed Central

    Adl, Sina M.; Simpson, Alastair. G.; Lane, Christopher E.; Lukeš, Julius; Bass, David; Bowser, Samuel S.; Brown, Matt; Burki, Fabien; Dunthorn, Micah; Hampl, Vladimir; Heiss, Aaron; Hoppenrath, Mona; Lara, Enrique; leGall, Line; Lynn, Denis H.; McManus, Hilary; Mitchell, Edward A. D.; Mozley-Stanridge, Sharon E.; Parfrey, Laura Wegener; Pawlowski, Jan; Rueckert, Sonja; Shadwick, Lora; Schoch, Conrad; Smirnov, Alexey; Spiegel, Frederick W.

    2012-01-01

    This revision of the classification of eukaryotes, which updates that of Adl et al. (2005), retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information. PMID:23020233

  6. The revised classification of eukaryotes.

    PubMed

    Adl, Sina M; Simpson, Alastair G B; Lane, Christopher E; Lukeš, Julius; Bass, David; Bowser, Samuel S; Brown, Matthew W; Burki, Fabien; Dunthorn, Micah; Hampl, Vladimir; Heiss, Aaron; Hoppenrath, Mona; Lara, Enrique; Le Gall, Line; Lynn, Denis H; McManus, Hilary; Mitchell, Edward A D; Mozley-Stanridge, Sharon E; Parfrey, Laura W; Pawlowski, Jan; Rueckert, Sonja; Shadwick, Laura; Shadwick, Lora; Schoch, Conrad L; Smirnov, Alexey; Spiegel, Frederick W

    2012-09-01

    This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information.

  7. Refuting phylogenetic relationships

    PubMed Central

    Bucknam, James; Boucher, Yan; Bapteste, Eric

    2006-01-01

    Background Phylogenetic methods are philosophically grounded, and so can be philosophically biased in ways that limit explanatory power. This constitutes an important methodologic dimension not often taken into account. Here we address this dimension in the context of concatenation approaches to phylogeny. Results We discuss some of the limits of a methodology restricted to verificationism, the philosophy on which gene concatenation practices generally rely. As an alternative, we describe a software which identifies and focuses on impossible or refuted relationships, through a simple analysis of bootstrap bipartitions, followed by multivariate statistical analyses. We show how refuting phylogenetic relationships could in principle facilitate systematics. We also apply our method to the study of two complex phylogenies: the phylogeny of the archaea and the phylogeny of the core of genes shared by all life forms. While many groups are rejected, our results left open a possible proximity of N. equitans and the Methanopyrales, of the Archaea and the Cyanobacteria, and as well the possible grouping of the Methanobacteriales/Methanoccocales and Thermosplasmatales, of the Spirochaetes and the Actinobacteria and of the Proteobacteria and firmicutes. Conclusion It is sometimes easier (and preferable) to decide which species do not group together than which ones do. When possible topologies are limited, identifying local relationships that are rejected may be a useful alternative to classical concatenation approaches aiming to find a globally resolved tree on the basis of weak phylogenetic markers. Reviewers This article was reviewed by Mark Ragan, Eugene V Koonin and J Peter Gogarten. PMID:16956399

  8. Why the Phylogenetic Species Concept?—Elementary

    PubMed Central

    Wheeler, Quentin D.

    1999-01-01

    Although species play a number of unique and necessary roles in biology, none are more important than as the elements of phylogeny, nomenclature, and biodiversity study. Species are not divisible into any smaller units among which shared derived characters can be recognized with fidelity. Biodiversity inventory, assessment, and conservation are dependent upon a uniformly applicable species concept. Species are the fundamental units in formal Linnaean classification and zoological nomenclature. The Biological Species Concept, long given nominal support by most zoologists, forced an essentialy taxonomic problem (what are species?) into a population genetics framework (why are there species?). Early efforts at a phylogenetic species concept focused on correcting problems in the Biological Species Concept associated with ancestral populations, then applying phylogenetic logic to species themselves. Subsequently, Eldredge and Cracraft, and Nelson and Platnick, each proposed essentially identical and truly phylogenetic species concepts that permitted the rigorous recognition of species prior to and for the purposes of phylogenetic analysis, yet maintained the integrity of the Phylogenetic Species Concept outside of cladistic analysis. Such phylogenetic elements have many benefits, including giving to biology a unit species concept applicable across all kinds of living things including sexual and asexual forms. This is possible because the Phylogenetic Species Concept is based on patterns of character distributions and is therefore consistent with the full range of possible evolutionary processes that contribute to species formation, including both biotic and abiotic (even random) factors. PMID:19270883

  9. ClassyFlu: classification of influenza A viruses with Discriminatively trained profile-HMMs.

    PubMed

    Van der Auwera, Sandra; Bulla, Ingo; Ziller, Mario; Pohlmann, Anne; Harder, Timm; Stanke, Mario

    2014-01-01

    Accurate and rapid characterization of influenza A virus (IAV) hemagglutinin (HA) and neuraminidase (NA) sequences with respect to subtype and clade is at the basis of extended diagnostic services and implicit to molecular epidemiologic studies. ClassyFlu is a new tool and web service for the classification of IAV sequences of the HA and NA gene into subtypes and phylogenetic clades using discriminatively trained profile hidden Markov models (HMMs), one for each subtype or clade. ClassyFlu merely requires as input unaligned, full-length or partial HA or NA DNA sequences. It enables rapid and highly accurate assignment of HA sequences to subtypes H1-H17 but particularly focusses on the finer grained assignment of sequences of highly pathogenic avian influenza viruses of subtype H5N1 according to the cladistics proposed by the H5N1 Evolution Working Group. NA sequences are classified into subtypes N1-N10. ClassyFlu was compared to semiautomatic classification approaches using BLAST and phylogenetics and additionally for H5 sequences to the new "Highly Pathogenic H5N1 Clade Classification Tool" (IRD-CT) proposed by the Influenza Research Database. Our results show that both web tools (ClassyFlu and IRD-CT), although based on different methods, are nearly equivalent in performance and both are more accurate and faster than semiautomatic classification. A retraining of ClassyFlu to altered cladistics as well as an extension of ClassyFlu to other IAV genome segments or fragments thereof is undemanding. This is exemplified by unambiguous assignment to a distinct cluster within subtype H7 of sequences of H7N9 viruses which emerged in China early in 2013 and caused more than 130 human infections. http://bioinf.uni-greifswald.de/ClassyFlu is a free web service. For local execution, the ClassyFlu source code in PERL is freely available.

  10. Phylogenetic versus functional signals in the evolution of form-function relationships in terrestrial vision.

    PubMed

    Motani, Ryosuke; Schmitz, Lars

    2011-08-01

    Phylogeny is deeply pertinent to evolutionary studies. Traits that perform a body function are expected to be strongly influenced by physical "requirements" of the function. We investigated if such traits exhibit phylogenetic signals, and, if so, how phylogenetic noises bias quantification of form-function relationships. A form-function system that is strongly influenced by physics, namely the relationship between eye morphology and visual optics in amniotes, was used. We quantified the correlation between form (i.e., eye morphology) and function (i.e., ocular optics) while varying the level of phylogenetic bias removal through adjusting Pagel's λ. Ocular soft-tissue dimensions exhibited the highest correlation with ocular optics when 1% of phylogenetic bias expected from Brownian motion was removed (i.e., λ= 0.01); the value for hard-tissue data were 8%. A small degree of phylogenetic bias therefore exists in morphology despite of the stringent functional constraints. We also devised a phylogenetically informed discriminant analysis and recorded the effects of phylogenetic bias on this method using the same data. Use of proper λ values during phylogenetic bias removal improved misidentification rates in resulting classifications when prior probabilities were assumed to be equal. Even a small degree of phylogenetic bias affected the classification resulting from phylogenetically informed discriminant analysis.

  11. Phylogenetic proximity revealed by neurodevelopmental event timings.

    PubMed

    Nagarajan, Radhakrishnan; Clancy, Barbara

    2008-01-01

    Statistical properties such as distribution and correlation signatures were investigated using a temporal database of common neurodevelopmental events in the three species most frequently used in experimental studies, rat, mouse, and macaque. There was a fine nexus between phylogenetic proximity and empirically derived dates of the occurrences of 40 common events including the neurogenesis of cortical layers and outgrowth milestones of developing axonal projections. Exponential and power-law approximations to the distribution of the events reveal strikingly similar decay patterns in rats and mice when compared to macaques. Subsequent hierarchical clustering of the common event timings also captures phylogenetic proximity, an association further supported by multivariate linear regression data. These preliminary results suggest that statistical analyses of the timing of developmental milestones may offer a novel measure of phylogenetic classifications. This may have added pragmatic value in the specific support it offers for the reliability of rat/mouse comparative modeling, as well as in the broader implications for the potential of meta-analyses using databases assembled from the extensive empirical literature.

  12. CREST--classification resources for environmental sequence tags.

    PubMed

    Lanzén, Anders; Jørgensen, Steffen L; Huson, Daniel H; Gorfer, Markus; Grindhaug, Svenn Helge; Jonassen, Inge; Øvreås, Lise; Urich, Tim

    2012-01-01

    Sequencing of taxonomic or phylogenetic markers is becoming a fast and efficient method for studying environmental microbial communities. This has resulted in a steadily growing collection of marker sequences, most notably of the small-subunit (SSU) ribosomal RNA gene, and an increased understanding of microbial phylogeny, diversity and community composition patterns. However, to utilize these large datasets together with new sequencing technologies, a reliable and flexible system for taxonomic classification is critical. We developed CREST (Classification Resources for Environmental Sequence Tags), a set of resources and tools for generating and utilizing custom taxonomies and reference datasets for classification of environmental sequences. CREST uses an alignment-based classification method with the lowest common ancestor algorithm. It also uses explicit rank similarity criteria to reduce false positives and identify novel taxa. We implemented this method in a web server, a command line tool and the graphical user interfaced program MEGAN. Further, we provide the SSU rRNA reference database and taxonomy SilvaMod, derived from the publicly available SILVA SSURef, for classification of sequences from bacteria, archaea and eukaryotes. Using cross-validation and environmental datasets, we compared the performance of CREST and SilvaMod to the RDP Classifier. We also utilized Greengenes as a reference database, both with CREST and the RDP Classifier. These analyses indicate that CREST performs better than alignment-free methods with higher recall rate (sensitivity) as well as precision, and with the ability to accurately identify most sequences from novel taxa. Classification using SilvaMod performed better than with Greengenes, particularly when applied to environmental sequences. CREST is freely available under a GNU General Public License (v3) from http://apps.cbu.uib.no/crest and http://lcaclassifier.googlecode.com.

  13. Associations of Leaf Spectra with Genetic and Phylogenetic Variation in Oaks: Prospects for Remote Detection of Biodiversity

    SciTech Connect

    Cavender-Bares, Jeannine; Meireles, Jose; Couture, John; Kaproth, Matthew; Kingdon, Clayton; Singh, Aditya; Serbin, Shawn; Center, Alyson; Zuniga, Esau; Pilz, George; Townsend, Philip

    2016-03-09

    Species and phylogenetic lineages have evolved to differ in the way that they acquire and deploy resources, with consequences for their physiological, chemical and structural attributes, many of which can be detected using spectral reflectance form leaves. Recent technological advances for assessing optical properties of plants offer opportunities to detect functional traits of organisms and differentiate levels of biological organization across the tree of life. We connect leaf-level full range spectral data (400–2400 nm) of leaves to the hierarchical organization of plant diversity within the oak genus (Quercus) using field and greenhouse experiments in which environmental factors and plant age are controlled. We show that spectral data significantly differentiate populations within a species and that spectral similarity is significantly associated with phylogenetic similarity among species. Furthermore, we show that hyperspectral information allows more accurate classification of taxa than spectrally-derived traits, which by definition are of lower dimensionality. Finally, model accuracy increases at higher levels in the hierarchical organization of plant diversity, such that we are able to better distinguish clades than species or populations. This pattern supports an evolutionary explanation for the degree of optical differentiation among plants and demonstrates potential for remote detection of genetic and phylogenetic diversity.

  14. Associations of Leaf Spectra with Genetic and Phylogenetic Variation in Oaks: Prospects for Remote Detection of Biodiversity

    DOE PAGES

    Cavender-Bares, Jeannine; Meireles, Jose; Couture, John; ...

    2016-03-09

    Species and phylogenetic lineages have evolved to differ in the way that they acquire and deploy resources, with consequences for their physiological, chemical and structural attributes, many of which can be detected using spectral reflectance form leaves. Recent technological advances for assessing optical properties of plants offer opportunities to detect functional traits of organisms and differentiate levels of biological organization across the tree of life. We connect leaf-level full range spectral data (400–2400 nm) of leaves to the hierarchical organization of plant diversity within the oak genus (Quercus) using field and greenhouse experiments in which environmental factors and plant agemore » are controlled. We show that spectral data significantly differentiate populations within a species and that spectral similarity is significantly associated with phylogenetic similarity among species. Furthermore, we show that hyperspectral information allows more accurate classification of taxa than spectrally-derived traits, which by definition are of lower dimensionality. Finally, model accuracy increases at higher levels in the hierarchical organization of plant diversity, such that we are able to better distinguish clades than species or populations. This pattern supports an evolutionary explanation for the degree of optical differentiation among plants and demonstrates potential for remote detection of genetic and phylogenetic diversity.« less

  15. Phylogenetic Comparative Assembly

    NASA Astrophysics Data System (ADS)

    Husemann, Peter; Stoye, Jens

    Recent high throughput sequencing technologies are capable of generating a huge amount of data for bacterial genome sequencing projects. Although current sequence assemblers successfully merge the overlapping reads, often several contigs remain which cannot be assembled any further. It is still costly and time consuming to close all the gaps in order to acquire the whole genomic sequence. Here we propose an algorithm that takes several related genomes and their phylogenetic relationships into account to create a contig adjacency graph. From this a layout graph can be computed which indicates putative adjacencies of the contigs in order to aid biologists in finishing the complete genomic sequence.

  16. Iteratively Refined Guide Trees Help Improving Alignment and Phylogenetic Inference in the Mushroom Family Bolbitiaceae

    PubMed Central

    Tóth, Annamária; Hausknecht, Anton; Krisai-Greilhuber, Irmgard; Papp, Tamás; Vágvölgyi, Csaba; Nagy, László G.

    2013-01-01

    Reconciling traditional classifications, morphology, and the phylogenetic relationships of brown-spored agaric mushrooms has proven difficult in many groups, due to extensive convergence in morphological features. Here, we address the monophyly of the Bolbitiaceae, a family with over 700 described species and examine the higher-level relationships within the family using a newly constructed multilocus dataset (ITS, nrLSU rDNA and EF1-alpha). We tested whether the fast-evolving Internal Transcribed Spacer (ITS) sequences can be accurately aligned across the family, by comparing the outcome of two iterative alignment refining approaches (an automated and a manual) and various indel-treatment strategies. We used PRANK to align sequences in both cases. Our results suggest that – although PRANK successfully evades overmatching of gapped sites, referred previously to as alignment overmatching – it infers an unrealistically high number of indel events with natively generated guide-trees. This 'alignment undermatching' could be avoided by using more rigorous (e.g. ML) guide trees. The trees inferred in this study support the monophyly of the core Bolbitiaceae, with the exclusion of Panaeolus, Agrocybe, and some of the genera formerly placed in the family. Bolbitius and Conocybe were found monophyletic, however, Pholiotina and Galerella require redefinition. The phylogeny revealed that stipe coverage type is a poor predictor of phylogenetic relationships, indicating the need for a revision of the intrageneric relationships within Conocybe. PMID:23418526

  17. Canopy phylogenetic, chemical and spectral assembly in a lowland Amazonian forest.

    PubMed

    Asner, Gregory P; Martin, Roberta E

    2011-03-01

    • Canopy chemistry and spectroscopy offer insight into community assembly and ecosystem processes in high-diversity tropical forests, but phylogenetic and environmental factors controlling chemical traits underpinning spectral signatures remain poorly understood. • We measured 21 leaf chemical traits and spectroscopic signatures of 594 canopy individuals on high-fertility Inceptisols and low-fertility Ultisols in a lowland Amazonian forest. The spectranomics approach, which explicitly connects phylogenetic, chemical and spectral patterns in tropical canopies, provided the basis for analysis. • Intracrown and intraspecific variation in chemical traits varied from 1.4 to 36.7% (median 9.3%), depending upon the chemical constituent. Principal components analysis showed that 14 orthogonal combinations were required to explain 95% of the variation among 21 traits, indicating the high dimensionality of canopy chemical signatures among taxa. Inceptisols and lianas were associated with high leaf nutrient concentrations and low concentrations of defense compounds. Independent of soils or plant habit, an average 70% (maximum 89%) of chemical trait variation was explained by taxonomy. At least 10 traits were quantitatively linked to remotely sensed signatures, which provided highly accurate species classification. • The results suggest that taxa found on fertile soils carry chemical portfolios with a deep evolutionary history, whereas taxa found on low-fertility soils have undergone trait evolution at the species level. Spectranomics provides a new connection between remote sensing and community assembly theory in high-diversity tropical canopies.

  18. Iteratively refined guide trees help improving alignment and phylogenetic inference in the mushroom family Bolbitiaceae.

    PubMed

    Tóth, Annamária; Hausknecht, Anton; Krisai-Greilhuber, Irmgard; Papp, Tamás; Vágvölgyi, Csaba; Nagy, László G

    2013-01-01

    Reconciling traditional classifications, morphology, and the phylogenetic relationships of brown-spored agaric mushrooms has proven difficult in many groups, due to extensive convergence in morphological features. Here, we address the monophyly of the Bolbitiaceae, a family with over 700 described species and examine the higher-level relationships within the family using a newly constructed multilocus dataset (ITS, nrLSU rDNA and EF1-alpha). We tested whether the fast-evolving Internal Transcribed Spacer (ITS) sequences can be accurately aligned across the family, by comparing the outcome of two iterative alignment refining approaches (an automated and a manual) and various indel-treatment strategies. We used PRANK to align sequences in both cases. Our results suggest that--although PRANK successfully evades overmatching of gapped sites, referred previously to as alignment overmatching--it infers an unrealistically high number of indel events with natively generated guide-trees. This 'alignment undermatching' could be avoided by using more rigorous (e.g. ML) guide trees. The trees inferred in this study support the monophyly of the core Bolbitiaceae, with the exclusion of Panaeolus, Agrocybe, and some of the genera formerly placed in the family. Bolbitius and Conocybe were found monophyletic, however, Pholiotina and Galerella require redefinition. The phylogeny revealed that stipe coverage type is a poor predictor of phylogenetic relationships, indicating the need for a revision of the intrageneric relationships within Conocybe.

  19. Entanglement, Invariants, and Phylogenetics

    NASA Astrophysics Data System (ADS)

    Sumner, J. G.

    2007-10-01

    This thesis develops and expands upon known techniques of mathematical physics relevant to the analysis of the popular Markov model of phylogenetic trees required in biology to reconstruct the evolutionary relationships of taxonomic units from biomolecular sequence data. The techniques of mathematical physics are plethora and have been developed for some time. The Markov model of phylogenetics and its analysis is a relatively new technique where most progress to date has been achieved by using discrete mathematics. This thesis takes a group theoretical approach to the problem by beginning with a remarkable mathematical parallel to the process of scattering in particle physics. This is shown to equate to branching events in the evolutionary history of molecular units. The major technical result of this thesis is the derivation of existence proofs and computational techniques for calculating polynomial group invariant functions on a multi-linear space where the group action is that relevant to a Markovian time evolution. The practical results of this thesis are an extended analysis of the use of invariant functions in distance based methods and the presentation of a new reconstruction technique for quartet trees which is consistent with the most general Markov model of sequence evolution.

  20. Phylogenetic trees in bioinformatics

    SciTech Connect

    Burr, Tom L

    2008-01-01

    Genetic data is often used to infer evolutionary relationships among a collection of viruses, bacteria, animal or plant species, or other operational taxonomic units (OTU). A phylogenetic tree depicts such relationships and provides a visual representation of the estimated branching order of the OTUs. Tree estimation is unique for several reasons, including: the types of data used to represent each OTU; the use ofprobabilistic nucleotide substitution models; the inference goals involving both tree topology and branch length, and the huge number of possible trees for a given sample of a very modest number of OTUs, which implies that fmding the best tree(s) to describe the genetic data for each OTU is computationally demanding. Bioinformatics is too large a field to review here. We focus on that aspect of bioinformatics that includes study of similarities in genetic data from multiple OTUs. Although research questions are diverse, a common underlying challenge is to estimate the evolutionary history of the OTUs. Therefore, this paper reviews the role of phylogenetic tree estimation in bioinformatics, available methods and software, and identifies areas for additional research and development.

  1. The phylogenetic diversity of metagenomes.

    PubMed

    Kembel, Steven W; Eisen, Jonathan A; Pollard, Katherine S; Green, Jessica L

    2011-01-01

    Phylogenetic diversity--patterns of phylogenetic relatedness among organisms in ecological communities--provides important insights into the mechanisms underlying community assembly. Studies that measure phylogenetic diversity in microbial communities have primarily been limited to a single marker gene approach, using the small subunit of the rRNA gene (SSU-rRNA) to quantify phylogenetic relationships among microbial taxa. In this study, we present an approach for inferring phylogenetic relationships among microorganisms based on the random metagenomic sequencing of DNA fragments. To overcome challenges caused by the fragmentary nature of metagenomic data, we leveraged fully sequenced bacterial genomes as a scaffold to enable inference of phylogenetic relationships among metagenomic sequences from multiple phylogenetic marker gene families. The resulting metagenomic phylogeny can be used to quantify the phylogenetic diversity of microbial communities based on metagenomic data sets. We applied this method to understand patterns of microbial phylogenetic diversity and community assembly along an oceanic depth gradient, and compared our findings to previous studies of this gradient using SSU-rRNA gene and metagenomic analyses. Bacterial phylogenetic diversity was highest at intermediate depths beneath the ocean surface, whereas taxonomic diversity (diversity measured by binning sequences into taxonomically similar groups) showed no relationship with depth. Phylogenetic diversity estimates based on the SSU-rRNA gene and the multi-gene metagenomic phylogeny were broadly concordant, suggesting that our approach will be applicable to other metagenomic data sets for which corresponding SSU-rRNA gene sequences are unavailable. Our approach opens up the possibility of using metagenomic data to study microbial diversity in a phylogenetic context.

  2. A revision of infrageneric classification in Astelia Banks & Sol. ex R.Br. (Asteliaceae)

    PubMed Central

    Birch, Joanne L.

    2015-01-01

    Abstract Systematic investigations and phylogenetic analyses have indicated that Astelia, as currently circumscribed, is paraphyletic, with Collospermum nested within it. Further, Astelia subgenus Astelia is polyphyletic, and Astelia subgenera Asteliopsis and Tricella are paraphyletic, as currently circumscribed. Revision of the subgeneric classification of Astelia is warranted to ensure classification accurately reflects the evolutionary history of these taxa. Collospermum is relegated to synonymy within Astelia. Astelia is dioecious or polygamodioecious, with a superior ovary, anthers dorsi- or basifixed, pistillodes or pistils that have a single short or poorly defined style, a 3 lobed stigma, and fleshy uni- or trilocular fruit with funicular hairs that are poorly to well developed. Astelia subgenus Collospermum (Skottsb.) Birch is described. A key to Astelia sections is provided. Astelia hastata Colenso, Astelia montana Seem., and Astelia microsperma Colenso pro parte are resurrected and the new combination Astelia samoense (Skottsb.) Birch, comb. nov. is made. PMID:26312037

  3. Incompletely resolved phylogenetic trees inflate estimates of phylogenetic conservatism.

    PubMed

    Davies, T Jonathan; Kraft, Nathan J B; Salamin, Nicolas; Wolkovich, Elizabeth M

    2012-02-01

    The tendency for more closely related species to share similar traits and ecological strategies can be explained by their longer shared evolutionary histories and represents phylogenetic conservatism. How strongly species traits co-vary with phylogeny can significantly impact how we analyze cross-species data and can influence our interpretation of assembly rules in the rapidly expanding field of community phylogenetics. Phylogenetic conservatism is typically quantified by analyzing the distribution of species values on the phylogenetic tree that connects them. Many phylogenetic approaches, however, assume a completely sampled phylogeny: while we have good estimates of deeper phylogenetic relationships for many species-rich groups, such as birds and flowering plants, we often lack information on more recent interspecific relationships (i.e., within a genus). A common solution has been to represent these relationships as polytomies on trees using taxonomy as a guide. Here we show that such trees can dramatically inflate estimates of phylogenetic conservatism quantified using S. P. Blomberg et al.'s K statistic. Using simulations, we show that even randomly generated traits can appear to be phylogenetically conserved on poorly resolved trees. We provide a simple rarefaction-based solution that can reliably retrieve unbiased estimates of K, and we illustrate our method using data on first flowering times from Thoreau's woods (Concord, Massachusetts, USA).

  4. The evolution of HIV: Inferences using phylogenetics

    PubMed Central

    Castro-Nallar, Eduardo; Pérez-Losada, Marcos; Burton, Gregory F.; Crandall, Keith A.

    2011-01-01

    Molecular phylogenetics has revolutionized the study of not only evolution but also disparate fields such as genomics, bioinformatics, epidemiology, ecology, microbiology, molecular biology and biochemistry. Particularly significant are its achievements in population genetics as a result of the development of coalescent theory, which have contributed to more accurate model-based parameter estimation and explicit hypothesis testing. The study of the evolution of many microorganisms, and HIV in particular, have benefited from these new methodologies. HIV is well suited for such sophisticated population analyses because of its large population sizes, short generation times, high substitution rates and relatively small genomes. All these factors make HIV an ideal and fascinating model to study molecular evolution in real time. Here we review the significant advances made in HIV evolution through the application of phylogenetic approaches. We first examine the relative roles of mutation and recombination on the molecular evolution of HIV and its adaptive response to drug therapy and tissue allocation. We then review some of the fundamental questions in HIV evolution in relation to its origin and diversification and describe some of the insights gained using phylogenies. Finally, we show how phylogenetic analysis has advanced our knowledge of HIV dynamics (i.e., phylodynamics). PMID:22138161

  5. Bayesian phylogenetic estimation of fossil ages

    PubMed Central

    Drummond, Alexei J.; Stadler, Tanja

    2016-01-01

    Recent advances have allowed for both morphological fossil evidence and molecular sequences to be integrated into a single combined inference of divergence dates under the rule of Bayesian probability. In particular, the fossilized birth–death tree prior and the Lewis-Mk model of discrete morphological evolution allow for the estimation of both divergence times and phylogenetic relationships between fossil and extant taxa. We exploit this statistical framework to investigate the internal consistency of these models by producing phylogenetic estimates of the age of each fossil in turn, within two rich and well-characterized datasets of fossil and extant species (penguins and canids). We find that the estimation accuracy of fossil ages is generally high with credible intervals seldom excluding the true age and median relative error in the two datasets of 5.7% and 13.2%, respectively. The median relative standard error (RSD) was 9.2% and 7.2%, respectively, suggesting good precision, although with some outliers. In fact, in the two datasets we analyse, the phylogenetic estimate of fossil age is on average less than 2 Myr from the mid-point age of the geological strata from which it was excavated. The high level of internal consistency found in our analyses suggests that the Bayesian statistical model employed is an adequate fit for both the geological and morphological data, and provides evidence from real data that the framework used can accurately model the evolution of discrete morphological traits coded from fossil and extant taxa. We anticipate that this approach will have diverse applications beyond divergence time dating, including dating fossils that are temporally unconstrained, testing of the ‘morphological clock', and for uncovering potential model misspecification and/or data errors when controversial phylogenetic hypotheses are obtained based on combined divergence dating analyses. This article is part of the themed issue ‘Dating species divergences

  6. Phylogenetic constraints on ecosystem functioning.

    PubMed

    Gravel, Dominique; Bell, Thomas; Barbera, Claire; Combe, Marine; Pommier, Thomas; Mouquet, Nicolas

    2012-01-01

    There is consensus that biodiversity losses will result in declining ecosystem functioning if species have different functional traits. Phylogenetic diversity has recently been suggested as a predictor of ecosystem functioning because it could approximate the functional complementarity among species. Here we describe an experiment that takes advantage of the rapid evolutionary response of bacteria to disentangle the role of phylogenetic and species diversity. We impose a strong selection regime on marine bacterial lineages and assemble the ancestral and evolved lines in microcosms of varying lineage and phylogenetic diversity. We find that the relationship between phylogenetic diversity and productivity is strong for the ancestral lineages but brakes down for the evolved lineages. Our results not only emphasize the potential of using phylogeny to evaluate ecosystem functioning, but also they warn against using phylogenetics as a proxy for functional diversity without good information on species evolutionary history.

  7. Phylogenetic Quantification of Intra-tumour Heterogeneity

    PubMed Central

    Schwarz, Roland F.; Trinh, Anne; Sipos, Botond; Brenton, James D.; Goldman, Nick; Markowetz, Florian

    2014-01-01

    Intra-tumour genetic heterogeneity is the result of ongoing evolutionary change within each cancer. The expansion of genetically distinct sub-clonal populations may explain the emergence of drug resistance, and if so, would have prognostic and predictive utility. However, methods for objectively quantifying tumour heterogeneity have been missing and are particularly difficult to establish in cancers where predominant copy number variation prevents accurate phylogenetic reconstruction owing to horizontal dependencies caused by long and cascading genomic rearrangements. To address these challenges, we present MEDICC, a method for phylogenetic reconstruction and heterogeneity quantification based on a Minimum Event Distance for Intra-tumour Copy-number Comparisons. Using a transducer-based pairwise comparison function, we determine optimal phasing of major and minor alleles, as well as evolutionary distances between samples, and are able to reconstruct ancestral genomes. Rigorous simulations and an extensive clinical study show the power of our method, which outperforms state-of-the-art competitors in reconstruction accuracy, and additionally allows unbiased numerical quantification of tumour heterogeneity. Accurate quantification and evolutionary inference are essential to understand the functional consequences of tumour heterogeneity. The MEDICC algorithms are independent of the experimental techniques used and are applicable to both next-generation sequencing and array CGH data. PMID:24743184

  8. Three Domains, Not Five Kingdoms: A Phylogenetic Classification System.

    ERIC Educational Resources Information Center

    Peirce, Susan K.

    1999-01-01

    Argues that the Woesian three domain view of life should replace the five kingdom taxonomic scheme presented in most general biology texts and courses. Presents evidence for employing the three domain scheme and a related activity for classroom use. Contains 11 references. (WRM)

  9. A phylogenetic analysis of the myxobacteria: basis for their classification

    NASA Technical Reports Server (NTRS)

    Shimkets, L.; Woese, C. R.

    1992-01-01

    The primary sequence and secondary structural features of the 16S rRNA were compared for 12 different myxobacteria representing all the known cultivated genera. Analysis of these data show the myxobacteria to form a monophyletic grouping consisting of three distinct families, which lies within the delta subdivision of the purple bacterial phylum. The composition of the families is consistent with differences in cell and spore morphology, cell behavior, and pigment and secondary metabolite production but is not correlated with the morphological complexity of the fruiting bodies. The Nannocystis exedens lineage has evolved at an unusually rapid pace and its rRNA shows numerous primary and secondary structural idiosyncrasies.

  10. High-resolution phylogenetic microbial community profiling

    SciTech Connect

    Singer, Esther; Coleman-Derr, Devin; Bowman, Brett; Schwientek, Patrick; Clum, Alicia; Copeland, Alex; Ciobanu, Doina; Cheng, Jan-Fang; Gies, Esther; Hallam, Steve; Tringe, Susannah; Woyke, Tanja

    2014-03-17

    The representation of bacterial and archaeal genome sequences is strongly biased towards cultivated organisms, which belong to merely four phylogenetic groups. Functional information and inter-phylum level relationships are still largely underexplored for candidate phyla, which are often referred to as microbial dark matter. Furthermore, a large portion of the 16S rRNA gene records in the GenBank database are labeled as environmental samples and unclassified, which is in part due to low read accuracy, potential chimeric sequences produced during PCR amplifications and the low resolution of short amplicons. In order to improve the phylogenetic classification of novel species and advance our knowledge of the ecosystem function of uncultivated microorganisms, high-throughput full length 16S rRNA gene sequencing methodologies with reduced biases are needed. We evaluated the performance of PacBio single-molecule real-time (SMRT) sequencing in high-resolution phylogenetic microbial community profiling. For this purpose, we compared PacBio and Illumina metagenomic shotgun and 16S rRNA gene sequencing of a mock community as well as of an environmental sample from Sakinaw Lake, British Columbia. Sakinaw Lake is known to contain a large age of microbial species from candidate phyla. Sequencing results show that community structure based on PacBio shotgun and 16S rRNA gene sequences is highly similar in both the mock and the environmental communities. Resolution power and community representation accuracy from SMRT sequencing data appeared to be independent of GC content of microbial genomes and was higher when compared to Illumina-based metagenome shotgun and 16S rRNA gene (iTag) sequences, e.g. full-length sequencing resolved all 23 OTUs in the mock community, while iTags did not resolve closely related species. SMRT sequencing hence offers various potential benefits when characterizing uncharted microbial communities.

  11. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  12. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  13. Phylogenetic metrics of community similarity.

    PubMed

    Ives, Anthony R; Helmus, Matthew R

    2010-11-01

    We derive a new metric of community similarity that takes into account the phylogenetic relatedness among species. This metric, phylogenetic community dissimilarity (PCD), can be partitioned into two components, a nonphylogenetic component that reflects shared species between communities (analogous to Sørensen' s similarity metric) and a phylogenetic component that reflects the evolutionary relationships among nonshared species. Therefore, even if a species is not shared between two communities, it will increase the similarity of the two communities if it is phylogenetically related to species in the other community. We illustrate PCD with data on fish and aquatic macrophyte communities from 59 temperate lakes. Dissimilarity between fish communities associated with environmental differences between lakes often has a phylogenetic component, whereas this is not the case for macrophyte communities. With simulations, we then compare PCD with two other metrics of phylogenetic community similarity, II(ST) and UniFrac. Of the three metrics, PCD was best at identifying environmental drivers of community dissimilarity, showing lower variability and greater statistical power. Thus, PCD is a statistically powerful metric that separates the effects of environmental drivers on compositional versus phylogenetic components of community structure.

  14. Accurate Transposable Element Annotation Is Vital When Analyzing New Genome Assemblies

    PubMed Central

    Platt, Roy N.; Blanco-Berdugo, Laura; Ray, David A.

    2016-01-01

    Transposable elements (TEs) are mobile genetic elements with the ability to replicate themselves throughout the host genome. In some taxa TEs reach copy numbers in hundreds of thousands and can occupy more than half of the genome. The increasing number of reference genomes from nonmodel species has begun to outpace efforts to identify and annotate TE content and methods that are used vary significantly between projects. Here, we demonstrate variation that arises in TE annotations when less than optimal methods are used. We found that across a variety of taxa, the ability to accurately identify TEs based solely on homology decreased as the phylogenetic distance between the queried genome and a reference increased. Next we annotated repeats using homology alone, as is often the case in new genome analyses, and a combination of homology and de novo methods as well as an additional manual curation step. Reannotation using these methods identified a substantial number of new TE subfamilies in previously characterized genomes, recognized a higher proportion of the genome as repetitive, and decreased the average genetic distance within TE families, implying recent TE accumulation. Finally, these finding—increased recognition of younger TEs—were confirmed via an analysis of the postman butterfly (Heliconius melpomene). These observations imply that complete TE annotation relies on a combination of homology and de novo–based repeat identification, manual curation, and classification and that relying on simple, homology-based methods is insufficient to accurately describe the TE landscape of a newly sequenced genome. PMID:26802115

  15. Accurate Transposable Element Annotation Is Vital When Analyzing New Genome Assemblies.

    PubMed

    Platt, Roy N; Blanco-Berdugo, Laura; Ray, David A

    2016-01-21

    Transposable elements (TEs) are mobile genetic elements with the ability to replicate themselves throughout the host genome. In some taxa TEs reach copy numbers in hundreds of thousands and can occupy more than half of the genome. The increasing number of reference genomes from nonmodel species has begun to outpace efforts to identify and annotate TE content and methods that are used vary significantly between projects. Here, we demonstrate variation that arises in TE annotations when less than optimal methods are used. We found that across a variety of taxa, the ability to accurately identify TEs based solely on homology decreased as the phylogenetic distance between the queried genome and a reference increased. Next we annotated repeats using homology alone, as is often the case in new genome analyses, and a combination of homology and de novo methods as well as an additional manual curation step. Reannotation using these methods identified a substantial number of new TE subfamilies in previously characterized genomes, recognized a higher proportion of the genome as repetitive, and decreased the average genetic distance within TE families, implying recent TE accumulation. Finally, these finding-increased recognition of younger TEs-were confirmed via an analysis of the postman butterfly (Heliconius melpomene). These observations imply that complete TE annotation relies on a combination of homology and de novo-based repeat identification, manual curation, and classification and that relying on simple, homology-based methods is insufficient to accurately describe the TE landscape of a newly sequenced genome.

  16. Phylogenetics and the Human Microbiome

    PubMed Central

    Matsen, Frederick A.

    2015-01-01

    The human microbiome is the ensemble of genes in the microbes that live inside and on the surface of humans. Because microbial sequencing information is now much easier to come by than phenotypic information, there has been an explosion of sequencing and genetic analysis of microbiome samples. Much of the analytical work for these sequences involves phylogenetics, at least indirectly, but methodology has developed in a somewhat different direction than for other applications of phylogenetics. In this article, I review the field and its methods from the perspective of a phylogeneticist, as well as describing current challenges for phylogenetics coming from this type of work. PMID:25102857

  17. Phylogenetics and the human microbiome.

    PubMed

    Matsen, Frederick A

    2015-01-01

    The human microbiome is the ensemble of genes in the microbes that live inside and on the surface of humans. Because microbial sequencing information is now much easier to come by than phenotypic information, there has been an explosion of sequencing and genetic analysis of microbiome samples. Much of the analytical work for these sequences involves phylogenetics, at least indirectly, but methodology has developed in a somewhat different direction than for other applications of phylogenetics. In this article, I review the field and its methods from the perspective of a phylogeneticist, as well as describing current challenges for phylogenetics coming from this type of work.

  18. An Optimization-Based Sampling Scheme for Phylogenetic Trees

    NASA Astrophysics Data System (ADS)

    Misra, Navodit; Blelloch, Guy; Ravi, R.; Schwartz, Russell

    Much modern work in phylogenetics depends on statistical sampling approaches to phylogeny construction to estimate probability distributions of possible trees for any given input data set. Our theoretical understanding of sampling approaches to phylogenetics remains far less developed than that for optimization approaches, however, particularly with regard to the number of sampling steps needed to produce accurate samples of tree partition functions. Despite the many advantages in principle of being able to sample trees from sophisticated probabilistic models, we have little theoretical basis for concluding that the prevailing sampling approaches do in fact yield accurate samples from those models within realistic numbers of steps. We propose a novel approach to phylogenetic sampling intended to be both efficient in practice and more amenable to theoretical analysis than the prevailing methods. The method depends on replacing the standard tree rearrangement moves with an alternative Markov model in which one solves a theoretically hard but practically tractable optimization problem on each step of sampling. The resulting method can be applied to a broad range of standard probability models, yielding practical algorithms for efficient sampling and rigorous proofs of accurate sampling for some important special cases. We demonstrate the efficiency and versatility of the method in an analysis of uncertainty in tree inference over varying input sizes. In addition to providing a new practical method for phylogenetic sampling, the technique is likely to prove applicable to many similar problems involving sampling over combinatorial objects weighted by a likelihood model.

  19. [Foundations of the new phylogenetics].

    PubMed

    Pavlinov, I Ia

    2004-01-01

    Evolutionary idea is the core of the modern biology. Due to this, phylogenetics dealing with historical reconstructions in biology takes a priority position among biological disciplines. The second half of the 20th century witnessed growth of a great interest to phylogenetic reconstructions at macrotaxonomic level which replaced microevolutionary studies dominating during the 30s-60s. This meant shift from population thinking to phylogenetic one but it was not revival of the classical phylogenetics; rather, a new approach emerged that was baptized The New Phylogenetics. It arose as a result of merging of three disciplines which were developing independently during 60s-70s, namely cladistics, numerical phyletics, and molecular phylogenetics (now basically genophyletics). Thus, the new phylogenetics could be defined as a branch of evolutionary biology aimed at elaboration of "parsimonious" cladistic hypotheses by means of numerical methods on the basis of mostly molecular data. Classical phylogenetics, as a historical predecessor of the new one, emerged on the basis of the naturphilosophical worldview which included a superorganismal idea of biota. Accordingly to that view, historical development (the phylogeny) was thought an analogy of individual one (the ontogeny) so its most basical features were progressive parallel developments of "parts" (taxa), supplemented with Darwinian concept of monophyly. Two predominating traditions were diverged within classical phylogenetics according to a particular interpretation of relation between these concepts. One of them (Cope, Severtzow) belittled monophyly and paid most attention to progressive parallel developments of morphological traits. Such an attitude turned this kind of phylogenetics to be rather the semogenetics dealing primarily with evolution of structures and not of taxa. Another tradition (Haeckel) considered both monophyletic and parallel origins of taxa jointly: in the middle of 20th century it was split into

  20. Contextual classification of multispectral image data: Approximate algorithm

    NASA Technical Reports Server (NTRS)

    Tilton, J. C. (Principal Investigator)

    1980-01-01

    An approximation to a classification algorithm incorporating spatial context information in a general, statistical manner is presented which is computationally less intensive. Classifications that are nearly as accurate are produced.

  1. Integrated classification of inflammatory myopathies.

    PubMed

    Allenbach, Y; Benveniste, O; Goebel, H-H; Stenzel, W

    2017-02-01

    Inflammatory myopathies comprise a multitude of diverse diseases, most often occurring in complex clinical settings. To ensure accurate diagnosis, multidisciplinary expertise is required. Here, we propose a comprehensive myositis classification that incorporates clinical, morphological and molecular data as well as autoantibody profile. This review focuses on recent advances in myositis research, in particular, the correlation between autoantibodies and morphological or clinical phenotypes that can be used as the basis for an 'integrated' classification system.

  2. Phylogenetics: bats united, microbats divided.

    PubMed

    Springer, Mark S

    2013-11-18

    Phylogenetic analyses on four new bat genomes provide convincing support for the placement of bats relative to other placental mammals, suggest that microbats are an unnatural group, and have important implications for understanding the evolution of echolocation.

  3. Community Phylogenetics: Assessing Tree Reconstruction Methods and the Utility of DNA Barcodes.

    PubMed

    Boyle, Elizabeth E; Adamowicz, Sarah J

    2015-01-01

    Studies examining phylogenetic community structure have become increasingly prevalent, yet little attention has been given to the influence of the input phylogeny on metrics that describe phylogenetic patterns of co-occurrence. Here, we examine the influence of branch length, tree reconstruction method, and amount of sequence data on measures of phylogenetic community structure, as well as the phylogenetic signal (Pagel's λ) in morphological traits, using Trichoptera larval communities from Churchill, Manitoba, Canada. We find that model-based tree reconstruction methods and the use of a backbone family-level phylogeny improve estimations of phylogenetic community structure. In addition, trees built using the barcode region of cytochrome c oxidase subunit I (COI) alone accurately predict metrics of phylogenetic community structure obtained from a multi-gene phylogeny. Input tree did not alter overall conclusions drawn for phylogenetic signal, as significant phylogenetic structure was detected in two body size traits across input trees. As the discipline of community phylogenetics continues to expand, it is important to investigate the best approaches to accurately estimate patterns. Our results suggest that emerging large datasets of DNA barcode sequences provide a vast resource for studying the structure of biological communities.

  4. Phylogenetic lineages in Pseudocercospora

    PubMed Central

    Crous, P.W.; Braun, U.; Hunter, G.C.; Wingfield, M.J.; Verkley, G.J.M.; Shin, H.-D.; Nakashima, C.; Groenewald, J.Z.

    2013-01-01

    Pseudocercospora is a large cosmopolitan genus of plant pathogenic fungi that are commonly associated with leaf and fruit spots as well as blights on a wide range of plant hosts. They occur in arid as well as wet environments and in a wide range of climates including cool temperate, sub-tropical and tropical regions. Pseudocercospora is now treated as a genus in its own right, although formerly recognised as either an anamorphic state of Mycosphaerella or having mycosphaerella-like teleomorphs. The aim of this study was to sequence the partial 28S nuclear ribosomal RNA gene of a selected set of isolates to resolve phylogenetic generic limits within the Pseudocercospora complex. From these data, 14 clades are recognised, six of which cluster in Mycosphaerellaceae. Pseudocercospora s. str. represents a distinct clade, sister to Passalora eucalypti, and a clade representing the genera Scolecostigmina, Trochophora and Pallidocercospora gen. nov., taxa formerly accommodated in the Mycosphaerella heimii complex and characterised by smooth, pale brown conidia, as well as the formation of red crystals in agar media. Other clades in Mycosphaerellaceae include Sonderhenia, Microcyclosporella, and Paracercospora. Pseudocercosporella resides in a large clade along with Phloeospora, Miuraea, Cercospora and Septoria. Additional clades represent Dissoconiaceae, Teratosphaeriaceae, Cladosporiaceae, and the genera Xenostigmina, Strelitziana, Cyphellophora and Thedgonia. The genus Phaeomycocentrospora is introduced to accommodate Mycocentrospora cantuariensis, primarily distinguished from Pseudocercospora based on its hyaline hyphae, broad conidiogenous loci and hila. Host specificity was considered for 146 species of Pseudocercospora occurring on 115 host genera from 33 countries. Partial nucleotide sequence data for three gene loci, ITS, EF-1α, and ACT suggest that the majority of these species are host specific. Species identified on the basis of host, symptomatology and general

  5. Molecular systematics of Volvocales (Chlorophyceae, Chlorophyta) based on exhaustive 18S rRNA phylogenetic analyses.

    PubMed

    Nakada, Takashi; Misawa, Kazuharu; Nozaki, Hisayoshi

    2008-07-01

    The taxonomy of Volvocales (Chlorophyceae, Chlorophyta) was traditionally based solely on morphological characteristics. However, because recent molecular phylogeny largely contradicts the traditional subordinal and familial classifications, no classification system has yet been established that describes the subdivision of Volvocales in a manner consistent with the phylogenetic relationships. Towards development of a natural classification system at and above the generic level, identification and sorting of hundreds of sequences based on subjective phylogenetic definitions is a significant step. We constructed an 18S rRNA gene phylogeny based on 449 volvocalean sequences collected using exhaustive BLAST searches of the GenBank database. Many chimeric sequences, which can cause fallacious phylogenetic trees, were detected and excluded during data collection. The results revealed 21 strongly supported primary clades within phylogenetically redefined Volvocales. Phylogenetic classification following PhyloCode was proposed based on the presented 18S rRNA gene phylogeny along with the results of previous combined 18S and 26S rRNA and chloroplast multigene analyses.

  6. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  7. Multiple Sparse Representations Classification

    PubMed Central

    Plenge, Esben; Klein, Stefan S.; Niessen, Wiro J.; Meijering, Erik

    2015-01-01

    Sparse representations classification (SRC) is a powerful technique for pixelwise classification of images and it is increasingly being used for a wide variety of image analysis tasks. The method uses sparse representation and learned redundant dictionaries to classify image pixels. In this empirical study we propose to further leverage the redundancy of the learned dictionaries to achieve a more accurate classifier. In conventional SRC, each image pixel is associated with a small patch surrounding it. Using these patches, a dictionary is trained for each class in a supervised fashion. Commonly, redundant/overcomplete dictionaries are trained and image patches are sparsely represented by a linear combination of only a few of the dictionary elements. Given a set of trained dictionaries, a new patch is sparse coded using each of them, and subsequently assigned to the class whose dictionary yields the minimum residual energy. We propose a generalization of this scheme. The method, which we call multiple sparse representations classification (mSRC), is based on the observation that an overcomplete, class specific dictionary is capable of generating multiple accurate and independent estimates of a patch belonging to the class. So instead of finding a single sparse representation of a patch for each dictionary, we find multiple, and the corresponding residual energies provides an enhanced statistic which is used to improve classification. We demonstrate the efficacy of mSRC for three example applications: pixelwise classification of texture images, lumen segmentation in carotid artery magnetic resonance imaging (MRI), and bifurcation point detection in carotid artery MRI. We compare our method with conventional SRC, K-nearest neighbor, and support vector machine classifiers. The results show that mSRC outperforms SRC and the other reference methods. In addition, we present an extensive evaluation of the effect of the main mSRC parameters: patch size, dictionary size, and

  8. Genomic biodiversity, phylogenetics, and coevolution in proteins

    PubMed Central

    Pollock, David D

    2010-01-01

    Comprehensive sampling of genomic biodiversity is fast becoming a reality for some genomic regions and complete organelle genomes. Genomic biodiversity is defined as large genomic sequences from many species, and here some recent work is reviewed that demonstrates the potential benefits of genomic biodiversity for molecular evolutionary analysis and phylogenetic reconstruction. This work shows that using likelihood-based approaches, taxon addition can dramatically improve phylogenetic reconstruction. Features or dynamics of the evolutionary process are much more easily inferred with large numbers of taxa, and large numbers are essential for discriminating differences in evolutionary patterns between sites. Accurate prediction of site-specific patterns can improve phylogenetic reconstruction by an amount equivalent to quadrupling sequence length. Genomic biodiversity is particularly central to research relating patterns of evolution, adaptation and coevolution to structural and functional features of proteins. Research on detecting coevolution between amino acid residues in proteins demonstrates a clear need for much greater numbers of closely related taxa to better discriminate site-specific patterns of interaction, and to allow more detailed analysis of coevolutionary interactions between subunits in protein complexes. It is argued that parsing out coevolutionary and other context-dependent substitution probabilities is essential for discriminating between coevolution and adaptation, and for more realistically modelling the evolution of proteins. Also reviewed is research that argues for increasing the efficiency of acquiring genomic biodiversity, and suggests that this might be done by simultaneously shotgun cloning and sequencing genomic mixtures from many species. Increased efficiency is a prerequisite if genomic biodiversity levels are to rapidly increase by orders of magnitude, and thus lead to dramatically improved understanding of interactions between

  9. apex: phylogenetics with multiple genes.

    PubMed

    Jombart, Thibaut; Archer, Frederick; Schliep, Klaus; Kamvar, Zhian; Harris, Rebecca; Paradis, Emmanuel; Goudet, Jérome; Lapp, Hilmar

    2017-01-01

    Genetic sequences of multiple genes are becoming increasingly common for a wide range of organisms including viruses, bacteria and eukaryotes. While such data may sometimes be treated as a single locus, in practice, a number of biological and statistical phenomena can lead to phylogenetic incongruence. In such cases, different loci should, at least as a preliminary step, be examined and analysed separately. The r software has become a popular platform for phylogenetics, with several packages implementing distance-based, parsimony and likelihood-based phylogenetic reconstruction, and an even greater number of packages implementing phylogenetic comparative methods. Unfortunately, basic data structures and tools for analysing multiple genes have so far been lacking, thereby limiting potential for investigating phylogenetic incongruence. In this study, we introduce the new r package apex to fill this gap. apex implements new object classes, which extend existing standards for storing DNA and amino acid sequences, and provides a number of convenient tools for handling, visualizing and analysing these data. In this study, we introduce the main features of the package and illustrate its functionalities through the analysis of a simple data set.

  10. BIOACCESSIBILITY TESTS ACCURATELY ESTIMATE ...

    EPA Pesticide Factsheets

    Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

  11. On the nature of global classification

    NASA Technical Reports Server (NTRS)

    Wheelis, M. L.; Kandler, O.; Woese, C. R.

    1992-01-01

    Molecular sequencing technology has brought biology into the era of global (universal) classification. Methodologically and philosophically, global classification differs significantly from traditional, local classification. The need for uniformity requires that higher level taxa be defined on the molecular level in terms of universally homologous functions. A global classification should reflect both principal dimensions of the evolutionary process: genealogical relationship and quality and extent of divergence within a group. The ultimate purpose of a global classification is not simply information storage and retrieval; such a system should also function as an heuristic representation of the evolutionary paradigm that exerts a directing influence on the course of biology. The global system envisioned allows paraphyletic taxa. To retain maximal phylogenetic information in these cases, minor notational amendments in existing taxonomic conventions should be adopted.

  12. Phylogenetic Approaches Toward Crocodylian History

    NASA Astrophysics Data System (ADS)

    Brochu, Christopher A.

    A review of crocodylian phylogeny reveals a more complex history than might have been anticipated from a direct reading of the fossil record without consideration of phylogenetic relationships. The three main extant crocodylian lineagesGavialoidea, Alligatoroidea, Crocodyloideaare known from fossils in the Late Cretaceous, and the group is found nearly worldwide during the Cenozoic. Some groups have distributions that are best explained by the crossing of marine barriers during the Tertiary. Early Tertiary crocodylian faunas are phylogenetically composite, and clades tend to be morphologically uniform and geographically widespread. Later in the Tertiary, Old World crocodylian faunas are more endemic. Crocodylian phylogeneticists face numerous challenges, the most important being the phylogenetic relationships and time of divergence of the two living gharials (Gavialis gangeticus and Tomistoma schlegelii), the relationships among living true crocodiles (Crocodylus), and the relationships among caimans.

  13. Absolute Pitch in Boreal Chickadees and Humans: Exceptions that Test a Phylogenetic Rule

    ERIC Educational Resources Information Center

    Weisman, Ronald G.; Balkwill, Laura-Lee; Hoeschele, Marisa; Moscicki, Michele K.; Bloomfield, Laurie L.; Sturdy, Christopher B.

    2010-01-01

    This research examined generality of the phylogenetic rule that birds discriminate frequency ranges more accurately than mammals. Human absolute pitch chroma possessors accurately tracked transitions between frequency ranges. Independent tests showed that they used note naming (pitch chroma) to remap the tones into ranges; neither possessors nor…

  14. Accurate spectral color measurements

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    1999-08-01

    Surface color measurement is of importance in a very wide range of industrial applications including paint, paper, printing, photography, textiles, plastics and so on. For a demanding color measurements spectral approach is often needed. One can measure a color spectrum with a spectrophotometer using calibrated standard samples as a reference. Because it is impossible to define absolute color values of a sample, we always work with approximations. The human eye can perceive color difference as small as 0.5 CIELAB units and thus distinguish millions of colors. This 0.5 unit difference should be a goal for the precise color measurements. This limit is not a problem if we only want to measure the color difference of two samples, but if we want to know in a same time exact color coordinate values accuracy problems arise. The values of two instruments can be astonishingly different. The accuracy of the instrument used in color measurement may depend on various errors such as photometric non-linearity, wavelength error, integrating sphere dark level error, integrating sphere error in both specular included and specular excluded modes. Thus the correction formulas should be used to get more accurate results. Another question is how many channels i.e. wavelengths we are using to measure a spectrum. It is obvious that the sampling interval should be short to get more precise results. Furthermore, the result we get is always compromise of measuring time, conditions and cost. Sometimes we have to use portable syste or the shape and the size of samples makes it impossible to use sensitive equipment. In this study a small set of calibrated color tiles measured with the Perkin Elmer Lamda 18 and the Minolta CM-2002 spectrophotometers are compared. In the paper we explain the typical error sources of spectral color measurements, and show which are the accuracy demands a good colorimeter should have.

  15. Molecular phylogenetics and evolutionary history of ariid catfishes revisited: a comprehensive sampling

    PubMed Central

    Betancur-R, Ricardo

    2009-01-01

    Background Ariids or sea catfishes are one of the two otophysan fish families (out of about 67 families in four orders) that inhabit mainly marine and brackish waters (although some species occur strictly in fresh waters). The group includes over 150 species placed in ~29 genera and two subfamilies (Galeichthyinae and Ariinae). Despite their global distribution, ariids are largely restricted to the continental shelves due in part to their specialized reproductive behavior (i.e., oral incubation). Thus, among marine fishes, ariids offer an excellent opportunity for inferring historical biogeographic scenarios. Phylogenetic hypotheses available for ariids have focused on restricted geographic areas and comprehensive phylogenies are still missing. This study inferred phylogenetic hypotheses for 123 ariid species in 28 genera from different biogeographic provinces using both mitochondrial and nuclear sequences (up to ~4 kb). Results While the topologies obtained support the monophyly of basal groups, up to ten genera validated in previous morphological studies were incongruent with the molecular topologies. New World ariines were recovered as paraphyletic and Old World ariines were grouped into a well-supported clade that was further divided into subclades mainly restricted to major Gondwanan landmasses. A general area cladogram derived from the area cladograms of ariines and three other fish groups was largely congruent with the geological area cladogram of Gondwana. Nonetheless, molecular clock estimations provided variable results on the timing of ariine diversification (~105-41 mya). Conclusion This study provides the most comprehensive phylogeny of sea catfishes to date and highlights the need for re-assessment of their classification. While from a topological standpoint the evolutionary history of ariines is mostly congruent with vicariance associated with the sequence of events during Gondwanan fragmentation, ambiguous divergence time estimations hinders

  16. Functional Basis of Microorganism Classification.

    PubMed

    Zhu, Chengsheng; Delmont, Tom O; Vogel, Timothy M; Bromberg, Yana

    2015-08-01

    Correctly identifying nearest "neighbors" of a given microorganism is important in industrial and clinical applications where close relationships imply similar treatment. Microbial classification based on similarity of physiological and genetic organism traits (polyphasic similarity) is experimentally difficult and, arguably, subjective. Evolutionary relatedness, inferred from phylogenetic markers, facilitates classification but does not guarantee functional identity between members of the same taxon or lack of similarity between different taxa. Using over thirteen hundred sequenced bacterial genomes, we built a novel function-based microorganism classification scheme, functional-repertoire similarity-based organism network (FuSiON; flattened to fusion). Our scheme is phenetic, based on a network of quantitatively defined organism relationships across the known prokaryotic space. It correlates significantly with the current taxonomy, but the observed discrepancies reveal both (1) the inconsistency of functional diversity levels among different taxa and (2) an (unsurprising) bias towards prioritizing, for classification purposes, relatively minor traits of particular interest to humans. Our dynamic network-based organism classification is independent of the arbitrary pairwise organism similarity cut-offs traditionally applied to establish taxonomic identity. Instead, it reveals natural, functionally defined organism groupings and is thus robust in handling organism diversity. Additionally, fusion can use organism meta-data to highlight the specific environmental factors that drive microbial diversification. Our approach provides a complementary view to cladistic assignments and holds important clues for further exploration of microbial lifestyles. Fusion is a more practical fit for biomedical, industrial, and ecological applications, as many of these rely on understanding the functional capabilities of the microbes in their environment and are less concerned with

  17. Classification of Instructional Programs: 2000 Edition.

    ERIC Educational Resources Information Center

    Morgan, Robert L.; Hunt, E. Stephen

    This third revision of the Classification of Instructional Programs (CIP) updates and modifies education program classifications, providing a taxonomic scheme that supports the accurate tracking, assessment, and reporting of field of study and program completions activity. This edition has also been adopted as the standard field of study taxonomy…

  18. Phylogenetic Analysis of a Spontaneous Cocoa Bean Fermentation Metagenome Reveals New Insights into Its Bacterial and Fungal Community Diversity

    PubMed Central

    Illeghems, Koen; De Vuyst, Luc; Papalexandratou, Zoi; Weckx, Stefan

    2012-01-01

    This is the first report on the phylogenetic analysis of the community diversity of a single spontaneous cocoa bean box fermentation sample through a metagenomic approach involving 454 pyrosequencing. Several sequence-based and composition-based taxonomic profiling tools were used and evaluated to avoid software-dependent results and their outcome was validated by comparison with previously obtained culture-dependent and culture-independent data. Overall, this approach revealed a wider bacterial (mainly γ-Proteobacteria) and fungal diversity than previously found. Further, the use of a combination of different classification methods, in a software-independent way, helped to understand the actual composition of the microbial ecosystem under study. In addition, bacteriophage-related sequences were found. The bacterial diversity depended partially on the methods used, as composition-based methods predicted a wider diversity than sequence-based methods, and as classification methods based solely on phylogenetic marker genes predicted a more restricted diversity compared with methods that took all reads into account. The metagenomic sequencing analysis identified Hanseniaspora uvarum, Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus as the prevailing species. Also, the presence of occasional members of the cocoa bean fermentation process was revealed (such as Erwinia tasmaniensis, Lactobacillus brevis, Lactobacillus casei, Lactobacillus rhamnosus, Lactococcus lactis, Leuconostoc mesenteroides, and Oenococcus oeni). Furthermore, the sequence reads associated with viral communities were of a restricted diversity, dominated by Myoviridae and Siphoviridae, and reflecting Lactobacillus as the dominant host. To conclude, an accurate overview of all members of a cocoa bean fermentation process sample was revealed, indicating the superiority of metagenomic sequencing over previously used techniques. PMID:22666442

  19. Two issues in archaeological phylogenetics: taxon construction and outgroup selection.

    PubMed

    O'Brien, Michael J; Lyman, R Lee; Saab, Youssef; Saab, Elias; Darwent, John; Glover, Daniel S

    2002-03-21

    Cladistics is widely used in biology and paleobiology to construct phylogenetic hypotheses, but rarely has it been applied outside those disciplines. There is, however, no reason to suppose that cladistics is not applicable to anything that evolves by cladogenesis and produces a nested hierarchy of taxa. This includes cultural phenomena such as languages and tools recovered from archaeological contexts. Two methodological issues assume primacy in attempts to extend cladistics to archaeological materials: the construction of analytical taxa and the selection of appropriate outgroups. In biology the species is the primary taxonomic unit used, irrespective of the debates that have arisen in phylogenetic theory over the nature of species. Also in biology the phylogenetic history of a group of taxa usually is well enough known that an appropriate taxon can be selected as an outgroup. No analytical unit parallel to the species exists in archaeology, and thus taxa have to be constructed specifically for phylogenetic analysis. One method of constructing taxa is paradigmatic classification, which defines classes (taxa) on the basis of co-occurring, unweighted character states. Once classes have been created, a form of occurrence seriation-an archaeological method based on the theory of cultural transmission and heritability-offers an objective basis for selecting an outgroup.

  20. Classification of spatially unresolved objects

    NASA Technical Reports Server (NTRS)

    Nalepka, R. F.; Horwitz, H. M.; Hyde, P. D.; Morgenstern, J. P.

    1972-01-01

    A proportion estimation technique for classification of multispectral scanner images is reported that uses data point averaging to extract and compute estimated proportions for a single average data point to classify spatial unresolved areas. Example extraction calculations of spectral signatures for bare soil, weeds, alfalfa, and barley prove quite accurate.

  1. Phylogenetic relationships among Maloideae species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maloideae is a highly diverse sub-family of the Rosaceae containing several agronomically important species (Malus sp. and Pyrus sp.) and their wild relatives. Previous phylogenetic work within the group has revealed extensive intergeneric hybridization and polyploidization. In order to develop...

  2. Molecular phylogenetics: testing evolutionary hypotheses.

    PubMed

    Walsh, David A; Sharma, Adrian K

    2009-01-01

    A common approach for investigating evolutionary relationships between genes and organisms is to compare extant DNA or protein sequences and infer an evolutionary tree. This methodology is known as molecular phylogenetics and may be the most informative means for exploring phage evolution, since there are few morphological features that can be used to differentiate between these tiny biological entities. In addition, phage genomes can be mosaic, meaning different genes or genomic regions can exhibit conflicting evolutionary histories due to lateral gene transfer or homologous recombination between different phage genomes. Molecular phylogenetics can be used to identify and study such genome mosaicism. This chapter provides a general introduction to the theory and methodology used to reconstruct phylogenetic relationships from molecular data. Also included is a discussion on how the evolutionary history of different genes within the same set of genomes can be compared, using a collection of T4-type phage genomes as an example. A compilation of programs and packages that are available for conducting phylogenetic analyses is supplied as an accompanying appendix.

  3. Learning classification trees

    NASA Technical Reports Server (NTRS)

    Buntine, Wray

    1991-01-01

    Algorithms for learning classification trees have had successes in artificial intelligence and statistics over many years. How a tree learning algorithm can be derived from Bayesian decision theory is outlined. This introduces Bayesian techniques for splitting, smoothing, and tree averaging. The splitting rule turns out to be similar to Quinlan's information gain splitting rule, while smoothing and averaging replace pruning. Comparative experiments with reimplementations of a minimum encoding approach, Quinlan's C4 and Breiman et al. Cart show the full Bayesian algorithm is consistently as good, or more accurate than these other approaches though at a computational price.

  4. Cyber-infrastructure for Fusarium (CiF): Three integrated platforms supporting strain identification, phylogenetics, comparative genomics, and knowledge sharing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal genus Fusarium includes many plant and/or animal pathogenic species and produces diverse toxins. Although accurate identification is critical for managing such threats, it is difficult to identify Fusarium morphologically. Fortunately, extensive molecular phylogenetic studies, founded on ...

  5. Phylogenetic evidence for a new genotype of Acanthamoeba (Amoebozoa, Acanthamoebida).

    PubMed

    Corsaro, Daniele; Venditti, Danielle

    2010-06-01

    Acanthamoeba are widespread free-living amoebae, able to cause infection in animals, with keratitis and granulomatous encephalitis as major diseases in humans. Recent developments in the subgenus classification are based on the determination of the nucleotide sequence of the 18S rDNA. By this mean, Acanthamoeba have been clustered into 15 sequence types or genotypes, called T1 to T15. In this study, we analysed near full 18S rDNA of an Acanthamoeba recovered from an environmental sample and various unidentified Acanthamoeba sequences retrieved from GenBank. We provided phylogenetic evidence for a new genotype, which we proposed to name T16.

  6. Classification Analysis.

    ERIC Educational Resources Information Center

    Ball, Geoffrey H.

    Sorting things into groups is a basic intellectual task that allows people to simplify with minimal reduction in information. Classification techniques, which include both clustering and discrimination, provide step-by-step computer-based procedures for sorting things based on notions of generalized similarity and on the "class description"…

  7. [A new method of determining ages: chronological classification].

    PubMed

    Gubry, P

    1983-01-01

    Two methods of determining ages, the historical calendar method and the classification method, are compared using data for Chad from the UDEAC-TCHAD demographic survey. Complementary processing shows that the classification method is more accurate for those born in villages, while the historical method is more accurate for those born elsewhere. (summary in ENG)

  8. Phylogenetics of Saccharomycetales, the ascomycete yeasts.

    PubMed

    Suh, Sung-Oui; Blackwell, Meredith; Kurtzman, Cletus P; Lachance, Marc-André

    2006-01-01

    Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial and biotechnological processes, including baking, brewing and synthesis of recombinant proteins. Species such as Saccharomyces cerevisiae are model organisms in research, some of which led to a Nobel Prize. Yeasts usually reproduce asexually by budding, and their sexual states are not enclosed in a fruiting body. The group also is well defined by synapomorphies visible at the ultrastructural level. Yeast identification and classification changed dramatically with the availability of DNA sequencing. Species identification now benefits from a constantly updated sequence database and no longer relies on ambiguous growth tests. A phylogeny based on single gene analyses has shown the order to be remarkably divergent despite morphological similarities among members. The limits of many previously described genera are not supported by sequence comparisons, and multigene phylogenetic studies are under way to provide a stable circumscription of genera, families and orders. One recent multigene study has resolved species of the Saccharomycetaceae into genera that differ markedly from those defined by analysis of morphology and growth responses, and similar changes are likely to occur in other branches of the yeast tree as additional sequences become available.

  9. A Phylogenetic Study of Tribe Euphorbieae (Euphorbiaceae).

    PubMed

    Park; Elisens

    2000-05-01

    A phylogenetic investigation of a monophyletic lineage of spurge plants, tribe Euphorbieae, was conducted to elucidate evolutionary relationships, to clarify biogeographic patterns, and to reexamine the previous classification of Euphorbieae. Cladistic analyses of the 52 morphological characters of 61 species resulted in 2922 equally most parsimonious trees of 193 steps with a consistency index of 0.34. The strict consensus tree indicates genus Anthostema of subtribe Anthosteminae as a likely sister group to all other members of tribe Euphorbieae. The morphological data support a monophyletic origin of subtribe Euphorbiinae, but the subtribes Anthosteminae and Neoquillauminiinae did not form monophyletic groups. Although the previous taxonomic treatments within tribe Euphorbieae have supported the generic status of Pedilanthus, Monadenium, Synadenium, Chamaesyce, and Elaeophorbia, the results of this analysis do not support generic placement of them based on cladistic principles. Recognition of these groups as genera results in Euphorbia becoming a paraphyletic group. One solution to this problem in Euphorbieae is to divide the largest genus Euphorbia into several monophyletic genera and to keep the generic ranks for previously recognized genera. The distribution of basal endemic genera in Euphorbieae showed African and east Gondwanan affinities and strongly indicated that the ancestor of Euphorbieae originated prior to the breakup of Gondwanaland from an old group in Euphorbiaceae. However, some recent African taxa of Euphorbia should be interpreted by transoceanic dispersal from the New World ancestors.

  10. Molecular identification and phylogenetic study of Demodex caprae.

    PubMed

    Zhao, Ya-E; Cheng, Juan; Hu, Li; Ma, Jun-Xian

    2014-10-01

    The DNA barcode has been widely used in species identification and phylogenetic analysis since 2003, but there have been no reports in Demodex. In this study, to obtain an appropriate DNA barcode for Demodex, molecular identification of Demodex caprae based on mitochondrial cox1 was conducted. Firstly, individual adults and eggs of D. caprae were obtained for genomic DNA (gDNA) extraction; Secondly, mitochondrial cox1 fragment was amplified, cloned, and sequenced; Thirdly, cox1 fragments of D. caprae were aligned with those of other Demodex retrieved from GenBank; Finally, the intra- and inter-specific divergences were computed and the phylogenetic trees were reconstructed to analyze phylogenetic relationship in Demodex. Results obtained from seven 429-bp fragments of D. caprae showed that sequence identities were above 99.1% among three adults and four eggs. The intraspecific divergences in D. caprae, Demodex folliculorum, Demodex brevis, and Demodex canis were 0.0-0.9, 0.5-0.9, 0.0-0.2, and 0.0-0.5%, respectively, while the interspecific divergences between D. caprae and D. folliculorum, D. canis, and D. brevis were 20.3-20.9, 21.8-23.0, and 25.0-25.3, respectively. The interspecific divergences were 10 times higher than intraspecific ones, indicating considerable barcoding gap. Furthermore, the phylogenetic trees showed that four Demodex species gathered separately, representing independent species; and Demodex folliculorum gathered with canine Demodex, D. caprae, and D. brevis in sequence. In conclusion, the selected 429-bp mitochondrial cox1 gene is an appropriate DNA barcode for molecular classification, identification, and phylogenetic analysis of Demodex. D. caprae is an independent species and D. folliculorum is closer to D. canis than to D. caprae or D. brevis.

  11. HIV classification using coalescent theory

    SciTech Connect

    Zhang, Ming; Letiner, Thomas K; Korber, Bette T

    2008-01-01

    Algorithms for subtype classification and breakpoint detection of HIV-I sequences are based on a classification system of HIV-l. Hence, their quality highly depend on this system. Due to the history of creation of the current HIV-I nomenclature, the current one contains inconsistencies like: The phylogenetic distance between the subtype B and D is remarkably small compared with other pairs of subtypes. In fact, it is more like the distance of a pair of subsubtypes Robertson et al. (2000); Subtypes E and I do not exist any more since they were discovered to be composed of recombinants Robertson et al. (2000); It is currently discussed whether -- instead of CRF02 being a recombinant of subtype A and G -- subtype G should be designated as a circulating recombination form (CRF) nd CRF02 as a subtype Abecasis et al. (2007); There are 8 complete and over 400 partial HIV genomes in the LANL-database which belong neither to a subtype nor to a CRF (denoted by U). Moreover, the current classification system is somehow arbitrary like all complex classification systems that were created manually. To this end, it is desirable to deduce the classification system of HIV systematically by an algorithm. Of course, this problem is not restricted to HIV, but applies to all fast mutating and recombining viruses. Our work addresses the simpler subproblem to score classifications of given input sequences of some virus species (classification denotes a partition of the input sequences in several subtypes and CRFs). To this end, we reconstruct ancestral recombination graphs (ARG) of the input sequences under restrictions determined by the given classification. These restritions are imposed in order to ensure that the reconstructed ARGs do not contradict the classification under consideration. Then, we find the ARG with maximal probability by means of Markov Chain Monte Carlo methods. The probability of the most probable ARG is interpreted as a score for the classification. To our

  12. Phylogenetic diversity of nonmarine picocyanobacteria.

    PubMed

    Callieri, Cristiana; Coci, Manuela; Corno, Gianluca; Macek, Miroslav; Modenutti, Beatriz; Balseiro, Esteban; Bertoni, Roberto

    2013-08-01

    We studied the phylogenetic diversity of nonmarine picocyanobacteria broadening the sequence data set with 43 new sequences of the 16S rRNA gene. The sequences were derived from monoclonal strains isolated from four volcanic high-altitude athalassohaline lakes in Mexico, five glacial ultraoligotrophic North Patagonian lakes and six Italian lakes of glacial, volcanic and morenic origin. The new sequences fall into a number of both novel and previously described clades within the phylogenetic tree of 16S rRNA gene. The new cluster of Lake Nahuel Huapi (North Patagonia) forms a sister clade to the subalpine cluster II and the marine Synechococcus subcluster 5.2. Our finding of the novel clade of 'halotolerants' close to the marine subcluster 5.3 (Synechococcus RCC307) constitutes an important demonstration that euryhaline and marine strains affiliate closely. The intriguing results obtained shed new light on the importance of the nonmarine halotolerants in the phylogenesis of picocyanobacteria.

  13. Point estimates in phylogenetic reconstructions

    PubMed Central

    Benner, Philipp; Bačák, Miroslav; Bourguignon, Pierre-Yves

    2014-01-01

    Motivation: The construction of statistics for summarizing posterior samples returned by a Bayesian phylogenetic study has so far been hindered by the poor geometric insights available into the space of phylogenetic trees, and ad hoc methods such as the derivation of a consensus tree makeup for the ill-definition of the usual concepts of posterior mean, while bootstrap methods mitigate the absence of a sound concept of variance. Yielding satisfactory results with sufficiently concentrated posterior distributions, such methods fall short of providing a faithful summary of posterior distributions if the data do not offer compelling evidence for a single topology. Results: Building upon previous work of Billera et al., summary statistics such as sample mean, median and variance are defined as the geometric median, Fréchet mean and variance, respectively. Their computation is enabled by recently published works, and embeds an algorithm for computing shortest paths in the space of trees. Studying the phylogeny of a set of plants, where several tree topologies occur in the posterior sample, the posterior mean balances correctly the contributions from the different topologies, where a consensus tree would be biased. Comparisons of the posterior mean, median and consensus trees with the ground truth using simulated data also reveals the benefits of a sound averaging method when reconstructing phylogenetic trees. Availability and implementation: We provide two independent implementations of the algorithm for computing Fréchet means, geometric medians and variances in the space of phylogenetic trees. TFBayes: https://github.com/pbenner/tfbayes, TrAP: https://github.com/bacak/TrAP. Contact: philipp.benner@mis.mpg.de PMID:25161244

  14. Vestige: Maximum likelihood phylogenetic footprinting

    PubMed Central

    Wakefield, Matthew J; Maxwell, Peter; Huttley, Gavin A

    2005-01-01

    Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational processes, DNA repair and

  15. Phylogenetic analysis of adenovirus sequences.

    PubMed

    Harrach, Balázs; Benko, Mária

    2007-01-01

    Members of the family Adenoviridae have been isolated from a large variety of hosts, including representatives from every major vertebrate class from fish to mammals. The high prevalence, together with the fairly conserved organization of the central part of their genomes, make the adenoviruses one of (if not the) best models for studying viral evolution on a larger time scale. Phylogenetic calculation can infer the evolutionary distance among adenovirus strains on serotype, species, and genus levels, thus helping the establishment of a correct taxonomy on the one hand, and speeding up the process of typing new isolates on the other. Initially, four major lineages corresponding to four genera were recognized. Later, the demarcation criteria of lower taxon levels, such as species or types, could also be defined with phylogenetic calculations. A limited number of possible host switches have been hypothesized and convincingly supported. Application of the web-based BLAST and MultAlin programs and the freely available PHYLIP package, along with the TreeView program, enables everyone to make correct calculations. In addition to step-by-step instruction on how to perform phylogenetic analysis, critical points where typical mistakes or misinterpretation of the results might occur will be identified and hints for their avoidance will be provided.

  16. Neuromuscular disease classification system

    NASA Astrophysics Data System (ADS)

    Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M.; Serrano, Carmen

    2013-06-01

    Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns.

  17. A Phylogenetic Re-Analysis of Groupers with Applications for Ciguatera Fish Poisoning

    PubMed Central

    Schoelinck, Charlotte; Hinsinger, Damien D.; Dettaï, Agnès; Cruaud, Corinne; Justine, Jean-Lou

    2014-01-01

    Background Ciguatera fish poisoning (CFP) is a significant public health problem due to dinoflagellates. It is responsible for one of the highest reported incidence of seafood-borne illness and Groupers are commonly reported as a source of CFP due to their position in the food chain. With the role of recent climate change on harmful algal blooms, CFP cases might become more frequent and more geographically widespread. Since there is no appropriate treatment for CFP, the most efficient solution is to regulate fish consumption. Such a strategy can only work if the fish sold are correctly identified, and it has been repeatedly shown that misidentifications and species substitutions occur in fish markets. Methods We provide here both a DNA-barcoding reference for groupers, and a new phylogenetic reconstruction based on five genes and a comprehensive taxonomical sampling. We analyse the correlation between geographic range of species and their susceptibility to ciguatera accumulation, and the co-occurrence of ciguatoxins in closely related species, using both character mapping and statistical methods. Results Misidentifications were encountered in public databases, precluding accurate species identifications. Epinephelinae now includes only twelve genera (vs. 15 previously). Comparisons with the ciguatera incidences show that in some genera most species are ciguateric, but statistical tests display only a moderate correlation with the phylogeny. Atlantic species were rarely contaminated, with ciguatera occurrences being restricted to the South Pacific. Conclusions The recent changes in classification based on the reanalyses of the relationships within Epinephelidae have an impact on the interpretation of the ciguatera distribution in the genera. In this context and to improve the monitoring of fish trade and safety, we need to obtain extensive data on contamination at the species level. Accurate species identifications through DNA barcoding are thus an essential tool in

  18. Making Mosquito Taxonomy Useful: A Stable Classification of Tribe Aedini that Balances Utility with Current Knowledge of Evolutionary Relationships.

    PubMed

    Wilkerson, Richard C; Linton, Yvonne-Marie; Fonseca, Dina M; Schultz, Ted R; Price, Dana C; Strickman, Daniel A

    2015-01-01

    The tribe Aedini (Family Culicidae) contains approximately one-quarter of the known species of mosquitoes, including vectors of deadly or debilitating disease agents. This tribe contains the genus Aedes, which is one of the three most familiar genera of mosquitoes. During the past decade, Aedini has been the focus of a series of extensive morphology-based phylogenetic studies published by Reinert, Harbach, and Kitching (RH&K). Those authors created 74 new, elevated or resurrected genera from what had been the single genus Aedes, almost tripling the number of genera in the entire family Culicidae. The proposed classification is based on subjective assessments of the "number and nature of the characters that support the branches" subtending particular monophyletic groups in the results of cladistic analyses of a large set of morphological characters of representative species. To gauge the stability of RH&K's generic groupings we reanalyzed their data with unweighted parsimony jackknife and maximum-parsimony analyses, with and without ordering 14 of the characters as in RH&K. We found that their phylogeny was largely weakly supported and their taxonomic rankings failed priority and other useful taxon-naming criteria. Consequently, we propose simplified aedine generic designations that 1) restore a classification system that is useful for the operational community; 2) enhance the ability of taxonomists to accurately place new species into genera; 3) maintain the progress toward a natural classification based on monophyletic groups of species; and 4) correct the current classification system that is subject to instability as new species are described and existing species more thoroughly defined. We do not challenge the phylogenetic hypotheses generated by the above-mentioned series of morphological studies. However, we reduce the ranks of the genera and subgenera of RH&K to subgenera or informal species groups, respectively, to preserve stability as new data become

  19. Making Mosquito Taxonomy Useful: A Stable Classification of Tribe Aedini that Balances Utility with Current Knowledge of Evolutionary Relationships

    PubMed Central

    Wilkerson, Richard C.; Linton, Yvonne-Marie; Fonseca, Dina M.; Schultz, Ted R.; Price, Dana C.; Strickman, Daniel A.

    2015-01-01

    The tribe Aedini (Family Culicidae) contains approximately one-quarter of the known species of mosquitoes, including vectors of deadly or debilitating disease agents. This tribe contains the genus Aedes, which is one of the three most familiar genera of mosquitoes. During the past decade, Aedini has been the focus of a series of extensive morphology-based phylogenetic studies published by Reinert, Harbach, and Kitching (RH&K). Those authors created 74 new, elevated or resurrected genera from what had been the single genus Aedes, almost tripling the number of genera in the entire family Culicidae. The proposed classification is based on subjective assessments of the “number and nature of the characters that support the branches” subtending particular monophyletic groups in the results of cladistic analyses of a large set of morphological characters of representative species. To gauge the stability of RH&K’s generic groupings we reanalyzed their data with unweighted parsimony jackknife and maximum-parsimony analyses, with and without ordering 14 of the characters as in RH&K. We found that their phylogeny was largely weakly supported and their taxonomic rankings failed priority and other useful taxon-naming criteria. Consequently, we propose simplified aedine generic designations that 1) restore a classification system that is useful for the operational community; 2) enhance the ability of taxonomists to accurately place new species into genera; 3) maintain the progress toward a natural classification based on monophyletic groups of species; and 4) correct the current classification system that is subject to instability as new species are described and existing species more thoroughly defined. We do not challenge the phylogenetic hypotheses generated by the above-mentioned series of morphological studies. However, we reduce the ranks of the genera and subgenera of RH&K to subgenera or informal species groups, respectively, to preserve stability as new data

  20. Comparison of tree-child phylogenetic networks.

    PubMed

    Cardona, Gabriel; Rosselló, Francesc; Valiente, Gabriel

    2009-01-01

    Phylogenetic networks are a generalization of phylogenetic trees that allow for the representation of nontreelike evolutionary events, like recombination, hybridization, or lateral gene transfer. While much progress has been made to find practical algorithms for reconstructing a phylogenetic network from a set of sequences, all attempts to endorse a class of phylogenetic networks (strictly extending the class of phylogenetic trees) with a well-founded distance measure have, to the best of our knowledge and with the only exception of the bipartition distance on regular networks, failed so far. In this paper, we present and study a new meaningful class of phylogenetic networks, called tree-child phylogenetic networks, and we provide an injective representation of these networks as multisets of vectors of natural numbers, their path multiplicity vectors. We then use this representation to define a distance on this class that extends the well-known Robinson-Foulds distance for phylogenetic trees and to give an alignment method for pairs of networks in this class. Simple polynomial algorithms for reconstructing a tree-child phylogenetic network from its path multiplicity vectors, for computing the distance between two tree-child phylogenetic networks and for aligning a pair of tree-child phylogenetic networks, are provided. They have been implemented as a Perl package and a Java applet, which can be found at http://bioinfo.uib.es/~recerca/phylonetworks/mudistance/.

  1. Multisensor classification of sedimentary rocks

    NASA Technical Reports Server (NTRS)

    Evans, Diane

    1988-01-01

    A comparison is made between linear discriminant analysis and supervised classification results based on signatures from the Landsat TM, the Thermal Infrared Multispectral Scanner (TIMS), and airborne SAR, alone and combined into extended spectral signatures for seven sedimentary rock units exposed on the margin of the Wind River Basin, Wyoming. Results from a linear discriminant analysis showed that training-area classification accuracies based on the multisensor data were improved an average of 15 percent over TM alone, 24 percent over TIMS alone, and 46 percent over SAR alone, with similar improvement resulting when supervised multisensor classification maps were compared to supervised, individual sensor classification maps. When training area signatures were used to map spectrally similar materials in an adjacent area, the average classification accuracy improved 19 percent using the multisensor data over TM alone, 2 percent over TIMS alone, and 11 percent over SAR alone. It is concluded that certain sedimentary lithologies may be accurately mapped using a single sensor, but classification of a variety of rock types can be improved using multisensor data sets that are sensitive to different characteristics such as mineralogy and surface roughness.

  2. Molecular phylogenetics of New World searobins (Triglidae; Prionotinae).

    PubMed

    Portnoy, David S; Willis, Stuart C; Hunt, Elizabeth; Swift, Dominic G; Gold, John R; Conway, Kevin W

    2017-02-01

    Phylogenetic relationships among members of the New World searobin genera Bellator and Prionotus (Family Triglidae, Subfamily Prionotinae) and among other searobins in the families Triglidae and Peristediidae were investigated using both mitochondrial and nuclear DNA sequences. Phylogenetic hypotheses derived from maximum likelihood and Bayesian methodologies supported a monophyletic Prionotinae that included four well resolved clades of uncertain relationship; three contained species in the genus Prionotus and one contained species in the genus Bellator. Bellator was always recovered within the genus Prionotus, a result supported by post hoc model testing. Two nominal species of Prionotus (P. alatus and P. paralatus) were not recovered as exclusive lineages, suggesting the two may comprise a single species. Phylogenetic hypotheses also supported a monophyletic Triglidae but only if armored searobins (Family Peristediidae) were included. A robust morphological assessment is needed to further characterize relationships and suggest classification of clades within Prionotinae; for the time being we recommend that Bellator be considered a synonym of Prionotus. Relationships between armored searobins (Family Peristediidae) and searobins (Family Triglidae) and relationships within Triglidae also warrant further study.

  3. Applicability of Phylogenetic Methods for Characterizing the Public Health Significance of Verocytotoxin-Producing Escherichia coli Strains▿

    PubMed Central

    Ziebell, Kim; Konczy, Paulina; Yong, Irene; Frost, Shelley; Mascarenhas, Mariola; Kropinski, Andrew M.; Whittam, Thomas S.; Read, Susan C.; Karmali, Mohamed A.

    2008-01-01

    Two phylogenetic methods (multilocus sequence typing [MLST] and a multiplex PCR) were investigated to determine whether phylogenetic classification of verocytotoxin-producing Escherichia coli serotypes correlates with their classification into groups (seropathotypes A to E) based on their relative incidence in human disease and on their association with outbreaks and serious complications. MLST was able to separate 96% of seropathotype D and E serotypes from those that cause serious disease (seropathotypes A to C), whereas the multiplex PCR lacked this level of seropathotype discrimination. PMID:18165362

  4. Phylogenetic trees and Euclidean embeddings.

    PubMed

    Layer, Mark; Rhodes, John A

    2017-01-01

    It was recently observed by de Vienne et al. (Syst Biol 60(6):826-832, 2011) that a simple square root transformation of distances between taxa on a phylogenetic tree allowed for an embedding of the taxa into Euclidean space. While the justification for this was based on a diffusion model of continuous character evolution along the tree, here we give a direct and elementary explanation for it that provides substantial additional insight. We use this embedding to reinterpret the differences between the NJ and BIONJ tree building algorithms, providing one illustration of how this embedding reflects tree structures in data.

  5. Phylogenetic placement of the Spirosomaceae

    NASA Technical Reports Server (NTRS)

    Woese, C. R.; Maloy, S.; Mandelco, L.; Raj, H. D.

    1990-01-01

    Comparative analysis of 16S rRNA sequences shows that the family Spirosomaceae belongs within the eubacterial phylum defined by the flavobacteria and bacteriodes. Its constituent genera, Spirosoma, Flectobacillus, and Runella form a monophyletic grouping therein. The phylogenetic assignment is based not only upon evolutionary distance analysis, but also upon sequence signatures and higher order structural synapomorphies in 16S rRNA. Another genus peripherally associated with the Spirosomaceae, Ancylobacter ("Microcyclus"), does not cluster with the flavobacteria and their relatives, but rather belongs to the alpha subdivision of the purple bacteria.

  6. Phylogenetic assignment of Mycobacterium tuberculosis Beijing clinical isolates in Japan by maximum a posteriori estimation.

    PubMed

    Seto, Junji; Wada, Takayuki; Iwamoto, Tomotada; Tamaru, Aki; Maeda, Shinji; Yamamoto, Kaori; Hase, Atsushi; Murakami, Koichi; Maeda, Eriko; Oishi, Akira; Migita, Yuji; Yamamoto, Taro; Ahiko, Tadayuki

    2015-10-01

    Intra-species phylogeny of Mycobacterium tuberculosis has been regarded as a clue to estimate its potential risk to develop drug-resistance and various epidemiological tendencies. Genotypic characterization of variable number of tandem repeats (VNTR), a standard tool to ascertain transmission routes, has been improving as a public health effort, but determining phylogenetic information from those efforts alone is difficult. We present a platform based on maximum a posteriori (MAP) estimation to estimate phylogenetic information for M. tuberculosis clinical isolates from individual profiles of VNTR types. This study used 1245 M. tuberculosis clinical isolates obtained throughout Japan for construction of an MAP estimation formula. Two MAP estimation formulae, classification of Beijing family and other lineages, and classification of five Beijing sublineages (ST11/26, STK, ST3, and ST25/19 belonging to the ancient Beijing subfamily and modern Beijing subfamily), were created based on 24 loci VNTR (24Beijing-VNTR) profiles and phylogenetic information of the isolates. Recursive estimation based on the formulae showed high concordance with their authentic phylogeny by multi-locus sequence typing (MLST) of the isolates. The formulae might further support phylogenetic estimation of the Beijing lineage M. tuberculosis from the VNTR genotype with various geographic backgrounds. These results suggest that MAP estimation can function as a reliable probabilistic process to append phylogenetic information to VNTR genotypes of M. tuberculosis independently, which might improve the usage of genotyping data for control, understanding, prevention, and treatment of TB.

  7. Experimental design in phylogenetics: testing predictions from expected information.

    PubMed

    San Mauro, Diego; Gower, David J; Cotton, James A; Zardoya, Rafael; Wilkinson, Mark; Massingham, Tim

    2012-07-01

    Taxon and character sampling are central to phylogenetic experimental design; yet, we lack general rules. Goldman introduced a method to construct efficient sampling designs in phylogenetics, based on the calculation of expected Fisher information given a probabilistic model of sequence evolution. The considerable potential of this approach remains largely unexplored. In an earlier study, we applied Goldman's method to a problem in the phylogenetics of caecilian amphibians and made an a priori evaluation and testable predictions of which taxon additions would increase information about a particular weakly supported branch of the caecilian phylogeny by the greatest amount. We have now gathered mitogenomic and rag1 sequences (some newly determined for this study) from additional caecilian species and studied how information (both expected and observed) and bootstrap support vary as each new taxon is individually added to our previous data set. This provides the first empirical test of specific predictions made using Goldman's method for phylogenetic experimental design. Our results empirically validate the top 3 (more intuitive) taxon addition predictions made in our previous study, but only information results validate unambiguously the 4th (less intuitive) prediction. This highlights a complex relationship between information and support, reflecting that each measures different things: Information is related to the ability to estimate branch length accurately and support to the ability to estimate the tree topology accurately. Thus, an increase in information may be correlated with but does not necessitate an increase in support. Our results also provide the first empirical validation of the widely held intuition that additional taxa that join the tree proximal to poorly supported internal branches are more informative and enhance support more than additional taxa that join the tree more distally. Our work supports the view that adding more data for a single (well

  8. Sparse and accurate high resolution SAR imaging

    NASA Astrophysics Data System (ADS)

    Vu, Duc; Zhao, Kexin; Rowe, William; Li, Jian

    2012-05-01

    We investigate the usage of an adaptive method, the Iterative Adaptive Approach (IAA), in combination with a maximum a posteriori (MAP) estimate to reconstruct high resolution SAR images that are both sparse and accurate. IAA is a nonparametric weighted least squares algorithm that is robust and user parameter-free. IAA has been shown to reconstruct SAR images with excellent side lobes suppression and high resolution enhancement. We first reconstruct the SAR images using IAA, and then we enforce sparsity by using MAP with a sparsity inducing prior. By coupling these two methods, we can produce a sparse and accurate high resolution image that are conducive for feature extractions and target classification applications. In addition, we show how IAA can be made computationally efficient without sacrificing accuracies, a desirable property for SAR applications where the size of the problems is quite large. We demonstrate the success of our approach using the Air Force Research Lab's "Gotcha Volumetric SAR Data Set Version 1.0" challenge dataset. Via the widely used FFT, individual vehicles contained in the scene are barely recognizable due to the poor resolution and high side lobe nature of FFT. However with our approach clear edges, boundaries, and textures of the vehicles are obtained.

  9. Phylogenetic Conservatism in Plant Phenology

    NASA Technical Reports Server (NTRS)

    Davies, T. Jonathan; Wolkovich, Elizabeth M.; Kraft, Nathan J. B.; Salamin, Nicolas; Allen, Jenica M.; Ault, Toby R.; Betancourt, Julio L.; Bolmgren, Kjell; Cleland, Elsa E.; Cook, Benjamin I.; Crimmins, Theresa M.; Mazer, Susan J.; McCabe, Gregory J.; Pau, Stephanie; Regetz, Jim; Schwartz, Mark D.; Travers, Steven E.

    2013-01-01

    Phenological events defined points in the life cycle of a plant or animal have been regarded as highly plastic traits, reflecting flexible responses to various environmental cues. The ability of a species to track, via shifts in phenological events, the abiotic environment through time might dictate its vulnerability to future climate change. Understanding the predictors and drivers of phenological change is therefore critical. Here, we evaluated evidence for phylogenetic conservatism the tendency for closely related species to share similar ecological and biological attributes in phenological traits across flowering plants. We aggregated published and unpublished data on timing of first flower and first leaf, encompassing 4000 species at 23 sites across the Northern Hemisphere. We reconstructed the phylogeny for the set of included species, first, using the software program Phylomatic, and second, from DNA data. We then quantified phylogenetic conservatism in plant phenology within and across sites. We show that more closely related species tend to flower and leaf at similar times. By contrasting mean flowering times within and across sites, however, we illustrate that it is not the time of year that is conserved, but rather the phenological responses to a common set of abiotic cues. Our findings suggest that species cannot be treated as statistically independent when modelling phenological responses.Closely related species tend to resemble each other in the timing of their life-history events, a likely product of evolutionarily conserved responses to environmental cues. The search for the underlying drivers of phenology must therefore account for species' shared evolutionary histories.

  10. Estimating Bayesian Phylogenetic Information Content

    PubMed Central

    Lewis, Paul O.; Chen, Ming-Hui; Kuo, Lynn; Lewis, Louise A.; Fučíková, Karolina; Neupane, Suman; Wang, Yu-Bo; Shi, Daoyuan

    2016-01-01

    Measuring the phylogenetic information content of data has a long history in systematics. Here we explore a Bayesian approach to information content estimation. The entropy of the posterior distribution compared with the entropy of the prior distribution provides a natural way to measure information content. If the data have no information relevant to ranking tree topologies beyond the information supplied by the prior, the posterior and prior will be identical. Information in data discourages consideration of some hypotheses allowed by the prior, resulting in a posterior distribution that is more concentrated (has lower entropy) than the prior. We focus on measuring information about tree topology using marginal posterior distributions of tree topologies. We show that both the accuracy and the computational efficiency of topological information content estimation improve with use of the conditional clade distribution, which also allows topological information content to be partitioned by clade. We explore two important applications of our method: providing a compelling definition of saturation and detecting conflict among data partitions that can negatively affect analyses of concatenated data. [Bayesian; concatenation; conditional clade distribution; entropy; information; phylogenetics; saturation.] PMID:27155008

  11. Phylogenetic inference of Indian malaria vectors from multilocus DNA sequences.

    PubMed

    Dixit, Jyotsana; Srivastava, Hemlata; Sharma, Meenu; Das, Manoj K; Singh, O P; Raghavendra, K; Nanda, Nutan; Dash, Aditya P; Saksena, D N; Das, Aparup

    2010-08-01

    Inferences on the taxonomic positions, phylogenetic interrelationships and divergence time among closely related species of medical importance is essential to understand evolutionary patterns among species, and based on which, disease control measures could be devised. To this respect, malaria is one of the important mosquito borne diseases of tropical and sub-tropical parts of the globe. Taxonomic status of malaria vectors has been so far documented based on morphological, cytological and few molecular genetic features. However, utilization of multilocus DNA sequences in phylogenetic inferences are still in dearth. India contains one of the richest resources of mosquito species diversity but little molecular taxonomic information is available in Indian malaria vectors. We herewith utilized the whole genome sequence information of An. gambiae to amplify and sequence three orthologous nuclear genetic regions in six Indian malaria vector species (An. culicifacies, An. minimus, An. sundaicus, An. fluviatilis, An. annularis and An. stephensi). Further, we utilized the previously published DNA sequence information on the COII and ITS2 genes in all the six species, making the total number of loci to five. Multilocus molecular phylogenetic study of Indian anophelines and An. gambiae was conducted at each individual genetic region using Neighbour Joining (NJ), Maximum Likelihood (ML), Maximum Parsimony (MP) and Bayesian approaches. Although tree topologies with COII, and ITS2 genes were similar, for no other three genetic regions similar tree topologies were observed. In general, the reconstructed phylogenetic status of Indian malaria vectors follows the pattern based on morphological and cytological classifications that was reconfirmed with COII and ITS2 genetic regions. Further, divergence times based on COII gene sequences were estimated among the seven Anopheles species which corroborate the earlier hypothesis on the radiation of different species of the Anopheles

  12. DNA sequence analysis using hierarchical ART-based classification networks

    SciTech Connect

    LeBlanc, C.; Hruska, S.I.; Katholi, C.R.; Unnasch, T.R.

    1994-12-31

    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.

  13. Accurate Evaluation of Quantum Integrals

    NASA Technical Reports Server (NTRS)

    Galant, D. C.; Goorvitch, D.; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    Combining an appropriate finite difference method with Richardson's extrapolation results in a simple, highly accurate numerical method for solving a Schrodinger's equation. Important results are that error estimates are provided, and that one can extrapolate expectation values rather than the wavefunctions to obtain highly accurate expectation values. We discuss the eigenvalues, the error growth in repeated Richardson's extrapolation, and show that the expectation values calculated on a crude mesh can be extrapolated to obtain expectation values of high accuracy.

  14. Molecular Phylogenetics: Concepts for a Newcomer.

    PubMed

    Ajawatanawong, Pravech

    2016-10-26

    Molecular phylogenetics is the study of evolutionary relationships among organisms using molecular sequence data. The aim of this review is to introduce the important terminology and general concepts of tree reconstruction to biologists who lack a strong background in the field of molecular evolution. Some modern phylogenetic programs are easy to use because of their user-friendly interfaces, but understanding the phylogenetic algorithms and substitution models, which are based on advanced statistics, is still important for the analysis and interpretation without a guide. Briefly, there are five general steps in carrying out a phylogenetic analysis: (1) sequence data preparation, (2) sequence alignment, (3) choosing a phylogenetic reconstruction method, (4) identification of the best tree, and (5) evaluating the tree. Concepts in this review enable biologists to grasp the basic ideas behind phylogenetic analysis and also help provide a sound basis for discussions with expert phylogeneticists.

  15. New Phylogenetic Groups of Torque Teno Virus Identified in Eastern Taiwan Indigenes

    PubMed Central

    Hsiao, Kuang-Liang; Wang, Li-Yu; Lin, Chiung-Ling; Liu, Hsin-Fu

    2016-01-01

    Torque teno virus (TTV) is a single-stranded DNA virus highly prevalent in the world. It has been detected in eastern Taiwan indigenes with a low prevalence of 11% by using N22 region of which known to underestimate TTV prevalence excessively. In order to clarify their realistic epidemiology, we re-analyzed TTV prevalence with UTR region. One hundred and forty serum samples from eastern Taiwanese indigenous population were collected and TTV DNA was detected in 133 (95%) samples. Direct sequencing revealed an extensive mix-infection of different TTV strains within the infected individual. Entire TTV open reading frame 1 was amplified and cloned from a TTV positive individual to distinguish mix-infected strains. Phylogenetic analysis showed eleven isolates were clustered into a monophyletic group that is distinct from all known groups. In addition, another our isolate was clustered with recently described Hebei-1 strain and formed an independent clade. Based on the distribution pattern of pairwise distances, both new clusters were placed at phylogenetic group level, designed as the 6th and 7th phylogenetic group. In present study, we showed a very high prevalence of TTV infection in eastern Taiwan indigenes and indentified new phylogenetic groups from the infected individual. Both intra- and inter-phylogenetic group mix-infections can be found from one healthy person. Our study has further broadened the field of human TTVs and proposed a robust criterion for classification of the major TTV phylogenetic groups. PMID:26901643

  16. Alu elements and hominid phylogenetics.

    PubMed

    Salem, Abdel-Halim; Ray, David A; Xing, Jinchuan; Callinan, Pauline A; Myers, Jeremy S; Hedges, Dale J; Garber, Randall K; Witherspoon, David J; Jorde, Lynn B; Batzer, Mark A

    2003-10-28

    Alu elements have inserted in primate genomes throughout the evolution of the order. One particular Alu lineage (Ye) began amplifying relatively early in hominid evolution and continued propagating at a low level as many of its members are found in a variety of hominid genomes. This study represents the first conclusive application of short interspersed elements, which are considered nearly homoplasy-free, to elucidate the phylogeny of hominids. Phylogenetic analysis of Alu Ye5 elements and elements from several other subfamilies reveals high levels of support for monophyly of Hominidae, tribe Hominini and subtribe Hominina. Here we present the strongest evidence reported to date for a sister relationship between humans and chimpanzees while clearly distinguishing the chimpanzee and human lineages.

  17. Demonstrating Biological Classification Using a Simulation of Natural Taxa.

    ERIC Educational Resources Information Center

    Vogt, Kenneth D.

    1995-01-01

    A review of introductory college level and high school biology texts reveals that concepts and theories behind classification are usually poorly discussed. Suggests ways in which card games can be used to teach differences between the phenetic and phylogenetic approaches. (LZ)

  18. Remote Sensing Information Classification

    NASA Technical Reports Server (NTRS)

    Rickman, Douglas L.

    2008-01-01

    This viewgraph presentation reviews the classification of Remote Sensing data in relation to epidemiology. Classification is a way to reduce the dimensionality and precision to something a human can understand. Classification changes SCALAR data into NOMINAL data.

  19. Classification and knowledge

    NASA Technical Reports Server (NTRS)

    Kurtz, Michael J.

    1989-01-01

    Automated procedures to classify objects are discussed. The classification problem is reviewed, and the relation of epistemology and classification is considered. The classification of stellar spectra and of resolved images of galaxies is addressed.

  20. Progress, pitfalls and parallel universes: a history of insect phylogenetics

    PubMed Central

    Simon, Chris; Yavorskaya, Margarita; Beutel, Rolf G.

    2016-01-01

    The phylogeny of insects has been both extensively studied and vigorously debated for over a century. A relatively accurate deep phylogeny had been produced by 1904. It was not substantially improved in topology until recently when phylogenomics settled many long-standing controversies. Intervening advances came instead through methodological improvement. Early molecular phylogenetic studies (1985–2005), dominated by a few genes, provided datasets that were too small to resolve controversial phylogenetic problems. Adding to the lack of consensus, this period was characterized by a polarization of philosophies, with individuals belonging to either parsimony or maximum-likelihood camps; each largely ignoring the insights of the other. The result was an unfortunate detour in which the few perceived phylogenetic revolutions published by both sides of the philosophical divide were probably erroneous. The size of datasets has been growing exponentially since the mid-1980s accompanied by a wave of confidence that all relationships will soon be known. However, large datasets create new challenges, and a large number of genes does not guarantee reliable results. If history is a guide, then the quality of conclusions will be determined by an improved understanding of both molecular and morphological evolution, and not simply the number of genes analysed. PMID:27558853

  1. Progress, pitfalls and parallel universes: a history of insect phylogenetics.

    PubMed

    Kjer, Karl M; Simon, Chris; Yavorskaya, Margarita; Beutel, Rolf G

    2016-08-01

    The phylogeny of insects has been both extensively studied and vigorously debated for over a century. A relatively accurate deep phylogeny had been produced by 1904. It was not substantially improved in topology until recently when phylogenomics settled many long-standing controversies. Intervening advances came instead through methodological improvement. Early molecular phylogenetic studies (1985-2005), dominated by a few genes, provided datasets that were too small to resolve controversial phylogenetic problems. Adding to the lack of consensus, this period was characterized by a polarization of philosophies, with individuals belonging to either parsimony or maximum-likelihood camps; each largely ignoring the insights of the other. The result was an unfortunate detour in which the few perceived phylogenetic revolutions published by both sides of the philosophical divide were probably erroneous. The size of datasets has been growing exponentially since the mid-1980s accompanied by a wave of confidence that all relationships will soon be known. However, large datasets create new challenges, and a large number of genes does not guarantee reliable results. If history is a guide, then the quality of conclusions will be determined by an improved understanding of both molecular and morphological evolution, and not simply the number of genes analysed.

  2. Hyperspectral image classification using functional data analysis.

    PubMed

    Li, Hong; Xiao, Guangrun; Xia, Tian; Tang, Y Y; Li, Luoqing

    2014-09-01

    The large number of spectral bands acquired by hyperspectral imaging sensors allows us to better distinguish many subtle objects and materials. Unlike other classical hyperspectral image classification methods in the multivariate analysis framework, in this paper, a novel method using functional data analysis (FDA) for accurate classification of hyperspectral images has been proposed. The central idea of FDA is to treat multivariate data as continuous functions. From this perspective, the spectral curve of each pixel in the hyperspectral images is naturally viewed as a function. This can be beneficial for making full use of the abundant spectral information. The relevance between adjacent pixel elements in the hyperspectral images can also be utilized reasonably. Functional principal component analysis is applied to solve the classification problem of these functions. Experimental results on three hyperspectral images show that the proposed method can achieve higher classification accuracies in comparison to some state-of-the-art hyperspectral image classification methods.

  3. Feature utility in polarimetric radar image classification

    NASA Technical Reports Server (NTRS)

    Cumming, Ian G.; Van Zyl, Jakob J.

    1989-01-01

    The information content in polarimetric SAR images is examined, and the polarimetric image variables containing the information that is important to the classification of terrain features in the images are determined. It is concluded that accurate classification can be done when just over half of the image variables are retained. A reduction in image data dimensionality gives storage savings, and can lead to the improvement of classifier performance. In addition, it is shown that a simplified radar system with only phase-calibrated CO-POL or SINGLE TX channels can give classification performance which approaches that of a fully polarimetric radar.

  4. Learning accurate very fast decision trees from uncertain data streams

    NASA Astrophysics Data System (ADS)

    Liang, Chunquan; Zhang, Yang; Shi, Peng; Hu, Zhengguo

    2015-12-01

    Most existing works on data stream classification assume the streaming data is precise and definite. Such assumption, however, does not always hold in practice, since data uncertainty is ubiquitous in data stream applications due to imprecise measurement, missing values, privacy protection, etc. The goal of this paper is to learn accurate decision tree models from uncertain data streams for classification analysis. On the basis of very fast decision tree (VFDT) algorithms, we proposed an algorithm for constructing an uncertain VFDT tree with classifiers at tree leaves (uVFDTc). The uVFDTc algorithm can exploit uncertain information effectively and efficiently in both the learning and the classification phases. In the learning phase, it uses Hoeffding bound theory to learn from uncertain data streams and yield fast and reasonable decision trees. In the classification phase, at tree leaves it uses uncertain naive Bayes (UNB) classifiers to improve the classification performance. Experimental results on both synthetic and real-life datasets demonstrate the strong ability of uVFDTc to classify uncertain data streams. The use of UNB at tree leaves has improved the performance of uVFDTc, especially the any-time property, the benefit of exploiting uncertain information, and the robustness against uncertainty.

  5. Classifying and counting linear phylogenetic invariants for the Jukes-Cantor model.

    PubMed

    Steel, M A; Fu, Y X

    1995-01-01

    Linear invariants are useful tools for testing phylogenetic hypotheses from aligned DNA/RNA sequences, particularly when the sites evolve at different rates. Here we give a simple, graph theoretic classification for each phylogenetic tree T, of its associated vector space I(T) of linear invariants under the Jukes-Cantor one-parameter model of nucleotide substitution. We also provide an easily described basis for I(T), and show that if I is a binary (fully resolved) phylogenetic tree with n sequences at its leaves then: dim[I(T)] = 4n-F2n-2 where Fn is the nth Fibonacci number. Our method applies a recently developed Hadamard matrix-based technique to describe elements of I(T) in terms of edge-disjoint packings of subtrees in T, and thereby complements earlier more algebraic treatments.

  6. Insect phylogenetics in the digital age.

    PubMed

    Dietrich, Christopher H; Dmitriev, Dmitry A

    2016-12-01

    Insect systematists have long used digital data management tools to facilitate phylogenetic research. Web-based platforms developed over the past several years support creation of comprehensive, openly accessible data repositories and analytical tools that support large-scale collaboration, accelerating efforts to document Earth's biota and reconstruct the Tree of Life. New digital tools have the potential to further enhance insect phylogenetics by providing efficient workflows for capturing and analyzing phylogenetically relevant data. Recent initiatives streamline various steps in phylogenetic studies and provide community access to supercomputing resources. In the near future, automated, web-based systems will enable researchers to complete a phylogenetic study from start to finish using resources linked together within a single portal and incorporate results into a global synthesis.

  7. Use of whole genome sequences to develop a molecular phylogenetic framework for Rhodococcus fascians and the Rhodococcus genus

    PubMed Central

    Creason, Allison L.; Davis, Edward W.; Putnam, Melodie L.; Vandeputte, Olivier M.; Chang, Jeff H.

    2014-01-01

    The accurate diagnosis of diseases caused by pathogenic bacteria requires a stable species classification. Rhodococcus fascians is the only documented member of its ill-defined genus that is capable of causing disease on a wide range of agriculturally important plants. Comparisons of genome sequences generated from isolates of Rhodococcus associated with diseased plants revealed a level of genetic diversity consistent with them representing multiple species. To test this, we generated a tree based on more than 1700 homologous sequences from plant-associated isolates of Rhodococcus, and obtained support from additional approaches that measure and cluster based on genome similarities. Results were consistent in supporting the definition of new Rhodococcus species within clades containing phytopathogenic members. We also used the genome sequences, along with other rhodococcal genome sequences to construct a molecular phylogenetic tree as a framework for resolving the Rhodococcus genus. Results indicated that Rhodococcus has the potential for having 20 species and also confirmed a need to revisit the taxonomic groupings within Rhodococcus. PMID:25237311

  8. Use of whole genome sequences to develop a molecular phylogenetic framework for Rhodococcus fascians and the Rhodococcus genus.

    PubMed

    Creason, Allison L; Davis, Edward W; Putnam, Melodie L; Vandeputte, Olivier M; Chang, Jeff H

    2014-01-01

    The accurate diagnosis of diseases caused by pathogenic bacteria requires a stable species classification. Rhodococcus fascians is the only documented member of its ill-defined genus that is capable of causing disease on a wide range of agriculturally important plants. Comparisons of genome sequences generated from isolates of Rhodococcus associated with diseased plants revealed a level of genetic diversity consistent with them representing multiple species. To test this, we generated a tree based on more than 1700 homologous sequences from plant-associated isolates of Rhodococcus, and obtained support from additional approaches that measure and cluster based on genome similarities. Results were consistent in supporting the definition of new Rhodococcus species within clades containing phytopathogenic members. We also used the genome sequences, along with other rhodococcal genome sequences to construct a molecular phylogenetic tree as a framework for resolving the Rhodococcus genus. Results indicated that Rhodococcus has the potential for having 20 species and also confirmed a need to revisit the taxonomic groupings within Rhodococcus.

  9. SUNPLIN: Simulation with Uncertainty for Phylogenetic Investigations

    PubMed Central

    2013-01-01

    Background Phylogenetic comparative analyses usually rely on a single consensus phylogenetic tree in order to study evolutionary processes. However, most phylogenetic trees are incomplete with regard to species sampling, which may critically compromise analyses. Some approaches have been proposed to integrate non-molecular phylogenetic information into incomplete molecular phylogenies. An expanded tree approach consists of adding missing species to random locations within their clade. The information contained in the topology of the resulting expanded trees can be captured by the pairwise phylogenetic distance between species and stored in a matrix for further statistical analysis. Thus, the random expansion and processing of multiple phylogenetic trees can be used to estimate the phylogenetic uncertainty through a simulation procedure. Because of the computational burden required, unless this procedure is efficiently implemented, the analyses are of limited applicability. Results In this paper, we present efficient algorithms and implementations for randomly expanding and processing phylogenetic trees so that simulations involved in comparative phylogenetic analysis with uncertainty can be conducted in a reasonable time. We propose algorithms for both randomly expanding trees and calculating distance matrices. We made available the source code, which was written in the C++ language. The code may be used as a standalone program or as a shared object in the R system. The software can also be used as a web service through the link: http://purl.oclc.org/NET/sunplin/. Conclusion We compare our implementations to similar solutions and show that significant performance gains can be obtained. Our results open up the possibility of accounting for phylogenetic uncertainty in evolutionary and ecological analyses of large datasets. PMID:24229408

  10. Plasmid Classification in an Era of Whole-Genome Sequencing: Application in Studies of Antibiotic Resistance Epidemiology.

    PubMed

    Orlek, Alex; Stoesser, Nicole; Anjum, Muna F; Doumith, Michel; Ellington, Matthew J; Peto, Tim; Crook, Derrick; Woodford, Neil; Walker, A Sarah; Phan, Hang; Sheppard, Anna E

    2017-01-01

    Plasmids are extra-chromosomal genetic elements ubiquitous in bacteria, and commonly transmissible between host cells. Their genomes include variable repertoires of 'accessory genes,' such as antibiotic resistance genes, as well as 'backbone' loci which are largely conserved within plasmid families, and often involved in key plasmid-specific functions (e.g., replication, stable inheritance, mobility). Classifying plasmids into different types according to their phylogenetic relatedness provides insight into the epidemiology of plasmid-mediated antibiotic resistance. Current typing schemes exploit backbone loci associated with replication (replicon typing), or plasmid mobility (MOB typing). Conventional PCR-based methods for plasmid typing remain widely used. With the emergence of whole-genome sequencing (WGS), large datasets can be analyzed using in silico plasmid typing methods. However, short reads from popular high-throughput sequencers can be challenging to assemble, so complete plasmid sequences may not be accurately reconstructed. Therefore, localizing resistance genes to specific plasmids may be difficult, limiting epidemiological insight. Long-read sequencing will become increasingly popular as costs decline, especially when resolving accurate plasmid structures is the primary goal. This review discusses the application of plasmid classification in WGS-based studies of antibiotic resistance epidemiology; novel in silico plasmid analysis tools are highlighted. Due to the diverse and plastic nature of plasmid genomes, current typing schemes do not classify all plasmids, and identifying conserved, phylogenetically concordant genes for subtyping and phylogenetics is challenging. Analyzing plasmids as nodes in a network that represents gene-sharing relationships between plasmids provides a complementary way to assess plasmid diversity, and allows inferences about horizontal gene transfer to be made.

  11. Plasmid Classification in an Era of Whole-Genome Sequencing: Application in Studies of Antibiotic Resistance Epidemiology

    PubMed Central

    Orlek, Alex; Stoesser, Nicole; Anjum, Muna F.; Doumith, Michel; Ellington, Matthew J.; Peto, Tim; Crook, Derrick; Woodford, Neil; Walker, A. Sarah; Phan, Hang; Sheppard, Anna E.

    2017-01-01

    Plasmids are extra-chromosomal genetic elements ubiquitous in bacteria, and commonly transmissible between host cells. Their genomes include variable repertoires of ‘accessory genes,’ such as antibiotic resistance genes, as well as ‘backbone’ loci which are largely conserved within plasmid families, and often involved in key plasmid-specific functions (e.g., replication, stable inheritance, mobility). Classifying plasmids into different types according to their phylogenetic relatedness provides insight into the epidemiology of plasmid-mediated antibiotic resistance. Current typing schemes exploit backbone loci associated with replication (replicon typing), or plasmid mobility (MOB typing). Conventional PCR-based methods for plasmid typing remain widely used. With the emergence of whole-genome sequencing (WGS), large datasets can be analyzed using in silico plasmid typing methods. However, short reads from popular high-throughput sequencers can be challenging to assemble, so complete plasmid sequences may not be accurately reconstructed. Therefore, localizing resistance genes to specific plasmids may be difficult, limiting epidemiological insight. Long-read sequencing will become increasingly popular as costs decline, especially when resolving accurate plasmid structures is the primary goal. This review discusses the application of plasmid classification in WGS-based studies of antibiotic resistance epidemiology; novel in silico plasmid analysis tools are highlighted. Due to the diverse and plastic nature of plasmid genomes, current typing schemes do not classify all plasmids, and identifying conserved, phylogenetically concordant genes for subtyping and phylogenetics is challenging. Analyzing plasmids as nodes in a network that represents gene-sharing relationships between plasmids provides a complementary way to assess plasmid diversity, and allows inferences about horizontal gene transfer to be made. PMID:28232822

  12. Classifying the bacterial gut microbiota of termites and cockroaches: A curated phylogenetic reference database (DictDb).

    PubMed

    Mikaelyan, Aram; Köhler, Tim; Lampert, Niclas; Rohland, Jeffrey; Boga, Hamadi; Meuser, Katja; Brune, Andreas

    2015-10-01

    Recent developments in sequencing technology have given rise to a large number of studies that assess bacterial diversity and community structure in termite and cockroach guts based on large amplicon libraries of 16S rRNA genes. Although these studies have revealed important ecological and evolutionary patterns in the gut microbiota, classification of the short sequence reads is limited by the taxonomic depth and resolution of the reference databases used in the respective studies. Here, we present a curated reference database for accurate taxonomic analysis of the bacterial gut microbiota of dictyopteran insects. The Dictyopteran gut microbiota reference Database (DictDb) is based on the Silva database but was significantly expanded by the addition of clones from 11 mostly unexplored termite and cockroach groups, which increased the inventory of bacterial sequences from dictyopteran guts by 26%. The taxonomic depth and resolution of DictDb was significantly improved by a general revision of the taxonomic guide tree for all important lineages, including a detailed phylogenetic analysis of the Treponema and Alistipes complexes, the Fibrobacteres, and the TG3 phylum. The performance of this first documented version of DictDb (v. 3.0) using the revised taxonomic guide tree in the classification of short-read libraries obtained from termites and cockroaches was highly superior to that of the current Silva and RDP databases. DictDb uses an informative nomenclature that is consistent with the literature also for clades of uncultured bacteria and provides an invaluable tool for anyone exploring the gut community structure of termites and cockroaches.

  13. Phylogenetic mapping of bacterial morphology

    NASA Technical Reports Server (NTRS)

    Siefert, J. L.; Fox, G. E.

    1998-01-01

    The availability of a meaningful molecular phylogeny for bacteria provides a context for examining the historical significance of various developments in bacterial evolution. Herein, the classical morphological descriptions of selected members of the domain Bacteria are mapped upon the genealogical ancestry deduced from comparison of small-subunit rRNA sequences. For the species examined in this study, a distinct pattern emerges which indicates that the coccus shape has arisen and accumulated independently multiple times in separate lineages and typically survived as a persistent end-state morphology. At least two other morphologies persist but have evolved only once. This study demonstrates that although bacterial morphology is not useful in defining bacterial phylogeny, it is remarkably consistent with that phylogeny once it is known. An examination of the experimental evidence available for morphogenesis as well as microbial fossil evidence corroborates these findings. It is proposed that the accumulation of persistent morphologies is a result of the biophysical properties of peptidoglycan and their genetic control, and that an evolved body-plan strategy based on peptidoglycan may have been a fate-sealing step in the evolution of Bacteria. More generally, this study illustrates that significant evolutionary insights can be obtained by examining biological and biochemical data in the context of a reliable phylogenetic structure.

  14. Phylogenetic fields of species: cross-species patterns of phylogenetic structure and geographical coexistence.

    PubMed

    Villalobos, Fabricio; Rangel, Thiago F; Diniz-Filho, José Alexandre F

    2013-04-07

    Differential coexistence among species underlies geographical patterns of biodiversity. Understanding such patterns has relied either on ecological or historical approaches applied separately. Recently, macroecology and community phylogenetics have tried to integrate both ecological and historical approaches. However, macroecology is mostly non-phylogenetic, whereas community phylogenetics is largely focused on local scales. Here, we propose a conceptual framework to link macroecology and community phylogenetics by exploring the evolutionary context of large-scale species coexistence, introducing the phylogenetic field concept. This is defined as the phylogenetic structure of species co-occurrence within a focal species' geographical range. We developed concepts and methods for analysing phylogenetic fields and applied them to study coexistence patterns of the bat family Phyllostomidae. Our analyses showed that phyllostomid bats coexist mostly with closely related species, revealing a north-south gradient from overdispersed to clustered phylogenetic fields. Patterns at different phylogenetic levels (i.e. all species versus close relatives only) presented the same gradient. Results support the tropical niche conservatism hypothesis, potentially mediated by higher speciation rates in the region of origin coupled with shared environmental preferences among species. The phylogenetic field approach enables species-based community phylogenetics, instead of those that are site-based, allowing the description of historical processes at more appropriate macroecological and biogeographic scales.

  15. Major clades of Agaricales: a multilocus phylogenetic overview.

    PubMed

    Matheny, P Brandon; Curtis, Judd M; Hofstetter, Valérie; Aime, M Catherine; Moncalvo, Jean-Marc; Ge, Zai-Wei; Slot, Jason C; Ammirati, Joseph F; Baroni, Timothy J; Bougher, Neale L; Hughes, Karen W; Lodge, D Jean; Kerrigan, Richard W; Seidl, Michelle T; Aanen, Duur K; DeNitis, Matthew; Daniele, Graciela M; Desjardin, Dennis E; Kropp, Bradley R; Norvell, Lorelei L; Parker, Andrew; Vellinga, Else C; Vilgalys, Rytas; Hibbett, David S

    2006-01-01

    An overview of the phylogeny of the Agaricales is presented based on a multilocus analysis of a six-gene region supermatrix. Bayesian analyses of 5611 nucleotide characters of rpb1, rpb1-intron 2, rpb2 and 18S, 25S, and 5.8S ribosomal RNA genes recovered six major clades, which are recognized informally and labeled the Agaricoid, Tricholomatoid, Marasmioid, Pluteoid, Hygrophoroid and Plicaturopsidoid clades. Each clade is discussed in terms of key morphological and ecological traits. At least 11 origins of the ectomycorrhizal habit appear to have evolved in the Agaricales, with possibly as many as nine origins in the Agaricoid plus Tricholomatoid clade alone. A family-based phylogenetic classification is sketched for the Agaricales, in which 30 families, four unplaced tribes and two informally named clades are recognized.

  16. Synopsis of Trichosanthes (Cucurbitaceae) based on recent molecular phylogenetic data.

    PubMed

    de Boer, Hugo J; Thulin, Mats

    2012-01-01

    The snake gourd genus, Trichosanthes, is the largest genus in the Cucurbitaceae family, with over 90 species. Recent molecular phylogenetic data have indicated that the genus Gymnopetalum is to be merged with Trichosanthes to maintain monophyly. A revised infrageneric classification of Trichosanthes including Gymnopetalum is proposed with two subgenera, (I) subg. Scotanthus comb. nov. and (II) subg. Trichosanthes, eleven sections, (i) sect. Asterospermae, (ii) sect. Cucumeroides, (iii) sect. Edulis, (iv) sect. Foliobracteola, (v) sect. Gymnopetalum, (vi) sect. Involucraria, (vii) sect. Pseudovariifera sect. nov., (viii) sect. Villosae stat. nov., (ix) sect. Trichosanthes, (x) sect. Tripodanthera, and (xi) sect. Truncata. A synopsis of Trichosanthes with the 91 species recognized here is presented, including four new combinations, Trichosanthes orientalis, Trichosanthes tubiflora, Trichosanthes scabra var. pectinata, Trichosanthes scabra var. penicaudii, and a clarified nomenclature of Trichosanthes costata and Trichosanthes scabra.

  17. Molecular and Morphological Analyses Reveal Phylogenetic Relationships of Stingrays Focusing on the Family Dasyatidae (Myliobatiformes)

    PubMed Central

    Lim, Kean Chong; Lim, Phaik-Eem; Chong, Ving Ching; Loh, Kar-Hoe

    2015-01-01

    Elucidating the phylogenetic relationships of the current but problematic Dasyatidae (Order Myliobatiformes) was the first priority of the current study. Here, we studied three molecular gene markers of 43 species (COI gene), 33 species (ND2 gene) and 34 species (RAG1 gene) of stingrays to draft out the phylogenetic tree of the order. Nine character states were identified and used to confirm the molecularly constructed phylogenetic trees. Eight or more clades (at different hierarchical level) were identified for COI, ND2 and RAG1 genes in the Myliobatiformes including four clades containing members of the present Dasyatidae, thus rendering the latter non-monophyletic. The uncorrected p-distance between these four ‘Dasytidae’ clades when compared to the distance between formally known families confirmed that these four clades should be elevated to four separate families. We suggest a revision of the present classification, retaining the Dasyatidae (Dasyatis and Taeniurops species) but adding three new families namely, Neotrygonidae (Neotrygon and Taeniura species), Himanturidae (Himantura species) and Pastinachidae (Pastinachus species). Our result indicated the need to further review the classification of Dasyatis microps. By resolving the non-monophyletic problem, the suite of nine character states enables the natural classification of the Myliobatiformes into at least thirteen families based on morphology. PMID:25867639

  18. Molecular phylogenetics and character evolution of morphologically diverse groups, Dendrobium section Dendrobium and allies

    PubMed Central

    Takamiya, Tomoko; Wongsawad, Pheravut; Sathapattayanon, Apirada; Tajima, Natsuko; Suzuki, Shunichiro; Kitamura, Saki; Shioda, Nao; Handa, Takashi; Kitanaka, Susumu; Iijima, Hiroshi; Yukawa, Tomohisa

    2014-01-01

    It is always difficult to construct coherent classification systems for plant lineages having diverse morphological characters. The genus Dendrobium, one of the largest genera in the Orchidaceae, includes ∼1100 species, and enormous morphological diversification has hindered the establishment of consistent classification systems covering all major groups of this genus. Given the particular importance of species in Dendrobium section Dendrobium and allied groups as floriculture and crude drug genetic resources, there is an urgent need to establish a stable classification system. To clarify phylogenetic relationships in Dendrobium section Dendrobium and allied groups, we analysed the macromolecular characters of the group. Phylogenetic analyses of 210 taxa of Dendrobium were conducted on DNA sequences of internal transcribed spacer (ITS) regions of 18S–26S nuclear ribosomal DNA and the maturase-coding gene (matK) located in an intron of the plastid gene trnK using maximum parsimony and Bayesian methods. The parsimony and Bayesian analyses revealed 13 distinct clades in the group comprising section Dendrobium and its allied groups. Results also showed paraphyly or polyphyly of sections Amblyanthus, Aporum, Breviflores, Calcarifera, Crumenata, Dendrobium, Densiflora, Distichophyllae, Dolichocentrum, Holochrysa, Oxyglossum and Pedilonum. On the other hand, the monophyly of section Stachyobium was well supported. It was found that many of the morphological characters that have been believed to reflect phylogenetic relationships are, in fact, the result of convergence. As such, many of the sections that have been recognized up to this point were found to not be monophyletic, so recircumscription of sections is required. PMID:25107672

  19. Hyperspectral image classification for mapping agricultural tillage practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An efficient classification framework for mapping agricultural tillage practice using hyperspectral remote sensing imagery is proposed, which has the potential to be implemented practically to provide rapid, accurate, and objective surveying data for precision agricultural management and appraisal f...

  20. Classification of the acanthocephala.

    PubMed

    Amin, Omar M

    2013-09-01

    In 1985, Amin presented a new system for the classification of the Acanthocephala in Crompton and Nickol's (1985) book 'Biology of the Acanthocephala' and recognized the concepts of Meyer (1931, 1932, 1933) and Van Cleave (1936, 1941, 1947, 1948, 1949, 1951, 1952). This system became the standard for the taxonomy of this group and remains so to date. Many changes have taken place and many new genera and species, as well as higher taxa, have been described since. An updated version of the 1985 scheme incorporating new concepts in molecular taxonomy, gene sequencing and phylogenetic studies is presented. The hierarchy has undergone a total face lift with Amin's (1987) addition of a new class, Polyacanthocephala (and a new order and family) to remove inconsistencies in the class Palaeacanthocephala. Amin and Ha (2008) added a third order (and a new family) to the Palaeacanthocephala, Heteramorphida, which combines features from the palaeacanthocephalan families Polymorphidae and Heteracanthocephalidae. Other families and subfamilies have been added but some have been eliminated, e.g. the three subfamilies of Arythmacanthidae: Arhythmacanthinae Yamaguti, 1935; Neoacanthocephaloidinae Golvan, 1960; and Paracanthocephaloidinae Golvan, 1969. Amin (1985) listed 22 families, 122 genera and 903 species (4, 4 and 14 families; 13, 28 and 81 genera; 167, 167 and 569 species in Archiacanthocephala, Eoacanthocephala and Palaeacanthocephala, respectively). The number of taxa listed in the present treatment is 26 families (18% increase), 157 genera (29%), and 1298 species (44%) (4, 4 and 16; 18, 29 and 106; 189, 255 and 845, in the same order), which also includes 1 family, 1 genus and 4 species in the class Polyacanthocephala Amin, 1987, and 3 genera and 5 species in the fossil family Zhijinitidae.

  1. Classification issues related to neuropathic trigeminal pain.

    PubMed

    Zakrzewska, Joanna M

    2004-01-01

    The goal of a classification system of medical conditions is to facilitate accurate communication, to ensure that each condition is described uniformly and universally and that all data banks for the storage and retrieval of research and clinical data related to the conditions are consistent. Classification entails deciding which kinds of diagnostic entities should be recognized and how to order them in a meaningful way. Currently there are 3 major pain classification systems of relevance to orofacial pain: The International Association for the Study of Pain classification system, the International Headache Society classification system, and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All use different methodologies, and only the RDC/TMD take into account social and psychologic factors in the classification of conditions. Classification systems need to be reliable, valid, comprehensive, generalizable, and flexible, and they need to be tested using consensus views of experts as well as the available literature. There is an urgent need for a robust classification system for neuropathic trigeminal pain.

  2. Phylogenetic relationships of American willows (Salix L., Salicaceae).

    PubMed

    Lauron-Moreau, Aurélien; Pitre, Frédéric E; Argus, George W; Labrecque, Michel; Brouillet, Luc

    2015-01-01

    Salix L. is the largest genus in the family Salicaceae (450 species). Several classifications have been published, but taxonomic subdivision has been under continuous revision. Our goal is to establish the phylogenetic structure of the genus using molecular data on all American willows, using three DNA markers. This complete phylogeny of American willows allows us to propose a biogeographic framework for the evolution of the genus. Material was obtained for the 122 native and introduced willow species of America. Sequences were obtained from the ITS (ribosomal nuclear DNA) and two plastid regions, matK and rbcL. Phylogenetic analyses (parsimony, maximum likelihood, Bayesian inference) were performed on the data. Geographic distribution was mapped onto the tree. The species tree provides strong support for a division of the genus into two subgenera, Salix and Vetrix. Subgenus Salix comprises temperate species from the Americas and Asia, and their disjunction may result from Tertiary events. Subgenus Vetrix is composed of boreo-arctic species of the Northern Hemisphere and their radiation may coincide with the Quaternary glaciations. Sixteen species have ambiguous positions; genetic diversity is lower in subg. Vetrix. A molecular phylogeny of all species of American willows has been inferred. It needs to be tested and further resolved using other molecular data. Nonetheless, the genus clearly has two clades that have distinct biogeographic patterns.

  3. Phylogenetic Relationships of American Willows (Salix L., Salicaceae)

    PubMed Central

    Lauron-Moreau, Aurélien; Pitre, Frédéric E.; Argus, George W.; Labrecque, Michel; Brouillet, Luc

    2015-01-01

    Salix L. is the largest genus in the family Salicaceae (450 species). Several classifications have been published, but taxonomic subdivision has been under continuous revision. Our goal is to establish the phylogenetic structure of the genus using molecular data on all American willows, using three DNA markers. This complete phylogeny of American willows allows us to propose a biogeographic framework for the evolution of the genus. Material was obtained for the 122 native and introduced willow species of America. Sequences were obtained from the ITS (ribosomal nuclear DNA) and two plastid regions, matK and rbcL. Phylogenetic analyses (parsimony, maximum likelihood, Bayesian inference) were performed on the data. Geographic distribution was mapped onto the tree. The species tree provides strong support for a division of the genus into two subgenera, Salix and Vetrix. Subgenus Salix comprises temperate species from the Americas and Asia, and their disjunction may result from Tertiary events. Subgenus Vetrix is composed of boreo-arctic species of the Northern Hemisphere and their radiation may coincide with the Quaternary glaciations. Sixteen species have ambiguous positions; genetic diversity is lower in subg. Vetrix. A molecular phylogeny of all species of American willows has been inferred. It needs to be tested and further resolved using other molecular data. Nonetheless, the genus clearly has two clades that have distinct biogeographic patterns. PMID:25880993

  4. Phylogenetic Relationships Matter: Antifungal Susceptibility among Clinically Relevant Yeasts

    PubMed Central

    Schmalreck, A. F.; Becker, K.; Fegeler, W.; Czaika, V.; Ulmer, H.; Lass-Flörl, C.

    2014-01-01

    The objective of this study was 2-fold: to evaluate whether phylogenetically closely related yeasts share common antifungal susceptibility profiles (ASPs) and whether these ASPs can be predicted from phylogeny. To address this question, 9,627 yeast strains were collected and tested for their antifungal susceptibility. Isolates were reidentified by considering recent changes in taxonomy and nomenclature. A phylogenetic (PHYLO) code based on the results of multilocus sequence analyses (large-subunit rRNA, small-subunit rRNA, translation elongation factor 1α, RNA polymerase II subunits 1 and 2) and the classification of the cellular neutral sugar composition of coenzyme Q and 18S ribosomal DNA was created to group related yeasts into PHYLO groups. The ASPs were determined for fluconazole, itraconazole, and voriconazole in each PHYLO group. The majority (95%) of the yeast strains were Ascomycetes. After reclassification, a total of 23 genera and 54 species were identified, resulting in an increase of 64% of genera and a decrease of 5% of species compared with the initial identification. These taxa were assigned to 17 distinct PHYLO groups (Ascomycota, n = 13; Basidiomycota, n = 4). ASPs for azoles were similar among members of the same PHYLO group and different between the various PHYLO groups. Yeast phylogeny may be an additional tool to significantly enhance the assessment of MIC values and to predict antifungal susceptibility, thereby more rapidly initiating appropriate patient management. PMID:24366735

  5. Testing for phylogenetic signal in biological traits: the ubiquity of cross-product statistics.

    PubMed

    Pavoine, Sandrine; Ricotta, Carlo

    2013-03-01

    To evaluate rates of evolution, to establish tests of correlation between two traits, or to investigate to what degree the phylogeny of a species assemblage is predictive of a trait value so-called tests for phylogenetic signal are used. Being based on different approaches, these tests are generally thought to possess quite different statistical performances. In this article, we show that the Blomberg et al. K and K*, the Abouheif index, the Moran's I, and the Mantel correlation are all based on a cross-product statistic, and are thus all related to each other when they are associated to a permutation test of phylogenetic signal. What changes is only the way phylogenetic and trait similarities (or dissimilarities) among the tips of a phylogeny are computed. The definitions of the phylogenetic and trait-based (dis)similarities among tips thus determines the performance of the tests. We shortly discuss the biological and statistical consequences (in terms of power and type I error of the tests) of the observed relatedness among the statistics that allow tests for phylogenetic signal. Blomberg et al. K* statistic appears as one on the most efficient approaches to test for phylogenetic signal. When branch lengths are not available or not accurate, Abouheif's Cmean statistic is a powerful alternative to K*.

  6. Phylogenetics of Lophodermium from pine.

    PubMed

    Ortiz-García, Sol; Gernandt, David S; Stone, Jeffrey K; Johnston, Peter R; Chapela, Ignacio H; Salas-Lizana, Rodolfo; Alvarez-Buylla, Elena R

    2003-01-01

    Lophodermium comprises ascomycetous fungi that are both needle-cast pathogens and asymptomatic endophytes on a diversity of plant hosts. It is distinguished from other genera in the family Rhytismataceae by its filiform ascospores and ascocarps that open by a longitudinal slit. Nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were used to infer phylogenetic relationships within Lophodermium. Twenty-nine sequences from approximately 11 species of Lophodermium were analyzed together with eight sequences from isolates thought to represent six other genera of Rhytismataceae: Elytroderma, Lirula, Meloderma, Terriera, Tryblidiopsis and Colpoma. Two putative Meloderma desmazieresii isolates occurred within the Lophodermium clade but separate from one another, one grouped with L. indianum and the other with L. nitens. An isolate of Elytroderma deformans also occurred within the Lophodermium clade but on a solitary branch. The occurrence of these genera within the Lophodermium clade might be due to problems in generic concepts in Rhytismataceae, such as emphasis on spore morphology to delimit genera, to difficulty of isolating Rhytismataceae needle pathogens from material that also is colonized by Lophodermium or to a combination of both factors. We also evaluated the congruence of host distribution and several morphological characters on the ITS phylogeny. Lophodermium species from pine hosts formed a monophyletic sister group to Lophodermium species from more distant hosts from the southern hemisphere, but not to L. piceae from Picea. The ITS topology indicated that Lophodermium does not show strict cospeciation with pines at deeper branches, although several closely related isolates have closely related hosts. Pathogenic species occupy derived positions in the pine clade, suggesting that pathogenicity has evolved from endophytism. A new combination is proposed, Terriera minor (Tehon) P.R. Johnst.

  7. Molecular Phylogenetics: Mathematical Framework and Unsolved Problems

    NASA Astrophysics Data System (ADS)

    Xia, Xuhua

    Phylogenetic relationship is essential in dating evolutionary events, reconstructing ancestral genes, predicting sites that are important to natural selection, and, ultimately, understanding genomic evolution. Three categories of phylogenetic methods are currently used: the distance-based, the maximum parsimony, and the maximum likelihood method. Here, I present the mathematical framework of these methods and their rationales, provide computational details for each of them, illustrate analytically and numerically the potential biases inherent in these methods, and outline computational challenges and unresolved problems. This is followed by a brief discussion of the Bayesian approach that has been recently used in molecular phylogenetics.

  8. Selecting Species Traits for Biomonitoring Applications in light of Phylogenetic Relationships among Lotic Insects

    NASA Astrophysics Data System (ADS)

    Poff, N.; Vieira, N. K.; Simmons, M. P.; Olden, J. D.; Kondratieff, B. C.; Finn, D. S.

    2005-05-01

    The use of species traits as indicators of environmental disturbance is being considered for biomonitoring programs globally. As such, methods to select relevant and informative traits for inclusion in biometrics need to be developed. In this research, we identified 20 traits of aquatic insects within six trait groups: morphology, mobility, life-history strategy, thermal tolerance, feeding guild and ecology (e.g., habitat preference). We constructed phylogenetic trees for 1) all lotic insect species of North America and 2) all Ephemeroptera, Plecoptera and Trichoptera species based on morphology- and molecular-based analyses and classifications. We then measured variability (i.e., plasticity) of the 20 traits and six trait groups across the two phylogenetic trees. Traits with higher degrees of plasticity indicated traits that were less phylogenetically constrained, and were considered informative for biomonitoring purposes. Thermal tolerance, rheophily, body size at maturity and feeding guild showed the highest plasticity across both phylogenetic trees. Two mobility traits, occurrence in drift and adult dispersal distance, showed moderate plasticity. By contrast, adult exiting ability, degree of attachment, adult lifespan and body shape showed low variability and were thus less informative. Plastic species traits that are less phylogenetically constrained may be most useful in detecting community change along environmental gradients.

  9. [Molecular phylogenetic analysis of the genus Abies (Pinaceae) based on the nucleotide sequence of chloroplast DNA].

    PubMed

    Semerikova, S A; Semerikov, V L

    2014-01-01

    A phylogenetic study of firs (Abies Mill.) was conducted using nucleotide sequences of several chloroplast DNA regions with a total length of 5580 bp. The analysis included 37 taxa, which represented the main evolutionary lineages of the genus, and Keteleeria daviana. According to phylogenetic reconstruction the Abies species were subdivided into six main groups, generally corresponding to their geographic distribution. The phylogenetic tree had three basal clades. All of these clades contained American species, and only one of them contained Eurasian species. The divergence time calibrations, based on paleobotanical data and the chloroplast DNA mutation rate estimates in Pinaceae, produced similar results..The age of diversification among the clades of the present-day Abies was estimated as the end of the Oligocene-beginning of Miocene. The age of the separation of Mediterranean firs from the Asian-North American branch corresponds to the Miocene. The age of diversification within the young groups of Mediterranean, Asian, and boreal American firs (A. lasiocarpa, A. balsamea, A. fraseri) was estimated as the Pliocene-Pleistocene. Based on the phylogenetic reconstruction obtained, the most plausible biogeographic scenarios were suggested. It is noted that the existing systematic classification of the genus Abies strongly contradicts with phylogenetic reconstruction and requires revision.

  10. Molecular systematics of the Amazonian genus Aldina, a phylogenetically enigmatic ectomycorrhizal lineage of papilionoid legumes.

    PubMed

    Ramos, Gustavo; de Lima, Haroldo Cavalcante; Prenner, Gerhard; de Queiroz, Luciano Paganucci; Zartman, Charles E; Cardoso, Domingos

    2016-04-01

    Aldina (Leguminosae) is among the very few ecologically successful ectomycorrhizal lineages in a family largely marked by the evolution of nodulating symbiosis. The genus comprises 20 species predominantly distributed in Amazonia and has been traditionally classified in the tribe Swartzieae because of its radial flowers with an entire calyx and numerous free stamens. The taxonomy of Aldina is complicated due to its poor representation in herbaria and the lack of a robust phylogenetic hypothesis of relationship. Recent phylogenetic analyses of matK and trnL sequences confirmed the placement of Aldina in the 50-kb inversion clade, although the genus remained phylogenetically isolated or unresolved in the context of the evolutionary history of the main early-branching papilionoid lineages. We performed maximum likelihood and Bayesian analyses of combined chloroplast datasets (matK, rbcL, and trnL) and explored the effect of incomplete taxa or missing data in order to shed light on the enigmatic phylogenetic position of Aldina. Unexpectedly, a sister relationship of Aldina with the Andira clade (Andira and Hymenolobium) is revealed. We suggest that a new tribal phylogenetic classification of the papilionoid legumes should place Aldina along with Andira and Hymenolobium. These results highlight yet another example of the independent evolution of radial floral symmetry within the early-branching Papilionoideae, a large collection of florally heterogeneous lineages dominated by papilionate or bilaterally symmetric flower morphology.

  11. Automated ribotyping provides rapid phylogenetic subgroup affiliation of clinical extraintestinal pathogenic Escherichia coli strains.

    PubMed

    Clermont, O; Cordevant, C; Bonacorsi, S; Marecat, A; Lange, M; Bingen, E

    2001-12-01

    Using the automated Riboprinter system, we have initiated the construction of an electronic Riboprint database composed of 72 ECOR reference strains and 15 archetypal virulent strains in order to provide a new simple molecular characterization method. More than 90% of the ECOR strains clustered in their original phylogenetic group. All but one of the archetypal virulent strains had a profile identical to that of one of the ECOR strains and could be easily affiliated with a phylogenetic group. This method appears to be an accurate and practical tool especially for investigating the genetic relationship between clinical extraintestinal pathogenic strains and B2 subgroup ECOR strains or archetypal pathotype strains.

  12. Trends and concepts in fern classification

    PubMed Central

    Christenhusz, Maarten J. M.; Chase, Mark W.

    2014-01-01

    Background and Aims Throughout the history of fern classification, familial and generic concepts have been highly labile. Many classifications and evolutionary schemes have been proposed during the last two centuries, reflecting different interpretations of the available evidence. Knowledge of fern structure and life histories has increased through time, providing more evidence on which to base ideas of possible relationships, and classification has changed accordingly. This paper reviews previous classifications of ferns and presents ideas on how to achieve a more stable consensus. Scope An historical overview is provided from the first to the most recent fern classifications, from which conclusions are drawn on past changes and future trends. The problematic concept of family in ferns is discussed, with a particular focus on how this has changed over time. The history of molecular studies and the most recent findings are also presented. Key Results Fern classification generally shows a trend from highly artificial, based on an interpretation of a few extrinsic characters, via natural classifications derived from a multitude of intrinsic characters, towards more evolutionary circumscriptions of groups that do not in general align well with the distribution of these previously used characters. It also shows a progression from a few broad family concepts to systems that recognized many more narrowly and highly controversially circumscribed families; currently, the number of families recognized is stabilizing somewhere between these extremes. Placement of many genera was uncertain until the arrival of molecular phylogenetics, which has rapidly been improving our understanding of fern relationships. As a collective category, the so-called ‘fern allies’ (e.g. Lycopodiales, Psilotaceae, Equisetaceae) were unsurprisingly found to be polyphyletic, and the term should be abandoned. Lycopodiaceae, Selaginellaceae and Isoëtaceae form a clade (the lycopods) that is

  13. Genome-Based Taxonomic Classification of Bacteroidetes.

    PubMed

    Hahnke, Richard L; Meier-Kolthoff, Jan P; García-López, Marina; Mukherjee, Supratim; Huntemann, Marcel; Ivanova, Natalia N; Woyke, Tanja; Kyrpides, Nikos C; Klenk, Hans-Peter; Göker, Markus

    2016-01-01

    The bacterial phylum Bacteroidetes, characterized by a distinct gliding motility, occurs in a broad variety of ecosystems, habitats, life styles, and physiologies. Accordingly, taxonomic classification of the phylum, based on a limited number of features, proved difficult and controversial in the past, for example, when decisions were based on unresolved phylogenetic trees of the 16S rRNA gene sequence. Here we use a large collection of type-strain genomes from Bacteroidetes and closely related phyla for assessing their taxonomy based on the principles of phylogenetic classification and trees inferred from genome-scale data. No significant conflict between 16S rRNA gene and whole-genome phylogenetic analysis is found, whereas many but not all of the involved taxa are supported as monophyletic groups, particularly in the genome-scale trees. Phenotypic and phylogenomic features support the separation of Balneolaceae as new phylum Balneolaeota from Rhodothermaeota and of Saprospiraceae as new class Saprospiria from Chitinophagia. Epilithonimonas is nested within the older genus Chryseobacterium and without significant phenotypic differences; thus merging the two genera is proposed. Similarly, Vitellibacter is proposed to be included in Aequorivita. Flexibacter is confirmed as being heterogeneous and dissected, yielding six distinct genera. Hallella seregens is a later heterotypic synonym of Prevotella dentalis. Compared to values directly calculated from genome sequences, the G+C content mentioned in many species descriptions is too imprecise; moreover, corrected G+C content values have a significantly better fit to the phylogeny. Corresponding emendations of species descriptions are provided where necessary. Whereas most observed conflict with the current classification of Bacteroidetes is already visible in 16S rRNA gene trees, as expected whole-genome phylogenies are much better resolved.

  14. Genome-Based Taxonomic Classification of Bacteroidetes

    PubMed Central

    Hahnke, Richard L.; Meier-Kolthoff, Jan P.; García-López, Marina; Mukherjee, Supratim; Huntemann, Marcel; Ivanova, Natalia N.; Woyke, Tanja; Kyrpides, Nikos C.; Klenk, Hans-Peter; Göker, Markus

    2016-01-01

    The bacterial phylum Bacteroidetes, characterized by a distinct gliding motility, occurs in a broad variety of ecosystems, habitats, life styles, and physiologies. Accordingly, taxonomic classification of the phylum, based on a limited number of features, proved difficult and controversial in the past, for example, when decisions were based on unresolved phylogenetic trees of the 16S rRNA gene sequence. Here we use a large collection of type-strain genomes from Bacteroidetes and closely related phyla for assessing their taxonomy based on the principles of phylogenetic classification and trees inferred from genome-scale data. No significant conflict between 16S rRNA gene and whole-genome phylogenetic analysis is found, whereas many but not all of the involved taxa are supported as monophyletic groups, particularly in the genome-scale trees. Phenotypic and phylogenomic features support the separation of Balneolaceae as new phylum Balneolaeota from Rhodothermaeota and of Saprospiraceae as new class Saprospiria from Chitinophagia. Epilithonimonas is nested within the older genus Chryseobacterium and without significant phenotypic differences; thus merging the two genera is proposed. Similarly, Vitellibacter is proposed to be included in Aequorivita. Flexibacter is confirmed as being heterogeneous and dissected, yielding six distinct genera. Hallella seregens is a later heterotypic synonym of Prevotella dentalis. Compared to values directly calculated from genome sequences, the G+C content mentioned in many species descriptions is too imprecise; moreover, corrected G+C content values have a significantly better fit to the phylogeny. Corresponding emendations of species descriptions are provided where necessary. Whereas most observed conflict with the current classification of Bacteroidetes is already visible in 16S rRNA gene trees, as expected whole-genome phylogenies are much better resolved. PMID:28066339

  15. A practical guide to phylogenetics for nonexperts.

    PubMed

    O'Halloran, Damien

    2014-02-05

    Many researchers, across incredibly diverse foci, are applying phylogenetics to their research question(s). However, many researchers are new to this topic and so it presents inherent problems. Here we compile a practical introduction to phylogenetics for nonexperts. We outline in a step-by-step manner, a pipeline for generating reliable phylogenies from gene sequence datasets. We begin with a user-guide for similarity search tools via online interfaces as well as local executables. Next, we explore programs for generating multiple sequence alignments followed by protocols for using software to determine best-fit models of evolution. We then outline protocols for reconstructing phylogenetic relationships via maximum likelihood and Bayesian criteria and finally describe tools for visualizing phylogenetic trees. While this is not by any means an exhaustive description of phylogenetic approaches, it does provide the reader with practical starting information on key software applications commonly utilized by phylogeneticists. The vision for this article would be that it could serve as a practical training tool for researchers embarking on phylogenetic studies and also serve as an educational resource that could be incorporated into a classroom or teaching-lab.

  16. A Practical Guide to Phylogenetics for Nonexperts

    PubMed Central

    O'Halloran, Damien

    2014-01-01

    Many researchers, across incredibly diverse foci, are applying phylogenetics to their research question(s). However, many researchers are new to this topic and so it presents inherent problems. Here we compile a practical introduction to phylogenetics for nonexperts. We outline in a step-by-step manner, a pipeline for generating reliable phylogenies from gene sequence datasets. We begin with a user-guide for similarity search tools via online interfaces as well as local executables. Next, we explore programs for generating multiple sequence alignments followed by protocols for using software to determine best-fit models of evolution. We then outline protocols for reconstructing phylogenetic relationships via maximum likelihood and Bayesian criteria and finally describe tools for visualizing phylogenetic trees. While this is not by any means an exhaustive description of phylogenetic approaches, it does provide the reader with practical starting information on key software applications commonly utilized by phylogeneticists. The vision for this article would be that it could serve as a practical training tool for researchers embarking on phylogenetic studies and also serve as an educational resource that could be incorporated into a classroom or teaching-lab. PMID:24562012

  17. Phylogenetic structure in tropical hummingbird communities.

    PubMed

    Graham, Catherine H; Parra, Juan L; Rahbek, Carsten; McGuire, Jimmy A

    2009-11-17

    How biotic interactions, current and historical environment, and biogeographic barriers determine community structure is a fundamental question in ecology and evolution, especially in diverse tropical regions. To evaluate patterns of local and regional diversity, we quantified the phylogenetic composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that humid, low-elevation communities are phylogenetically overdispersed (coexistence of distant relatives), a pattern that is consistent with the idea that competition influences the local composition of hummingbirds. At higher elevations communities are phylogenetically clustered (coexistence of close relatives), consistent with the expectation of environmental filtering, which may result from the challenge of sustaining an expensive means of locomotion at high elevations. We found that communities in the lowlands on opposite sides of the Andes tend to be phylogenetically similar despite their large differences in species composition, a pattern implicating the Andes as an important dispersal barrier. In contrast, along the steep environmental gradient between the lowlands and the Andes we found evidence that species turnover is comprised of relatively distantly related species. The integration of local and regional patterns of diversity across environmental gradients and biogeographic barriers provides insight into the potential underlying mechanisms that have shaped community composition and phylogenetic diversity in one of the most species-rich, complex regions of the world.

  18. Phylogenetic structure in tropical hummingbird communities

    PubMed Central

    Graham, Catherine H.; Parra, Juan L.; Rahbek, Carsten; McGuire, Jimmy A.

    2009-01-01

    How biotic interactions, current and historical environment, and biogeographic barriers determine community structure is a fundamental question in ecology and evolution, especially in diverse tropical regions. To evaluate patterns of local and regional diversity, we quantified the phylogenetic composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that humid, low-elevation communities are phylogenetically overdispersed (coexistence of distant relatives), a pattern that is consistent with the idea that competition influences the local composition of hummingbirds. At higher elevations communities are phylogenetically clustered (coexistence of close relatives), consistent with the expectation of environmental filtering, which may result from the challenge of sustaining an expensive means of locomotion at high elevations. We found that communities in the lowlands on opposite sides of the Andes tend to be phylogenetically similar despite their large differences in species composition, a pattern implicating the Andes as an important dispersal barrier. In contrast, along the steep environmental gradient between the lowlands and the Andes we found evidence that species turnover is comprised of relatively distantly related species. The integration of local and regional patterns of diversity across environmental gradients and biogeographic barriers provides insight into the potential underlying mechanisms that have shaped community composition and phylogenetic diversity in one of the most species-rich, complex regions of the world. PMID:19805042

  19. Orthologous repeats and mammalian phylogenetic inference

    PubMed Central

    Bashir, Ali; Ye, Chun; Price, Alkes L.; Bafna, Vineet

    2005-01-01

    Determining phylogenetic relationships between species is a difficult problem, and many phylogenetic relationships remain unresolved, even among eutherian mammals. Repetitive elements provide excellent markers for phylogenetic analysis, because their mode of evolution is predominantly homoplasy-free and unidirectional. Historically, phylogenetic studies using repetitive elements have relied on biological methods such as PCR analysis, and computational inference is limited to a few isolated repeats. Here, we present a novel computational method for inferring phylogenetic relationships from partial sequence data using orthologous repeats. We apply our method to reconstructing the phylogeny of 28 mammals, using more than 1000 orthologous repeats obtained from sequence data available from the NISC Comparative Sequencing Program. The resulting phylogeny has robust bootstrap numbers, and broadly matches results from previous studies which were obtained using entirely different data and methods. In addition, we shed light on some of the debatable aspects of the phylogeny. With rapid expansion of available partial sequence data, computational analysis of repetitive elements holds great promise for the future of phylogenetic inference. PMID:15998912

  20. How does cognition evolve? Phylogenetic comparative psychology.

    PubMed

    MacLean, Evan L; Matthews, Luke J; Hare, Brian A; Nunn, Charles L; Anderson, Rindy C; Aureli, Filippo; Brannon, Elizabeth M; Call, Josep; Drea, Christine M; Emery, Nathan J; Haun, Daniel B M; Herrmann, Esther; Jacobs, Lucia F; Platt, Michael L; Rosati, Alexandra G; Sandel, Aaron A; Schroepfer, Kara K; Seed, Amanda M; Tan, Jingzhi; van Schaik, Carel P; Wobber, Victoria

    2012-03-01

    Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution.

  1. Maximizing the phylogenetic diversity of seed banks.

    PubMed

    Griffiths, Kate E; Balding, Sharon T; Dickie, John B; Lewis, Gwilym P; Pearce, Tim R; Grenyer, Richard

    2015-04-01

    Ex situ conservation efforts such as those of zoos, botanical gardens, and seed banks will form a vital complement to in situ conservation actions over the coming decades. It is therefore necessary to pay the same attention to the biological diversity represented in ex situ conservation facilities as is often paid to protected-area networks. Building the phylogenetic diversity of ex situ collections will strengthen our capacity to respond to biodiversity loss. Since 2000, the Millennium Seed Bank Partnership has banked seed from 14% of the world's plant species. We assessed the taxonomic, geographic, and phylogenetic diversity of the Millennium Seed Bank collection of legumes (Leguminosae). We compared the collection with all known legume genera, their known geographic range (at country and regional levels), and a genus-level phylogeny of the legume family constructed for this study. Over half the phylogenetic diversity of legumes at the genus level was represented in the Millennium Seed Bank. However, pragmatic prioritization of species of economic importance and endangerment has led to the banking of a less-than-optimal phylogenetic diversity and prioritization of range-restricted species risks an underdispersed collection. The current state of the phylogenetic diversity of legumes in the Millennium Seed Bank could be substantially improved through the strategic banking of relatively few additional taxa. Our method draws on tools that are widely applied to in situ conservation planning, and it can be used to evaluate and improve the phylogenetic diversity of ex situ collections.

  2. A statistical approach to root system classification

    PubMed Central

    Bodner, Gernot; Leitner, Daniel; Nakhforoosh, Alireza; Sobotik, Monika; Moder, Karl; Kaul, Hans-Peter

    2013-01-01

    Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for “plant functional type” identification in ecology can be applied to the classification of root systems. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. The study demonstrates that principal component based rooting types provide efficient and meaningful multi-trait classifiers. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems) is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Rooting types emerging from measured data, mainly distinguished by diameter/weight and density dominated types. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement techniques are essential. PMID:23914200

  3. Classification of TTV and related viruses (anelloviruses).

    PubMed

    Biagini, P

    2009-01-01

    Ten years after the identification of the first partial sequences of Torque teno virus (TTV), more than 200 full-length related genomes have been characterized in humans and in several animal species. As suspected in the earlier stages of their description, a considerable genetic variability characterizes TTV and related viruses, the current members of the floating genus Anellovirous. Since information related to anelloviruses diversity is in constant evolution, the challenge in their taxonomic classification is to take into account all pertinent parameters, along with the taxonomic situation of other viruses having circular single-stranded DNA genomes. Past, present and future phylogenetic and taxonomic considerations are exposed.

  4. Phylogenetic tree and sequence similarity of beta-lactamases.

    PubMed

    Ogawara, H

    1993-06-01

    beta-Lactamases are the main cause of beta-lactam resistance in many pathogenic bacteria. These enzymes can be detected in a variety of pathogenic as well as non-pathogenic bacteria. The cyanobacteria are also known to produce a beta-lactamase. Recently, the amino acid sequences and the three-dimensional structures of some of these beta-lactamases have been clarified. On the basis of the amino acid sequences of 47 beta-lactamases and the computer-aided analysis, a phylogenetic tree is proposed in this paper. According to the tree, beta-lactamases are classified into six groups. Group 1 beta-lactamases are mainly composed of plasmid-mediated enzymes from gram-negative bacteria. However, chromosome-derived beta-lactamases from Klebsiella pneumoniae and Rhodopseudomonas capsulata take part in this group. Group 2 enzymes consist of a part of the chromosome-encoded beta-lactamases from Streptomyces, and chromosome-mediated enzymes from Yersinia enterocolitica, Citrobacter diversus, and Klebsiella oxytoca. Chromosome-encoded beta-lactamases from gram-negative bacteria form group 3. Group 4 is composed of metalloenzymes, whereas group 5 consists of OXA type beta-lactamases. Chromosome-encoded beta-lactamases from gram-positive bacteria form group 6. Comparison of the amino acid sequences among these groups confirmed the phylogenetic tree and the classification: the beta-lactamases in each group have its particular conserved amino acid sequences. In addition, the tree provides more detailed classification and time-scale mutual relationships and predicts new types of beta-lactamases that may be found. Furthermore, the classification deduced from the tree is generally in accord with the one based on the amino acid sequences reported previously. However, the class A beta-lactamases are clearly divided into three groups: groups 1, 2, and 6. RDF2 analysis shows that some combinations between beta-lactamases and beta-lactam-interacting proteins as well as eukaryotic proteins

  5. Influence of pansharpening techniques in obtaining accurate vegetation thematic maps

    NASA Astrophysics Data System (ADS)

    Ibarrola-Ulzurrun, Edurne; Gonzalo-Martin, Consuelo; Marcello-Ruiz, Javier

    2016-10-01

    In last decades, there have been a decline in natural resources, becoming important to develop reliable methodologies for their management. The appearance of very high resolution sensors has offered a practical and cost-effective means for a good environmental management. In this context, improvements are needed for obtaining higher quality of the information available in order to get reliable classified images. Thus, pansharpening enhances the spatial resolution of the multispectral band by incorporating information from the panchromatic image. The main goal in the study is to implement pixel and object-based classification techniques applied to the fused imagery using different pansharpening algorithms and the evaluation of thematic maps generated that serve to obtain accurate information for the conservation of natural resources. A vulnerable heterogenic ecosystem from Canary Islands (Spain) was chosen, Teide National Park, and Worldview-2 high resolution imagery was employed. The classes considered of interest were set by the National Park conservation managers. 7 pansharpening techniques (GS, FIHS, HCS, MTF based, Wavelet `à trous' and Weighted Wavelet `à trous' through Fractal Dimension Maps) were chosen in order to improve the data quality with the goal to analyze the vegetation classes. Next, different classification algorithms were applied at pixel-based and object-based approach, moreover, an accuracy assessment of the different thematic maps obtained were performed. The highest classification accuracy was obtained applying Support Vector Machine classifier at object-based approach in the Weighted Wavelet `à trous' through Fractal Dimension Maps fused image. Finally, highlight the difficulty of the classification in Teide ecosystem due to the heterogeneity and the small size of the species. Thus, it is important to obtain accurate thematic maps for further studies in the management and conservation of natural resources.

  6. On numerically accurate finite element

    NASA Technical Reports Server (NTRS)

    Nagtegaal, J. C.; Parks, D. M.; Rice, J. R.

    1974-01-01

    A general criterion for testing a mesh with topologically similar repeat units is given, and the analysis shows that only a few conventional element types and arrangements are, or can be made suitable for computations in the fully plastic range. Further, a new variational principle, which can easily and simply be incorporated into an existing finite element program, is presented. This allows accurate computations to be made even for element designs that would not normally be suitable. Numerical results are given for three plane strain problems, namely pure bending of a beam, a thick-walled tube under pressure, and a deep double edge cracked tensile specimen. The effects of various element designs and of the new variational procedure are illustrated. Elastic-plastic computation at finite strain are discussed.

  7. Phylogenetic signal in bone microstructure of sauropsids.

    PubMed

    Cubo, J; Ponton, F; Laurin, M; de Margerie, E; Castanet, J

    2005-08-01

    In spite of the fact that the potential usefulness of bone histology in systematics has been discussed for over one and a half centuries, the presence of a phylogenetic signal in the variation of histological characters has rarely been assessed. A quantitative assessment of phylogenetic signal in bone histological characters could provide a justification for performing optimizations of these traits onto independently generated phylogenetic trees (as has been done in recent years). Here we present an investigation on the quantification of the phylogenetic signal in the following bone histological, microanatomical, and morphological traits in a sample of femora of 35 species of sauropsids: vascular density, vascular orientation, index of Haversian remodeling, cortical thickness, and cross-sectional area (bone size). For this purpose, we use two methods, regressions on distance matrices tested for significance using permutations (a Mantel test) and random tree length distribution. Within sauropsids, these bone microstructural traits have an optimal systematic value in archosaurs. In this taxon, a Mantel test shows that the phylogeny explains 81.8% of the variation of bone size and 86.2% of the variation of cortical thickness. In contrast, a Mantel test suggests that the phylogenetic signal in histological traits is weak: although the phylogeny explains 18.7% of the variation of vascular density in archosaurs, the phylogenetic signal is not significant either for vascular orientation or for the index of Haversian remodeling. However, Mantel tests seem to underestimate the proportion of variance of the dependent character explained by the phylogeny, as suggested by a PVR (phylogenetic eigenvector) analysis. We also deal with some complementary questions. First, we evaluate the functional dependence of bone vascular density on bone size by using phylogenetically independent contrasts. Second, we perform a variation partitioning analysis and show that the phylogenetic

  8. Fast and accurate estimation for astrophysical problems in large databases

    NASA Astrophysics Data System (ADS)

    Richards, Joseph W.

    2010-10-01

    A recent flood of astronomical data has created much demand for sophisticated statistical and machine learning tools that can rapidly draw accurate inferences from large databases of high-dimensional data. In this Ph.D. thesis, methods for statistical inference in such databases will be proposed, studied, and applied to real data. I use methods for low-dimensional parametrization of complex, high-dimensional data that are based on the notion of preserving the connectivity of data points in the context of a Markov random walk over the data set. I show how this simple parameterization of data can be exploited to: define appropriate prototypes for use in complex mixture models, determine data-driven eigenfunctions for accurate nonparametric regression, and find a set of suitable features to use in a statistical classifier. In this thesis, methods for each of these tasks are built up from simple principles, compared to existing methods in the literature, and applied to data from astronomical all-sky surveys. I examine several important problems in astrophysics, such as estimation of star formation history parameters for galaxies, prediction of redshifts of galaxies using photometric data, and classification of different types of supernovae based on their photometric light curves. Fast methods for high-dimensional data analysis are crucial in each of these problems because they all involve the analysis of complicated high-dimensional data in large, all-sky surveys. Specifically, I estimate the star formation history parameters for the nearly 800,000 galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 7 spectroscopic catalog, determine redshifts for over 300,000 galaxies in the SDSS photometric catalog, and estimate the types of 20,000 supernovae as part of the Supernova Photometric Classification Challenge. Accurate predictions and classifications are imperative in each of these examples because these estimates are utilized in broader inference problems

  9. Phylogenetic relationship of phototrophic purple sulfur bacteria according to pufL and pufM genes.

    PubMed

    Tank, Marcus; Thiel, Vera; Imhoff, Johannes F

    2009-09-01

    The phylogenetic relationship of purple sulfur bacteria (PSB), of the order Chromatiales (class Gammaproteobacteria), was analyzed based on photosynthetic gene sequences of the pufL and pufM genes, and the results compared to phylogenetic trees and groupings of the 16S rRNA gene. Primers for pufL and pufM genes were constructed and successfully used to amplify the pufLM genes of members of 16 genera of Chromatiales. In total, pufLM and 16S rRNA gene sequences of 66 PSB strains were analyzed, including 29 type strains and 28 new isolates. The inferred phylogenetic trees of the pufLM and 16S rRNA genes reflected a largely similar phylogenetic development suggesting coevolution of these essential genes within the PSB. It is concluded that horizontal gene transfer of pufLM genes within the PSB is highly unlikely, in contrast to the situation in other groups of anoxygenic phototrophic bacteria belonging to Alpha- and Betaproteobacteria. The phylogeny of pufLM is therefore in good agreement with the current taxonomic classification of PSB. A phylogenetic classification of PSB to the genus level is possible based on their pufL or pufM sequences, and in many cases even to the species level. In addition, our data support a correlation between Puf protein structure and the type of internal photosynthetic membranes (vesicular, lamellar, or tubular).

  10. The Transporter Classification Database (TCDB): recent advances

    PubMed Central

    Saier, Milton H.; Reddy, Vamsee S.; Tsu, Brian V.; Ahmed, Muhammad Saad; Li, Chun; Moreno-Hagelsieb, Gabriel

    2016-01-01

    The Transporter Classification Database (TCDB; http://www.tcdb.org) is a freely accessible reference database for transport protein research, which provides structural, functional, mechanistic, evolutionary and disease/medical information about transporters from organisms of all types. TCDB is the only transport protein classification database adopted by the International Union of Biochemistry and Molecular Biology (IUBMB). It consists of more than 10 000 non-redundant transport systems with more than 11 000 reference citations, classified into over 1000 transporter families. Transporters in TCDB can be single or multi-component systems, categorized in a functional/phylogenetic hierarchical system of classes, subclasses, families, subfamilies and transport systems. TCDB also includes updated software designed to analyze the distinctive features of transport proteins, extending its usefulness. Here we present a comprehensive update of the database contents and features and summarize recent discoveries recorded in TCDB. PMID:26546518

  11. Classification Shell Game.

    ERIC Educational Resources Information Center

    Etzold, Carol

    1983-01-01

    Discusses shell classification exercises. Through keying students advanced from the "I know what a shell looks like" stage to become involved in the classification process: observing, labeling, making decisions about categories, and identifying marine animals. (Author/JN)

  12. Aircraft Operations Classification System

    NASA Technical Reports Server (NTRS)

    Harlow, Charles; Zhu, Weihong

    2001-01-01

    Accurate data is important in the aviation planning process. In this project we consider systems for measuring aircraft activity at airports. This would include determining the type of aircraft such as jet, helicopter, single engine, and multiengine propeller. Some of the issues involved in deploying technologies for monitoring aircraft operations are cost, reliability, and accuracy. In addition, the system must be field portable and acceptable at airports. A comparison of technologies was conducted and it was decided that an aircraft monitoring system should be based upon acoustic technology. A multimedia relational database was established for the study. The information contained in the database consists of airport information, runway information, acoustic records, photographic records, a description of the event (takeoff, landing), aircraft type, and environmental information. We extracted features from the time signal and the frequency content of the signal. A multi-layer feed-forward neural network was chosen as the classifier. Training and testing results were obtained. We were able to obtain classification results of over 90 percent for training and testing for takeoff events.

  13. Indel Reliability in Indel-Based Phylogenetic Inference

    PubMed Central

    Ashkenazy, Haim; Cohen, Ofir; Pupko, Tal; Huchon, Dorothée

    2014-01-01

    It is often assumed that it is unlikely that the same insertion or deletion (indel) event occurred at the same position in two independent evolutionary lineages, and thus, indel-based inference of phylogeny should be less subject to homoplasy compared with standard inference which is based on substitution events. Indeed, indels were successfully used to solve debated evolutionary relationships among various taxonomical groups. However, indels are never directly observed but rather inferred from the alignment and thus indel-based inference may be sensitive to alignment errors. It is hypothesized that phylogenetic reconstruction would be more accurate if it relied only on a subset of reliable indels instead of the entire indel data. Here, we developed a method to quantify the reliability of indel characters by measuring how often they appear in a set of alternative multiple sequence alignments. Our approach is based on the assumption that indels that are consistently present in most alternative alignments are more reliable compared with indels that appear only in a small subset of these alignments. Using simulated and empirical data, we studied the impact of filtering and weighting indels by their reliability scores on the accuracy of indel-based phylogenetic reconstruction. The new method is available as a web-server at http://guidance.tau.ac.il/RELINDEL/. PMID:25409663

  14. Cirrhosis classification based on texture classification of random features.

    PubMed

    Liu, Hui; Shao, Ying; Guo, Dongmei; Zheng, Yuanjie; Zhao, Zuowei; Qiu, Tianshuang

    2014-01-01

    Accurate staging of hepatic cirrhosis is important in investigating the cause and slowing down the effects of cirrhosis. Computer-aided diagnosis (CAD) can provide doctors with an alternative second opinion and assist them to make a specific treatment with accurate cirrhosis stage. MRI has many advantages, including high resolution for soft tissue, no radiation, and multiparameters imaging modalities. So in this paper, multisequences MRIs, including T1-weighted, T2-weighted, arterial, portal venous, and equilibrium phase, are applied. However, CAD does not meet the clinical needs of cirrhosis and few researchers are concerned with it at present. Cirrhosis is characterized by the presence of widespread fibrosis and regenerative nodules in the hepatic, leading to different texture patterns of different stages. So, extracting texture feature is the primary task. Compared with typical gray level cooccurrence matrix (GLCM) features, texture classification from random features provides an effective way, and we adopt it and propose CCTCRF for triple classification (normal, early, and middle and advanced stage). CCTCRF does not need strong assumptions except the sparse character of image, contains sufficient texture information, includes concise and effective process, and makes case decision with high accuracy. Experimental results also illustrate the satisfying performance and they are also compared with typical NN with GLCM.

  15. Increased taxon sampling greatly reduces phylogenetic error.

    PubMed

    Zwickl, Derrick J; Hillis, David M

    2002-08-01

    Several authors have argued recently that extensive taxon sampling has a positive and important effect on the accuracy of phylogenetic estimates. However, other authors have argued that there is little benefit of extensive taxon sampling, and so phylogenetic problems can or should be reduced to a few exemplar taxa as a means of reducing the computational complexity of the phylogenetic analysis. In this paper we examined five aspects of study design that may have led to these different perspectives. First, we considered the measurement of phylogenetic error across a wide range of taxon sample sizes, and conclude that the expected error based on randomly selecting trees (which varies by taxon sample size) must be considered in evaluating error in studies of the effects of taxon sampling. Second, we addressed the scope of the phylogenetic problems defined by different samples of taxa, and argue that phylogenetic scope needs to be considered in evaluating the importance of taxon-sampling strategies. Third, we examined the claim that fast and simple tree searches are as effective as more thorough searches at finding near-optimal trees that minimize error. We show that a more complete search of tree space reduces phylogenetic error, especially as the taxon sample size increases. Fourth, we examined the effects of simple versus complex simulation models on taxonomic sampling studies. Although benefits of taxon sampling are apparent for all models, data generated under more complex models of evolution produce higher overall levels of error and show greater positive effects of increased taxon sampling. Fifth, we asked if different phylogenetic optimality criteria show different effects of taxon sampling. Although we found strong differences in effectiveness of different optimality criteria as a function of taxon sample size, increased taxon sampling improved the results from all the common optimality criteria. Nonetheless, the method that showed the lowest overall

  16. Characterization of a branch of the phylogenetic tree

    SciTech Connect

    Samuel, Stuart A.; Weng, Gezhi

    2003-04-11

    We use a combination of analytic models and computer simulations to gain insight into the dynamics of evolution. Our results suggest that certain interesting phenomena should eventually emerge from the fossil record. For example, there should be a ''tortoise and hare effect'': Those genera with the smallest species death rate are likely to survive much longer than genera with large species birth and death rates. A complete characterization of the behavior of a branch of the phylogenetic tree corresponding to a genus and accurate mathematical representations of the various stages are obtained. We apply our results to address certain controversial issues that have arisen in paleontology such as the importance of punctuated equilibrium and whether unique Cambrian phyla have survived to the present.

  17. Genotypic Identification of Fusarium Species from Ocular Sources: Comparison to Morphologic Classification and Antifungal Sensitivity Testing (An AOS Thesis)

    PubMed Central

    Alfonso, Eduardo C.

    2008-01-01

    Purpose Ocular infections caused by fungal organisms can cause significant ocular morbidity, particularly when diagnosis and treatment are delayed. Rapid and accurate identification of Fusarium species at the subgenus level using current diagnostic standards is timely and insensitive. The purpose of this study is to examine the usefulness of polymerase chain reaction (PCR) analysis of the internal transcribed spacer (ITS) regions (ITS1, 5.8S, and ITS2) in detecting and differentiating Fusarium species from isolates of ocular infections, and to assess the correlation between the genotypic and morphologic classification. Methods Fifty-eight isolates from 52 patients diagnosed with Fusarium ocular infections were retrieved from storage at the Bascom Palmer Eye Institute’s ocular microbiology laboratory. Morphologic classification was determined at both a general and a reference microbiology laboratory. DNA was extracted and purified, and the ITS region was amplified and sequenced. Following DNA sequences, alignment and phylogenetic analysis were done. Susceptibility to antifungal drugs was measured according to the Clinical and Laboratory Standards Institute reference method. Results Sequence analysis demonstrated 15 unique sequences among the 58 isolates. The grouping showed that the 58 isolates were distributed among 4 main species complexes. At the species level, morphologic classification correlated with genotypic classification in 25% and 97% of the isolates in a general microbiology and a reference mycology laboratory, respectively. Conclusions The sequence variation within the ITS provides a sufficient quantitative basis for the development of a molecular diagnostic approach to the Fusarium pathogens isolated from ocular infections. Morphology based on microscopic and macroscopic observations yields inconsistent results, particularly at nonreference laboratories, emphasizing the need for a more reproducible test with less user-dependent variability. Fusarium

  18. Worldwide Phylogenetic Relationship of Avian Poxviruses

    PubMed Central

    Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

    2013-01-01

    Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of the Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups, and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g., starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy. PMID:23408635

  19. Prioritizing Populations for Conservation Using Phylogenetic Networks

    PubMed Central

    Volkmann, Logan; Martyn, Iain; Moulton, Vincent; Spillner, Andreas; Mooers, Arne O.

    2014-01-01

    In the face of inevitable future losses to biodiversity, ranking species by conservation priority seems more than prudent. Setting conservation priorities within species (i.e., at the population level) may be critical as species ranges become fragmented and connectivity declines. However, existing approaches to prioritization (e.g., scoring organisms by their expected genetic contribution) are based on phylogenetic trees, which may be poor representations of differentiation below the species level. In this paper we extend evolutionary isolation indices used in conservation planning from phylogenetic trees to phylogenetic networks. Such networks better represent population differentiation, and our extension allows populations to be ranked in order of their expected contribution to the set. We illustrate the approach using data from two imperiled species: the spotted owl Strix occidentalis in North America and the mountain pygmy-possum Burramys parvus in Australia. Using previously published mitochondrial and microsatellite data, we construct phylogenetic networks and score each population by its relative genetic distinctiveness. In both cases, our phylogenetic networks capture the geographic structure of each species: geographically peripheral populations harbor less-redundant genetic information, increasing their conservation rankings. We note that our approach can be used with all conservation-relevant distances (e.g., those based on whole-genome, ecological, or adaptive variation) and suggest it be added to the assortment of tools available to wildlife managers for allocating effort among threatened populations. PMID:24586451

  20. Primate molecular phylogenetics in a genomic era.

    PubMed

    Ting, Nelson; Sterner, Kirstin N

    2013-02-01

    A primary objective of molecular phylogenetics is to use molecular data to elucidate the evolutionary history of living organisms. Dr. Morris Goodman founded the journal Molecular Phylogenetics and Evolution as a forum where scientists could further our knowledge about the tree of life, and he recognized that the inference of species trees is a first and fundamental step to addressing many important evolutionary questions. In particular, Dr. Goodman was interested in obtaining a complete picture of the primate species tree in order to provide an evolutionary context for the study of human adaptations. A number of recent studies use multi-locus datasets to infer well-resolved and well-supported primate phylogenetic trees using consensus approaches (e.g., supermatrices). It is therefore tempting to assume that we have a complete picture of the primate tree, especially above the species level. However, recent theoretical and empirical work in the field of molecular phylogenetics demonstrates that consensus methods might provide a false sense of support at certain nodes. In this brief review we discuss the current state of primate molecular phylogenetics and highlight the importance of exploring the use of coalescent-based analyses that have the potential to better utilize information contained in multi-locus data.

  1. Worldwide phylogenetic relationship of avian poxviruses

    USGS Publications Warehouse

    Gyuranecz, Miklós; Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

    2013-01-01

    Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we have expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g. starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy.

  2. Genomic Repeat Abundances Contain Phylogenetic Signal

    PubMed Central

    Dodsworth, Steven; Chase, Mark W.; Kelly, Laura J.; Leitch, Ilia J.; Macas, Jiří; Novák, Petr; Piednoël, Mathieu; Weiss-Schneeweiss, Hanna; Leitch, Andrew R.

    2015-01-01

    A large proportion of genomic information, particularly repetitive elements, is usually ignored when researchers are using next-generation sequencing. Here we demonstrate the usefulness of this repetitive fraction in phylogenetic analyses, utilizing comparative graph-based clustering of next-generation sequence reads, which results in abundance estimates of different classes of genomic repeats. Phylogenetic trees are then inferred based on the genome-wide abundance of different repeat types treated as continuously varying characters; such repeats are scattered across chromosomes and in angiosperms can constitute a majority of nuclear genomic DNA. In six diverse examples, five angiosperms and one insect, this method provides generally well-supported relationships at interspecific and intergeneric levels that agree with results from more standard phylogenetic analyses of commonly used markers. We propose that this methodology may prove especially useful in groups where there is little genetic differentiation in standard phylogenetic markers. At the same time as providing data for phylogenetic inference, this method additionally yields a wealth of data for comparative studies of genome evolution. PMID:25261464

  3. Phylogenetic tree shapes resolve disease transmission patterns

    PubMed Central

    Colijn, Caroline; Gardy, Jennifer

    2014-01-01

    Background and Objectives: Whole-genome sequencing is becoming popular as a tool for understanding outbreaks of communicable diseases, with phylogenetic trees being used to identify individual transmission events or to characterize outbreak-level overall transmission dynamics. Existing methods to infer transmission dynamics from sequence data rely on well-characterized infectious periods, epidemiological and clinical metadata which may not always be available, and typically require computationally intensive analysis focusing on the branch lengths in phylogenetic trees. We sought to determine whether the topological structures of phylogenetic trees contain signatures of the transmission patterns underlying an outbreak. Methodology: We use simulated outbreaks to train and then test computational classifiers. We test the method on data from two real-world outbreaks. Results: We show that different transmission patterns result in quantitatively different phylogenetic tree shapes. We describe topological features that summarize a phylogeny’s structure and find that computational classifiers based on these are capable of predicting an outbreak’s transmission dynamics. The method is robust to variations in the transmission parameters and network types, and recapitulates known epidemiology of previously characterized real-world outbreaks. Conclusions and implications: There are simple structural properties of phylogenetic trees which, when combined, can distinguish communicable disease outbreaks with a super-spreader, homogeneous transmission and chains of transmission. This is possible using genome data alone, and can be done during an outbreak. We discuss the implications for management of outbreaks. PMID:24916411

  4. Fungal phylogenetic diversity drives plant facilitation.

    PubMed

    Montesinos-Navarro, Alicia; Segarra-Moragues, J G; Valiente-Banuet, A; Verdú, M

    2016-06-01

    Plant-plant facilitation is a crucial ecological process, as many plant species (facilitated) require the presence of an established individual (nurse) to recruit. Some plant facilitative interactions disappear during the ontogenetic development of the facilitated plant but others persist, even when the two plants are adults. We test whether the persistence of plant facilitative interactions is explained by the phylogenetic diversity of mutualistic and non-mutualistic fungi that the nurse and the facilitated species add to the shared rhizosphere. We classify plant facilitative interactions as persistent and non-persistent interactions and quantify the phylogenetic diversity of mutualistic and non-mutualistic fungi added by the plant species to the shared rhizosphere. Our results show that the facilitated species add less phylogenetic diversity of non-mutualistic fungi when plant facilitative interactions persist than when they do not persist. However, persistent and non-persistent facilitative interactions did not differ in the phylogenetic diversity of mutualistic fungi added by the facilitated species to the shared rhizosphere. Finally, the fungal phylogenetic diversity added by the nurse to the shared rhizosphere did not differ between persistent and non-persistent interactions. This study suggests that considering the fungal associates of the plant species involved in facilitative interactions can shed light on the mechanisms of persistence for plant-plant interactions.

  5. Quantifying phylogenetic beta diversity: distinguishing between 'true' turnover of lineages and phylogenetic diversity gradients.

    PubMed

    Leprieur, Fabien; Albouy, Camille; De Bortoli, Julien; Cowman, Peter F; Bellwood, David R; Mouillot, David

    2012-01-01

    The evolutionary dissimilarity between communities (phylogenetic beta diversity PBD) has been increasingly explored by ecologists and biogeographers to assess the relative roles of ecological and evolutionary processes in structuring natural communities. Among PBD measures, the PhyloSor and UniFrac indices have been widely used to assess the level of turnover of lineages over geographical and environmental gradients. However, these indices can be considered as 'broad-sense' measures of phylogenetic turnover as they incorporate different aspects of differences in evolutionary history between communities that may be attributable to phylogenetic diversity gradients. In the present study, we extend an additive partitioning framework proposed for compositional beta diversity to PBD. Specifically, we decomposed the PhyloSor and UniFrac indices into two separate components accounting for 'true' phylogenetic turnover and phylogenetic diversity gradients, respectively. We illustrated the relevance of this framework using simple theoretical and archetypal examples, as well as an empirical study based on coral reef fish communities. Overall, our results suggest that using PhyloSor and UniFrac may greatly over-estimate the level of spatial turnover of lineages if the two compared communities show contrasting levels of phylogenetic diversity. We therefore recommend that future studies use the 'true' phylogenetic turnover component of these indices when the studied communities encompass a large phylogenetic diversity gradient.

  6. Teaching Molecular Phylogenetics through Investigating a Real-World Phylogenetic Problem

    ERIC Educational Resources Information Center

    Zhang, Xiaorong

    2012-01-01

    A phylogenetics exercise is incorporated into the "Introduction to biocomputing" course, a junior-level course at Savannah State University. This exercise is designed to help students learn important concepts and practical skills in molecular phylogenetics through solving a real-world problem. In this application, students are required to identify…

  7. Accurate ab Initio Spin Densities.

    PubMed

    Boguslawski, Katharina; Marti, Konrad H; Legeza, Ors; Reiher, Markus

    2012-06-12

    We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as a basic quantity for the spatially resolved spin density distribution. The spin density matrix elements are directly determined from the second-quantized elementary operators optimized by the DMRG algorithm. As an analytic convergence criterion for the spin density distribution, we employ our recently developed sampling-reconstruction scheme [J. Chem. Phys.2011, 134, 224101] to build an accurate complete-active-space configuration-interaction (CASCI) wave function from the optimized matrix product states. The spin density matrix elements can then also be determined as an expectation value employing the reconstructed wave function expansion. Furthermore, the explicit reconstruction of a CASCI-type wave function provides insight into chemically interesting features of the molecule under study such as the distribution of α and β electrons in terms of Slater determinants, CI coefficients, and natural orbitals. The methodology is applied to an iron nitrosyl complex which we have identified as a challenging system for standard approaches [J. Chem. Theory Comput.2011, 7, 2740].

  8. Phylogenetic analysis of the Trypanosoma genus based on the heat-shock protein 70 gene.

    PubMed

    Fraga, Jorge; Fernández-Calienes, Aymé; Montalvo, Ana Margarita; Maes, Ilse; Deborggraeve, Stijn; Büscher, Philippe; Dujardin, Jean-Claude; Van der Auwera, Gert

    2016-09-01

    Trypanosome evolution was so far essentially studied on the basis of phylogenetic analyses of small subunit ribosomal RNA (SSU-rRNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) genes. We used for the first time the 70kDa heat-shock protein gene (hsp70) to investigate the phylogenetic relationships among 11 Trypanosoma species on the basis of 1380 nucleotides from 76 sequences corresponding to 65 strains. We also constructed a phylogeny based on combined datasets of SSU-rDNA, gGAPDH and hsp70 sequences. The obtained clusters can be correlated with the sections and subgenus classifications of mammal-infecting trypanosomes except for Trypanosoma theileri and Trypanosoma rangeli. Our analysis supports the classification of Trypanosoma species into clades rather than in sections and subgenera, some of which being polyphyletic. Nine clades were recognized: Trypanosoma carassi, Trypanosoma congolense, Trypanosoma cruzi, Trypanosoma grayi, Trypanosoma lewisi, T. rangeli, T. theileri, Trypanosoma vivax and Trypanozoon. These results are consistent with existing knowledge of the genus' phylogeny. Within the T. cruzi clade, three groups of T. cruzi discrete typing units could be clearly distinguished, corresponding to TcI, TcIII, and TcII+V+VI, while support for TcIV was lacking. Phylogenetic analyses based on hsp70 demonstrated that this molecular marker can be applied for discriminating most of the Trypanosoma species and clades.

  9. Visualizing Phylogenetic Treespace Using Cartographic Projections

    NASA Astrophysics Data System (ADS)

    Sundberg, Kenneth; Clement, Mark; Snell, Quinn

    Phylogenetic analysis is becoming an increasingly important tool for biological research. Applications include epidemiological studies, drug development, and evolutionary analysis. Phylogenetic search is a known NP-Hard problem. The size of the data sets which can be analyzed is limited by the exponential growth in the number of trees that must be considered as the problem size increases. A better understanding of the problem space could lead to better methods, which in turn could lead to the feasible analysis of more data sets. We present a definition of phylogenetic tree space and a visualization of this space that shows significant exploitable structure. This structure can be used to develop search methods capable of handling much larger datasets.

  10. Phylogenetic conservatism of extinctions in marine bivalves.

    PubMed

    Roy, Kaustuv; Hunt, Gene; Jablonski, David

    2009-08-07

    Evolutionary histories of species and lineages can influence their vulnerabilities to extinction, but the importance of this effect remains poorly explored for extinctions in the geologic past. When analyzed using a standardized taxonomy within a phylogenetic framework, extinction rates of marine bivalves estimated from the fossil record for the last approximately 200 million years show conservatism at multiple levels of evolutionary divergence, both within individual families and among related families. The strength of such phylogenetic clustering varies over time and is influenced by earlier extinction history, especially by the demise of volatile taxa in the end-Cretaceous mass extinction. Analyses of the evolutionary roles of ancient extinctions and predictive models of vulnerability of taxa to future natural and anthropogenic stressors should take phylogenetic relationships and extinction history into account.

  11. Morphological and molecular convergences in mammalian phylogenetics.

    PubMed

    Zou, Zhengting; Zhang, Jianzhi

    2016-09-02

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference.

  12. A Comprehensive Phylogenetic Analysis of Deadenylases

    PubMed Central

    Pavlopoulou, Athanasia; Vlachakis, Dimitrios; Balatsos, Nikolaos A.A.; Kossida, Sophia

    2013-01-01

    Deadenylases catalyze the shortening of the poly(A) tail at the messenger ribonucleic acid (mRNA) 3′-end in eukaryotes. Therefore, these enzymes influence mRNA decay, and constitute a major emerging group of promising anti-cancer pharmacological targets. Herein, we conducted full phylogenetic analyses of the deadenylase homologs in all available genomes in an effort to investigate evolutionary relationships between the deadenylase families and to identify invariant residues, which probably play key roles in the function of deadenylation across species. Our study includes both major Asp-Glu-Asp-Asp (DEDD) and exonuclease-endonuclease-phospatase (EEP) deadenylase superfamilies. The phylogenetic analysis has provided us with important information regarding conserved and invariant deadenylase amino acids across species. Knowledge of the phylogenetic properties and evolution of the domain of deadenylases provides the foundation for the targeted drug design in the pharmaceutical industry and modern exonuclease anti-cancer scientific research. PMID:24348009

  13. Morphological and molecular convergences in mammalian phylogenetics

    PubMed Central

    Zou, Zhengting; Zhang, Jianzhi

    2016-01-01

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference. PMID:27585543

  14. Molecular phylogenetics of the hummingbird genus Coeligena.

    PubMed

    Parra, Juan Luis; Remsen, J V; Alvarez-Rebolledo, Mauricio; McGuire, Jimmy A

    2009-11-01

    Advances in the understanding of biological radiations along tropical mountains depend on the knowledge of phylogenetic relationships among species. Here we present a species-level molecular phylogeny based on a multilocus dataset for the Andean hummingbird genus Coeligena. We compare this phylogeny to previous hypotheses of evolutionary relationships and use it as a framework to understand patterns in the evolution of sexual dichromatism and in the biogeography of speciation within the Andes. Previous phylogenetic hypotheses based mostly on similarities in coloration conflicted with our molecular phylogeny, emphasizing the unreliability of color characters for phylogenetic inference. Two major clades, one monochromatic and the other dichromatic, were found in Coeligena. Closely related species were either allopatric or parapatric on opposite mountain slopes. No sister lineages replaced each other along an elevational gradient. Our results indicate the importance of geographic isolation for speciation in this group and the potential interaction between isolation and sexual selection to promote diversification.

  15. Computational Prediction of Phylogenetically Conserved Sequence Motifs for Five Different Candidate Genes in Type II Diabetic Nephropathy

    PubMed Central

    Sindhu, T; Rajamanikandan, S; Srinivasan, P

    2012-01-01

    Background: Computational identification of phylogenetic motifs helps to understand the knowledge about known functional features that includes catalytic site, substrate binding epitopes, and protein-protein interfaces. Furthermore, they are strongly conserved among orthologs, indicating their evolutionary importance. The study aimed to analyze five candidate genes involved in type II diabetic nephropathy and to predict phylogenetic motifs from their corresponding orthologous protein sequences. Methods: AKR1B1, APOE, ENPP1, ELMO1 and IGFBP1 are the genes that have been identified as an important target for type II diabetic nephropathy through experimental studies. Their corresponding protein sequences, structures, orthologous sequences were retrieved from UniprotKB, PDB, and PHOG database respectively. Multiple sequence alignments were constructed using ClustalW and phylogenetic motifs were identified using MINER. The occurrence of amino acids in the obtained phylogenetic motifs was generated using WebLogo and false positive expectations were calculated against phylogenetic similarity. Results: In total, 17 phylogenetic motifs were identified from the five proteins and the residues such as glycine, leucine, tryptophan, aspartic acid were found in appreciable frequency whereas arginine identified in all the predicted PMs. The result implies that these residues can be important to the functional and structural role of the proteins and calculated false positive expectations implies that they were generally conserved in traditional sense. Conclusion: The prediction of phylogenetic motifs is an accurate method for detecting functionally important conserved residues. The conserved motifs can be used as a potential drug target for type II diabetic nephropathy. PMID:23113206

  16. Probabilistic graphical model representation in phylogenetics.

    PubMed

    Höhna, Sebastian; Heath, Tracy A; Boussau, Bastien; Landis, Michael J; Ronquist, Fredrik; Huelsenbeck, John P

    2014-09-01

    Recent years have seen a rapid expansion of the model space explored in statistical phylogenetics, emphasizing the need for new approaches to statistical model representation and software development. Clear communication and representation of the chosen model is crucial for: (i) reproducibility of an analysis, (ii) model development, and (iii) software design. Moreover, a unified, clear and understandable framework for model representation lowers the barrier for beginners and nonspecialists to grasp complex phylogenetic models, including their assumptions and parameter/variable dependencies. Graphical modeling is a unifying framework that has gained in popularity in the statistical literature in recent years. The core idea is to break complex models into conditionally independent distributions. The strength lies in the comprehensibility, flexibility, and adaptability of this formalism, and the large body of computational work based on it. Graphical models are well-suited to teach statistical models, to facilitate communication among phylogeneticists and in the development of generic software for simulation and statistical inference. Here, we provide an introduction to graphical models for phylogeneticists and extend the standard graphical model representation to the realm of phylogenetics. We introduce a new graphical model component, tree plates, to capture the changing structure of the subgraph corresponding to a phylogenetic tree. We describe a range of phylogenetic models using the graphical model framework and introduce modules to simplify the representation of standard components in large and complex models. Phylogenetic model graphs can be readily used in simulation, maximum likelihood inference, and Bayesian inference using, for example, Metropolis-Hastings or Gibbs sampling of the posterior distribution.

  17. Understanding phylogenetic incongruence: lessons from phyllostomid bats

    PubMed Central

    Dávalos, Liliana M; Cirranello, Andrea L; Geisler, Jonathan H; Simmons, Nancy B

    2012-01-01

    All characters and trait systems in an organism share a common evolutionary history that can be estimated using phylogenetic methods. However, differential rates of change and the evolutionary mechanisms driving those rates result in pervasive phylogenetic conflict. These drivers need to be uncovered because mismatches between evolutionary processes and phylogenetic models can lead to high confidence in incorrect hypotheses. Incongruence between phylogenies derived from morphological versus molecular analyses, and between trees based on different subsets of molecular sequences has become pervasive as datasets have expanded rapidly in both characters and species. For more than a decade, evolutionary relationships among members of the New World bat family Phyllostomidae inferred from morphological and molecular data have been in conflict. Here, we develop and apply methods to minimize systematic biases, uncover the biological mechanisms underlying phylogenetic conflict, and outline data requirements for future phylogenomic and morphological data collection. We introduce new morphological data for phyllostomids and outgroups and expand previous molecular analyses to eliminate methodological sources of phylogenetic conflict such as taxonomic sampling, sparse character sampling, or use of different algorithms to estimate the phylogeny. We also evaluate the impact of biological sources of conflict: saturation in morphological changes and molecular substitutions, and other processes that result in incongruent trees, including convergent morphological and molecular evolution. Methodological sources of incongruence play some role in generating phylogenetic conflict, and are relatively easy to eliminate by matching taxa, collecting more characters, and applying the same algorithms to optimize phylogeny. The evolutionary patterns uncovered are consistent with multiple biological sources of conflict, including saturation in morphological and molecular changes, adaptive

  18. Phylogenetic relationships between chlorophytes, chrysophytes, and oomycetes.

    PubMed Central

    Gunderson, J H; Elwood, H; Ingold, A; Kindle, K; Sogin, M L

    1987-01-01

    The phylogenetic relationships among the chlorophyte Chlamydomonas reinhardtii, the chrysophyte Ochromonas danica, and the oomycete Achyla bisexualis were explored by comparing the sequences of their small-subunit ribosomal RNA coding regions. Comparisons of similarity values or inspection of phylogenetic trees constructed by distance matrix methods reveal a very close relationship between oomycetes and chrysophytes. The separation of chrysophytes from chlorophytes is comparable to that of plants from animals, and both separations are far antedated by the divergence of a number of other protist groups. PMID:3475703

  19. Automatic classification of blank substrate defects

    NASA Astrophysics Data System (ADS)

    Boettiger, Tom; Buck, Peter; Paninjath, Sankaranarayanan; Pereira, Mark; Ronald, Rob; Rost, Dan; Samir, Bhamidipati

    2014-10-01

    Mask preparation stages are crucial in mask manufacturing, since this mask is to later act as a template for considerable number of dies on wafer. Defects on the initial blank substrate, and subsequent cleaned and coated substrates, can have a profound impact on the usability of the finished mask. This emphasizes the need for early and accurate identification of blank substrate defects and the risk they pose to the patterned reticle. While Automatic Defect Classification (ADC) is a well-developed technology for inspection and analysis of defects on patterned wafers and masks in the semiconductors industry, ADC for mask blanks is still in the early stages of adoption and development. Calibre ADC is a powerful analysis tool for fast, accurate, consistent and automatic classification of defects on mask blanks. Accurate, automated classification of mask blanks leads to better usability of blanks by enabling defect avoidance technologies during mask writing. Detailed information on blank defects can help to select appropriate job-decks to be written on the mask by defect avoidance tools [1][4][5]. Smart algorithms separate critical defects from the potentially large number of non-critical defects or false defects detected at various stages during mask blank preparation. Mechanisms used by Calibre ADC to identify and characterize defects include defect location and size, signal polarity (dark, bright) in both transmitted and reflected review images, distinguishing defect signals from background noise in defect images. The Calibre ADC engine then uses a decision tree to translate this information into a defect classification code. Using this automated process improves classification accuracy, repeatability and speed, while avoiding the subjectivity of human judgment compared to the alternative of manual defect classification by trained personnel [2]. This paper focuses on the results from the evaluation of Automatic Defect Classification (ADC) product at MP Mask

  20. kdetrees: non-parametric estimation of phylogenetic tree distributions

    PubMed Central

    Weyenberg, Grady; Huggins, Peter M.; Schardl, Christopher L.; Howe, Daniel K.; Yoshida, Ruriko

    2014-01-01

    Motivation: Although the majority of gene histories found in a clade of organisms are expected to be generated by a common process (e.g. the coalescent process), it is well known that numerous other coexisting processes (e.g. horizontal gene transfers, gene duplication and subsequent neofunctionalization) will cause some genes to exhibit a history distinct from those of the majority of genes. Such ‘outlying’ gene trees are considered to be biologically interesting, and identifying these genes has become an important problem in phylogenetics. Results: We propose and implement kdetrees, a non-parametric method for estimating distributions of phylogenetic trees, with the goal of identifying trees that are significantly different from the rest of the trees in the sample. Our method compares favorably with a similar recently published method, featuring an improvement of one polynomial order of computational complexity (to quadratic in the number of trees analyzed), with simulation studies suggesting only a small penalty to classification accuracy. Application of kdetrees to a set of Apicomplexa genes identified several unreliable sequence alignments that had escaped previous detection, as well as a gene independently reported as a possible case of horizontal gene transfer. We also analyze a set of Epichloë genes, fungi symbiotic with grasses, successfully identifying a contrived instance of paralogy. Availability and implementation: Our method for estimating tree distributions and identifying outlying trees is implemented as the R package kdetrees and is available for download from CRAN. Contact: ruriko.yoshida@uky.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24764459

  1. Phylogenetic and Structural Analysis of Polyketide Synthases in Aspergilli

    PubMed Central

    Bhetariya, Preetida J.; Prajapati, Madhvi; Bhaduri, Asani; Mandal, Rahul Shubhra; Varma, Anupam; Madan, Taruna; Singh, Yogendra; Sarma, P. Usha

    2016-01-01

    Polyketide synthases (PKSs) of Aspergillus species are multidomain and multifunctional megaenzymes that play an important role in the synthesis of diverse polyketide compounds. Putative PKS protein sequences from Aspergillus species representing medically, agriculturally, and industrially important Aspergillus species were chosen and screened for in silico studies. Six candidate Aspergillus species, Aspergillus fumigatus Af293, Aspergillus flavus NRRL3357, Aspergillus niger CBS 513.88, Aspergillus terreus NIH2624, Aspergillus oryzae RIB40, and Aspergillus clavatus NRRL1, were selected to study the PKS phylogeny. Full-length PKS proteins and only ketosynthase (KS) domain sequence were retrieved for independent phylogenetic analysis from the aforementioned species, and phylogenetic analysis was performed with characterized fungal PKS. This resulted into grouping of Aspergilli PKSs into nonreducing (NR), partially reducing (PR), and highly reducing (HR) PKS enzymes. Eight distinct clades with unique domain arrangements were classified based on homology with functionally characterized PKS enzymes. Conserved motif signatures corresponding to each type of PKS were observed. Three proteins from Protein Data Bank corresponding to NR, PR, and HR type of PKS (XP_002384329.1, XP_753141.2, and XP_001402408.2, respectively) were selected for mapping of conserved motifs on three-dimensional structures of KS domain. Structural variations were found at the active sites on modeled NR, PR, and HR enzymes of Aspergillus. It was observed that the number of iteration cycles was dependent on the size of the cavity in the active site of the PKS enzyme correlating with a type with reducing or NR products, such as pigment, 6MSA, and lovastatin. The current study reports the grouping and classification of PKS proteins of Aspergilli for possible exploration of novel polyketides based on sequence homology; this information can be useful for selection of PKS for polyketide exploration and

  2. The phylogenetic significance of colour patterns in marine teleost larvae

    PubMed Central

    Baldwin, Carole C

    2013-01-01

    Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic

  3. Phylogenetic relationships and species circumscription in Trentepohlia and Printzina (Trentepohliales, Chlorophyta).

    PubMed

    Rindi, Fabio; Lam, Daryl W; López-Bautista, Juan M

    2009-08-01

    Subaerial green microalgae represent a polyphyletic complex of organisms, whose genetic diversity is much higher than their simple morphologies suggest. The order Trentepohliales is the only species-rich group of subaerial algae belonging to the class Ulvophyceae and represents an ideal model taxon to investigate evolutionary patterns of these organisms. We studied phylogenetic relationships in two common genera of Trentepohliales (Trentepohlia and Printzina) by separate and combined analyses of the rbcL and 18S rRNA genes. Trentepohlia and Printzina were not resolved as monophyletic groups. Three main clades were recovered in all analyses, but none corresponded to any trentepohlialean genus as defined based on morphological grounds. The rbcL and 18S rRNA datasets provided congruent phylogenetic signals and similar topologies were recovered in single-gene analyses. Analyses performed on the combined 2-gene dataset inferred generally higher nodal support. The results clarified several taxonomic problems and showed that the evolution of these algae has been characterized by considerable morphological convergence. Trentepohlia abietina and T. flava were shown to be separate species from T. aurea; Printzina lagenifera, T. arborum and T. umbrina were resolved as polyphyletic taxa, whose vegetative morphology appears to have evolved independently in separate lineages. Incongruence between phylogenetic relationships and traditional morphological classification was demonstrated, showing that the morphological characters commonly used in the taxonomy of the Trentepohliales are phylogenetically irrelevant.

  4. Accurate three-dimensional documentation of distinct sites

    NASA Astrophysics Data System (ADS)

    Singh, Mahesh K.; Dutta, Ashish; Subramanian, Venkatesh K.

    2017-01-01

    One of the most critical aspects of documenting distinct sites is acquiring detailed and accurate range information. Several three-dimensional (3-D) acquisition techniques are available, but each has its own limitations. This paper presents a range data fusion method with the aim to enhance the descriptive contents of the entire 3-D reconstructed model. A kernel function is introduced for supervised classification of the range data using a kernelized support vector machine. The classification method is based on the local saliency features of the acquired range data. The range data acquired from heterogeneous range sensors are transformed into a defined common reference frame. Based on the segmentation criterion, the fusion of range data is performed by integrating finer regions of range data acquired from a laser range scanner with the coarser region of Kinect's range data. After fusion, the Delaunay triangulation algorithm is applied to generate the highly accurate, realistic 3-D model of the scene. Finally, experimental results show the robustness of the proposed approach.

  5. Active learning framework with iterative clustering for bioimage classification.

    PubMed

    Kutsuna, Natsumaro; Higaki, Takumi; Matsunaga, Sachihiro; Otsuki, Tomoshi; Yamaguchi, Masayuki; Fujii, Hirofumi; Hasezawa, Seiichiro

    2012-01-01

    Advances in imaging systems have yielded a flood of images into the research field. A semi-automated facility can reduce the laborious task of classifying this large number of images. Here we report the development of a novel framework, CARTA (Clustering-Aided Rapid Training Agent), applicable to bioimage classification that facilitates annotation and selection of features. CARTA comprises an active learning algorithm combined with a genetic algorithm and self-organizing map. The framework provides an easy and interactive annotation method and accurate classification. The CARTA framework enables classification of subcellular localization, mitotic phases and discrimination of apoptosis in images of plant and human cells with an accuracy level greater than or equal to annotators. CARTA can be applied to classification of magnetic resonance imaging of cancer cells or multicolour time-course images after surgery. Furthermore, CARTA can support development of customized features for classification, high-throughput phenotyping and application of various classification schemes dependent on the user's purpose.

  6. Hierarchical image classification in the bioscience literature.

    PubMed

    Kim, Daehyun; Yu, Hong

    2009-11-14

    Our previous work has shown that images appearing in bioscience articles can be classified into five types: Gel-Image, Image-of-Thing, Graph, Model, and Mix. For this paper, we explored and analyzed features strongly associated with each image type and developed a hierarchical image classification approach for classifying an image into one of the five types. First, we applied texture features to separate images into two groups: 1) a texture group comprising Gel Image, Image-of-Thing, and Mix, and 2) a non-texture group comprising Graph and Model. We then applied entropy, skewness, and uniformity for the first group, and edge difference, uniformity, and smoothness for the second group to classify images into specific types. Our results show that hierarchical image classification accurately divided images into the two groups during the initial classification and that the overall accuracy of the image classification was higher than that of our previous approach. In particular, the recall of hierarchical image classification was greatly improved due to the high accuracy of the initial classification.

  7. Prostate segmentation by sparse representation based classification

    PubMed Central

    Gao, Yaozong; Liao, Shu; Shen, Dinggang

    2012-01-01

    Purpose: The segmentation of prostate in CT images is of essential importance to external beam radiotherapy, which is one of the major treatments for prostate cancer nowadays. During the radiotherapy, the prostate is radiated by high-energy x rays from different directions. In order to maximize the dose to the cancer and minimize the dose to the surrounding healthy tissues (e.g., bladder and rectum), the prostate in the new treatment image needs to be accurately localized. Therefore, the effectiveness and efficiency of external beam radiotherapy highly depend on the accurate localization of the prostate. However, due to the low contrast of the prostate with its surrounding tissues (e.g., bladder), the unpredicted prostate motion, and the large appearance variations across different treatment days, it is challenging to segment the prostate in CT images. In this paper, the authors present a novel classification based segmentation method to address these problems. Methods: To segment the prostate, the proposed method first uses sparse representation based classification (SRC) to enhance the prostate in CT images by pixel-wise classification, in order to overcome the limitation of poor contrast of the prostate images. Then, based on the classification results, previous segmented prostates of the same patient are used as patient-specific atlases to align onto the current treatment image and the majority voting strategy is finally adopted to segment the prostate. In order to address the limitations of the traditional SRC in pixel-wise classification, especially for the purpose of segmentation, the authors extend SRC from the following four aspects: (1) A discriminant subdictionary learning method is proposed to learn a discriminant and compact representation of training samples for each class so that the discriminant power of SRC can be increased and also SRC can be applied to the large-scale pixel-wise classification. (2) The L1 regularized sparse coding is replaced by

  8. Identification and Classification of Rhizobia by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry.

    PubMed

    Jia, Rui Zong; Zhang, Rong Juan; Wei, Qing; Chen, Wen Feng; Cho, Il Kyu; Chen, Wen Xin; Li, Qing X

    Mass spectrometry (MS) has been widely used for specific, sensitive and rapid analysis of proteins and has shown a high potential for bacterial identification and characterization. Type strains of four species of rhizobia and Escherichia coli DH5α were employed as reference bacteria to optimize various parameters for identification and classification of species of rhizobia by matrix-assisted laser desorption/ionization time-of-flight MS (MALDI TOF MS). The parameters optimized included culture medium states (liquid or solid), bacterial growth phases, colony storage temperature and duration, and protein data processing to enhance the bacterial identification resolution, accuracy and reliability. The medium state had little effects on the mass spectra of protein profiles. A suitable sampling time was between the exponential phase and the stationary phase. Consistent protein mass spectral profiles were observed for E. coli colonies pre-grown for 14 days and rhizobia for 21 days at 4°C or 21°C. A dendrogram of 75 rhizobial strains of 4 genera was constructed based on MALDI TOF mass spectra and the topological patterns agreed well with those in the 16S rDNA phylogenetic tree. The potential of developing a mass spectral database for all rhizobia species was assessed with blind samples. The entire process from sample preparation to accurate identification and classification of species required approximately one hour.

  9. Security classification of information

    SciTech Connect

    Quist, A.S.

    1993-04-01

    This document is the second of a planned four-volume work that comprehensively discusses the security classification of information. The main focus of Volume 2 is on the principles for classification of information. Included herein are descriptions of the two major types of information that governments classify for national security reasons (subjective and objective information), guidance to use when determining whether information under consideration for classification is controlled by the government (a necessary requirement for classification to be effective), information disclosure risks and benefits (the benefits and costs of classification), standards to use when balancing information disclosure risks and benefits, guidance for assigning classification levels (Top Secret, Secret, or Confidential) to classified information, guidance for determining how long information should be classified (classification duration), classification of associations of information, classification of compilations of information, and principles for declassifying and downgrading information. Rules or principles of certain areas of our legal system (e.g., trade secret law) are sometimes mentioned to .provide added support to some of those classification principles.

  10. Recursive heuristic classification

    NASA Technical Reports Server (NTRS)

    Wilkins, David C.

    1994-01-01

    The author will describe a new problem-solving approach called recursive heuristic classification, whereby a subproblem of heuristic classification is itself formulated and solved by heuristic classification. This allows the construction of more knowledge-intensive classification programs in a way that yields a clean organization. Further, standard knowledge acquisition and learning techniques for heuristic classification can be used to create, refine, and maintain the knowledge base associated with the recursively called classification expert system. The method of recursive heuristic classification was used in the Minerva blackboard shell for heuristic classification. Minerva recursively calls itself every problem-solving cycle to solve the important blackboard scheduler task, which involves assigning a desirability rating to alternative problem-solving actions. Knowing these ratings is critical to the use of an expert system as a component of a critiquing or apprenticeship tutoring system. One innovation of this research is a method called dynamic heuristic classification, which allows selection among dynamically generated classification categories instead of requiring them to be prenumerated.

  11. Constructing Student Problems in Phylogenetic Tree Construction.

    ERIC Educational Resources Information Center

    Brewer, Steven D.

    Evolution is often equated with natural selection and is taught from a primarily functional perspective while comparative and historical approaches, which are critical for developing an appreciation of the power of evolutionary theory, are often neglected. This report describes a study of expert problem-solving in phylogenetic tree construction.…

  12. Mitochondrial phylogenetics and evolution of mysticete whales.

    PubMed

    Sasaki, Takeshi; Nikaido, Masato; Hamilton, Healy; Goto, Mutsuo; Kato, Hidehiro; Kanda, Naohisa; Pastene, Luis; Cao, Ying; Fordyce, R; Hasegawa, Masami; Okada, Norihiro

    2005-02-01

    The phylogenetic relationships among baleen whales (Order: Cetacea) remain uncertain despite extensive research in cetacean molecular phylogenetics and a potential morphological sample size of over 2 million animals harvested. Questions remain regarding the number of species and the monophyly of genera, as well as higher order relationships. Here, we approach mysticete phylogeny with complete mitochondrial genome sequence analysis. We determined complete mtDNA sequences of 10 extant Mysticeti species, inferred their phylogenetic relationships, and estimated node divergence times. The mtDNA sequence analysis concurs with previous molecular studies in the ordering of the principal branches, with Balaenidae (right whales) as sister to all other mysticetes base, followed by Neobalaenidae (pygmy right whale), Eschrichtiidae (gray whale), and finally Balaenopteridae (rorquals + humpback whale). The mtDNA analysis further suggests that four lineages exist within the clade of Eschrichtiidae + Balaenopteridae, including a sister relationship between the humpback and fin whales, and a monophyletic group formed by the blue, sei, and Bryde's whales, each of which represents a newly recognized phylogenetic relationship in Mysticeti. We also estimated the divergence times of all extant mysticete species, accounting for evolutionary rate heterogeneity among lineages. When the mtDNA divergence estimates are compared with the mysticete fossil record, several lineages have molecular divergence estimates strikingly older than indicated by paleontological data. We suggest this discrepancy reflects both a large amount of ancestral polymorphism and long generation times of ancestral baleen whale populations.

  13. On the analysis of phylogenetically paired designs

    PubMed Central

    Funk, Jennifer L; Rakovski, Cyril S; Macpherson, J Michael

    2015-01-01

    As phylogenetically controlled experimental designs become increasingly common in ecology, the need arises for a standardized statistical treatment of these datasets. Phylogenetically paired designs circumvent the need for resolved phylogenies and have been used to compare species groups, particularly in the areas of invasion biology and adaptation. Despite the widespread use of this approach, the statistical analysis of paired designs has not been critically evaluated. We propose a mixed model approach that includes random effects for pair and species. These random effects introduce a “two-layer” compound symmetry variance structure that captures both the correlations between observations on related species within a pair as well as the correlations between the repeated measurements within species. We conducted a simulation study to assess the effect of model misspecification on Type I and II error rates. We also provide an illustrative example with data containing taxonomically similar species and several outcome variables of interest. We found that a mixed model with species and pair as random effects performed better in these phylogenetically explicit simulations than two commonly used reference models (no or single random effect) by optimizing Type I error rates and power. The proposed mixed model produces acceptable Type I and II error rates despite the absence of a phylogenetic tree. This design can be generalized to a variety of datasets to analyze repeated measurements in clusters of related subjects/species. PMID:25750719

  14. Quantifying MCMC Exploration of Phylogenetic Tree Space

    PubMed Central

    Whidden, Chris; Matsen, Frederick A.

    2015-01-01

    In order to gain an understanding of the effectiveness of phylogenetic Markov chain Monte Carlo (MCMC), it is important to understand how quickly the empirical distribution of the MCMC converges to the posterior distribution. In this article, we investigate this problem on phylogenetic tree topologies with a metric that is especially well suited to the task: the subtree prune-and-regraft (SPR) metric. This metric directly corresponds to the minimum number of MCMC rearrangements required to move between trees in common phylogenetic MCMC implementations. We develop a novel graph-based approach to analyze tree posteriors and find that the SPR metric is much more informative than simpler metrics that are unrelated to MCMC moves. In doing so, we show conclusively that topological peaks do occur in Bayesian phylogenetic posteriors from real data sets as sampled with standard MCMC approaches, investigate the efficiency of Metropolis-coupled MCMC (MCMCMC) in traversing the valleys between peaks, and show that conditional clade distribution (CCD) can have systematic problems when there are multiple peaks. PMID:25631175

  15. Quantifying MCMC exploration of phylogenetic tree space.

    PubMed

    Whidden, Chris; Matsen, Frederick A

    2015-05-01

    In order to gain an understanding of the effectiveness of phylogenetic Markov chain Monte Carlo (MCMC), it is important to understand how quickly the empirical distribution of the MCMC converges to the posterior distribution. In this article, we investigate this problem on phylogenetic tree topologies with a metric that is especially well suited to the task: the subtree prune-and-regraft (SPR) metric. This metric directly corresponds to the minimum number of MCMC rearrangements required to move between trees in common phylogenetic MCMC implementations. We develop a novel graph-based approach to analyze tree posteriors and find that the SPR metric is much more informative than simpler metrics that are unrelated to MCMC moves. In doing so, we show conclusively that topological peaks do occur in Bayesian phylogenetic posteriors from real data sets as sampled with standard MCMC approaches, investigate the efficiency of Metropolis-coupled MCMC (MCMCMC) in traversing the valleys between peaks, and show that conditional clade distribution (CCD) can have systematic problems when there are multiple peaks.

  16. pplacer: linear time maximum-likelihood and Bayesian phylogenetic placement of sequences onto a fixed reference tree

    PubMed Central

    2010-01-01

    Background Likelihood-based phylogenetic inference is generally considered to be the most reliable classification method for unknown sequences. However, traditional likelihood-based phylogenetic methods cannot be applied to large volumes of short reads from next-generation sequencing due to computational complexity issues and lack of phylogenetic signal. "Phylogenetic placement," where a reference tree is fixed and the unknown query sequences are placed onto the tree via a reference alignment, is a way to bring the inferential power offered by likelihood-based approaches to large data sets. Results This paper introduces pplacer, a software package for phylogenetic placement and subsequent visualization. The algorithm can place twenty thousand short reads on a reference tree of one thousand taxa per hour per processor, has essentially linear time and memory complexity in the number of reference taxa, and is easy to run in parallel. Pplacer features calculation of the posterior probability of a placement on an edge, which is a statistically rigorous way of quantifying uncertainty on an edge-by-edge basis. It also can inform the user of the positional uncertainty for query sequences by calculating expected distance between placement locations, which is crucial in the estimation of uncertainty with a well-sampled reference tree. The software provides visualizations using branch thickness and color to represent number of placements and their uncertainty. A simulation study using reads generated from 631 COG alignments shows a high level of accuracy for phylogenetic placement over a wide range of alignment diversity, and the power of edge uncertainty estimates to measure placement confidence. Conclusions Pplacer enables efficient phylogenetic placement and subsequent visualization, making likelihood-based phylogenetics methodology practical for large collections of reads; it is freely available as source code, binaries, and a web service. PMID:21034504

  17. Threat Diversity Will Erode Mammalian Phylogenetic Diversity in the Near Future

    PubMed Central

    Jono, Clémentine M. A.; Pavoine, Sandrine

    2012-01-01

    To reduce the accelerating rate of phylogenetic diversity loss, many studies have searched for mechanisms that could explain why certain species are at risk, whereas others are not. In particular, it has been demonstrated that species might be affected by both extrinsic threat factors as well as intrinsic biological traits that could render a species more sensitive to extinction; here, we focus on extrinsic factors. Recently, the International Union for Conservation of Nature developed a new classification of threat types, including climate change, urbanization, pollution, agriculture and aquaculture, and harvesting/hunting. We have used this new classification to analyze two main factors that could explain the expected future loss of mammalian phylogenetic diversity: 1. differences in the type of threats that affect mammals and 2. differences in the number of major threats that accumulate for a single species. Our results showed that Cetartiodactyla, Diprotodontia, Monotremata, Perissodactyla, Primates, and Proboscidea could lose a high proportion of their current phylogenetic diversity in the coming decades. In contrast, Chiroptera, Didelphimorphia, and Rodentia could lose less phylogenetic diversity than expected if extinctions were random. Some mammalian clades, including Marsupiala, Chiroptera, and a subclade of Primates, are affected by particular threat types, most likely due solely to their geographic locations and associations with particular habitats. However, regardless of the geography, habitat, and taxon considered, it is not the threat type, but the threat diversity that determines the extinction risk for species and clades. Thus, some mammals might be randomly located in areas subjected to a large diversity of threats; they might also accumulate detrimental traits that render them sensitive to different threats, which is a characteristic that could be associated with large body size. Any action reducing threat diversity is expected to have a

  18. Threat diversity will erode mammalian phylogenetic diversity in the near future.

    PubMed

    Jono, Clémentine M A; Pavoine, Sandrine

    2012-01-01

    To reduce the accelerating rate of phylogenetic diversity loss, many studies have searched for mechanisms that could explain why certain species are at risk, whereas others are not. In particular, it has been demonstrated that species might be affected by both extrinsic threat factors as well as intrinsic biological traits that could render a species more sensitive to extinction; here, we focus on extrinsic factors. Recently, the International Union for Conservation of Nature developed a new classification of threat types, including climate change, urbanization, pollution, agriculture and aquaculture, and harvesting/hunting. We have used this new classification to analyze two main factors that could explain the expected future loss of mammalian phylogenetic diversity: 1. differences in the type of threats that affect mammals and 2. differences in the number of major threats that accumulate for a single species. Our results showed that Cetartiodactyla, Diprotodontia, Monotremata, Perissodactyla, Primates, and Proboscidea could lose a high proportion of their current phylogenetic diversity in the coming decades. In contrast, Chiroptera, Didelphimorphia, and Rodentia could lose less phylogenetic diversity than expected if extinctions were random. Some mammalian clades, including Marsupiala, Chiroptera, and a subclade of Primates, are affected by particular threat types, most likely due solely to their geographic locations and associations with particular habitats. However, regardless of the geography, habitat, and taxon considered, it is not the threat type, but the threat diversity that determines the extinction risk for species and clades. Thus, some mammals might be randomly located in areas subjected to a large diversity of threats; they might also accumulate detrimental traits that render them sensitive to different threats, which is a characteristic that could be associated with large body size. Any action reducing threat diversity is expected to have a

  19. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  20. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  1. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  2. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  3. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  4. Cnidarian phylogenetic relationships as revealed by mitogenomics

    PubMed Central

    2013-01-01

    Background Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia + Octocorallia) – cnidarians with a reproductive polyp and the absence of a medusa stage – and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) – cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. Results We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia + Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae + Coronatae], Acraspeda [Cubozoa + Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. Conclusions Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that

  5. Phyloclimatic modeling: combining phylogenetics and bioclimatic modeling.

    PubMed

    Yesson, C; Culham, A

    2006-10-01

    We investigate the impact of past climates on plant diversification by tracking the "footprint" of climate change on a phylogenetic tree. Diversity within the cosmopolitan carnivorous plant genus Drosera (Droseraceae) is focused within Mediterranean climate regions. We explore whether this diversity is temporally linked to Mediterranean-type climatic shifts of the mid-Miocene and whether climate preferences are conservative over phylogenetic timescales. Phyloclimatic modeling combines environmental niche (bioclimatic) modeling with phylogenetics in order to study evolutionary patterns in relation to climate change. We present the largest and most complete such example to date using Drosera. The bioclimatic models of extant species demonstrate clear phylogenetic patterns; this is particularly evident for the tuberous sundews from southwestern Australia (subgenus Ergaleium). We employ a method for establishing confidence intervals of node ages on a phylogeny using replicates from a Bayesian phylogenetic analysis. This chronogram shows that many clades, including subgenus Ergaleium and section Bryastrum, diversified during the establishment of the Mediterranean-type climate. Ancestral reconstructions of bioclimatic models demonstrate a pattern of preference for this climate type within these groups. Ancestral bioclimatic models are projected into palaeo-climate reconstructions for the time periods indicated by the chronogram. We present two such examples that each generate plausible estimates of ancestral lineage distribution, which are similar to their current distributions. This is the first study to attempt bioclimatic projections on evolutionary time scales. The sundews appear to have diversified in response to local climate development. Some groups are specialized for Mediterranean climates, others show wide-ranging generalism. This demonstrates that Phyloclimatic modeling could be repeated for other plant groups and is fundamental to the understanding of

  6. Phylogenetic placement of two species known only from resting spores: Zoophthora independentia sp. nov. and Z. porteri comb. nov. (Entomophthorales: Entomophthoraceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular methods were used to determine the generic placement of two species of Entomophthorales known only from resting spores. Historically, these species would belong in the form-genus Tarichium, but this classification provides no information about phylogenetic relationships. Using DNA from res...

  7. Classification of Stellar Spectra

    NASA Astrophysics Data System (ADS)

    Garrison, R.; Murdin, P.

    2000-11-01

    How does a scientist approach the problem of trying to understand countless billions of objects? One of the first steps is to organize the data and set up a classification scheme which can provide the best insights into the nature of the objects. Perception and insight are the main purposes of classification. In astronomy, where there are `billions and billions' of stars, classification is an ong...

  8. Classiology and soil classification

    NASA Astrophysics Data System (ADS)

    Rozhkov, V. A.

    2012-03-01

    Classiology can be defined as a science studying the principles and rules of classification of objects of any nature. The development of the theory of classification and the particular methods for classifying objects are the main challenges of classiology; to a certain extent, they are close to the challenges of pattern recognition. The methodology of classiology integrates a wide range of methods and approaches: from expert judgment to formal logic, multivariate statistics, and informatics. Soil classification assumes generalization of available data and practical experience, formalization of our notions about soils, and their representation in the form of an information system. As an information system, soil classification is designed to predict the maximum number of a soil's properties from the position of this soil in the classification space. The existing soil classification systems do not completely satisfy the principles of classiology. The violation of logical basis, poor structuring, low integrity, and inadequate level of formalization make these systems verbal schemes rather than classification systems sensu stricto. The concept of classification as listing (enumeration) of objects makes it possible to introduce the notion of the information base of classification. For soil objects, this is the database of soil indices (properties) that might be applied for generating target-oriented soil classification system. Mathematical methods enlarge the prognostic capacity of classification systems; they can be applied to assess the quality of these systems and to recognize new soil objects to be included in the existing systems. The application of particular principles and rules of classiology for soil classification purposes is discussed in this paper.

  9. Phylogenetic character mapping of proteomic diversity shows high correlation with subspecific phylogenetic diversity in Trypanosoma cruzi

    PubMed Central

    Telleria, Jenny; Biron, David G.; Brizard, Jean-Paul; Demettre, Edith; Séveno, Martial; Barnabé, Christian; Ayala, Francisco J.; Tibayrenc, Michel

    2010-01-01

    We performed a phylogenetic character mapping on 26 stocks of Trypanosoma cruzi, the parasite responsible for Chagas disease, and 2 stocks of the sister taxon T. cruzi marinkellei to test for possible associations between T. cruzi–subspecific phylogenetic diversity and levels of protein expression, as examined by proteomic analysis and mass spectrometry. We observed a high level of correlation (P < 10−4) between genetic distance, as established by multilocus enzyme electrophoresis, and proteomic dissimilarities estimated by proteomic Euclidian distances. Several proteins were found to be specifically associated to T. cruzi phylogenetic subdivisions (discrete typing units). This study explores the previously uncharacterized links between infraspecific phylogenetic diversity and gene expression in a human pathogen. It opens the way to searching for new vaccine and drug targets and for identification of specific biomarkers at the subspecific level of pathogens. PMID:21059959

  10. A standardized framework for accurate, high-throughput genotyping of recombinant and non-recombinant viral sequences.

    PubMed

    Alcantara, Luiz Carlos Junior; Cassol, Sharon; Libin, Pieter; Deforche, Koen; Pybus, Oliver G; Van Ranst, Marc; Galvão-Castro, Bernardo; Vandamme, Anne-Mieke; de Oliveira, Tulio

    2009-07-01

    Human immunodeficiency virus type-1 (HIV-1), hepatitis B and C and other rapidly evolving viruses are characterized by extremely high levels of genetic diversity. To facilitate diagnosis and the development of prevention and treatment strategies that efficiently target the diversity of these viruses, and other pathogens such as human T-lymphotropic virus type-1 (HTLV-1), human herpes virus type-8 (HHV8) and human papillomavirus (HPV), we developed a rapid high-throughput-genotyping system. The method involves the alignment of a query sequence with a carefully selected set of pre-defined reference strains, followed by phylogenetic analysis of multiple overlapping segments of the alignment using a sliding window. Each segment of the query sequence is assigned the genotype and sub-genotype of the reference strain with the highest bootstrap (>70%) and bootscanning (>90%) scores. Results from all windows are combined and displayed graphically using color-coded genotypes. The new Virus-Genotyping Tools provide accurate classification of recombinant and non-recombinant viruses and are currently being assessed for their diagnostic utility. They have incorporated into several HIV drug resistance algorithms including the Stanford (http://hivdb.stanford.edu) and two European databases (http://www.umcutrecht.nl/subsite/spread-programme/ and http://www.hivrdb.org.uk/) and have been successfully used to genotype a large number of sequences in these and other databases. The tools are a PHP/JAVA web application and are freely accessible on a number of servers including: http://bioafrica.mrc.ac.za/rega-genotype/html/, http://lasp.cpqgm.fiocruz.br/virus-genotype/html/, http://jose.med.kuleuven.be/genotypetool/html/.

  11. Evaluating Support for the Current Classification of Eukaryotic Diversity

    PubMed Central

    Parfrey, Laura Wegener; Barbero, Erika; Lasser, Elyse; Dunthorn, Micah; Bhattacharya, Debashish; Patterson, David J; Katz, Laura A

    2006-01-01

    Perspectives on the classification of eukaryotic diversity have changed rapidly in recent years, as the four eukaryotic groups within the five-kingdom classification—plants, animals, fungi, and protists—have been transformed through numerous permutations into the current system of six “supergroups.” The intent of the supergroup classification system is to unite microbial and macroscopic eukaryotes based on phylogenetic inference. This supergroup approach is increasing in popularity in the literature and is appearing in introductory biology textbooks. We evaluate the stability and support for the current six-supergroup classification of eukaryotes based on molecular genealogies. We assess three aspects of each supergroup: (1) the stability of its taxonomy, (2) the support for monophyly (single evolutionary origin) in molecular analyses targeting a supergroup, and (3) the support for monophyly when a supergroup is included as an out-group in phylogenetic studies targeting other taxa. Our analysis demonstrates that supergroup taxonomies are unstable and that support for groups varies tremendously, indicating that the current classification scheme of eukaryotes is likely premature. We highlight several trends contributing to the instability and discuss the requirements for establishing robust clades within the eukaryotic tree of life. PMID:17194223

  12. Molecular phylogenetics of mastodon and Tyrannosaurus rex.

    PubMed

    Organ, Chris L; Schweitzer, Mary H; Zheng, Wenxia; Freimark, Lisa M; Cantley, Lewis C; Asara, John M

    2008-04-25

    We report a molecular phylogeny for a nonavian dinosaur, extending our knowledge of trait evolution within nonavian dinosaurs into the macromolecular level of biological organization. Fragments of collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a variety of phylogenetic methods. Despite missing sequence data, the mastodon groups with elephant and the T. rex groups with birds, consistent with predictions based on genetic and morphological data for mastodon and on morphological data for T. rex. Our findings suggest that molecular data from long-extinct organisms may have the potential for resolving relationships at critical areas in the vertebrate evolutionary tree that have, so far, been phylogenetically intractable.

  13. A phylogenetic analysis of the phylum Fibrobacteres.

    PubMed

    Jewell, Kelsea A; Scott, Jarrod J; Adams, Sandra M; Suen, Garret

    2013-09-01

    Members of the phylum Fibrobacteres are highly efficient cellulolytic bacteria, best known for their role in rumen function and as potential sources of novel enzymes for bioenergy applications. Despite being key members of ruminants and other digestive microbial communities, our knowledge of this phylum remains incomplete, as much of our understanding is focused on two recognized species, Fibrobacter succinogenes and F. intestinalis. As a result, we lack insights regarding the environmental niche, host range, and phylogenetic organization of this phylum. Here, we analyzed over 1000 16S rRNA Fibrobacteres sequences available from public databases to establish a phylogenetic framework for this phylum. We identify both species- and genus-level clades that are suggestive of previously unknown taxonomic relationships between Fibrobacteres in addition to their putative lifestyles as host-associated or free-living. Our results shed light on this poorly understood phylum and will be useful for elucidating the function, distribution, and diversity of these bacteria in their niches.

  14. Morphological Phylogenetics in the Genomic Age.

    PubMed

    Lee, Michael S Y; Palci, Alessandro

    2015-10-05

    Evolutionary trees underpin virtually all of biology, and the wealth of new genomic data has enabled us to reconstruct them with increasing detail and confidence. While phenotypic (typically morphological) traits are becoming less important in reconstructing evolutionary trees, they still serve vital and unique roles in phylogenetics, even for living taxa for which vast amounts of genetic information are available. Morphology remains a powerful independent source of evidence for testing molecular clades, and - through fossil phenotypes - the primary means for time-scaling phylogenies. Morphological phylogenetics is therefore vital for transforming undated molecular topologies into dated evolutionary trees. However, if morphology is to be employed to its full potential, biologists need to start scrutinising phenotypes in a more objective fashion, models of phenotypic evolution need to be improved, and approaches for analysing phenotypic traits and fossils together with genomic data need to be refined.

  15. Alignment-free phylogenetics and population genetics.

    PubMed

    Haubold, Bernhard

    2014-05-01

    Phylogenetics and population genetics are central disciplines in evolutionary biology. Both are based on comparative data, today usually DNA sequences. These have become so plentiful that alignment-free sequence comparison is of growing importance in the race between scientists and sequencing machines. In phylogenetics, efficient distance computation is the major contribution of alignment-free methods. A distance measure should reflect the number of substitutions per site, which underlies classical alignment-based phylogeny reconstruction. Alignment-free distance measures are either based on word counts or on match lengths, and I apply examples of both approaches to simulated and real data to assess their accuracy and efficiency. While phylogeny reconstruction is based on the number of substitutions, in population genetics, the distribution of mutations along a sequence is also considered. This distribution can be explored by match lengths, thus opening the prospect of alignment-free population genomics.

  16. Consensus Protein Design Without Phylogenetic Bias

    PubMed Central

    Jäckel, Christian; Bloom, Jesse D; Kast, Peter; Arnold, Frances H; Hilvert, Donald

    2010-01-01

    Consensus design is an appealing strategy for the stabilization of proteins. It exploits amino acid conservation in sets of homologous proteins to identify likely beneficial mutations. Nevertheless, its success depends on the phylogenetic diversity of the sequence set available. Here we show that randomization of a single protein represents a reliable alternative source of sequence diversity essentially free of phylogenetic bias. A small number of functional protein sequences selected from binary-patterned libraries suffices as input for consensus design of active enzymes that are easier to produce and substantially more stable than individual members of the starting data set. Although catalytic activity correlates less consistently with sequence conservation in these extensively randomized proteins, less extreme mutagenesis strategies might be adopted in practice to augment stability while maintaining function. PMID:20433850

  17. Multilayer Perceptrons for Classification

    DTIC Science & Technology

    1992-03-01

    retention/ separation rates fu, input to force projection models. The second application concerns the classification of Armor Piercing Incendiary (API...Air Force pilot reten- tion/ separation rates for input to force projection models. The second application concerns the classification of Armor...methodologies for predicting pilot retention/ separation rates for input to personnel inventory projection models were e::plored. Specifically, the multilayer

  18. Phylogenetics and Computational Biology of Multigene Families

    NASA Astrophysics Data System (ADS)

    Liò, Pietro; Brilli, Matteo; Fani, Renato

    This chapter introduces the study of the major evolutionary forces operating in large gene families. The reconstruction of duplication history and phylogenetic analysis provide an interpretative framework of the evolution of multigene families. We present here two case studies, the first coming from Eukaryotes (chemokine receptors) and the second from Prokaryotes (TIM barrel proteins), showing how functional and structural constraints have shaped gene duplication events.

  19. DOE LLW classification rationale

    SciTech Connect

    Flores, A.Y.

    1991-09-16

    This report was about the rationale which the US Department of Energy had with low-level radioactive waste (LLW) classification. It is based on the Nuclear Regulatory Commission`s classification system. DOE site operators met to review the qualifications and characteristics of the classification systems. They evaluated performance objectives, developed waste classification tables, and compiled dose limits on the waste. A goal of the LLW classification system was to allow each disposal site the freedom to develop limits to radionuclide inventories and concentrations according to its own site-specific characteristics. This goal was achieved with the adoption of a performance objectives system based on a performance assessment, with site-specific environmental conditions and engineered disposal systems.

  20. DOE LLW classification rationale

    SciTech Connect

    Flores, A.Y.

    1991-09-16

    This report was about the rationale which the US Department of Energy had with low-level radioactive waste (LLW) classification. It is based on the Nuclear Regulatory Commission's classification system. DOE site operators met to review the qualifications and characteristics of the classification systems. They evaluated performance objectives, developed waste classification tables, and compiled dose limits on the waste. A goal of the LLW classification system was to allow each disposal site the freedom to develop limits to radionuclide inventories and concentrations according to its own site-specific characteristics. This goal was achieved with the adoption of a performance objectives system based on a performance assessment, with site-specific environmental conditions and engineered disposal systems.

  1. Uncertain-tree: discriminating among competing approaches to the phylogenetic analysis of phenotype data

    PubMed Central

    Tanner, Alastair R.; Fleming, James F.; Tarver, James E.; Pisani, Davide

    2017-01-01

    Morphological data provide the only means of classifying the majority of life's history, but the choice between competing phylogenetic methods for the analysis of morphology is unclear. Traditionally, parsimony methods have been favoured but recent studies have shown that these approaches are less accurate than the Bayesian implementation of the Mk model. Here we expand on these findings in several ways: we assess the impact of tree shape and maximum-likelihood estimation using the Mk model, as well as analysing data composed of both binary and multistate characters. We find that all methods struggle to correctly resolve deep clades within asymmetric trees, and when analysing small character matrices. The Bayesian Mk model is the most accurate method for estimating topology, but with lower resolution than other methods. Equal weights parsimony is more accurate than implied weights parsimony, and maximum-likelihood estimation using the Mk model is the least accurate method. We conclude that the Bayesian implementation of the Mk model should be the default method for phylogenetic estimation from phenotype datasets, and we explore the implications of our simulations in reanalysing several empirical morphological character matrices. A consequence of our finding is that high levels of resolution or the ability to classify species or groups with much confidence should not be expected when using small datasets. It is now necessary to depart from the traditional parsimony paradigms of constructing character matrices, towards datasets constructed explicitly for Bayesian methods. PMID:28077778

  2. Uncertain-tree: discriminating among competing approaches to the phylogenetic analysis of phenotype data.

    PubMed

    Puttick, Mark N; O'Reilly, Joseph E; Tanner, Alastair R; Fleming, James F; Clark, James; Holloway, Lucy; Lozano-Fernandez, Jesus; Parry, Luke A; Tarver, James E; Pisani, Davide; Donoghue, Philip C J

    2017-01-11

    Morphological data provide the only means of classifying the majority of life's history, but the choice between competing phylogenetic methods for the analysis of morphology is unclear. Traditionally, parsimony methods have been favoured but recent studies have shown that these approaches are less accurate than the Bayesian implementation of the Mk model. Here we expand on these findings in several ways: we assess the impact of tree shape and maximum-likelihood estimation using the Mk model, as well as analysing data composed of both binary and multistate characters. We find that all methods struggle to correctly resolve deep clades within asymmetric trees, and when analysing small character matrices. The Bayesian Mk model is the most accurate method for estimating topology, but with lower resolution than other methods. Equal weights parsimony is more accurate than implied weights parsimony, and maximum-likelihood estimation using the Mk model is the least accurate method. We conclude that the Bayesian implementation of the Mk model should be the default method for phylogenetic estimation from phenotype datasets, and we explore the implications of our simulations in reanalysing several empirical morphological character matrices. A consequence of our finding is that high levels of resolution or the ability to classify species or groups with much confidence should not be expected when using small datasets. It is now necessary to depart from the traditional parsimony paradigms of constructing character matrices, towards datasets constructed explicitly for Bayesian methods.

  3. Phylogenetic Stochastic Mapping Without Matrix Exponentiation

    PubMed Central

    Irvahn, Jan; Minin, Vladimir N.

    2014-01-01

    Abstract Phylogenetic stochastic mapping is a method for reconstructing the history of trait changes on a phylogenetic tree relating species/organism carrying the trait. State-of-the-art methods assume that the trait evolves according to a continuous-time Markov chain (CTMC) and works well for small state spaces. The computations slow down considerably for larger state spaces (e.g., space of codons), because current methodology relies on exponentiating CTMC infinitesimal rate matrices—an operation whose computational complexity grows as the size of the CTMC state space cubed. In this work, we introduce a new approach, based on a CTMC technique called uniformization, which does not use matrix exponentiation for phylogenetic stochastic mapping. Our method is based on a new Markov chain Monte Carlo (MCMC) algorithm that targets the distribution of trait histories conditional on the trait data observed at the tips of the tree. The computational complexity of our MCMC method grows as the size of the CTMC state space squared. Moreover, in contrast to competing matrix exponentiation methods, if the rate matrix is sparse, we can leverage this sparsity and increase the computational efficiency of our algorithm further. Using simulated data, we illustrate advantages of our MCMC algorithm and investigate how large the state space needs to be for our method to outperform matrix exponentiation approaches. We show that even on the moderately large state space of codons our MCMC method can be significantly faster than currently used matrix exponentiation methods. PMID:24918812

  4. Exploring hierarchical visualization designs using phylogenetic trees

    NASA Astrophysics Data System (ADS)

    Li, Shaomeng; Crouser, R. Jordan; Griffin, Garth; Gramazio, Connor; Schulz, Hans-Jörg; Childs, Hank; Chang, Remco

    2015-01-01

    Ongoing research on information visualization has produced an ever-increasing number of visualization designs. Despite this activity, limited progress has been made in categorizing this large number of information visualizations. This makes understanding their common design features challenging, and obscures the yet unexplored areas of novel designs. With this work, we provide categorization from an evolutionary perspective, leveraging a computational model to represent evolutionary processes, the phylogenetic tree. The result - a phylogenetic tree of a design corpus of hierarchical visualizations - enables better understanding of the various design features of hierarchical information visualizations, and further illuminates the space in which the visualizations lie, through support for interactive clustering and novel design suggestions. We demonstrate these benefits with our software system, where a corpus of two-dimensional hierarchical visualization designs is constructed into a phylogenetic tree. This software system supports visual interactive clustering and suggesting for novel designs; the latter capacity is also demonstrated via collaboration with an artist who sketched new designs using our system.

  5. Phylogenetic analysis of cubilin (CUBN) gene

    PubMed Central

    Shaik, Abjal Pasha; Alsaeed, Abbas H; Kiranmayee, S; Bammidi, VK; Sultana, Asma

    2013-01-01

    Cubilin, (CUBN; also known as intrinsic factor-cobalamin receptor [Homo sapiens Entrez Pubmed ref NM_001081.3; NG_008967.1; GI: 119606627]), located in the epithelium of intestine and kidney acts as a receptor for intrinsic factor – vitamin B12 complexes. Mutations in CUBN may play a role in autosomal recessive megaloblastic anemia. The current study investigated the possible role of CUBN in evolution using phylogenetic testing. A total of 588 BLAST hits were found for the cubilin query sequence and these hits showed putative conserved domain, CUB superfamily (as on 27th Nov 2012). A first-pass phylogenetic tree was constructed to identify the taxa which most often contained the CUBN sequences. Following this, we narrowed down the search by manually deleting sequences which were not CUBN. A repeat phylogenetic analysis of 25 taxa was performed using PhyML, RAxML and TreeDyn softwares to confirm that CUBN is a conserved protein emphasizing its importance as an extracellular domain and being present in proteins mostly known to be involved in development in many chordate taxa but not found in prokaryotes, plants and yeast.. No horizontal gene transfers have been found between different taxa. PMID:23390341

  6. Phylogenetic analysis of cubilin (CUBN) gene.

    PubMed

    Shaik, Abjal Pasha; Alsaeed, Abbas H; Kiranmayee, S; Bammidi, Vk; Sultana, Asma

    2013-01-01

    Cubilin, (CUBN; also known as intrinsic factor-cobalamin receptor [Homo sapiens Entrez Pubmed ref NM_001081.3; NG_008967.1; GI: 119606627]), located in the epithelium of intestine and kidney acts as a receptor for intrinsic factor - vitamin B12 complexes. Mutations in CUBN may play a role in autosomal recessive megaloblastic anemia. The current study investigated the possible role of CUBN in evolution using phylogenetic testing. A total of 588 BLAST hits were found for the cubilin query sequence and these hits showed putative conserved domain, CUB superfamily (as on 27(th) Nov 2012). A first-pass phylogenetic tree was constructed to identify the taxa which most often contained the CUBN sequences. Following this, we narrowed down the search by manually deleting sequences which were not CUBN. A repeat phylogenetic analysis of 25 taxa was performed using PhyML, RAxML and TreeDyn softwares to confirm that CUBN is a conserved protein emphasizing its importance as an extracellular domain and being present in proteins mostly known to be involved in development in many chordate taxa but not found in prokaryotes, plants and yeast.. No horizontal gene transfers have been found between different taxa.

  7. A Consistent Phylogenetic Backbone for the Fungi

    PubMed Central

    Ebersberger, Ingo; de Matos Simoes, Ricardo; Kupczok, Anne; Gube, Matthias; Kothe, Erika; Voigt, Kerstin; von Haeseler, Arndt

    2012-01-01

    The kingdom of fungi provides model organisms for biotechnology, cell biology, genetics, and life sciences in general. Only when their phylogenetic relationships are stably resolved, can individual results from fungal research be integrated into a holistic picture of biology. However, and despite recent progress, many deep relationships within the fungi remain unclear. Here, we present the first phylogenomic study of an entire eukaryotic kingdom that uses a consistency criterion to strengthen phylogenetic conclusions. We reason that branches (splits) recovered with independent data and different tree reconstruction methods are likely to reflect true evolutionary relationships. Two complementary phylogenomic data sets based on 99 fungal genomes and 109 fungal expressed sequence tag (EST) sets analyzed with four different tree reconstruction methods shed light from different angles on the fungal tree of life. Eleven additional data sets address specifically the phylogenetic position of Blastocladiomycota, Ustilaginomycotina, and Dothideomycetes, respectively. The combined evidence from the resulting trees supports the deep-level stability of the fungal groups toward a comprehensive natural system of the fungi. In addition, our analysis reveals methodologically interesting aspects. Enrichment for EST encoded data—a common practice in phylogenomic analyses—introduces a strong bias toward slowly evolving and functionally correlated genes. Consequently, the generalization of phylogenomic data sets as collections of randomly selected genes cannot be taken for granted. A thorough characterization of the data to assess possible influences on the tree reconstruction should therefore become a standard in phylogenomic analyses. PMID:22114356

  8. Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium.

    PubMed

    Gaudet, Pascale; Livstone, Michael S; Lewis, Suzanna E; Thomas, Paul D

    2011-09-01

    The goal of the Gene Ontology (GO) project is to provide a uniform way to describe the functions of gene products from organisms across all kingdoms of life and thereby enable analysis of genomic data. Protein annotations are either based on experiments or predicted from protein sequences. Since most sequences have not been experimentally characterized, most available annotations need to be based on predictions. To make as accurate inferences as possible, the GO Consortium's Reference Genome Project is using an explicit evolutionary framework to infer annotations of proteins from a broad set of genomes from experimental annotations in a semi-automated manner. Most components in the pipeline, such as selection of sequences, building multiple sequence alignments and phylogenetic trees, retrieving experimental annotations and depositing inferred annotations, are fully automated. However, the most crucial step in our pipeline relies on software-assisted curation by an expert biologist. This curation tool, Phylogenetic Annotation and INference Tool (PAINT) helps curators to infer annotations among members of a protein family. PAINT allows curators to make precise assertions as to when functions were gained and lost during evolution and record the evidence (e.g. experimentally supported GO annotations and phylogenetic information including orthology) for those assertions. In this article, we describe how we use PAINT to infer protein function in a phylogenetic context with emphasis on its strengths, limitations and guidelines. We also discuss specific examples showing how PAINT annotations compare with those generated by other highly used homology-based methods.

  9. Improved Surgical Site Infection (SSI) rate through accurately assessed surgical wounds.

    PubMed

    John, Honeymol; Nimeri, Abdelrahman; Ellahham, Samer

    2015-01-01

    Sheikh Khalifa Medical City's (SKMC) Surgery Institute was identified as a high outlier in Surgical Site Infections (SSI) based on the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) - Semi-Annual Report (SAR) in January 2012. The aim of this project was to improve SSI rates through accurate wound classification. We identified SSI rate reduction as a performance improvement and safety priority at SKMC, a tertiary referral center. We used the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) best practice guidelines as a guide. ACS NSQIP is a clinical registry that provides risk-adjusted clinical outcome reports every six months. The rates of SSI are reported in an observed/expected ratio. The expected ratio is calculated based on the risk factors of the patients which include wound classification. We established a multidisciplinary SSI taskforce. The members of the SSI taskforce included the ACS NSQIP team members, quality, surgeons, nurses, infection control, IT, pharmacy, microbiology, and it was chaired by a colorectal surgeon. The taskforce focused on five areas: pre-op showering and hair removal, skin antisepsis, prophylactic antibiotics, peri-operative maintenance of glycaemia, and normothermia. We planned audits to evaluate our wound classification and our SSI rates based on the SAR. Our expected SSI rates in general surgery and the whole department were 2.52% and 1.70% respectively, while our observed SSI rates were 4.68% and 3.57% respectively, giving us a high outlier status with an odd's ratio of 1.72 and 2.03. Wound classifications were identified as an area of concern. For example, wound classifications were preoperatively selected based on the default wound classification of the booked procedure in the Electronic Medical Record (EMR) which led to under classifying wounds in many occasions. A total of 998 cases were reviewed, our rate of incorrect wound classification

  10. Improved Surgical Site Infection (SSI) rate through accurately assessed surgical wounds

    PubMed Central

    John, Honeymol; Nimeri, Abdelrahman; ELLAHHAM, SAMER

    2015-01-01

    Sheikh Khalifa Medical City's (SKMC) Surgery Institute was identified as a high outlier in Surgical Site Infections (SSI) based on the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) - Semi-Annual Report (SAR) in January 2012. The aim of this project was to improve SSI rates through accurate wound classification. We identified SSI rate reduction as a performance improvement and safety priority at SKMC, a tertiary referral center. We used the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) best practice guidelines as a guide. ACS NSQIP is a clinical registry that provides risk-adjusted clinical outcome reports every six months. The rates of SSI are reported in an observed/expected ratio. The expected ratio is calculated based on the risk factors of the patients which include wound classification. We established a multidisciplinary SSI taskforce. The members of the SSI taskforce included the ACS NSQIP team members, quality, surgeons, nurses, infection control, IT, pharmacy, microbiology, and it was chaired by a colorectal surgeon. The taskforce focused on five areas: pre-op showering and hair removal, skin antisepsis, prophylactic antibiotics, peri-operative maintenance of glycaemia, and normothermia. We planned audits to evaluate our wound classification and our SSI rates based on the SAR. Our expected SSI rates in general surgery and the whole department were 2.52% and 1.70% respectively, while our observed SSI rates were 4.68% and 3.57% respectively, giving us a high outlier status with an odd's ratio of 1.72 and 2.03. Wound classifications were identified as an area of concern. For example, wound classifications were preoperatively selected based on the default wound classification of the booked procedure in the Electronic Medical Record (EMR) which led to under classifying wounds in many occasions. A total of 998 cases were reviewed, our rate of incorrect wound classification

  11. Photometric Supernova Classification with Machine Learning

    NASA Astrophysics Data System (ADS)

    Lochner, Michelle; McEwen, Jason D.; Peiris, Hiranya V.; Lahav, Ofer; Winter, Max K.

    2016-08-01

    Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope, given that spectroscopic confirmation of type for all supernovae discovered will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques that fit parametric models to curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k-nearest neighbors, support vector machines, artificial neural networks, and boosted decision trees (BDTs). We test the pipeline on simulated multi-band DES light curves from the Supernova Photometric Classification Challenge. Using the commonly used area under the curve (AUC) of the Receiver Operating Characteristic as a metric, we find that the SALT2 fits and the wavelet approach, with the BDTs algorithm, each achieve an AUC of 0.98, where 1 represents perfect classification. We find that a representative training set is essential for good classification, whatever the feature set or algorithm, with implications for spectroscopic follow-up. Importantly, we find that by using either the SALT2 or the wavelet feature sets with a BDT algorithm, accurate classification is possible purely from light curve data, without the need for any redshift information.

  12. Temporal context in floristic classification

    NASA Astrophysics Data System (ADS)

    Fitzgerald, R. W.; Lees, B. G.

    1996-11-01

    Multi-temporal remote sensing data present a number of significant problems for the statistical and spatial competence of a classifier. Ideally, a classifier of multi-temporal data should be temporally invariant. It must have the capacity to account for the variations in season, growth cycle, radiometric, and atmospheric conditions at any point in time when classifying the land cover. This paper tests two methods of creating a temporally invariant classifier based on the pattern recognition capabilities of a neural network. A suite of twelve multi-temporal datasets spread over 5 yr along with a comprehensive mix of environmental variables are fused into floristic classification images by the neural network. Uncertainties in the classifications are addressed explicitly with a confidence mask generated from the fuzzy membership value's output by the neural network. These confidence masks are used to produce constrained classification images. The overall accuracy percentage achieved from a study site containing highly disturbed undulating terrain averages 60%. The first method of training, sequential learning of temporal context, is tested by an examination of the step-by-step evolution of the sequential training process. This reveals that the sequential classifier may not have learned about time, because time was constant during each network training session. It also suggests that there are optimal times during the annual cycle to train the classifier for particular floristic classes. The second method of training the classifier is randomised exposure to the entire temporal training suite. Time was now a fluctuating input variable during the network training process. This method produced the best spatially accurate results. The performance of this classifier as a temporally invariant classifier is tested amongst four multi-temporal datasets with encouraging results. The classifier consistently achieved an overall accuracy percentage of 60%. The pairwise predicted

  13. Structured sparse models for classification

    NASA Astrophysics Data System (ADS)

    Castrodad, Alexey

    The main focus of this thesis is the modeling and classification of high dimensional data using structured sparsity. Sparse models, where data is assumed to be well represented as a linear combination of a few elements from a dictionary, have gained considerable attention in recent years, and its use has led to state-of-the-art results in many signal and image processing tasks. The success of sparse modeling is highly due to its ability to efficiently use the redundancy of the data and find its underlying structure. On a classification setting, we capitalize on this advantage to properly model and separate the structure of the classes. We design and validate modeling solutions to challenging problems arising in computer vision and remote sensing. We propose both supervised and unsupervised schemes for the modeling of human actions from motion imagery under a wide variety of acquisition condi- tions. In the supervised case, the main goal is to classify the human actions in the video given a predefined set of actions to learn from. In the unsupervised case, the main goal is to an- alyze the spatio-temporal dynamics of the individuals in the scene without having any prior information on the actions themselves. We also propose a model for remotely sensed hysper- spectral imagery, where the main goal is to perform automatic spectral source separation and mapping at the subpixel level. Finally, we present a sparse model for sensor fusion to exploit the common structure and enforce collaboration of hyperspectral with LiDAR data for better mapping capabilities. In all these scenarios, we demonstrate that these data can be expressed as a combination of atoms from a class-structured dictionary. These data representation becomes essentially a "mixture of classes," and by directly exploiting the sparse codes, one can attain highly accurate classification performance with relatively unsophisticated classifiers.

  14. Multisensor Target Detection And Classification

    NASA Astrophysics Data System (ADS)

    Ruck, Dennis W.; Rogers, Steven K.; Mills, James P.; Kabrisky, Matthew

    1988-08-01

    In this paper a new approach to the detection and classification of tactical targets using a multifunction laser radar sensor is developed. Targets of interest are tanks, jeeps, trucks, and other vehicles. Doppler images are segmented by developing a new technique which compensates for spurious doppler returns. Relative range images are segmented using an approach based on range gradients. The resultant shapes in the segmented images are then classified using Zernike moment invariants as shape descriptors. Two classification decision rules are implemented: a classical statistical nearest-neighbor approach and a multilayer perceptron architecture. The doppler segmentation algorithm was applied to a set of 180 real sensor images. An accurate segmentation was obtained for 89 percent of the images. The new doppler segmentation proved to be a robust method, and the moment invariants were effective in discriminating the tactical targets. Tanks were classified correctly 86 percent of the time. The most important result of this research is the demonstration of the use of a new information processing architecture for image processing applications.

  15. Comparative evolutionary diversity and phylogenetic structure across multiple forest dynamics plots: a mega-phylogeny approach.

    PubMed

    Erickson, David L; Jones, Frank A; Swenson, Nathan G; Pei, Nancai; Bourg, Norman A; Chen, Wenna; Davies, Stuart J; Ge, Xue-Jun; Hao, Zhanqing; Howe, Robert W; Huang, Chun-Lin; Larson, Andrew J; Lum, Shawn K Y; Lutz, James A; Ma, Keping; Meegaskumbura, Madhava; Mi, Xiangcheng; Parker, John D; Fang-Sun, I; Wright, S Joseph; Wolf, Amy T; Ye, W; Xing, Dingliang; Zimmerman, Jess K; Kress, W John

    2014-01-01

    Forest dynamics plots, which now span longitudes, latitudes, and habitat types across the globe, offer unparalleled insights into the ecological and evolutionary processes that determine how species are assembled into communities. Understanding phylogenetic relationships among species in a community has become an important component of assessing assembly processes. However, the application of evolutionary information to questions in community ecology has been limited in large part by the lack of accurate estimates of phylogenetic relationships among individual species found within communities, and is particularly limiting in comparisons between communities. Therefore, streamlining and maximizing the information content of these community phylogenies is a priority. To test the viability and advantage of a multi-community phylogeny, we constructed a multi-plot mega-phylogeny of 1347 species of trees across 15 forest dynamics plots in the ForestGEO network using DNA barcode sequence data (rbcL, matK, and psbA-trnH) and compared community phylogenies for each individual plot with respect to support for topology and branch lengths, which affect evolutionary inference of community processes. The levels of taxonomic differentiation across the phylogeny were examined by quantifying the frequency of resolved nodes throughout. In addition, three phylogenetic distance (PD) metrics that are commonly used to infer assembly processes were estimated for each plot [PD, Mean Phylogenetic Distance (MPD), and Mean Nearest Taxon Distance (MNTD)]. Lastly, we examine the partitioning of phylogenetic diversity among community plots through quantification of inter-community MPD and MNTD. Overall, evolutionary relationships were highly resolved across the DNA barcode-based mega-phylogeny, and phylogenetic resolution for each community plot was improved when estimated within the context of the mega-phylogeny. Likewise, when compared with phylogenies for individual plots, estimates of

  16. Comparative evolutionary diversity and phylogenetic structure across multiple forest dynamics plots: a mega-phylogeny approach

    PubMed Central

    Erickson, David L.; Jones, Frank A.; Swenson, Nathan G.; Pei, Nancai; Bourg, Norman A.; Chen, Wenna; Davies, Stuart J.; Ge, Xue-jun; Hao, Zhanqing; Howe, Robert W.; Huang, Chun-Lin; Larson, Andrew J.; Lum, Shawn K. Y.; Lutz, James A.; Ma, Keping; Meegaskumbura, Madhava; Mi, Xiangcheng; Parker, John D.; Fang-Sun, I.; Wright, S. Joseph; Wolf, Amy T.; Ye, W.; Xing, Dingliang; Zimmerman, Jess K.; Kress, W. John

    2014-01-01

    Forest dynamics plots, which now span longitudes, latitudes, and habitat types across the globe, offer unparalleled insights into the ecological and evolutionary processes that determine how species are assembled into communities. Understanding phylogenetic relationships among species in a community has become an important component of assessing assembly processes. However, the application of evolutionary information to questions in community ecology has been limited in large part by the lack of accurate estimates of phylogenetic relationships among individual species found within communities, and is particularly limiting in comparisons between communities. Therefore, streamlining and maximizing the information content of these community phylogenies is a priority. To test the viability and advantage of a multi-community phylogeny, we constructed a multi-plot mega-phylogeny of 1347 species of trees across 15 forest dynamics plots in the ForestGEO network using DNA barcode sequence data (rbcL, matK, and psbA-trnH) and compared community phylogenies for each individual plot with respect to support for topology and branch lengths, which affect evolutionary inference of community processes. The levels of taxonomic differentiation across the phylogeny were examined by quantifying the frequency of resolved nodes throughout. In addition, three phylogenetic distance (PD) metrics that are commonly used to infer assembly processes were estimated for each plot [PD, Mean Phylogenetic Distance (MPD), and Mean Nearest Taxon Distance (MNTD)]. Lastly, we examine the partitioning of phylogenetic diversity among community plots through quantification of inter-community MPD and MNTD. Overall, evolutionary relationships were highly resolved across the DNA barcode-based mega-phylogeny, and phylogenetic resolution for each community plot was improved when estimated within the context of the mega-phylogeny. Likewise, when compared with phylogenies for individual plots, estimates of

  17. A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families

    PubMed Central

    Miadlikowska, Jolanta; Kauff, Frank; Högnabba, Filip; Oliver, Jeffrey C.; Molnár, Katalin; Fraker, Emily; Gaya, Ester; Hafellner, Josef; Hofstetter, Valérie; Gueidan, Cécile; Otálora, Mónica A.G.; Hodkinson, Brendan; Kukwa, Martin; Lücking, Robert; Björk, Curtis; Sipman, Harrie J.M.; Burgaz, Ana Rosa; Thell, Arne; Passo, Alfredo; Myllys, Leena; Goward, Trevor; Fernández-Brime, Samantha; Hestmark, Geir; Lendemer, James; Lumbsch, H. Thorsten; Schmull, Michaela; Schoch, Conrad; Sérusiaux, Emmanuël; Maddison, David R.; Arnold, A. Elizabeth; Lutzoni, François; Stenroos, Soili

    2014-01-01

    The Lecanoromycetes is the largest class of lichenized Fungi, and one of the most species-rich classes in the kingdom. Here we provide a multigene phylogenetic synthesis (using three ribosomal RNA-coding and two protein-coding genes) of the Lecanoromycetes based on 642 newly generated and 3329 publicly available sequences representing 1139 taxa, 317 genera, 66 families, 17 orders and five subclasses (four currently recognized: Acarosporomycetidae, Lecanoromycetidae, Ostropomycetidae, Umbilicariomycetidae; and one provisionarily recognized, ‘Candelariomycetidae’). Maximum likelihood phylogenetic analyses on four multigene datasets assembled using a cumulative supermatrix approach with a progressively higher number of species and missing data (5-gene, 5+4-gene, 5+4+3-gene and 5+4+3+2-gene datasets) show that the current classification includes non-monophyletic taxa at various ranks, which need to be recircumscribed and require revisionary treatments based on denser taxon sampling and more loci. Two newly circumscribed orders (Arctomiales and Hymeneliales in the Ostropomycetidae) and three families (Ramboldiaceae and Psilolechiaceae in the Lecanorales, and Strangosporaceae in the Lecanoromycetes inc. sed.) are introduced. The potential resurrection of the families Eigleraceae and Lopadiaceae is considered here to alleviate phylogenetic and classification disparities. An overview of the photobionts associated with the main fungal lineages in the Lecanoromycetes based on available published records is provided. A revised schematic classification at the family level in the phylogenetic context of widely accepted and newly revealed relationships across Lecanoromycetes is included. The cumulative addition of taxa with an increasing amount of missing data (i.e., a cumulative supermatrix approach, starting with taxa for which sequences were available for all five targeted genes and ending with the addition of taxa for which only two genes have been sequenced) revealed

  18. A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families.

    PubMed

    Miadlikowska, Jolanta; Kauff, Frank; Högnabba, Filip; Oliver, Jeffrey C; Molnár, Katalin; Fraker, Emily; Gaya, Ester; Hafellner, Josef; Hofstetter, Valérie; Gueidan, Cécile; Otálora, Mónica A G; Hodkinson, Brendan; Kukwa, Martin; Lücking, Robert; Björk, Curtis; Sipman, Harrie J M; Burgaz, Ana Rosa; Thell, Arne; Passo, Alfredo; Myllys, Leena; Goward, Trevor; Fernández-Brime, Samantha; Hestmark, Geir; Lendemer, James; Lumbsch, H Thorsten; Schmull, Michaela; Schoch, Conrad L; Sérusiaux, Emmanuël; Maddison, David R; Arnold, A Elizabeth; Lutzoni, François; Stenroos, Soili

    2014-10-01

    The Lecanoromycetes is the largest class of lichenized Fungi, and one of the most species-rich classes in the kingdom. Here we provide a multigene phylogenetic synthesis (using three ribosomal RNA-coding and two protein-coding genes) of the Lecanoromycetes based on 642 newly generated and 3329 publicly available sequences representing 1139 taxa, 317 genera, 66 families, 17 orders and five subclasses (four currently recognized: Acarosporomycetidae, Lecanoromycetidae, Ostropomycetidae, Umbilicariomycetidae; and one provisionarily recognized, 'Candelariomycetidae'). Maximum likelihood phylogenetic analyses on four multigene datasets assembled using a cumulative supermatrix approach with a progressively higher number of species and missing data (5-gene, 5+4-gene, 5+4+3-gene and 5+4+3+2-gene datasets) show that the current classification includes non-monophyletic taxa at various ranks, which need to be recircumscribed and require revisionary treatments based on denser taxon sampling and more loci. Two newly circumscribed orders (Arctomiales and Hymeneliales in the Ostropomycetidae) and three families (Ramboldiaceae and Psilolechiaceae in the Lecanorales, and Strangosporaceae in the Lecanoromycetes inc. sed.) are introduced. The potential resurrection of the families Eigleraceae and Lopadiaceae is considered here to alleviate phylogenetic and classification disparities. An overview of the photobionts associated with the main fungal lineages in the Lecanoromycetes based on available published records is provided. A revised schematic classification at the family level in the phylogenetic context of widely accepted and newly revealed relationships across Lecanoromycetes is included. The cumulative addition of taxa with an increasing amount of missing data (i.e., a cumulative supermatrix approach, starting with taxa for which sequences were available for all five targeted genes and ending with the addition of taxa for which only two genes have been sequenced) revealed

  19. A novel ensemble machine learning for robust microarray data classification.

    PubMed

    Peng, Yonghong

    2006-06-01

    Microarray data analysis and classification has demonstrated convincingly that it provides an effective methodology for the effective diagnosis of diseases and cancers. Although much research has been performed on applying machine learning techniques for microarray data classification during the past years, it has been shown that conventional machine learning techniques have intrinsic drawbacks in achieving accurate and robust classifications. This paper presents a novel ensemble machine learning approach for the development of robust microarray data classification. Different from the conventional ensemble learning techniques, the approach presented begins with generating a pool of candidate base classifiers based on the gene sub-sampling and then the selection of a sub-set of appropriate base classifiers to construct the classification committee based on classifier clustering. Experimental results have demonstrated that the classifiers constructed by the proposed method outperforms not only the classifiers generated by the conventional machine learning but also the classifiers generated by two widely used conventional ensemble learning methods (bagging and boosting).

  20. Behavior Based Social Dimensions Extraction for Multi-Label Classification

    PubMed Central

    Li, Le; Xu, Junyi; Xiao, Weidong; Ge, Bin

    2016-01-01

    Classification based on social dimensions is commonly used to handle the multi-label classification task in heterogeneous networks. However, traditional methods, which mostly rely on the community detection algorithms to extract the latent social dimensions, produce unsatisfactory performance when community detection algorithms fail. In this paper, we propose a novel behavior based social dimensions extraction method to improve the classification performance in multi-label heterogeneous networks. In our method, nodes’ behavior features, instead of community memberships, are used to extract social dimensions. By introducing Latent Dirichlet Allocation (LDA) to model the network generation process, nodes’ connection behaviors with different communities can be extracted accurately, which are applied as latent social dimensions for classification. Experiments on various public datasets reveal that the proposed method can obtain satisfactory classification results in comparison to other state-of-the-art methods on smaller social dimensions. PMID:27049849

  1. The revised lung adenocarcinoma classification-an imaging guide.

    PubMed

    Gardiner, Natasha; Jogai, Sanjay; Wallis, Adam

    2014-10-01

    Advances in our understanding of the pathology, radiology and clinical behaviour of peripheral lung adenocarcinomas facilitated a more robust terminology and classification of these lesions. The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification introduced new terminology to better reflect this heterogeneous group of adenocarcinomas formerly known as bronchoalveolar cell carcinoma (BAC). There is now a clear distinction between pre-invasive, minimally invasive and frankly invasive lesions. The radiographic appearance of these ranges from pure ground glass nodules to solid mass lesions. Radiologists must be aware of the new classification in order to work alongside multidisciplinary colleagues to allow accurate staging and treatment. This article reviews the new classification of lung adenocarcinomas. Management options of these lesions with particular focus on radiological implications of the new classification will be reviewed.

  2. Intraregional classification of wine via ICP-MS elemental fingerprinting.

    PubMed

    Coetzee, P P; van Jaarsveld, F P; Vanhaecke, F

    2014-12-01

    The feasibility of elemental fingerprinting in the classification of wines according to their provenance vineyard soil was investigated in the relatively small geographical area of a single wine district. Results for the Stellenbosch wine district (Western Cape Wine Region, South Africa), comprising an area of less than 1,000 km(2), suggest that classification of wines from different estates (120 wines from 23 estates) is indeed possible using accurate elemental data and multivariate statistical analysis based on a combination of principal component analysis, cluster analysis, and discriminant analysis. This is the first study to demonstrate the successful classification of wines at estate level in a single wine district in South Africa. The elements B, Ba, Cs, Cu, Mg, Rb, Sr, Tl and Zn were identified as suitable indicators. White and red wines were grouped in separate data sets to allow successful classification of wines. Correlation between wine classification and soil type distributions in the area was observed.

  3. Classification of earth terrain using polarimetric synthetic aperture radar images

    NASA Technical Reports Server (NTRS)

    Lim, H. H.; Swartz, A. A.; Yueh, H. A.; Kong, J. A.; Shin, R. T.; Van Zyl, J. J.

    1989-01-01

    Supervised and unsupervised classification techniques are developed and used to classify the earth terrain components from SAR polarimetric images of San Francisco Bay and Traverse City, Michigan. The supervised techniques include the Bayes classifiers, normalized polarimetric classification, and simple feature classification using discriminates such as the absolute and normalized magnitude response of individual receiver channel returns and the phase difference between receiver channels. An algorithm is developed as an unsupervised technique which classifies terrain elements based on the relationship between the orientation angle and the handedness of the transmitting and receiving polariation states. It is found that supervised classification produces the best results when accurate classifier training data are used, while unsupervised classification may be applied when training data are not available.

  4. Behavior Based Social Dimensions Extraction for Multi-Label Classification.

    PubMed

    Li, Le; Xu, Junyi; Xiao, Weidong; Ge, Bin

    2016-01-01

    Classification based on social dimensions is commonly used to handle the multi-label classification task in heterogeneous networks. However, traditional methods, which mostly rely on the community detection algorithms to extract the latent social dimensions, produce unsatisfactory performance when community detection algorithms fail. In this paper, we propose a novel behavior based social dimensions extraction method to improve the classification performance in multi-label heterogeneous networks. In our method, nodes' behavior features, instead of community memberships, are used to extract social dimensions. By introducing Latent Dirichlet Allocation (LDA) to model the network generation process, nodes' connection behaviors with different communities can be extracted accurately, which are applied as latent social dimensions for classification. Experiments on various public datasets reveal that the proposed method can obtain satisfactory classification results in comparison to other state-of-the-art methods on smaller social dimensions.

  5. Phylogenetic relationships of Proboscoida Broch, 1910 (Cnidaria, Hydrozoa): Are traditional morphological diagnostic characters relevant for the delimitation of lineages at the species, genus, and family levels?

    PubMed

    Cunha, Amanda F; Collins, Allen G; Marques, Antonio C

    2017-01-01

    Overlapping variation of morphological characters can lead to misinterpretation in taxonomic diagnoses and the delimitation of different lineages. This is the case for hydrozoans that have traditionally been united in the family Campanulariidae, a group known for its wide morphological variation and complicated taxonomic history. In a recently proposed phylogenetic classification of leptothecate hydrozoans, this family was restricted to a more narrow sense while a larger clade containing most species traditionally classified in Campanulariidae, along with members of Bonneviellidae, was established as the suborder Proboscoida. We used molecular data to infer the phylogenetic relationships among campanulariids and assess the traditional classification of the family, as well as the new classification scheme for the group. The congruity and relevance of diagnostic characters were also evaluated. While mostly consistent with the new phylogenetic classification of Proboscoida, our increased taxon sampling resulted in some conflicts at the family level, specially regarding the monophyly of Clytiidae and Obeliidae. Considering the traditional classification, only Obeliidae is close to its original scope (as subfamily Obeliinae). At the genus level, Campanularia and Clytia are not monophyletic. Species with Obelia-like medusae do not form a monophyletic group, nor do species with fixed gonophores, indicating that these characters do not readily diagnose different genera. Finally, the species Orthopyxis integra, Clytia gracilis, and Obelia dichotoma are not monophyletic, suggesting that most of their current diagnostic characters are not informative for their delimitation. Several diagnostic characters in this group need to be reassessed, with emphasis on their variation, in order to have a consistent taxonomic and phylogenetic framework for the classification of campanulariid hydrozoans.

  6. Target classification algorithm based on feature aided tracking

    NASA Astrophysics Data System (ADS)

    Zhan, Ronghui; Zhang, Jun

    2013-03-01

    An effective target classification algorithm based on feature aided tracking (FAT) is proposed, using the length of target (target extent) as the classification information. To implement the algorithm, the Rao-Blackwellised unscented Kalman filter (RBUKF) is used to jointly estimate the kinematic state and target extent; meanwhile the joint probability data association (JPDA) algorithm is exploited to implement multi-target data association aided by target down-range extent. Simulation results under different condition show the presented algorithm is both accurate and robust, and it is suitable for the application of near spaced targets tracking and classification under the environment of dense clutters.

  7. Methodology for hyperspectral image classification using novel neural network

    SciTech Connect

    Subramanian, S., Gat, N., Sheffield, M.,; Barhen, J.; Toomarian, N.

    1997-04-01

    A novel feed forward neural network is used to classify hyperspectral data from the AVIRIS sector. The network applies an alternating direction singular value decomposition technique to achieve rapid training times (few seconds per class). Very few samples (10-12) are required for training. 100% accurate classification is obtained using test data sets. The methodology combines this rapid training neural network together with data reduction and maximal feature separation techniques such as principal component analysis and simultaneous diagonalization of covariance matrices, for rapid and accurate classification of large hyperspectral images. The results are compared to those of standard statistical classifiers. 21 refs., 3 figs., 5 tabs.

  8. Mapping Phylogenetic Trees to Reveal Distinct Patterns of Evolution

    PubMed Central

    Kendall, Michelle; Colijn, Caroline

    2016-01-01

    Evolutionary relationships are frequently described by phylogenetic trees, but a central barrier in many fields is the difficulty of interpreting data containing conflicting phylogenetic signals. We present a metric-based method for comparing trees which extracts distinct alternative evolutionary relationships embedded in data. We demonstrate detection and resolution of phylogenetic uncertainty in a recent study of anole lizards, leading to alternate hypotheses about their evolutionary relationships. We use our approach to compare trees derived from different genes of Ebolavirus and find that the VP30 gene has a distinct phylogenetic signature composed of three alternatives that differ in the deep branching structure. Key words: phylogenetics, evolution, tree metrics, genetics, sequencing. PMID:27343287

  9. Phylogenetic analysis reveals the evolution and diversification of cyclins in eukaryotes.

    PubMed

    Ma, Zhaowu; Wu, Yuliang; Jin, Jialu; Yan, Jun; Kuang, Shuzhen; Zhou, Mi; Zhang, Yuexuan; Guo, An-Yuan

    2013-03-01

    Cyclins are a family of diverse proteins that play fundamental roles in regulating cell cycle progression in Eukaryotes. Cyclins have been identified from protists to higher Eukaryotes, while its evolution remains vague and the findings turn out controversial. Current classification of cyclins is mainly based on their functions, which may not be appropriate for the systematic evolutionary analysis. In this work, we performed comparative and phylogenetic analysis of cyclins to investigate their classification, origin and evolution. Cyclins originated in early Eukaryotes and evolved from protists to plants, fungi and animals. Based on the phylogenetic tree, cyclins can be divided into three major groups designated as the group I, II and III with different functions and features. Group I plays key roles in cell cycle, group II varied in actions are kingdom (plant, fungi and animal) specific, and group III functions in transcription regulation. Our results showed that the dominating cyclins (group I) diverged from protists to plants, fungi and animals, while divergence of the other cyclins (groups II and III) has occurred in protists. We also discussed the evolutionary relationships between cyclins and cyclin-dependent kinases (CDKs) and found that the cyclins have undergone divergence in protists before the divergence of animal CDKs. This reclassification and evolutionary analysis of cyclins might facilitate understanding eukaryotic cell cycle control.

  10. Phylogenetic Inferences Reveal a Large Extent of Novel Biodiversity in Chemically Rich Tropical Marine Cyanobacteria

    PubMed Central

    Gunasekera, Sarath P.; Gerwick, William H.

    2013-01-01

    Benthic marine cyanobacteria are known for their prolific biosynthetic capacities to produce structurally diverse secondary metabolites with biomedical application and their ability to form cyanobacterial harmful algal blooms. In an effort to provide taxonomic clarity to better guide future natural product drug discovery investigations and harmful algal bloom monitoring, this study investigated the taxonomy of tropical and subtropical natural product-producing marine cyanobacteria on the basis of their evolutionary relatedness. Our phylogenetic inferences of marine cyanobacterial strains responsible for over 100 bioactive secondary metabolites revealed an uneven taxonomic distribution, with a few groups being responsible for the vast majority of these molecules. Our data also suggest a high degree of novel biodiversity among natural product-producing strains that was previously overlooked by traditional morphology-based taxonomic approaches. This unrecognized biodiversity is primarily due to a lack of proper classification systems since the taxonomy of tropical and subtropical, benthic marine cyanobacteria has only recently been analyzed by phylogenetic methods. This evolutionary study provides a framework for a more robust classification system to better understand the taxonomy of tropical and subtropical marine cyanobacteria and the distribution of natural products in marine cyanobacteria. PMID:23315747

  11. Diversity of Clonostachys species assessed by molecular phylogenetics and MALDI-TOF mass spectrometry.

    PubMed

    Abreu, Lucas M; Moreira, Gláucia M; Ferreira, Douglas; Rodrigues-Filho, Edson; Pfenning, Ludwig H

    2014-12-01

    We assessed the species diversity among 45 strains of Clonostachys from different substrates and localities in Brazil using molecular phylogenetics, and compared the results with the phenotypic classification of strains obtained from matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Phylogenetic analyses were based on beta tubulin (Tub), ITS-LSU rDNA, and a combined Tub-ITS DNA dataset. MALDI-TOF MS analyses were performed using intact conidia and conidiophores of strains cultivated on oatmeal agar and 4% malt extract agar. Six known species were identified: Clonostachys byssicola, Clonostachys candelabrum, Clonostachys pseudochroleuca, Clonostachys rhizophaga, Clonostachys rogersoniana, and Clonostachys rosea. Two clades and two singleton lineages did not correspond to known species represented in the reference DNA dataset and were identified as Clonostachys sp. 1-4. Multivariate cluster analyses of MALDI-TOF MS data classified the strains into eight clusters and three singletons, corresponding to the ten identified species plus one additional cluster containing two strains of C. rogersoniana that split from the other co-specific strains. The consistent results of MALDI-TOF MS supported the identification of strains assigned to C. byssicola and C. pseudochroleuca, which did not form well supported clades in all phylogenetic analyses, but formed distinct clusters in the MALDI-TOF dendrograms.

  12. Phylogenetic diversity and biogeography of the Mamiellophyceae lineage of eukaryotic phytoplankton across the oceans.

    PubMed

    Monier, Adam; Worden, Alexandra Z; Richards, Thomas A

    2016-08-01

    High-throughput diversity amplicon sequencing of marine microbial samples has revealed that members of the Mamiellophyceae lineage are successful phytoplankton in many oceanic habitats. Indeed, these eukaryotic green algae can dominate the picoplanktonic biomass, however, given the broad expanses of the oceans, their geographical distributions and the phylogenetic diversity of some groups remain poorly characterized. As these algae play a foundational role in marine food webs, it is crucial to assess their global distribution in order to better predict potential changes in abundance and community structure. To this end, we analyzed the V9-18S small subunit rDNA sequences deposited from the Tara Oceans expedition to evaluate the diversity and biogeography of these phytoplankton. Our results show that the phylogenetic composition of Mamiellophyceae communities is in part determined by geographical provenance, and do not appear to be influenced - in the samples recovered - by water depth, at least at the resolution possible with the V9-18S. Phylogenetic classification of Mamiellophyceae sequences revealed that the Dolichomastigales order encompasses more sequence diversity than other orders in this lineage. These results indicate that a large fraction of the Mamiellophyceae diversity has been hitherto overlooked, likely because of a combination of size fraction, sequencing and geographical limitations.

  13. Molecular phylogenetics and historical biogeography amid shifting continents in the cockles and giant clams (Bivalvia: Cardiidae).

    PubMed

    Herrera, Nathanael D; Ter Poorten, Jan Johan; Bieler, Rüdiger; Mikkelsen, Paula M; Strong, Ellen E; Jablonski, David; Steppan, Scott J

    2015-12-01

    Reconstructing historical biogeography of the marine realm is complicated by indistinct barriers and, over deeper time scales, a dynamic landscape shaped by plate tectonics. Here we present the most extensive examination of model-based historical biogeography among marine invertebrates to date. We conducted the largest phylogenetic and molecular clock analyses to date for the bivalve family Cardiidae (cockles and giant clams) with three unlinked loci for 110 species representing 37 of the 50 genera. Ancestral ranges were reconstructed using the dispersal-extinction-cladogenesis (DEC) method with a time-stratified paleogeographic model wherein dispersal rates varied with shifting tectonics. Results were compared to previous classifications and the extensive paleontological record. Six of the eight prior subfamily groupings were found to be para- or polyphyletic. Cardiidae originated and subsequently diversified in the tropical Indo-Pacific starting in the Late Triassic. Eastern Atlantic species were mainly derived from the tropical Indo-Mediterranean region via the Tethys Sea. In contrast, the western Atlantic fauna was derived from Indo-Pacific clades. Our phylogenetic results demonstrated greater concordance with geography than did previous phylogenies based on morphology. Time-stratifying the DEC reconstruction improved the fit and was highly consistent with paleo-ocean currents and paleogeography. Lastly, combining molecular phylogenetics with a rich and well-documented fossil record allowed us to test the accuracy and precision of biogeographic range reconstructions.

  14. DNA sequence support for a close phylogenetic relationship between some storks and New World vultures.

    PubMed Central

    Avise, J C; Nelson, W S; Sibley, C G

    1994-01-01

    Nucleotide sequences from the mitochondrial cytochrome b gene were used to address a controversial suggestion that New World vultures are related more closely to storks than to Old World vultures. Phylogenetic analyses of 1-kb sequences from 18 relevant avian species indicate that the similarities in morphology and behavior between New World and Old World vultures probably manifest convergent adaptations associated with carrion-feeding, rather than propinquity of descent. Direct sequence evidence for a close phylogenetic alliance between at least some New World vultures and storks lends support to conclusions reached previously from DNA.DNA hybridization methods and detailed morphology-based appraisals, and it illustrates how mistaken assumptions of homology for organismal adaptations can compromise biological classifications. However, there was a lack of significant resolution for most other branches in the cytochrome b phylogenetic reconstructions. This irresolution is most likely attributable to a close temporal clustering of nodes, rather than to ceiling effects (mutational saturation) producing an inappropriate window of resolution for the cytochrome b sequences. Images PMID:8197203

  15. Automated Protein Subfamily Identification and Classification

    PubMed Central

    Brown, Duncan P; Krishnamurthy, Nandini; Sjölander, Kimmen

    2007-01-01

    Function prediction by homology is widely used to provide preliminary functional annotations for genes for which experimental evidence of function is unavailable or limited. This approach has been shown to be prone to systematic error, including percolation of annotation errors through sequence databases. Phylogenomic analysis avoids these errors in function prediction but has been difficult to automate for high-throughput application. To address this limitation, we present a computationally efficient pipeline for phylogenomic classification of proteins. This pipeline uses the SCI-PHY (Subfamily Classification in Phylogenomics) algorithm for automatic subfamily identification, followed by subfamily hidden Markov model (HMM) construction. A simple and computationally efficient scoring scheme using family and subfamily HMMs enables classification of novel sequences to protein families and subfamilies. Sequences representing entirely novel subfamilies are differentiated from those that can be classified to subfamilies in the input training set using logistic regression. Subfamily HMM parameters are estimated using an information-sharing protocol, enabling subfamilies containing even a single sequence to benefit from conservation patterns defining the family as a whole or in related subfamilies. SCI-PHY subfamilies correspond closely to functional subtypes defined by experts and to conserved clades found by phylogenetic analysis. Extensive comparisons of subfamily and family HMM performances show that subfamily HMMs dramatically improve the separation between homologous and non-homologous proteins in sequence database searches. Subfamily HMMs also provide extremely high specificity of classification and can be used to predict entirely novel subtypes. The SCI-PHY Web server at http://phylogenomics.berkeley.edu/SCI-PHY/ allows users to upload a multiple sequence alignment for subfamily identification and subfamily HMM construction. Biologists wishing to provide their own

  16. Complete mitochondrial genomes elucidate phylogenetic relationships of the deep-sea octocoral families Coralliidae and Paragorgiidae

    NASA Astrophysics Data System (ADS)

    Figueroa, Diego F.; Baco, Amy R.

    2014-01-01

    In the past decade, molecular phylogenetic analyses of octocorals have shown that the current morphological taxonomic classification of these organisms needs to be revised. The latest phylogenetic analyses show that most octocorals can be divided into three main clades. One of these clades contains the families Coralliidae and Paragorgiidae. These families share several taxonomically important characters and it has been suggested that they may not be monophyletic; with the possibility of the Coralliidae being a derived branch of the Paragorgiidae. Uncertainty exists not only in the relationship of these two families, but also in the classification of the two genera that make up the Coralliidae, Corallium and Paracorallium. Molecular analyses suggest that the genus Corallium is paraphyletic, and it can be divided into two main clades, with the Paracorallium as members of one of these clades. In this study we sequenced the whole mitochondrial genome of five species of Paragorgia and of five species of Corallium to use in a phylogenetic analysis to achieve two main objectives; the first to elucidate the phylogenetic relationship between the Paragorgiidae and Coralliidae and the second to determine whether the genera Corallium and Paracorallium are monophyletic. Our results show that other members of the Coralliidae share the two novel mitochondrial gene arrangements found in a previous study in Corallium konojoi and Paracorallium japonicum; and that the Corallium konojoi arrangement is also found in the Paragorgiidae. Our phylogenetic reconstruction based on all the protein coding genes and ribosomal RNAs of the mitochondrial genome suggest that the Coralliidae are not a derived branch of the Paragorgiidae, but rather a monophyletic sister branch to the Paragorgiidae. While our manuscript was in review a study was published using morphological data and several fragments from mitochondrial genes to redefine the taxonomy of the Coralliidae. Paracorallium was subsumed

  17. Classification criteria for rheumatoid arthritis.

    PubMed

    MacGregor, A J

    1995-05-01

    incorporate features of past disease activity, for example by allowing deformity to substitute for swelling and by incorporating data on the past occurrence of rheumatoid factor and rheumatoid nodules. Developments in the immunology and genetics of RA may in the future provide more accurate tools for classification and may lead to recognition of more precise disease subsets. At present, however, the 1987 ARA criteria provide the most appropriate basis for case recognition in both clinic and population-based studies.

  18. Does Shamblin's classification predict postoperative morbidity in carotid body tumors? A proposal to modify Shamblin's classification.

    PubMed

    Luna-Ortiz, Kuauhyama; Rascon-Ortiz, Mario; Villavicencio-Valencia, Veronica; Herrera-Gomez, Angel

    2006-02-01

    The objective of this study was to analyze the possible correlation between Shamblin's classification and post-surgical morbidity in the treatment of carotid body tumors (CBTs). Seventy-two patients with carotid body tumors were seen over a 22-year period. Twenty-three patients were excluded as they did not comply with the criteria of the objectives. All patients were grouped according to Shamblin's classification. We propose a modification to this classification and make a comparison by analyzing the surgical time and bleeding, as well as the neurological and vascular damage. We resected 50 CBTs in 49 patients, ranging in age from 18 to 73 years. Three groups were formed: group I with 8 (16%) patients, group II with 17 (34%) and group III with 24 (49%). Post-surgical neurological damage was observed in one patient (12.5%) from group I, in six (35%) from group II and in nine patients (37.5%) from group III. Vascular sacrifice had to be performed in 21% of class II tumors and in 8.7% of class III. None of the class I tumors required vascular sacrifice. No statistically significant difference existed for vascular or neurological risk in relation to Shamblin's classification. However, when analyzed according to the classification proposed herein, there was a correlation between Shamblin's classification and vascular sacrifice (P =0.001). There was a statistically significant correlation between the original Shamblin and the modified Shamblin regarding surgical time and bleeding. Shamblin's classification predicts only vascular morbidity. Neurological morbidity is not reflected in it and only reflects the surgeon's experience with CBT resections. Surgical time and bleeding are directly related to the Shamblin as it reflects the size of tumors in relation to the blood vessels. Shamblin's classification must be modified to be more objective so that the international reports can accurately reflect the morbidity related to it.

  19. Molecular phylogenetic study in genus Hydra.

    PubMed

    Kawaida, Hitomi; Shimizu, Hiroshi; Fujisawa, Toshitaka; Tachida, Hidenori; Kobayakawa, Yoshitaka

    2010-11-15

    Among 8000-9000 species of Cnidaria, only several dozens of species of Hydrozoa have been found in the fresh water. Hydra is such a fresh water polyp and has been used as a good material for research in developmental biology, regeneration and pattern formation. Although the genus Hydra has only a few ten species, its distribution is cosmopolitan. The phylogenetic relationship between hydra species is fascinating from the aspect of evolutionary biology and biogeography. However, only a few molecular phylogenetic studies have been reported on hydra. Therefore, we conducted a molecular phylogenetic study of the genus Hydra based on mitochondrial and nuclear nucleotide sequences using a hydra collection that has been kept in the National Institute of Genetics (NIG) of Japan. The results support the idea that four species groups comprise the genus Hydra. Within the viridissima group (green hydra) and braueri group, genetic distances between strains were relatively large. In contrast, genetic distances between strains among the vulgaris and oligactis groups were small irrespective of their geographic distribution. The vulgaris group strains were classified at least (as far as our investigated samples) into three sub-groups, vulgaris sub-group, carnea sub-group, and H. sp. (K5 and K6) sub-group. All of the vulgaris sub-group and H. sp. (K5 and K6) sub-group strains were collected in Eurasia. The carnea sub-group strains in NIG collection were all collected in North America. A few newly collected samples in Japan, however, suggested belonging to the carnea sub-group according to the molecular phylogenic analysis. This suggests a trans-Pacific distribution of the carnea sub-group hydra.

  20. Modularized Evolution in Archaeal Methanogens Phylogenetic Forest

    PubMed Central

    Li, Jun; Wong, Chi-Fat; Wong, Mabel Ting; Huang, He; Leung, Frederick C.

    2014-01-01

    Methanogens are methane-producing archaea that plays a key role in the global carbon cycle. To date, the evolutionary history of methanogens and closely related nonmethanogen species remains unresolved among studies conducted upon different genetic markers, attributing to horizontal gene transfers (HGTs). With an effort to decipher both congruent and conflicting evolutionary events, reconstruction of coevolved gene clusters and hierarchical structure in the archaeal methanogen phylogenetic forest, comprehensive evolution, and network analyses were performed upon 3,694 gene families from 41 methanogens and 33 closely related archaea. Our results show that 1) greater than 50% of genes are in topological dissonance with others; 2) the prevalent interorder HGTs, even for core genes, in methanogen genomes led to their scrambled phylogenetic relationships; 3) most methanogenesis-related genes have experienced at least one HGT; 4) greater than 20% of the genes in methanogen genomes were transferred horizontally from other archaea, with genes involved in cell-wall synthesis and defense system having been transferred most frequently; 5) the coevolution network contains seven statistically robust modules, wherein the central module has the highest average node strength and comprises a majority of the core genes; 6) different coevolutionary module genes boomed in different time and evolutionary lineage, constructing diversified pan-genome structures; 7) the modularized evolution is also closely related to the vertical evolution signals and the HGT rate of the genes. Overall, this study presented a modularized phylogenetic forest that describes a combination of complicated vertical and nonvertical evolutionary processes for methanogenic archaeal species. PMID:25502908

  1. [Classification of cardiomyopathy].

    PubMed

    Asakura, Masanori; Kitakaze, Masafumi

    2014-01-01

    Cardiomyopathy is a group of cardiovascular diseases with poor prognosis. Some patients with dilated cardiomyopathy need heart transplantations due to severe heart failure. Some patients with hypertrophic cardiomyopathy die unexpectedly due to malignant ventricular arrhythmias. Various phenotypes of cardiomyopathies are due to the heterogeneous group of diseases. The classification of cardiomyopathies is important and indispensable in the clinical situation. However, their classification has not been established, because the causes of cardiomyopathies have not been fully elucidated. We usually use definition and classification offered by WHO/ISFC task force in 1995. Recently, several new definitions and classifications of the cardiomyopathies have been published by American Heart Association, European Society of Cardiology and Japanese Circulation Society.

  2. Delaware Alternative Classifications

    ERIC Educational Resources Information Center

    Miller, Jay

    1975-01-01

    This article discusses the species designation and taxonomies of Delaware and Algonkian and presents eight classifications of taxa by form, habitat, color, movement, sound, use, relationship, and appearance. Relevant research is also reviewed. (CLK)

  3. Postprocessing classification images

    NASA Technical Reports Server (NTRS)

    Kan, E. P.

    1979-01-01

    Program cleans up remote-sensing maps. It can be used with existing image-processing software. Remapped images closely resemble familiar resource information maps and can replace or supplement classification images not postprocessed by this program.

  4. A phylum-level phylogenetic classification of zygomycete fungi based on genome-scale data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zygomycete fungi were classified as a single phylum, Zygomycota, based on sexual reproduction by zygospores, frequent asexual reproduction by sporangia, absence of multicellular sporocarps, and production of coenocytic hyphae, all with some exceptions. Molecular phylogenies based on one or a few gen...

  5. MINER: software for phylogenetic motif identification.

    PubMed

    La, David; Livesay, Dennis R

    2005-07-01

    MINER is web-based software for phylogenetic motif (PM) identification. PMs are sequence regions (fragments) that conserve the overall familial phylogeny. PMs have been shown to correspond to a wide variety of catalytic regions, substrate-binding sites and protein interfaces, making them ideal functional site predictions. The MINER output provides an intuitive interface for interactive PM sequence analysis and structural visualization. The web implementation of MINER is freely available at http://www.pmap.csupomona.edu/MINER/. Source code is available to the academic community on request.

  6. Budgeted phylogenetic diversity on circular split systems.

    PubMed

    Minh, Bui Quang; Pardi, Fabio; Klaere, Steffen; von Haeseler, Arndt

    2009-01-01

    In the last 15 years, Phylogenetic Diversity (PD) has gained interest in the community of conservation biologists as a surrogate measure for assessing biodiversity. We have recently proposed two approaches to select taxa for maximizing PD, namely PD with budget constraints and PD on split systems. In this paper, we will unify these two strategies and present a dynamic programming algorithm to solve the unified framework of selecting taxa with maximal PD under budget constraints on circular split systems. An improved algorithm will also be given if the underlying split system is a tree.

  7. Phylogenetic and Biological Significance of Evolutionary Elements from Metazoan Mitochondrial Genomes

    PubMed Central

    Yuan, Jianbo; Zhu, Qingming; Liu, Bin

    2014-01-01

    The evolutionary history of living species is usually inferred through the phylogenetic analysis of molecular and morphological information using various mathematical models. New challenges in phylogenetic analysis are centered mostly on the search for accurate and efficient methods to handle the huge amounts of sequence data generated from newer genome sequencing. The next major challenge is the determination of relationships between the evolution of structural elements and their functional implementation, which is largely ignored in previous analyses. Here, we described the discovery of structural elements in metazoan mitochondrial genomes, termed key K-strings, that can serve as a basis for phylogenetic tree construction. Although comprising only a small fraction (0.73%) of all K-strings, these key K-strings are pivotal to the tree construction because they allow for a significant reduction in the computational time required to construct phylogenetic trees, and more importantly, they make significant improvement to the results of phylogenetic inference. The trees constructed from the key K-strings were consistent overall to our current view of metazoan phylogeny and exhibited a more rational topology than the trees constructed by using other conventional methods. Surprisingly, the key K-strings tended to accumulate in the conserved regions of the original sequences, which were most likely due to strong selection pressure. Furthermore, the special structural features of the key K-strings should have some potential applications in the study of the structures and functions relationship of proteins and in the determination of evolutionary trajectory of species. The novelty and potential importance of key K-strings lead us to believe that they are essential evolutionary elements. As such, they may play important roles in the process of species evolution and their physical existence. Further studies could lead to discoveries regarding the relationship between

  8. Adaptive Gaussian Pattern Classification

    DTIC Science & Technology

    1988-08-01

    redundant model of the data to be used in classification . There are two classes of learning, or adaptation schemes. The first, unsupervised learning...37, No. 3, pp. 242-247, 1983. [2] E. F. Codd, Cellular Automata , Academic Press, 1968. [31 H. Everett, G. Gilbreath, S. Alderson, D. J. Marchette...Na al Oca aytm aete !JTI FL E COPY AD-A 199 030 Technical Document 1335 August 1988 Adaptive Gaussian Pattern Classif ication C. E. Priebe D. J

  9. Progressive Classification Using Support Vector Machines

    NASA Technical Reports Server (NTRS)

    Wagstaff, Kiri; Kocurek, Michael

    2009-01-01

    An algorithm for progressive classification of data, analogous to progressive rendering of images, makes it possible to compromise between speed and accuracy. This algorithm uses support vector machines (SVMs) to classify data. An SVM is a machine learning algorithm that builds a mathematical model of the desired classification concept by identifying the critical data points, called support vectors. Coarse approximations to the concept require only a few support vectors, while precise, highly accurate models require far more support vectors. Once the model has been constructed, the SVM can be applied to new observations. The cost of classifying a new observation is proportional to the number of support vectors in the model. When computational resources are limited, an SVM of the appropriate complexity can be produced. However, if the constraints are not known when the model is constructed, or if they can change over time, a method for adaptively responding to the current resource constraints is required. This capability is particularly relevant for spacecraft (or any other real-time systems) that perform onboard data analysis. The new algorithm enables the fast, interactive application of an SVM classifier to a new set of data. The classification process achieved by this algorithm is characterized as progressive because a coarse approximation to the true classification is generated rapidly and thereafter iteratively refined. The algorithm uses two SVMs: (1) a fast, approximate one and (2) slow, highly accurate one. New data are initially classified by the fast SVM, producing a baseline approximate classification. For each classified data point, the algorithm calculates a confidence index that indicates the likelihood that it was classified correctly in the first pass. Next, the data points are sorted by their confidence indices and progressively reclassified by the slower, more accurate SVM, starting with the items most likely to be incorrectly classified. The user

  10. Supernova Photometric Lightcurve Classification

    NASA Astrophysics Data System (ADS)

    Zaidi, Tayeb; Narayan, Gautham

    2016-01-01

    This is a preliminary report on photometric supernova classification. We first explore the properties of supernova light curves, and attempt to restructure the unevenly sampled and sparse data from assorted datasets to allow for processing and classification. The data was primarily drawn from the Dark Energy Survey (DES) simulated data, created for the Supernova Photometric Classification Challenge. This poster shows a method for producing a non-parametric representation of the light curve data, and applying a Random Forest classifier algorithm to distinguish between supernovae types. We examine the impact of Principal Component Analysis to reduce the dimensionality of the dataset, for future classification work. The classification code will be used in a stage of the ANTARES pipeline, created for use on the Large Synoptic Survey Telescope alert data and other wide-field surveys. The final figure-of-merit for the DES data in the r band was 60% for binary classification (Type I vs II).Zaidi was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

  11. Separation of Benign and Malicious Network Events for Accurate Malware Family Classification

    DTIC Science & Technology

    2015-09-28

    malware at runtime, including memory access patterns, network traces, OS system calls, file system changes, and registry modifica- tions. Static...statistical features extracted from either static bi- naries [2–4], or from artifacts collected during the execution of the binary [5, 6]. These traces...same features extracted from mixed traffic that is collected on user machines, since these machines generate traffic containing both malware- and

  12. Leveraging IMU data for accurate exercise performance classification and musculoskeletal injury risk screening.

    PubMed

    Whelan, Darragh; O'Reilly, Martin; Huang, Bingquan; Giggins, Oonagh; Kechadi, Tahar; Caulfield, Brian

    2016-08-01

    Inertial measurement units (IMUs) are becoming increasingly prevalent as a method for low cost and portable biomechanical analysis. However, to date they have not been accepted into routine clinical practice. This is often due to a disconnect between translating the data collected by the sensors into meaningful and actionable information for end users. This paper outlines the work completed by our group in attempting to achieve this. We discuss the conceptual framework involved in our work, the methodological approach taken in analysing sensor signals and discuss possible application models. Our work indicates that IMU based systems have the potential to bridge the gap between laboratory and clinical movement analysis. Future studies will focus on collecting a diverse range of movement data and using more sophisticated data analysis techniques to refine systems.

  13. Using minimum DNA marker loci for accurate population classification in rice (Oryza sativa L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using few DNA markers to classify genetic background of a germplasm pool will help breeders make a quick decision while saving time and resources. WHICHLOCI is a computer program that selects the best combination of loci for population assignment through empiric analysis of molecular marker data. Th...

  14. DiScRIBinATE: a rapid method for accurate taxonomic classification of metagenomic sequences

    PubMed Central

    2010-01-01

    Background In metagenomic sequence data, majority of sequences/reads originate from new or partially characterized genomes, the corresponding sequences of which are absent in existing reference databases. Since taxonomic assignment of reads is based on their similarity to sequences from known organisms, the presence of reads originating from new organisms poses a major challenge to taxonomic binning methods. The recently published SOrt-ITEMS algorithm uses an elaborate work-flow to assign reads originating from hitherto unknown genomes with significant accuracy and specificity. Nevertheless, a significant proportion of reads still get misclassified. Besides, the use of an alignment-based orthology step (for improving the specificity of assignments) increases the total binning time of SOrt-ITEMS. Results In this paper, we introduce a rapid binning approach called DiScRIBinATE (Distance Score Ratio for Improved Binning And Taxonomic Estimation). DiScRIBinATE replaces the orthology approach of SOrt-ITEMS with a quicker 'alignment-free' approach. We demonstrate that incorporating this approach reduces binning time by half without any loss in the specificity and accuracy of assignments. Besides, a novel reclassification strategy incorporated in DiScRIBinATE results in reducing the overall misclassification rate to around 3 - 7%. This misclassification rate is 1.5 - 3 times lower as compared to that by SOrt-ITEMS, and 3 - 30 times lower as compared to that by MEGAN. Conclusions A significant reduction in binning time, coupled with a superior assignment accuracy (as compared to existing binning methods), indicates the immense applicability of the proposed algorithm in rapidly mapping the taxonomic diversity of large metagenomic samples with high accuracy and specificity. Availability The program is available on request from the authors. PMID:21106121

  15. Spatial Pattern Classification for More Accurate Forecasting of Variable Energy Resources

    NASA Astrophysics Data System (ADS)

    Novakovskaia, E.; Hayes, C.; Collier, C.

    2014-12-01

    The accuracy of solar and wind forecasts is becoming increasingly essential as grid operators continue to integrate additional renewable generation onto the electric grid. Forecast errors affect rate payers, grid operators, wind and solar plant maintenance crews and energy traders through increases in prices, project down time or lost revenue. While extensive and beneficial efforts were undertaken in recent years to improve physical weather models for a broad spectrum of applications these improvements have generally not been sufficient to meet the accuracy demands of system planners. For renewables, these models are often used in conjunction with additional statistical models utilizing both meteorological observations and the power generation data. Forecast accuracy can be dependent on specific weather regimes for a given location. To account for these dependencies it is important that parameterizations used in statistical models change as the regime changes. An automated tool, based on an artificial neural network model, has been developed to identify different weather regimes as they impact power output forecast accuracy at wind or solar farms. In this study, improvements in forecast accuracy were analyzed for varying time horizons for wind farms and utility-scale PV plants located in different geographical regions.

  16. TIME-INTEGRATED EXPOSURE MEASURES TO IMPROVE THE PREDICTIVE POWER OF EXPOSURE CLASSIFICATION FOR EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

  17. Accurate estimation of sigma(exp 0) using AIRSAR data

    NASA Technical Reports Server (NTRS)

    Holecz, Francesco; Rignot, Eric

    1995-01-01

    During recent years signature analysis, classification, and modeling of Synthetic Aperture Radar (SAR) data as well as estimation of geophysical parameters from SAR data have received a great deal of interest. An important requirement for the quantitative use of SAR data is the accurate estimation of the backscattering coefficient sigma(exp 0). In terrain with relief variations radar signals are distorted due to the projection of the scene topography into the slant range-Doppler plane. The effect of these variations is to change the physical size of the scattering area, leading to errors in the radar backscatter values and incidence angle. For this reason the local incidence angle, derived from sensor position and Digital Elevation Model (DEM) data must always be considered. Especially in the airborne case, the antenna gain pattern can be an additional source of radiometric error, because the radar look angle is not known precisely as a result of the the aircraft motions and the local surface topography. Consequently, radiometric distortions due to the antenna gain pattern must also be corrected for each resolution cell, by taking into account aircraft displacements (position and attitude) and position of the backscatter element, defined by the DEM data. In this paper, a method to derive an accurate estimation of the backscattering coefficient using NASA/JPL AIRSAR data is presented. The results are evaluated in terms of geometric accuracy, radiometric variations of sigma(exp 0), and precision of the estimated forest biomass.

  18. Iris Image Classification Based on Hierarchical Visual Codebook.

    PubMed

    Zhenan Sun; Hui Zhang; Tieniu Tan; Jianyu Wang

    2014-06-01

    Iris recognition as a reliable method for personal identification has been well-studied with the objective to assign the class label of each iris image to a unique subject. In contrast, iris image classification aims to classify an iris image to an application specific category, e.g., iris liveness detection (classification of genuine and fake iris images), race classification (e.g., classification of iris images of Asian and non-Asian subjects), coarse-to-fine iris identification (classification of all iris images in the central database into multiple categories). This paper proposes a general framework for iris image classification based on texture analysis. A novel texture pattern representation method called Hierarchical Visual Codebook (HVC) is proposed to encode the texture primitives of iris images. The proposed HVC method is an integration of two existing Bag-of-Words models, namely Vocabulary Tree (VT), and Locality-constrained Linear Coding (LLC). The HVC adopts a coarse-to-fine visual coding strategy and takes advantages of both VT and LLC for accurate and sparse representation of iris texture. Extensive experimental results demonstrate that the proposed iris image classification method achieves state-of-the-art performance for iris liveness detection, race classification, and coarse-to-fine iris identification. A comprehensive fake iris image database simulating four types of iris spoof attacks is developed as the benchmark for research of iris liveness detection.

  19. Assessment of available anatomical characters for linking living mammals to fossil taxa in phylogenetic analyses

    PubMed Central

    2016-01-01

    Analyses of living and fossil taxa are crucial for understanding biodiversity through time. The total evidence method allows living and fossil taxa to be combined in phylogenies, using molecular data for living taxa and morphological data for living and fossil taxa. With this method, substantial overlap of coded anatomical characters among living and fossil taxa is vital for accurately inferring topology. However, although molecular data for living species are widely available, scientists generating morphological data mainly focus on fossils. Therefore, there are fewer coded anatomical characters in living taxa, even in well-studied groups such as mammals. We investigated the number of coded anatomical characters available in phylogenetic matrices for living mammals and how these were phylogenetically distributed across orders. Eleven of 28 mammalian orders have less than 25% species with available characters; this has implications for the accurate placement of fossils, although the issue is less pronounced at higher taxonomic levels. In most orders, species with available characters are randomly distributed across the phylogeny, which may reduce the impact of the problem. We suggest that increased morphological data collection efforts for living taxa are needed to produce accurate total evidence phylogenies. PMID:27146442

  20. A phylogenetic blueprint for a modern whale.

    PubMed

    Gatesy, John; Geisler, Jonathan H; Chang, Joseph; Buell, Carl; Berta, Annalisa; Meredith, Robert W; Springer, Mark S; McGowen, Michael R

    2013-02-01

    The emergence of Cetacea in the Paleogene represents one of the most profound macroevolutionary transitions within Mammalia. The move from a terrestrial habitat to a committed aquatic lifestyle engendered wholesale changes in anatomy, physiology, and behavior. The results of this remarkable transformation are extant whales that include the largest, biggest brained, fastest swimming, loudest, deepest diving mammals, some of which can detect prey with a sophisticated echolocation system (Odontoceti - toothed whales), and others that batch feed using racks of baleen (Mysticeti - baleen whales). A broad-scale reconstruction of the evolutionary remodeling that culminated in extant cetaceans has not yet been based on integration of genomic and paleontological information. Here, we first place Cetacea relative to extant mammalian diversity, and assess the distribution of support among molecular datasets for relationships within Artiodactyla (even-toed ungulates, including Cetacea). We then merge trees derived from three large concatenations of molecular and fossil data to yield a composite hypothesis that encompasses many critical events in the evolutionary history of Cetacea. By combining diverse evidence, we infer a phylogenetic blueprint that outlines the stepwise evolutionary development of modern whales. This hypothesis represents a starting point for more detailed, comprehensive phylogenetic reconstructions in the future, and also highlights the synergistic interaction between modern (genomic) and traditional (morphological+paleontological) approaches that ultimately must be exploited to provide a rich understanding of evolutionary history across the entire tree of Life.

  1. Phylogenetic relationships among Ehrlichia ruminantium isolates.

    PubMed

    Allsopp, M T E P; Van Heerden, H; Steyn, H C; Allsopp, B A

    2003-06-01

    Ehrlichia ruminantium, the causative agent of heartwater, is a tick-borne pathogen infecting ruminants throughout sub-Saharan Africa and on some Caribbean islands. The most reliable test for E. ruminantium is PCR-based, but this gives positive results in some areas free of clinical heartwater and of the known Amblyomma spp. tick vectors. To investigate the molecular basis for this finding we have sequenced and carried out phylogenetic analysis of a range of genes from a number of E. ruminantium isolates. The genes include ribonuclease III and cytochrome c oxidase assembly protein genes (the pCS20 region), groESL, citrate synthase (gltA), and 16S ribosomal RNA. Relationships among major antigenic protein (map1) genes have been exhaustively investigated in a previous study that showed that the genes are variable in length, have non-synonymous mutations, and show no geographical specificity among isolates. The 16S sequences are highly conserved, except in the V1 loop region. The pCS20, groESL, and gltA genes show only single nucleotide polymorphisms (SNPs) dispersed throughout the sequenced regions. Phylogenetic analysis using pCS20 data differentiates the western African isolates into a single clade, which also includes a southern African isolate. All other southern African isolates and a Caribbean isolate fall into a further clade, which is subdivided into two groups. Sequence variation within this clade is greater than that within the western African clade, suggesting that E. ruminantium originated in southern Africa.

  2. A Distance Measure for Genome Phylogenetic Analysis

    NASA Astrophysics Data System (ADS)

    Cao, Minh Duc; Allison, Lloyd; Dix, Trevor

    Phylogenetic analyses of species based on single genes or parts of the genomes are often inconsistent because of factors such as variable rates of evolution and horizontal gene transfer. The availability of more and more sequenced genomes allows phylogeny construction from complete genomes that is less sensitive to such inconsistency. For such long sequences, construction methods like maximum parsimony and maximum likelihood are often not possible due to their intensive computational requirement. Another class of tree construction methods, namely distance-based methods, require a measure of distances between any two genomes. Some measures such as evolutionary edit distance of gene order and gene content are computational expensive or do not perform well when the gene content of the organisms are similar. This study presents an information theoretic measure of genetic distances between genomes based on the biological compression algorithm expert model. We demonstrate that our distance measure can be applied to reconstruct the consensus phylogenetic tree of a number of Plasmodium parasites from their genomes, the statistical bias of which would mislead conventional analysis methods. Our approach is also used to successfully construct a plausible evolutionary tree for the γ-Proteobacteria group whose genomes are known to contain many horizontally transferred genes.

  3. Phylogenetic analysis of honey bee behavioral evolution.

    PubMed

    Raffiudin, Rika; Crozier, Ross H

    2007-05-01

    DNA sequences from three mitochondrial (rrnL, cox2, nad2) and one nuclear gene (itpr) from all 9 known honey bee species (Apis), a 10th possible species, Apis dorsata binghami, and three outgroup species (Bombus terrestris, Melipona bicolor and Trigona fimbriata) were used to infer Apis phylogenetic relationships using Bayesian analysis. The dwarf honey bees were confirmed as basal, and the giant and cavity-nesting species to be monophyletic. All nodes were strongly supported except that grouping Apis cerana with A. nigrocincta. Two thousand post-burnin trees from the phylogenetic analysis were used in a Bayesian comparative analysis to explore the evolution of dance type, nest structure, comb structure and dance sound within Apis. The ancestral honey bee species was inferred with high support to have nested in the open, and to have more likely than not had a silent vertical waggle dance and a single comb. The common ancestor of the giant and cavity-dwelling bees is strongly inferred to have had a buzzing vertical directional dance. All pairwise combinations of characters showed strong association, but the multiple comparisons problem reduces the ability to infer associations between states between characters. Nevertheless, a buzzing dance is significantly associated with cavity-nesting, several vertical combs, and dancing vertically, a horizontal dance is significantly associated with a nest with a single comb wrapped around the support, and open nesting with a single pendant comb and a silent waggle dance.

  4. Phylogenetic relationships and the evolution of BMP4 in triggerfishes and filefishes (Balistoidea).

    PubMed

    McCord, Charlene L; Westneat, Mark W

    2016-01-01

    The triggerfishes (family Balistidae) and filefishes (family Monacanthidae) comprise a charismatic superfamily (Balistoidea) within the diverse order Tetraodontiformes. This group of largely marine fishes occupies an impressive ecological range across the world's oceans, and is well known for its locomotor and feeding diversity, unusual body shapes, small genome size, and ecological and economic importance. In order to investigate the evolutionary history of these important fish families, we used multiple phylogenetic methods to analyze molecular data from 86 species spanning the extant biodiversity of Balistidae and Monacanthidae. In addition to three gene regions that have been used extensively in phylogenetic analyses, we include sequence data for two mitochondrial regions, two nuclear markers, and the growth factor gene bmp4, which is involved with cranial development. Phylogenetic analyses strongly support the monophyly of the superfamily Balistoidea, the sister-family relationship of Balistidae and Monacanthidae, as well as three triggerfish and four filefish clades that are well resolved. A new classification for the Balistidae is proposed based on phylogenetic groups. Bayesian topology, as well as the timing of major cladogenesis events, is largely congruent with previous hypotheses of balistid phylogeny. However, we present a novel topology for major clades in the filefish family that illustrate the genera Aluterus and Stephanolepis are more closely related than previously posited. Molecular rates suggest a Miocene and Oligocene origin for the families Balistidae and Monacanthidae, respectively, and significant divergence of species in both families within the past 5 million years. A second key finding of this study is that, relative to the other protein-coding gene regions in our DNA supermatrix, bmp4 shows a rapid accumulation of both synonymous and non-synonymous substitutions, especially within the family Monacanthidae. Overall substitution patterns in

  5. Strong phylogenetic signals and phylogenetic niche conservatism in ecophysiological traits across divergent lineages of Magnoliaceae

    PubMed Central

    Liu, Hui; Xu, Qiuyuan; He, Pengcheng; Santiago, Louis S.; Yang, Keming; Ye, Qing

    2015-01-01

    The early diverged Magnoliaceae shows a historical temperate-tropical distribution among lineages indicating divergent evolution, yet which ecophysiological traits are phylogenetically conserved, and whether these traits are involved in correlated evolution remain unclear. Integrating phylogeny and 20 ecophysiological traits of 27 species, from the four largest sections of Magnoliaceae, we tested the phylogenetic signals of these traits and the correlated evolution between trait pairs. Phylogenetic niche conservatism (PNC) in water-conducting and nutrient-use related traits was identified, and correlated evolution of several key functional traits was demonstrated. Among the three evergreen sections of tropical origin, Gwillimia had the lowest hydraulic-photosynthetic capacity and the highest drought tolerance compared with Manglietia and Michelia. Contrastingly, the temperate centred deciduous section, Yulania, showed high rates of hydraulic conductivity and photosynthesis at the cost of drought tolerance. This study elucidated the regulation of hydraulic and photosynthetic processes in the temperate-tropical adaptations for Magnoliaceae species, which led to strong phylogenetic signals and PNC in ecophysiological traits across divergent lineages of Magnoliaceae. PMID:26179320

  6. Strong phylogenetic signals and phylogenetic niche conservatism in ecophysiological traits across divergent lineages of Magnoliaceae.

    PubMed

    Liu, Hui; Xu, Qiuyuan; He, Pengcheng; Santiago, Louis S; Yang, Keming; Ye, Qing

    2015-07-16

    The early diverged Magnoliaceae shows a historical temperate-tropical distribution among lineages indicating divergent evolution, yet which ecophysiological traits are phylogenetically conserved, and whether these traits are involved in correlated evolution remain unclear. Integrating phylogeny and 20 ecophysiological traits of 27 species, from the four largest sections of Magnoliaceae, we tested the phylogenetic signals of these traits and the correlated evolution between trait pairs. Phylogenetic niche conservatism (PNC) in water-conducting and nutrient-use related traits was identified, and correlated evolution of several key functional traits was demonstrated. Among the three evergreen sections of tropical origin, Gwillimia had the lowest hydraulic-photosynthetic capacity and the highest drought tolerance compared with Manglietia and Michelia. Contrastingly, the temperate centred deciduous section, Yulania, showed high rates of hydraulic conductivity and photosynthesis at the cost of drought tolerance. This study elucidated the regulation of hydraulic and photosynthetic processes in the temperate-tropical adaptations for Magnoliaceae species, which led to strong phylogenetic signals and PNC in ecophysiological traits across divergent lineages of Magnoliaceae.

  7. Mill profiler machines soft materials accurately

    NASA Technical Reports Server (NTRS)

    Rauschl, J. A.

    1966-01-01

    Mill profiler machines bevels, slots, and grooves in soft materials, such as styrofoam phenolic-filled cores, to any desired thickness. A single operator can accurately control cutting depths in contour or straight line work.

  8. Comparative assessment of performance and genome dependence among phylogenetic profiling methods

    PubMed Central

    Snitkin, Evan S; Gustafson, Adam M; Mellor, Joseph; Wu, Jie; DeLisi, Charles

    2006-01-01

    Background The rapidly increasing speed with which genome sequence data can be generated will be accompanied by an exponential increase in the number of sequenced eukaryotes. With the increasing number of sequenced eukaryotic genomes comes a need for bioinformatic techniques to aid in functional annotation. Ideally, genome context based techniques such as proximity, fusion, and phylogenetic profiling, which have been so successful in prokaryotes, could be utilized in eukaryotes. Here we explore the application of phylogenetic profiling, a method that exploits the evolutionary co-occurrence of genes in the assignment of functional linkages, to eukaryotic genomes. Results In order to evaluate the performance of phylogenetic profiling in eukaryotes, we assessed the relative performance of commonly used profile construction techniques and genome compositions in predicting functional linkages in both prokaryotic and eukaryotic organisms. When predicting linkages in E. coli with a prokaryotic profile, the use of continuous values constructed from transformed BLAST bit-scores performed better than profiles composed of discretized E-values; the use of discretized E-values resulted in more accurate linkages when using S. cerevisiae as the query organism. Extending this analysis by incorporating several eukaryotic genomes in profiles containing a majority of prokaryotes resulted in similar overall accuracy, but with a surprising reduction in pathway diversity among the most significant linkages. Furthermore, the application of phylogenetic profiling using profiles composed of only eukaryotes resulted in the loss of the strong correlation between common KEGG pathway membership and profile similarity score. Profile construction methods, orthology definitions, ontology and domain complexity were explored as possible sources of the poor performance of eukaryotic profiles, but with no improvement in results. Conclusion Given the current set of completely sequenced eukaryotic

  9. A Novel Vehicle Classification Using Embedded Strain Gauge Sensors.

    PubMed

    Zhang, Wenbin; Wang, Qi; Suo, Chunguang

    2008-11-05

    This paper presents a new vehicle classification and develops a traffic monitoring detector to provide reliable vehicle classification to aid traffic management systems. The basic principle of this approach is based on measuring the dynamic strain caused by vehicles across pavement to obtain the corresponding vehicle parameters - wheelbase and number of axles - to then accurately classify the vehicle. A system prototype with five embedded strain sensors was developed to validate the accuracy and effectiveness of the classification method. According to the special arrangement of the sensors and the different time a vehicle arrived at the sensors one can estimate the vehicle's speed accurately, corresponding to the estimated vehicle wheelbase and number of axles. Because of measurement errors and vehicle characteristics, there is a lot of overlap between vehicle wheelbase patterns. Therefore, directly setting up a fixed threshold for vehicle classification often leads to low-accuracy results. Using the machine learning pattern recognition method to deal with this problem is believed as one of the most effective tools. In this study, support vector machines (SVMs) were used to integrate the classification features extracted from the strain sensors to automatically classify vehicles into five types, ranging from small vehicles to combination trucks, along the lines of the Federal Highway Administration vehicle classification guide. Test bench and field experiments will be introduced in this paper. Two support vector machines classification algorithms (one-against-all, one-against-one) are used to classify single sensor data and multiple sensor combination data. Comparison of the two classification method results shows that the classification accuracy is very close using single data or multiple data. Our results indicate that using multiclass SVM-based fusion multiple sensor data significantly improves the results of a single sensor data, which is trained on the whole

  10. A Novel Vehicle Classification Using Embedded Strain Gauge Sensors

    PubMed Central

    Zhang, Wenbin; Wang, Qi; Suo, Chunguang

    2008-01-01

    This paper presents a new vehicle classification and develops a traffic monitoring detector to provide reliable vehicle classification to aid traffic management systems. The basic principle of this approach is based on measuring the dynamic strain caused by vehicles across pavement to obtain the corresponding vehicle parameters – wheelbase and number of axles – to then accurately classify the vehicle. A system prototype with five embedded strain sensors was developed to validate the accuracy and effectiveness of the classification method. According to the special arrangement of the sensors and the different time a vehicle arrived at the sensors one can estimate the vehicle's speed accurately, corresponding to the estimated vehicle wheelbase and number of axles. Because of measurement errors and vehicle characteristics, there is a lot of overlap between vehicle wheelbase patterns. Therefore, directly setting up a fixed threshold for vehicle classification often leads to low-accuracy results. Using the machine learning pattern recognition method to deal with this problem is believed as one of the most effective tools. In this study, support vector machines (SVMs) were used to integrate the classification features extracted from the strain sensors to automatically classify vehicles into five types, ranging from small vehicles to combination trucks, along the lines of the Federal Highway Administration vehicle classification guide. Test bench and field experiments will be introduced in this paper. Two support vector machines classification algorithms (one-against-all, one-against-one) are used to classify single sensor data and multiple sensor combination data. Comparison of the two classification method results shows that the classification accuracy is very close using single data or multiple data. Our results indicate that using multiclass SVM-based fusion multiple sensor data significantly improves the results of a single sensor data, which is trained on the

  11. What should an ideal spinal injury classification system consist of? A methodological review and conceptual proposal for future classifications

    PubMed Central

    Audigé, Laurent; Hanson, Beate; Chapman, Jens R.; Hosman, Allard J. F.

    2010-01-01

    Since Böhler published the first categorization of spinal injuries based on plain radiographic examinations in 1929, numerous classifications have been proposed. Despite all these efforts, however, only a few have been tested for reliability and validity. This methodological, conceptual review summarizes that a spinal injury classification system should be clinically relevant, reliable and accurate. The clinical relevance of a classification is directly related to its content validity. The ideal content of a spinal injury classification should only include injury characteristics of the vertebral column, is primarily based on the increasingly routinely performed CT imaging, and is clearly distinctive from severity scales and treatment algorithms. Clearly defined observation and conversion criteria are crucial determinants of classification systems’ reliability and accuracy. Ideally, two principle spinal injury characteristics should be easy to discern on diagnostic images: the specific location and morphology of the injured spinal structure. Given the current evidence and diagnostic imaging technology, descriptions of the mechanisms of injury and ligamentous injury should not be included in a spinal injury classification. The presence of concomitant neurologic deficits can be integrated in a spinal injury severity scale, which in turn can be considered in a spinal injury treatment algorithm. Ideally, a validation pathway of a spinal injury classification system should be completed prior to its clinical and scientific implementation. This review provides a methodological concept which might be considered prior to the synthesis of new or modified spinal injury classifications. PMID:20464432

  12. Phylogenetic diversity and nature conservation: where are we?

    PubMed

    Winter, Marten; Devictor, Vincent; Schweiger, Oliver

    2013-04-01

    To date, there is little evidence that phylogenetic diversity has contributed to nature conservation. Here, we discuss the scientific justification of using phylogenetic diversity in conservation and the reasons for its neglect. We show that, apart from valuing the rarity and richness aspect, commonly quoted justifications based on the usage of phylogenetic diversity as a proxy for functional diversity or evolutionary potential are still based on uncertainties. We discuss how a missing guideline through the variety of phylogenetic diversity metrics and their relevance for conservation might be responsible for the hesitation to include phylogenetic diversity in conservation practice. We outline research routes that can help to ease uncertainties and bridge gaps between research and conservation with respect to phylogenetic diversity.

  13. Accurate identification of periodic oscillations buried in white or colored noise using fast orthogonal search.

    PubMed

    Chon, K H

    2001-06-01

    We use a previously introduced fast orthogonal search algorithm to detect sinusoidal frequency components buried in either white or colored noise. We show that the method outperforms the correlogram, modified covariance autoregressive (MODCOVAR) and multiple-signal classification (MUSIC) methods. Fast orthogonal search method achieves accurate detection of sinusoids even with signal-to-noise ratios as low as -10 dB, and is superior at detecting sinusoids buried in 1/f noise. Since the utilized method accurately detects sinusoids even under colored noise, it can be used to extract a 1/f noise process observed in physiological signals such as heart rate and renal blood pressure and flow data.

  14. Segmentation Assisted Food Classification for Dietary Assessment.

    PubMed

    Zhu, Fengqing; Bosch, Marc; Schap, Tusarebecca; Khanna, Nitin; Ebert, David S; Boushey, Carol J; Delp, Edward J

    2011-01-24

    Accurate methods and tools to assess food and nutrient intake are essential for the association between diet and health. Preliminary studies have indicated that the use of a mobile device with a built-in camera to obtain images of the food consumed may provide a less burdensome and more accurate method for dietary assessment. We are developing methods to identify food items using a single image acquired from the mobile device. Our goal is to automatically determine the regions in an image where a particular food is located (segmentation) and correctly identify the food type based on its features (classification or food labeling). Images of foods are segmented using Normalized Cuts based on intensity and color. Color and texture features are extracted from each segmented food region. Classification decisions for each segmented region are made using support vector machine methods. The segmentation of each food region is refined based on feedback from the output of classifier to provide more accurate estimation of the quantity of food consumed.

  15. Segmentation assisted food classification for dietary assessment

    NASA Astrophysics Data System (ADS)

    Zhu, Fengqing; Bosch, Marc; Schap, TusaRebecca; Khanna, Nitin; Ebert, David S.; Boushey, Carol J.; Delp, Edward J.

    2011-03-01

    Accurate methods and tools to assess food and nutrient intake are essential for the association between diet and health. Preliminary studies have indicated that the use of a mobile device with a built-in camera to obtain images of the food consumed may provide a less burdensome and more accurate method for dietary assessment. We are developing methods to identify food items using a single image acquired from the mobile device. Our goal is to automatically determine the regions in an image where a particular food is located (segmentation) and correctly identify the food type based on its features (classification or food labeling). Images of foods are segmented using Normalized Cuts based on intensity and color. Color and texture features are extracted from each segmented food region. Classification decisions for each segmented region are made using support vector machine methods. The segmentation of each food region is refined based on feedback from the output of classifier to provide more accurate estimation of the quantity of food consumed.

  16. Implementing the North American Industry Classification System at BLS.

    ERIC Educational Resources Information Center

    Walker, James A.; Murphy, John B.

    2001-01-01

    The United States, Canada, and Mexico developed the North American Industry Classification System, which captures new and emerging industries, uses a unified concept to define industries, and is a consistent and comparable tool for measuring the nations' economies. Despite initial conversion difficulties, the new system will be a more accurate way…

  17. Preprocessing remotely-sensed data for efficient analysis and classification

    SciTech Connect

    Kelly, P.M.; White, J.M.

    1993-02-01

    Interpreting remotely-sensed data typically requires expensive, specialized computing machinery capable of storing and manipulating large amounts of data quickly. In this paper, we present a method for accurately analyzing and categorizing remotely-sensed data on much smaller, less expensive platforms. Data size is reduced in such a way an efficient, interactive method of data classification.

  18. Role of electronmicroscopy in the classification of lupus nephritis.

    PubMed

    Pirani, C L; Olesnicky, L

    1982-07-01

    The role of transmission electronmicroscopy in the clarification of the pleomorphic lesions of lupus nephritis is reviewed. Emphasis is placed on the WHO classification of glomerular lesions and in the importance of electronmicroscopy, particularly the precise identification of the milder forms of glomerular involvement. This is essential for the proper therapeutic management of patients with lupus nephritis and to establish a more accurate prognosis.

  19. Phylogenetic tree construction based on 2D graphical representation

    NASA Astrophysics Data System (ADS)

    Liao, Bo; Shan, Xinzhou; Zhu, Wen; Li, Renfa

    2006-04-01

    A new approach based on the two-dimensional (2D) graphical representation of the whole genome sequence [Bo Liao, Chem. Phys. Lett., 401(2005) 196.] is proposed to analyze the phylogenetic relationships of genomes. The evolutionary distances are obtained through measuring the differences among the 2D curves. The fuzzy theory is used to construct phylogenetic tree. The phylogenetic relationships of H5N1 avian influenza virus illustrate the utility of our approach.

  20. Phylogenetic Interrelationships of Ginglymodian Fishes (Actinopterygii: Neopterygii)

    PubMed Central

    López-Arbarello, Adriana

    2012-01-01

    The Ginglymodi is one of the most common, though poorly understood groups of neopterygians, which includes gars, macrosemiiforms, and “semionotiforms.” In particular, the phylogenetic relationships between the widely distributed “semionotiforms,” and between them and other ginglymodians have been enigmatic. Here, the phylogenetic relationships between eight of the 11 “semionotiform” genera, five genera of living and fossil gars and three macrosemiid genera, are analysed through cladistic analysis, based on 90 morphological characters and 37 taxa, including 7 out-group taxa. The results of the analysis show that the Ginglymodi includes two main lineages: Lepisosteiformes and †Semionotiformes. The genera †Pliodetes, †Araripelepidotes, †Lepidotes, †Scheenstia, and †Isanichthys are lepisosteiforms, and not semionotiforms, as previously thought, and these taxa extend the stratigraphic range of the lineage leading to gars back up to the Early Jurassic. A monophyletic †Lepidotes is restricted to the Early Jurassic species, whereas the strongly tritoral species previously referred to †Lepidotes are referred to †Scheenstia. Other species previously referred to †Lepidotes represent other genera or new taxa. The macrosemiids are well nested within semionotiforms, together with †Semionotidae, here restricted to †Semionotus, and a new family including †Callipurbeckia n. gen. minor (previously referred to †Lepidotes), †Macrosemimimus, †Tlayuamichin, †Paralepidotus, and †Semiolepis. Due to the numerous taxonomic changes needed according to the phylogenetic analysis, this article also includes formal taxonomic definitions and diagnoses for all generic and higher taxa, which are new or modified. The study of Mesozoic ginglymodians led to confirm Patterson’s observation that these fishes show morphological affinities with both halecomorphs and teleosts. Therefore, the compilation of large data sets including the Mesozoic

  1. S1 gene-based phylogeny of infectious bronchitis virus: An attempt to harmonize virus classification.

    PubMed

    Valastro, Viviana; Holmes, Edward C; Britton, Paul; Fusaro, Alice; Jackwood, Mark W; Cattoli, Giovanni; Monne, Isabella

    2016-04-01

    Infectious bronchitis virus (IBV) is the causative agent of a highly contagious disease that results in severe economic losses to the global poultry industry. The virus exists in a wide variety of genetically distinct viral types, and both phylogenetic analysis and measures of pairwise similarity among nucleotide or amino acid sequences have been used to classify IBV strains. However, there is currently no consensus on the method by which IBV sequences should be compared, and heterogeneous genetic group designations that are inconsistent with phylogenetic history have been adopted, leading to the confusing coexistence of multiple genotyping schemes. Herein, we propose a simple and repeatable phylogeny-based classification system combined with an unambiguous and rationale lineage nomenclature for the assignment of IBV strains. By using complete nucleotide sequences of the S1 gene we determined the phylogenetic structure of IBV, which in turn allowed us to define 6 genotypes that together comprise 32 distinct viral lineages and a number of inter-lineage recombinants. Because of extensive rate variation among IBVs, we suggest that the inference of phylogenetic relationships alone represents a more appropriate criterion for sequence classification than pairwise sequence comparisons. The adoption of an internationally accepted viral nomenclature is crucial for future studies of IBV epidemiology and evolution, and the classification scheme presented here can be updated and revised novel S1 sequences should become available.

  2. Convolutional Neural Networks for patient-specific ECG classification.

    PubMed

    Kiranyaz, Serkan; Ince, Turker; Hamila, Ridha; Gabbouj, Moncef

    2015-01-01

    We propose a fast and accurate patient-specific electrocardiogram (ECG) classification and monitoring system using an adaptive implementation of 1D Convolutional Neural Networks (CNNs) that can fuse feature extraction and classification into a unified learner. In this way, a dedicated CNN will be trained for each patient by using relatively small common and patient-specific training data and thus it can also be used to classify long ECG records such as Holter registers in a fast and accurate manner. Alternatively, such a solution can conveniently be used for real-time ECG monitoring and early alert system on a light-weight wearable device. The experimental results demonstrate that the proposed system achieves a superior classification performance for the detection of ventricular ectopic beats (VEB) and supraventricular ectopic beats (SVEB).

  3. Applications of phylogenetics to solve practical problems in insect conservation.

    PubMed

    Buckley, Thomas R

    2016-12-01

    Phylogenetic approaches have much promise for the setting of conservation priorities and resource allocation. There has been significant development of analytical methods for the measurement of phylogenetic diversity within and among ecological communities as a way of setting conservation priorities. Application of these tools to insects has been low as has been the uptake by conservation managers. A critical reason for the lack of uptake includes the scarcity of detailed phylogenetic and species distribution data from much of insect diversity. Environmental DNA technologies offer a means for the high throughout collection of phylogenetic data across landscapes for conservation planning.

  4. Disentangling the phylogenetic and ecological components of spider phenotypic variation.

    PubMed

    Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

    2014-01-01

    An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

  5. treespace: statistical exploration of landscapes of phylogenetic trees.

    PubMed

    Jombart, Thibaut; Kendall, Michelle; Almagro-Garcia, Jacob; Colijn, Caroline

    2017-04-04

    The increasing availability of large genomic datasets as well as the advent of Bayesian phylogenetics facilitate the investigation of phylogenetic incongruence, which can result in the impossibility of representing phylogenetic relationships using a single tree. While sometimes considered as a nuisance, phylogenetic incongruence can also reflect meaningful biological processes as well as relevant statistical uncertainty, both of which can yield valuable insights in evolutionary studies. We introduce a new tool for investigating phylogenetic incongruence through the exploration of phylogenetic tree landscapes. Our approach, implemented in the R package treespace, combines tree metrics and multivariate analysis to provide low dimensional representations of the topological variability in a set of trees, which can be used for identifying clusters of similar trees and group-specific consensus phylogenies. treespace also provides a user-friendly web interface for interactive data analysis. treespace is integrated alongside existing standards for phylogenetics and is easily accessible through a web interface. It fills a gap in the current phylogenetics toolbox in R and will facilitate the investigation of phylogenetic results. This article is protected by copyright. All rights reserved.

  6. The rapidly changing landscape of insect phylogenetics.

    PubMed

    Maddison, David R

    2016-12-01

    Insect phylogenetics is being profoundly changed by many innovations. Although rapid developments in genomics have center stage, key progress has been made in phenomics, field and museum science, digital databases and pipelines, analytical tools, and the culture of science. The importance of these methodological and cultural changes to the pace of inference of the hexapod Tree of Life is discussed. The innovations have the potential, when synthesized and mobilized in ways as yet unforeseen, to shine light on the million or more clades in insects, and infer their composition with confidence. There are many challenges to overcome before insects can enter the 'phylocognisant age', but because of the promise of genomics, phenomics, and informatics, that is now an imaginable future.

  7. Tanglegrams: a Reduction Tool for Mathematical Phylogenetics.

    PubMed

    Matsen, Frederick; Billey, Sara; Kas, Arnold; Konvalinka, Matjaz

    2016-10-03

    Many discrete mathematics problems in phylogenetics are defined in terms of the relative labeling of pairsof leaf-labeled trees. These relative labelings are naturally formalized as tanglegrams, which have previously been an object of study in coevolutionary analysis. Although there has been considerable work on planar drawings of tanglegrams, they have not been fully explored as combinatorial objects until recently. In this paper, we describe how many discrete mathematical questions on trees "factor" through a problem on tanglegrams, and how understanding that factoring can simplify analysis. Depending on the problem, it may be useful to consider a unordered version of tanglegrams, and/or their unrooted counterparts. For all of these definitions, we show how the isomorphism types of tanglegrams can be understood in terms of double cosets of the symmetric group, and we investigate their automorphisms. Understanding tanglegrams better will isolate the distinct problems on leaf-labeled pairs of trees and reveal natural symmetries of spaces associated with such problems.

  8. Zika Virus: Emergence, Phylogenetics, Challenges, and Opportunities.

    PubMed

    Rajah, Maaran M; Pardy, Ryan D; Condotta, Stephanie A; Richer, Martin J; Sagan, Selena M

    2016-11-11

    Zika virus (ZIKV) is an emerging arthropod-borne pathogen that has recently gained notoriety due to its rapid and ongoing geographic expansion and its novel association with neurological complications. Reports of ZIKV-associated Guillain-Barré syndrome as well as fetal microcephaly place emphasis on the need to develop preventative measures and therapeutics to combat ZIKV infection. Thus, it is imperative that models to study ZIKV replication and pathogenesis and the immune response are developed in conjunction with integrated vector control strategies to mount an efficient response to the pandemic. This paper summarizes the current state of knowledge on ZIKV, including the clinical features, phylogenetic analyses, pathogenesis, and the immune response to infection. Potential challenges in developing diagnostic tools, treatment, and prevention strategies are also discussed.

  9. Dating human cultural capacity using phylogenetic principles

    PubMed Central

    Lind, J.; Lindenfors, P.; Ghirlanda, S.; Lidén, K.; Enquist, M.

    2013-01-01

    Humans have genetically based unique abilities making complex culture possible; an assemblage of traits which we term “cultural capacity”. The age of this capacity has for long been subject to controversy. We apply phylogenetic principles to date this capacity, integrating evidence from archaeology, genetics, paleoanthropology, and linguistics. We show that cultural capacity is older than the first split in the modern human lineage, and at least 170,000 years old, based on data on hyoid bone morphology, FOXP2 alleles, agreement between genetic and language trees, fire use, burials, and the early appearance of tools comparable to those of modern hunter-gatherers. We cannot exclude that Neanderthals had cultural capacity some 500,000 years ago. A capacity for complex culture, therefore, must have existed before complex culture itself. It may even originated long before. This seeming paradox is resolved by theoretical models suggesting that cultural evolution is exceedingly slow in its initial stages. PMID:23648831

  10. Dating human cultural capacity using phylogenetic principles.

    PubMed

    Lind, J; Lindenfors, P; Ghirlanda, S; Lidén, K; Enquist, M

    2013-01-01

    Humans have genetically based unique abilities making complex culture possible; an assemblage of traits which we term "cultural capacity". The age of this capacity has for long been subject to controversy. We apply phylogenetic principles to date this capacity, integrating evidence from archaeology, genetics, paleoanthropology, and linguistics. We show that cultural capacity is older than the first split in the modern human lineage, and at least 170,000 years old, based on data on hyoid bone morphology, FOXP2 alleles, agreement between genetic and language trees, fire use, burials, and the early appearance of tools comparable to those of modern hunter-gatherers. We cannot exclude that Neanderthals had cultural capacity some 500,000 years ago. A capacity for complex culture, therefore, must have existed before complex culture itself. It may even originated long before. This seeming paradox is resolved by theoretical models suggesting that cultural evolution is exceedingly slow in its initial stages.

  11. Commission 45: Spectral Classification

    NASA Astrophysics Data System (ADS)

    Giridhar, Sunetra; Gray, Richard O.; Corbally, Christopher J.; Bailer-Jones, Coryn A. L.; Eyer, Laurent; Irwin, Michael J.; Kirkpatrick, J. Davy; Majewski, Steven; Minniti, Dante; Nordström, Birgitta

    This report gives an update of developments (since the last General Assembly at Prague) in the areas that are of relevance to the commission. In addition to numerous papers, a new monograph entitled Stellar Spectral Classification with Richard Gray and Chris Corbally as leading authors will be published by Princeton University Press as part of their Princeton Series in Astrophysics in April 2009. This book is an up-to-date and encyclopedic review of stellar spectral classification across the H-R diagram, including the traditional MK system in the blue-violet, recent extensions into the ultraviolet and infrared, the newly defined L-type and T-type spectral classes, as well as spectral classification of carbon stars, S-type stars, white dwarfs, novae, supernovae and Wolf-Rayet stars.

  12. Information gathering for CLP classification.

    PubMed

    Marcello, Ida; Giordano, Felice; Costamagna, Francesca Marina

    2011-01-01

    Regulation 1272/2008 includes provisions for two types of classification: harmonised classification and self-classification. The harmonised classification of substances is decided at Community level and a list of harmonised classifications is included in the Annex VI of the classification, labelling and packaging Regulation (CLP). If a chemical substance is not included in the harmonised classification list it must be self-classified, based on available information, according to the requirements of Annex I of the CLP Regulation. CLP appoints that the harmonised classification will be performed for carcinogenic, mutagenic or toxic to reproduction substances (CMR substances) and for respiratory sensitisers category 1 and for other hazard classes on a case-by-case basis. The first step of classification is the gathering of available and relevant information. This paper presents the procedure for gathering information and to obtain data. The data quality is also discussed.

  13. A New Classification Based on the Kaban's Modification for Surgical Management of Craniofacial Microsomia

    PubMed Central

    Madrid, Jose Rolando Prada; Montealegre, Giovanni; Gomez, Viviana

    2010-01-01

    In medicine, classifications are designed to describe accurately and reliably all anatomic and structural components, establish a prognosis, and guide a given treatment. Classifications should be useful in a universal way to facilitate communication between health professionals and to formulate management protocols. In many situations and particularly with craniofacial microsomia, there have been many different classifications that do not achieve this goal. In fact, when there are so many classifications, one can conclude that there is not a clear one that accomplishes all these ends and defines a treatment protocol. It is our intent to present a new classification based on the Pruzansky's classification, later modified by Kaban, to determine treatment protocols based on the degree of osseous deficiency present in the body, ramus, and temporomandibular joint. Different mandibular defects are presented in two patients with craniofacial microsomia type III and IV according to our classification with the corresponding management proposed for each type and adequate functional results. PMID:22110812

  14. Ensemble polarimetric SAR image classification based on contextual sparse representation

    NASA Astrophysics Data System (ADS)

    Zhang, Lamei; Wang, Xiao; Zou, Bin; Qiao, Zhijun

    2016-05-01

    Polarimetric SAR image interpretation has become one of the most interesting topics, in which the construction of the reasonable and effective technique of image classification is of key importance. Sparse representation represents the data using the most succinct sparse atoms of the over-complete dictionary and the advantages of sparse representation also have been confirmed in the field of PolSAR classification. However, it is not perfect, like the ordinary classifier, at different aspects. So ensemble learning is introduced to improve the issue, which makes a plurality of different learners training and obtained the integrated results by combining the individual learner to get more accurate and ideal learning results. Therefore, this paper presents a polarimetric SAR image classification method based on the ensemble learning of sparse representation to achieve the optimal classification.

  15. Land Cover Classification Using ALOS Imagery For Penang, Malaysia

    NASA Astrophysics Data System (ADS)

    Sim, C. K.; Abdullah, K.; MatJafri, M. Z.; Lim, H. S.

    2014-02-01

    This paper presents the potential of integrating optical and radar remote sensing data to improve automatic land cover mapping. The analysis involved standard image processing, and consists of spectral signature extraction and application of a statistical decision rule to identify land cover categories. A maximum likelihood classifier is utilized to determine different land cover categories. Ground reference data from sites throughout the study area are collected for training and validation. The land cover information was extracted from the digital data using PCI Geomatica 10.3.2 software package. The variations in classification accuracy due to a number of radar imaging processing techniques are studied. The relationship between the processing window and the land classification is also investigated. The classification accuracies from the optical and radar feature combinations are studied. Our research finds that fusion of radar and optical significantly improved classification accuracies. This study indicates that the land cover/use can be mapped accurately by using this approach.

  16. Classification of cardiac patient states using artificial neural networks

    PubMed Central

    Kannathal, N; Acharya, U Rajendra; Lim, Choo Min; Sadasivan, PK; Krishnan, SM

    2003-01-01

    Electrocardiogram (ECG) is a nonstationary signal; therefore, the disease indicators may occur at random in the time scale. This may require the patient be kept under observation for long intervals in the intensive care unit of hospitals for accurate diagnosis. The present study examined the classification of the states of patients with certain diseases in the intensive care unit using their ECG and an Artificial Neural Networks (ANN) classification system. The states were classified into normal, abnormal and life threatening. Seven significant features extracted from the ECG were fed as input parameters to the ANN for classification. Three neural network techniques, namely, back propagation, self-organizing maps and radial basis functions, were used for classification of the patient states. The ANN classifier in this case was observed to be correct in approximately 99% of the test cases. This result was further improved by taking 13 features of the ECG as input for the ANN classifier. PMID:19649222

  17. Identification of an Efficient Gene Expression Panel for Glioblastoma Classification

    PubMed Central

    Zelaya, Ivette; Laks, Dan R.; Zhao, Yining; Kawaguchi, Riki; Gao, Fuying; Kornblum, Harley I.; Coppola, Giovanni

    2016-01-01

    We present here a novel genetic algorithm-based random forest (GARF) modeling technique that enables a reduction in the complexity of large gene disease signatures to highly accurate, greatly simplified gene panels. When applied to 803 glioblastoma multiforme samples, this method allowed the 840-gene Verhaak et al. gene panel (the standard in the field) to be reduced to a 48-gene classifier, while retaining 90.91% classification accuracy, and outperforming the best available alternative methods. Additionally, using this approach we produced a 32-gene panel which allows for better consistency between RNA-seq and microarray-based classifications, improving cross-platform classification retention from 69.67% to 86.07%. A webpage producing these classifications is available at http://simplegbm.semel.ucla.edu. PMID:27855170

  18. [New WHO-classification of lung and pleural tumors].

    PubMed

    Wagenaar, S S

    1999-05-08

    A new classification of the World Health Organization (WHO) of lung and pleural tumours will be published presently. Compared with the previous edition of 1981 the changed parts more accurately reflect the available therapeutic choices and the prognostic characteristics of the different tumour types. The classification is based on conventional light-microscopical typing. Additional techniques (from histochemistry, immune histochemistry, electron microscopy and molecular biology) have not yet decisive influence on tumour typing. The dichotomy between small-cell and large-cell carcinomas is too simplistic, as the group of large-cell carcinomas is heterogeneous, and further differentiation leads to identification of tumour types with distinct therapeutic options and prognostic characteristics. There are new criteria for the classification of neuroendocrine tumours, such as the mitotic index. It is recommended to use the newly revised classification for diagnostic purposes, epidemiology and biologic studies.

  19. Land use/cover classification in the Brazilian Amazon using satellite images.

    PubMed

    Lu, Dengsheng; Batistella, Mateus; Li, Guiying; Moran, Emilio; Hetrick, Scott; Freitas, Corina da Costa; Dutra, Luciano Vieira; Sant'anna, Sidnei João Siqueira

    2012-09-01

    Land use/cover classification is one of the most important applications in remote sensing. However, mapping accurate land use/cover spatial distribution is a challenge, particularly in moist tropical regions, due to the complex biophysical environment and limitations of remote sensing data per se. This paper reviews experiments related to land use/cover classification in the Brazilian Amazon for a decade. Through comprehensive analysis of the classification results, it is concluded that spatial information inherent in remote sensing data plays an essential role in improving land use/cover classification. Incorporation of suitable textural images into multispectral bands and use of segmentation-based method are valuable ways to improve land use/cover classification, especially for high spatial resolution images. Data fusion of multi-resolution images within optical sensor data is vital for visual interpretation, but may not improve classification performance. In contrast, integration of optical and radar data did improve classification performance when the proper data fusion method was used. Of the classification algorithms available, the maximum likelihood classifier is still an important method for providing reasonably good accuracy, but nonparametric algorithms, such as classification tree analysis, has the potential to provide better results. However, they often require more time to achieve parametric optimization. Proper use of hierarchical-based methods is fundamental for developing accurate land use/cover classification, mainly from historical remotely sensed data.

  20. Land use/cover classification in the Brazilian Amazon using satellite images

    PubMed Central

    Lu, Dengsheng; Batistella, Mateus; Li, Guiying; Moran, Emilio; Hetrick, Scott; Freitas, Corina da Costa; Dutra, Luciano Vieira; Sant’Anna, Sidnei João Siqueira

    2013-01-01

    Land use/cover classification is one of the most important applications in remote sensing. However, mapping accurate land use/cover spatial distribution is a challenge, particularly in moist tropical regions, due to the complex biophysical environment and limitations of remote sensing data per se. This paper reviews experiments related to land use/cover classification in the Brazilian Amazon for a decade. Through comprehensive analysis of the classification results, it is concluded that spatial information inherent in remote sensing data plays an essential role in improving land use/cover classification. Incorporation of suitable textural images into multispectral bands and use of segmentation-based method are valuable ways to improve land use/cover classification, especially for high spatial resolution images. Data fusion of multi-resolution images within optical sensor data is vital for visual interpretation, but may not improve classification performance. In contrast, integration of optical and radar data did improve classification performance when the proper data fusion method was used. Of the classification algorithms available, the maximum likelihood classifier is still an important method for providing reasonably good accuracy, but nonparametric algorithms, such as classification tree analysis, has the potential to provide better results. However, they often require more time to achieve parametric optimization. Proper use of hierarchical-based methods is fundamental for developing accurate land use/cover classification, mainly from historical remotely sensed data. PMID:24353353

  1. The Complete Chloroplast Genome Sequences of Five Epimedium Species: Lights into Phylogenetic and Taxonomic Analyses

    PubMed Central

    Zhang, Yanjun; Du, Liuwen; Liu, Ao; Chen, Jianjun; Wu, Li; Hu, Weiming; Zhang, Wei; Kim, Kyunghee; Lee, Sang-Choon; Yang, Tae-Jin; Wang, Ying

    2016-01-01

    Epimedium L. is a phylogenetically and economically important genus in the family Berberidaceae. We here sequenced the complete chloroplast (cp) genomes of four Epimedium species using Illumina sequencing technology via a combination of de novo and reference-guided assembly, which was also the first comprehensive cp genome analysis on Epimedium combining the cp genome sequence of E. koreanum previously reported. The five Epimedium cp genomes exhibited typical quadripartite and circular structure that was rather conserved in genomic structure and the synteny of gene order. However, these cp genomes presented obvious variations at the boundaries of the four regions because of the expansion and contraction of the inverted repeat (IR) region and the single-copy (SC) boundary regions. The trnQ-UUG duplication occurred in the five Epimedium cp genomes, which was not found in the other basal eudicotyledons. The rapidly evolving cp genome regions were detected among the five cp genomes, as well as the difference of simple sequence repeats (SSR) and repeat sequence were identified. Phylogenetic relationships among the five Epimedium species based on their cp genomes showed accordance with the updated system of the genus on the whole, but reminded that the evolutionary relationships and the divisions of the genus need further investigation applying more evidences. The availability of these cp genomes provided valuable genetic information for accurately identifying species, taxonomy and phylogenetic resolution and evolution of Epimedium, and assist in exploration and utilization of Epimedium plants. PMID:27014326

  2. morePhyML: improving the phylogenetic tree space exploration with PhyML 3.

    PubMed

    Criscuolo, Alexis

    2011-12-01

    PhyML is a widely used Maximum Likelihood (ML) phylogenetic tree inference software based on a standard hill-climbing method. Starting from an initial tree, the version 3 of PhyML explores the tree space by using "Nearest Neighbor Interchange" (NNI) or "Subtree Pruning and Regrafting" (SPR) tree swapping techniques in order to find the ML phylogenetic tree. NNI-based local searches are fast but can often get trapped in local optima, whereas it is expected that the larger (but slower to cover) SPR-based neighborhoods will lead to trees with higher likelihood. Here, I verify that PhyML infers more likely trees with SPRs than with NNIs in almost all cases. However, I also show that the SPR-based local search of PhyML often does not succeed at locating the ML tree. To improve the tree space exploration, I deliver a script, named morePhyML, which allows escaping from local optima by performing character reweighting. This ML tree search strategy, named ratchet, often leads to higher likelihood estimates. Based on the analysis of a large number of amino acid and nucleotide data, I show that morePhyML allows inferring more accurate phylogenetic trees than several other recently developed ML tree inference softwares in many cases.

  3. Multi-locus phylogenetic analysis reveals the pattern and tempo of bony fish evolution

    PubMed Central

    Broughton, Richard E.; Betancur-R., Ricardo; Li, Chenhong; Arratia, Gloria; Ortí, Guillermo

    2013-01-01

    Over half of all vertebrates are “fishes”, which exhibit enormous diversity in morphology, physiology, behavior, reproductive biology, and ecology. Investigation of fundamental areas of vertebrate biology depend critically on a robust phylogeny of fishes, yet evolutionary relationships among the major actinopterygian and sarcopterygian lineages have not been conclusively resolved. Although a consensus phylogeny of teleosts has been emerging recently, it has been based on analyses of various subsets of actinopterygian taxa, but not on a full sample of all bony fishes. Here we conducted a comprehensive phylogenetic study on a broad taxonomic sample of 61 actinopterygian and sarcopterygian lineages (with a chondrichthyan outgroup) using a molecular data set of 21 independent loci. These data yielded a resolved phylogenetic hypothesis for extant Osteichthyes, including 1) reciprocally monophyletic Sarcopterygii and Actinopterygii, as currently understood, with polypteriforms as the first diverging lineage within Actinopterygii; 2) a monophyletic group containing gars and bowfin (= Holostei) as sister group to teleosts; and 3) the earliest diverging lineage among teleosts being Elopomorpha, rather than Osteoglossomorpha. Relaxed-clock dating analysis employing a set of 24 newly applied fossil calibrations reveals divergence times that are more consistent with paleontological estimates than previous studies. Establishing a new phylogenetic pattern with accurate divergence dates for bony fishes illustrates several areas where the fossil record is incomplete and provides critical new insights on diversification of this important vertebrate group. PMID:23788273

  4. Hybrid Classification of Pulmonary Nodules

    NASA Astrophysics Data System (ADS)

    Lee, S. L. A.; Kouzani, A. Z.; Hu, E. J.

    Automated classification of lung nodules is challenging because of the variation in shape and size of lung nodules, as well as their associated differences in their images. Ensemble based learners have demonstrated the potentialof good performance. Random forests are employed for pulmonary nodule classification where each tree in the forest produces a classification decision, and an integrated output is calculated. A classification aided by clustering approach is proposed to improve the lung nodule classification performance. Three experiments are performed using the LIDC lung image database of 32 cases. The classification performance and execution times are presented and discussed.

  5. Consistency between molecular phylogeny and morphological classification of the Salix matsudana Koidz. complex (Salicaceae).

    PubMed

    Du, S H; Wang, Z S; Li, Y X; Wang, D S; Zhang, J G

    2015-07-31

    The morphological species concept is based on morpho-logical traits, which are often subject to subjectivity or artifact. Molecular evidence is needed to test the reliability of morphological classification of taxa that are controversial and to provide appropriate taxonomic de-limitation. In this study, we used 15 single-copy nuclear loci and 2 chloroplast fragments to verify the morphological classification of the Salix matsudana Koidz. complex using phylogenetic approaches. Complete sequence alignment showed slight diversification in nuclear sequences and no variety in chloroplast DNA fragments. Phylogenetic trees revealed a monophyletic group consisting of all individuals of S. matsudana and 2 clades within this group, with a 100% bootstrap support value and 1.00 posterior probability. The topology of the phylogenetic trees was highly consistent with the morphological classification of the S. matsudana complex. Verifying the genetic background of these classification units based on remarkable morphological differences will provide a foundation for future studies of Salix and the breeding of new horticultural varieties.

  6. Conservation biology of Malagasy strepsirhines: a phylogenetic approach.

    PubMed

    Lehman, Shawn M

    2006-06-01

    The phylogenetic diversity of extant lemurs represents one of the most important but least studied aspects of the conservation biology of primates. The phylogenetic diversity of a species is inversely proportional to the relative number and closeness of its phylogenetic relatives. Phylogenetic diversity can then be used to determine conservation priorities for specific biogeographic regions. Although Malagasy strepsirhines represent the highest phylogenetic diversity among primates at the global level, there are few phylogenetic data on species-specific and regional conservation plans for lemurs in Madagascar. Therefore, in this paper the following questions are addressed for extant lemurs: 1) how does the measure of taxonomic uniqueness used by Mittermeier et al. (1992 Lemurs of Madagascar; Gland, Switzerland: IUCN) equate with an index of phylogenetic diversity, 2) what are the regional conservation priorities based on analyses of phylogenetic diversity in extant lemurs, and 3) what conservation recommendations can be made based on analyses of phylogenetic diversity in lemurs? Taxonomic endemicity standardized weight (TESW) indices of phylogenetic diversity were used to determine the evolutionary component of biodiversity and to prioritize regions for conserving lemur taxa. TESW refers to the standardization of phylogenetic diversity indices for widespread taxa and endemicity of species. The phylogenetic data came from recent genetic studies of Malagasy strepsirhines at the species level. Lemur species were assigned as being either present or absent in six biogeographic regions. TESW indices were combined with data on lemur complementarity and protected areas to assign conservation priorities at the regional level. Although there were no overall differences between taxonomic ranks and phylogenetic rankings, there were significant differences for the top-ranked taxa. The phylogenetic component of lemur diversity is greatest for Daubentonia madagascariensis

  7. Evidence for phylogenetic correlation of plant–AMF assemblages?

    PubMed Central

    Montesinos-Navarro, A.; Segarra-Moragues, J. G.; Valiente-Banuet, A.; Verdú, M.

    2015-01-01

    Background and Aims Specificity in biotic interactions is mediated' by functional traits inducing shifts in the community species composition. Functional traits are often evolutionarily conserved, resulting in closely related species tending to interact with similar species. This tendency may initially shape the phylogenetic composition of coexisting guilds, but other intraguild ecological processes may either blur or promote the mirroring of the phylogenetic compositions between guilds. The roles of intra- and interguild interactions in shaping the phylogenetic community composition are largely unknown, beyond the mere selectivity in the interguild interactions. Plant facilitation is a phylogenetically structured species-specific process involving interactions not only between the same guild of plants, but also between plants and other guilds such as arbuscular mycorrhizal fungi (AMF). In this study it is hypothesized that reciprocal plant–AMF interactions will leave an interdependent phylogenetic signal in the community composition of both plants and AMF. Methods A correlation was used to test for a relationship between the phylogenetic composition of plant and AMF assemblages in a patchy xeric shrubland environment shaped by plant facilitation. In addition, a null model was used to test whether this correlation can be solely explained by selectivity in plant–AMF interactions. Key Results A significant correlation was observed between the phylogenetic composition of plant and AMF assemblages. Plant phylogenetic composition in a patch was related to the predominance of plant species with high nursery quality that can influence the community assembly. AMF phylogenetic composition was related to the AMF phylogenetic diversity in each patch. Conclusions This study shows that shifts in the phylogenetic composition of plants and AMF assemblages do not occur independently. It is suggested that besides selectivity in plant–AMF interactions, inter-related succession

  8. Flotation classification of ultrafine particles -- A novel classification approach

    SciTech Connect

    Qiu Guanzhou; Luo Lin; Hu Yuehua; Xu Jin; Wang Dianzuo

    1995-12-31

    This paper introduces a novel classification approach named the flotation classification approach which works by controlling interactions between particles. It differs considerably from the conventional classification processes operating on mechanical forces. In the present test, the micro-bubble flotation technology is grafted onto hydro-classification. Selective aggregation and dispersion of ultrafine particles are achieved through governing the interactions in the classification process. A series of laboratory classification tests for {minus}44 gm kaolin have been conducted on a classification column. As a result, about 92% recovery for minus 2 {micro}m size fraction Kaolin in the final product is obtained. In addition, two criteria for the classification are set up. Finally, a principle of classifying and controlling the interactions between particles is discussed in terms of surface thermodynamics and hydrodynamics.

  9. Phylogenetic relationship among horseshoe crab species: effect of substitution models on phylogenetic analyses.

    PubMed

    Xia, X

    2000-03-01

    The horseshoe crabs, known as living fossils, have maintained their morphology almost unchanged for the past 150 million years. The little morphological differentiation among horseshoe crab lineages has resulted in substantial controversy concerning the phylogenetic relationship among the extant species of horseshoe crabs, especially among the three species in the Indo-Pacific region. Previous studies suggest that the three species constitute a phylogenetically unresolvable trichotomy, the result of a cladogenetic process leading to the formation of all three Indo-Pacific species in a short geological time. Data from two mitochondrial genes (for 16S ribosomal rRNA and cytochrome oxidase subunit I) and one nuclear gene (for coagulogen) in the four species of horseshoe crabs and outgroup species were used in a phylogenetic analysis with various substitution models. All three genes yield the same tree topology, with Tachypleus-gigas and Carcinoscorpius-rotundicauda grouped together as a monophyletic taxon. This topology is significantly better than all the alternatives when evaluated with the RELL (resampling estimated log-likelihood) method.

  10. Indigenous vs. International soil classification system in Ohangwena Region, Namibia

    NASA Astrophysics Data System (ADS)

    Prudat, Brice; Kuhn, Nikolaus J.; Bloemertz, Lena

    2014-05-01

    This poster will present soil diversity in North-Central Namibia, with a focus on soil fertility. It aims to show the correspondence and differences between an international and an indigenous soil classification system. International classifications, like World Reference Base for Soil Resources (WRB), are very helpful tools to share information in soil science and agriculture. However, these classification are meaningful for large scale soil processes understanding but local specificities cannot be understood and differentiated. On the other hand, knowledge that farmers have on cultivated soils is very accurate and adapted to local agricultural use. However, their knowledge should be properly defined and translated to be used by scientists. Once their knowledge can be read by scientists, it provides very powerful tools for soil mapping and characterization. Analysis so far has focused on the area of Ondobe (30 km West from Eenhana, Ohangwena region). This area is located between two major systems, the Cuvelai floodplain to the West and the Kalahari Woodlands to the East. While all the cultivated soils from this region would be classified as Arenosols (WRB), the local classification differentiates five major soil types (Omutunda, Ehenge, Omufitu, Elondo, Ehenene). In WRB classification, these soils correspond, roughly, to specific Arenosols, respectively Hypereutric, Albic, Haplic, Rubic and Salic Arenosols. Further work will evaluate, the local variation inside each indigenous soil types. Hierarchical classification using soil field descriptors will be used to create statistic soil groups. These new groups will then be compared to each classification system.

  11. Equivalent Diagnostic Classification Models

    ERIC Educational Resources Information Center

    Maris, Gunter; Bechger, Timo

    2009-01-01

    Rupp and Templin (2008) do a good job at describing the ever expanding landscape of Diagnostic Classification Models (DCM). In many ways, their review article clearly points to some of the questions that need to be answered before DCMs can become part of the psychometric practitioners toolkit. Apart from the issues mentioned in this article that…

  12. Shark Teeth Classification

    ERIC Educational Resources Information Center

    Brown, Tom; Creel, Sally; Lee, Velda

    2009-01-01

    On a recent autumn afternoon at Harmony Leland Elementary in Mableton, Georgia, students in a fifth-grade science class investigated the essential process of classification--the act of putting things into groups according to some common characteristics or attributes. While they may have honed these skills earlier in the week by grouping their own…

  13. The Classification Conundrum.

    ERIC Educational Resources Information Center

    Granger, Charles R.

    1983-01-01

    Argues against the five-kingdom scheme of classification as using inconsistent criteria, ending up with divisions that are forced, not natural. Advocates an approach using cell type/complexity and modification of the metabolic machinery, recommending the five-kingdom scheme as starting point for class discussion on taxonomy and its conceptual…

  14. Improving Student Question Classification

    ERIC Educational Resources Information Center

    Heiner, Cecily; Zachary, Joseph L.

    2009-01-01

    Students in introductory programming classes often articulate their questions and information needs incompletely. Consequently, the automatic classification of student questions to provide automated tutorial responses is a challenging problem. This paper analyzes 411 questions from an introductory Java programming course by reducing the natural…

  15. Soil Classification and Treatment.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This instructional unit was designed to enable students, primarily at the secondary level, to (1) classify soils according to current capability classifications of the Soil Conservation Service, (2) select treatments needed for a given soil class according to current recommendations provided by the Soil Conservation Service, and (3) interpret a…

  16. The Biglan Classification Revisited.

    ERIC Educational Resources Information Center

    Stoecker, Judith L.

    This study replicated previous research that tested the validity of A. Biglan's classification scheme, a theoretical framework for empirically examining the differences among academic disciplines and classifying them according to three dimensions (hard-soft, pure-applied, life-nonlife). In addition, new data were used to attempt continued…

  17. Accurate pointing of tungsten welding electrodes

    NASA Technical Reports Server (NTRS)

    Ziegelmeier, P.

    1971-01-01

    Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

  18. Student Interpretations of Phylogenetic Trees in an Introductory Biology Course

    ERIC Educational Resources Information Center

    Dees, Jonathan; Momsen, Jennifer L.; Niemi, Jarad; Montplaisir, Lisa

    2014-01-01

    Phylogenetic trees are widely used visual representations in the biological sciences and the most important visual representations in evolutionary biology. Therefore, phylogenetic trees have also become an important component of biology education. We sought to characterize reasoning used by introductory biology students in interpreting taxa…

  19. Efficient Fingercode Classification

    NASA Astrophysics Data System (ADS)

    Sun, Hong-Wei; Law, Kwok-Yan; Gollmann, Dieter; Chung, Siu-Leung; Li, Jian-Bin; Sun, Jia-Guang

    In this paper, we present an efficient fingerprint classification algorithm which is an essential component in many critical security application systems e. g. systems in the e-government and e-finance domains. Fingerprint identification is one of the most important security requirements in homeland security systems such as personnel screening and anti-money laundering. The problem of fingerprint identification involves searching (matching) the fingerprint of a person against each of the fingerprints of all registered persons. To enhance performance and reliability, a common approach is to reduce the search space by firstly classifying the fingerprints and then performing the search in the respective class. Jain et al. proposed a fingerprint classification algorithm based on a two-stage classifier, which uses a K-nearest neighbor classifier in its first stage. The fingerprint classification algorithm is based on the fingercode representation which is an encoding of fingerprints that has been demonstrated to be an effective fingerprint biometric scheme because of its ability to capture both local and global details in a fingerprint image. We enhance this approach by improving the efficiency of the K-nearest neighbor classifier for fingercode-based fingerprint classification. Our research firstly investigates the various fast search algorithms in vector quantization (VQ) and the potential application in fingerprint classification, and then proposes two efficient algorithms based on the pyramid-based search algorithms in VQ. Experimental results on DB1 of FVC 2004 demonstrate that our algorithms can outperform the full search algorithm and the original pyramid-based search algorithms in terms of computational efficiency without sacrificing accuracy.

  20. Phylogenetic framework and molecular signatures for the main clades of the phylum Actinobacteria.

    PubMed

    Gao, Beile; Gupta, Radhey S

    2012-03-01

    The phylum Actinobacteria harbors many important human pathogens and also provides one of the richest sources of natural products, including numerous antibiotics and other compounds of biotechnological interest. Thus, a reliable phylogeny of this large phylum and the means to accurately identify its different constituent groups are of much interest. Detailed phylogenetic and comparative analyses of >150 actinobacterial genomes reported here form the basis for achieving these objectives. In phylogenetic trees based upon 35 conserved proteins, most of the main groups of Actinobacteria as well as a number of their superageneric clades are resolved. We also describe large numbers of molecular markers consisting of conserved signature indels in protein sequences and whole proteins that are specific for either all Actinobacteria or their different clades (viz., orders, families, genera, and subgenera) at various taxonomic levels. These signatures independently support the existence of different phylogenetic clades, and based upon them, it is now possible to delimit the phylum Actinobacteria (excluding Coriobacteriia) and most of its major groups in clear molecular terms. The species distribution patterns of these markers also provide important information regarding the interrelationships among different main orders of Actinobacteria. The identified molecular markers, in addition to enabling the development of a stable and reliable phylogenetic framework for this phylum, also provide novel and powerful means for the identification of different groups of Actinobacteria in diverse environments. Genetic and biochemical studies on these Actinobacteria-specific markers should lead to the discovery of novel biochemical and/or other properties that are unique to different groups of Actinobacteria.

  1. Phylogenetic Framework and Molecular Signatures for the Main Clades of the Phylum Actinobacteria

    PubMed Central

    Gao, Beile

    2012-01-01

    Summary: The phylum Actinobacteria harbors many important human pathogens and also provides one of the richest sources of natural products, including numerous antibiotics and other compounds of biotechnological interest. Thus, a reliable phylogeny of this large phylum and the means to accurately identify its different constituent groups are of much interest. Detailed phylogenetic and comparative analyses of >150 actinobacterial genomes reported here form the basis for achieving these objectives. In phylogenetic trees based upon 35 conserved proteins, most of the main groups of Actinobacteria as well as a number of their superageneric clades are resolved. We also describe large numbers of molecular markers consisting of conserved signature indels in protein sequences and whole proteins that are specific for either all Actinobacteria or their different clades (viz., orders, families, genera, and subgenera) at various taxonomic levels. These signatures independently support the existence of different phylogenetic clades, and based upon them, it is now possible to delimit the phylum Actinobacteria (excluding Coriobacteriia) and most of its major groups in clear molecular terms. The species distribution patterns of these markers also provide important information regarding the interrelationships among different main orders of Actinobacteria. The identified molecular markers, in addition to enabling the development of a stable and reliable phylogenetic framework for this phylum, also provide novel and powerful means for the identification of different groups of Actinobacteria in diverse environments. Genetic and biochemical studies on these Actinobacteria-specific markers should lead to the discovery of novel biochemical and/or other properties that are unique to different groups of Actinobacteria. PMID:22390973

  2. Site-specific time heterogeneity of the substitution process and its impact on phylogenetic inference

    PubMed Central

    2011-01-01

    Background Model violations constitute the major limitation in inferring accurate phylogenies. Characterizing properties of the data that are not being correctly handled by current models is therefore of prime importance. One of the properties of protein evolution is the variation of the relative rate of substitutions across sites and over time, the latter is the phenomenon called heterotachy. Its effect on phylogenetic inference has recently obtained considerable attention, which led to the development of new models of sequence evolution. However, thus far focus has been on the quantitative heterogeneity of the evolutionary process, thereby overlooking more qualitative variations. Results We studied the importance of variation of the site-specific amino-acid substitution process over time and its possible impact on phylogenetic inference. We used the CAT model to define an infinite mixture of substitution processes characterized by equilibrium frequencies over the twenty amino acids, a useful proxy for qualitatively estimating the evolutionary process. Using two large datasets, we show that qualitative changes in site-specific substitution properties over time occurred significantly. To test whether this unaccounted qualitative variation can lead to an erroneous phylogenetic tree, we analyzed a concatenation of mitochondrial proteins in which Cnidaria and Porifera were erroneously grouped. The progressive removal of the sites with the most heterogeneous CAT profiles across clades led to the recovery of the monophyly of Eumetazoa (Cnidaria+Bilateria), suggesting that this heterogeneity can negatively influence phylogenetic inference. Conclusion The time-heterogeneity of the amino-acid replacement process is therefore an important evolutionary aspect that should be incorporated in future models of sequence change. PMID:21235782

  3. [Classification of primary bone tumors].

    PubMed

    Dominok, G W; Frege, J

    1986-01-01

    An expanded classification for bone tumors is presented based on the well known international classification as well as earlier systems. The current status and future trends in this area are discussed.

  4. Automatic Classification in Information Retrieval.

    ERIC Educational Resources Information Center

    van Rijsbergen, C. J.

    1978-01-01

    Addresses the application of automatic classification methods to the problems associated with computerized document retrieval. Different kinds of classifications are described, and both document and term clustering methods are discussed. References and notes are provided. (Author/JD)

  5. Classification: Purposes, Principles, Progress, Prospects

    ERIC Educational Resources Information Center

    Sokal, Robert R.

    1974-01-01

    Clustering and other new techniques have changed classificatory principles and practice in many sciences. Discussed are defintions, purposes of classification, principles of classification, and recent trends. (Author/RH)

  6. Open Reading Frame Phylogenetic Analysis on the Cloud

    PubMed Central

    2013-01-01

    Phylogenetic analysis has become essential in researching the evolutionary relationships between viruses. These relationships are depicted on phylogenetic trees, in which viruses are grouped based on sequence similarity. Viral evolutionary relationships are identified from open reading frames rather than from complete sequences. Recently, cloud computing has become popular for developing internet-based bioinformatics tools. Biocloud is an efficient, scalable, and robust bioinformatics computing service. In this paper, we propose a cloud-based open reading frame phylogenetic analysis service. The proposed service integrates the Hadoop framework, virtualization technology, and phylogenetic analysis methods to provide a high-availability, large-scale bioservice. In a case study, we analyze the phylogenetic relationships among Norovirus. Evolutionary relationships are elucidated by aligning different open reading frame sequences. The proposed platform correctly identifies the evolutionary relationships between members of Norovirus. PMID:23671843

  7. Plant DNA sequencing for phylogenetic analyses: from plants to sequences.

    PubMed

    Neves, Susana S; Forrest, Laura L

    2011-01-01

    DNA sequences are important sources of data for phylogenetic analysis. Nowadays, DNA sequencing is a routine technique in molecular biology laboratories. However, there are specific questions associated with project design and sequencing of plant samples for phylogenetic analysis, which may not be familiar to researchers starting in the field. This chapter gives an overview of methods and protocols involved in the sequencing of plant samples, including general recommendations on the selection of species/taxa and DNA regions to be sequenced, and field collection of plant samples. Protocols of plant sample preparation, DNA extraction, PCR and cloning, which are critical to the success of molecular phylogenetic projects, are described in detail. Common problems of sequencing (using the Sanger method) are also addressed. Possible applications of second-generation sequencing techniques in plant phylogenetics are briefly discussed. Finally, orientation on the preparation of sequence data for phylogenetic analyses and submission to public databases is also given.

  8. Free classification of American English dialects by native and non-native listeners

    PubMed Central

    Clopper, Cynthia G.; Bradlow, Ann R.

    2009-01-01

    Most second language acquisition research focuses on linguistic structures, and less research has examined the acquisition of sociolinguistic patterns. The current study explored the perceptual classification of regional dialects of American English by native and non-native listeners using a free classification task. Results revealed similar classification strategies for the native and non-native listeners. However, the native listeners were more accurate overall than the non-native listeners. In addition, the non-native listeners were less able to make use of constellations of cues to accurately classify the talkers by dialect. However, the non-native listeners were able to attend to cues that were either phonologically or sociolinguistically relevant in their native language. These results suggest that non-native listeners can use information in the speech signal to classify talkers by regional dialect, but that their lack of signal-independent cultural knowledge about variation in the second language leads to less accurate classification performance. PMID:20161400

  9. Novel Accurate Bacterial Discrimination by MALDI-Time-of-Flight MS Based on Ribosomal Proteins Coding in S10-spc-alpha Operon at Strain Level S10-GERMS

    NASA Astrophysics Data System (ADS)

    Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

    2013-08-01

    Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S 10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

  10. Reading List in Classification Theory.

    ERIC Educational Resources Information Center

    Richmond, Phyllis A.

    The reading list contains 180 references and serves as an introduction to classification research literature. While the list includes major viewpoints on basic work in the field of classification as well as related areas, it excludes critical literature. The major divisions of the reading list are: (1) Definition: What is Classification, (2)…

  11. Feedback about More Accurate versus Less Accurate Trials: Differential Effects on Self-Confidence and Activation

    ERIC Educational Resources Information Center

    Badami, Rokhsareh; VaezMousavi, Mohammad; Wulf, Gabriele; Namazizadeh, Mahdi

    2012-01-01

    One purpose of the present study was to examine whether self-confidence or anxiety would be differentially affected by feedback from more accurate rather than less accurate trials. The second purpose was to determine whether arousal variations (activation) would predict performance. On Day 1, participants performed a golf putting task under one of…

  12. Phylogenetic biodiversity assessment based on systematic nomenclature

    PubMed Central

    Crozier, Ross H; Dunnett, Lisa J; Agapow, Paul-Michael

    2007-01-01

    Biodiversity assessment demands objective measures, because ultimately conservation decisions must prioritize the use of limited resources for preserving taxa. The most general framework for the objective assessment of conservation worth are those that assess evolutionary distinctiveness, e.g. Genetic (Crozier 1992) and Phylogenetic Diversity (Faith 1992), and Evolutionary History (Nee & May 1997). These measures all attempt to assess the conservation worth of any scheme based on how much of the encompassing phylogeny of organisms is preserved. However, their general applicability is limited by the small proportion of taxa that have been reliably placed in a phylogeny. Given that phylogenizaton of many interesting taxa or important is unlikely to occur soon, we present a framework for using taxonomy as a reasonable surrogate for phylogeny. Combining this framework with exhaustive searches for combinations of sites containing maximal diversity, we provide a proof-of-concept for assessing conservation schemes for systematized but un-phylogenised taxa spread over a series of sites. This is illustrated with data from four studies, on North Queensland flightless insects (Yeates et al. 2002), ants from a Florida Transect (Lubertazzi & Tschinkel 2003), New England bog ants (Gotelli & Ellison 2002) and a simulated distribution of the known New Zealand Lepidosauria (Daugherty et al. 1994). The results support this approach, indicating that species, genus and site numbers predict evolutionary history, to a degree depending on the size of the data set. PMID:19325850

  13. Ultrastructure, biology, and phylogenetic relationships of kinorhyncha.

    PubMed

    Neuhaus, Birger; Higgins, Robert P

    2002-07-01

    The article summarizes current knowledge mainly about the (functional) morphology and ultrastructure, but also about the biology, development, and evolution of the Kinorhyncha. The Kinorhyncha are microscopic, bilaterally symmetrical, exclusively free-living, benthic, marine animals and ecologically part of the meiofauna. They occur throughout the world from the intertidal to the deep sea, generally in sediments but sometimes associated with plants or other animals. From adult stages 141 species are known, but 38 species have been described from juvenile stages. The trunk is arranged into 11 segments as evidenced by cuticular plates, sensory spots, setae or spines, nervous system, musculature, and subcuticular glands. The ultrastructure of several organ systems and the postembryonic development are known for very few species. Almost no data are available about the embryology and only a single gene has been sequenced for a single species. The phylogenetic relationships within Kinorhyncha are unresolved. Priapulida, Loricifera, and Kinorhyncha are grouped together as Scalidophora, but arguments are found for every possible sistergroup relationship within this taxon. The recently published Ecdysozoa hypothesis suggests a closer relationship of the Scalidophora, Nematoda, Nematomorpha, Tardigrada, Onychophora, and Arthropoda.

  14. An accurate method of extracting fat droplets in liver images for quantitative evaluation

    NASA Astrophysics Data System (ADS)

    Ishikawa, Masahiro; Kobayashi, Naoki; Komagata, Hideki; Shinoda, Kazuma; Yamaguchi, Masahiro; Abe, Tokiya; Hashiguchi, Akinori; Sakamoto, Michiie

    2015-03-01

    The steatosis in liver pathological tissue images is a promising indicator of nonalcoholic fatty liver disease (NAFLD) and the possible risk of hepatocellular carcinoma (HCC). The resulting values are also important for ensuring the automatic and accurate classification of HCC images, because the existence of many fat droplets is likely to create errors in quantifying the morphological features used in the process. In this study we propose a method that can automatically detect, and exclude regions with many fat droplets by using the feature values of colors, shapes and the arrangement of cell nuclei. We implement the method and confirm that it can accurately detect fat droplets and quantify the fat droplet ratio of actual images. This investigation also clarifies the effective characteristics that contribute to accurate detection.

  15. Application of COI Sequences in Studies of Phylogenetic Relationships Among 40 Apionidae Species

    PubMed Central

    Ptaszyńska, Aneta A.; Łętowski, Jacek; Gnat, Sebastian; Małek, Wanda

    2012-01-01

    The systematics of the family Apionidae, as well as the superfamily Curculionoidea, is currently in a state of flux. The comparative analyses of COI sequences from our studies shed some light on the systematics of these weevils. To study the relationship among the organisms of the family Apionidae, we determined the COI sequences of representatives of 23 species and 15 genera, i.e., Apion, Betulapion, Catapion, Ceratapion, Cyanapion, Eutrichapion, Exapion, Hemitrichapion, Holotrichapion, Ischnopterapion, Protapion, Pseudoperapion, Psudoprotapion, Pseudostenapion, and Stenopterapion. Then, they were compared with the COI sequences of 19 species and eight genera from GenBank (Aspidapion, Ceratapion, Exapion, Ischnopterapion, Lepidapion, Omphalapion, Oxystoma, and Protapion). The phylogenetic relationships inferred from molecular data are similar to the classification system developed by Alonso-Zarazaga and Lyal (1999), with some exceptions within the tribe Oxystomatini, and genera Ceratapion and Exapion. PMID:22934614

  16. Mayaro virus: complete nucleotide sequence and phylogenetic relationships with other alphaviruses.

    PubMed

    Lavergne, Anne; de Thoisy, Benoît; Lacoste, Vincent; Pascalis, Hervé; Pouliquen, Jean-François; Mercier, Véronique; Tolou, Hugues; Dussart, Philippe; Morvan, Jacques; Talarmin, Antoine; Kazanji, Mirdad

    2006-05-01

    Mayaro (MAY) virus is a member of the genus Alphavirus in the family Togaviridae. Alphaviruses are distributed throughout the world and cause a wide range of diseases in humans and animals. Here, we determined the complete nucleotide sequence of MAY from a viral strain isolated from a French Guianese patient. The deduced MAY genome was 11,429 nucleotides in length, excluding the 5' cap nucleotide and 3' poly(A) tail. Nucleotide and amino acid homologies, as well as phylogenetic analyses of the obtained sequence confirmed that MAY is not a recombinant virus and belongs to the Semliki Forest complex according to the antigenic complex classification. Furthermore, analyses based on the E1 region revealed that MAY is closely related to Una virus, the only other South American virus clustering with the Old World viruses. On the basis of our results and of the alphaviruses diversity and pathogenicity, we suggest that alphaviruses may have an Old World origin.

  17. Accurate Guitar Tuning by Cochlear Implant Musicians

    PubMed Central

    Lu, Thomas; Huang, Juan; Zeng, Fan-Gang

    2014-01-01

    Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task. PMID:24651081

  18. New model accurately predicts reformate composition

    SciTech Connect

    Ancheyta-Juarez, J.; Aguilar-Rodriguez, E. )

    1994-01-31

    Although naphtha reforming is a well-known process, the evolution of catalyst formulation, as well as new trends in gasoline specifications, have led to rapid evolution of the process, including: reactor design, regeneration mode, and operating conditions. Mathematical modeling of the reforming process is an increasingly important tool. It is fundamental to the proper design of new reactors and revamp of existing ones. Modeling can be used to optimize operating conditions, analyze the effects of process variables, and enhance unit performance. Instituto Mexicano del Petroleo has developed a model of the catalytic reforming process that accurately predicts reformate composition at the higher-severity conditions at which new reformers are being designed. The new AA model is more accurate than previous proposals because it takes into account the effects of temperature and pressure on the rate constants of each chemical reaction.

  19. Accurate colorimetric feedback for RGB LED clusters

    NASA Astrophysics Data System (ADS)

    Man, Kwong; Ashdown, Ian

    2006-08-01

    We present an empirical model of LED emission spectra that is applicable to both InGaN and AlInGaP high-flux LEDs, and which accurately predicts their relative spectral power distributions over a wide range of LED junction temperatures. We further demonstrate with laboratory measurements that changes in LED spectral power distribution with temperature can be accurately predicted with first- or second-order equations. This provides the basis for a real-time colorimetric feedback system for RGB LED clusters that can maintain the chromaticity of white light at constant intensity to within +/-0.003 Δuv over a range of 45 degrees Celsius, and to within 0.01 Δuv when dimmed over an intensity range of 10:1.

  20. Accurate guitar tuning by cochlear implant musicians.

    PubMed

    Lu, Thomas; Huang, Juan; Zeng, Fan-Gang

    2014-01-01

    Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼ 30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task.

  1. An Accurate, Simplified Model Intrabeam Scattering

    SciTech Connect

    Bane, Karl LF

    2002-05-23

    Beginning with the general Bjorken-Mtingwa solution for intrabeam scattering (IBS) we derive an accurate, greatly simplified model of IBS, valid for high energy beams in normal storage ring lattices. In addition, we show that, under the same conditions, a modified version of Piwinski's IBS formulation (where {eta}{sub x,y}{sup 2}/{beta}{sub x,y} has been replaced by {Eta}{sub x,y}) asymptotically approaches the result of Bjorken-Mtingwa.

  2. An accurate registration technique for distorted images

    NASA Technical Reports Server (NTRS)

    Delapena, Michele; Shaw, Richard A.; Linde, Peter; Dravins, Dainis

    1990-01-01

    Accurate registration of International Ultraviolet Explorer (IUE) images is crucial because the variability of the geometrical distortions that are introduced by the SEC-Vidicon cameras ensures that raw science images are never perfectly aligned with the Intensity Transfer Functions (ITFs) (i.e., graded floodlamp exposures that are used to linearize and normalize the camera response). A technique for precisely registering IUE images which uses a cross correlation of the fixed pattern that exists in all raw IUE images is described.

  3. On accurate determination of contact angle

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.

    1992-01-01

    Methods are proposed that exploit a microgravity environment to obtain highly accurate measurement of contact angle. These methods, which are based on our earlier mathematical results, do not require detailed measurement of a liquid free-surface, as they incorporate discontinuous or nearly-discontinuous behavior of the liquid bulk in certain container geometries. Physical testing is planned in the forthcoming IML-2 space flight and in related preparatory ground-based experiments.

  4. Fast Image Texture Classification Using Decision Trees

    NASA Technical Reports Server (NTRS)

    Thompson, David R.

    2011-01-01

    Texture analysis would permit improved autonomous, onboard science data interpretation for adaptive navigation, sampling, and downlink decisions. These analyses would assist with terrain analysis and instrument placement in both macroscopic and microscopic image data products. Unfortunately, most state-of-the-art texture analysis demands computationally expensive convolutions of filters involving many floating-point operations. This makes them infeasible for radiation- hardened computers and spaceflight hardware. A new method approximates traditional texture classification of each image pixel with a fast decision-tree classifier. The classifier uses image features derived from simple filtering operations involving integer arithmetic. The texture analysis method is therefore amenable to implementation on FPGA (field-programmable gate array) hardware. Image features based on the "integral image" transform produce descriptive and efficient texture descriptors. Training the decision tree on a set of training data yields a classification scheme that produces reasonable approximations of optimal "texton" analysis at a fraction of the computational cost. A decision-tree learning algorithm employing the traditional k-means criterion of inter-cluster variance is used to learn tree structure from training data. The result is an efficient and accurate summary of surface morphology in images. This work is an evolutionary advance that unites several previous algorithms (k-means clustering, integral images, decision trees) and applies them to a new problem domain (morphology analysis for autonomous science during remote exploration). Advantages include order-of-magnitude improvements in runtime, feasibility for FPGA hardware, and significant improvements in texture classification accuracy.

  5. Phylogenetic Relationships in Bupleurum (Apiaceae) Based on Nuclear Ribosomal DNA ITS Sequence Data

    PubMed Central

    NEVES, SUSANA S.; WATSON, MARK F.

    2004-01-01

    • Backgroud and Aims The genus Bupleurum has long been recognized as a natural group, but its infrageneric classification is controversial and has not yet been studied in the light of sequence data. • Methods Phylogenetic relationships among 32 species (35 taxa) of the genus Bupleurum were investigated by comparative sequencing of the ITS region of the 18–26S nuclear ribosomal DNA repeat. Exemplar taxa from all currently accepted sections and subsections of the genus were included, along with outgroups from four other early branching Apioideae genera (Anginon, Heteromorpha, Physospermum and Pleurospermum). • Key Results Phylogenies generated by maximum parsimony, maximum likelihood, and neighbour‐joining methods show similar topologies, demonstrating monophyly of Bupleurum and the division of the genus into two major clades. This division is also supported by analysis of the 5.8S coding sequence alone. The first branching clade is formed by all the species of the genus with pinnate‐reticulate veined leaves and B. rigidum with a unique type of leaf venation. The other major clade includes the remaining species studied, all of which have more or less parallel‐veined leaves. • Conclusions These phylogenetic results do not agree with any previous classifications of the genus. Molecular data also suggest that the endemic Macaronesian species B. salicifolium is a neoendemic, as the sequence divergence between the populations in Madeira and Canary Islands, and closer mainland relatives in north‐west Africa is small. All endemic north‐west African taxa are included in a single unresolved but well‐supported clade, and the low nucleotide variation of ITS suggests a recent radiation within this group. The only southern hemisphere species, B. mundii (southern Africa), is shown to be a neoendemic, apparently closely related to B. falcatum, a Eurasian species. PMID:14980972

  6. Phylogenetic and environmental diversity of DsrAB-type dissimilatory (bi)sulfite reductases

    PubMed Central

    Müller, Albert Leopold; Kjeldsen, Kasper Urup; Rattei, Thomas; Pester, Michael; Loy, Alexander

    2015-01-01

    The energy metabolism of essential microbial guilds in the biogeochemical sulfur cycle is based on a DsrAB-type dissimilatory (bi)sulfite reductase that either catalyzes the reduction of sulfite to sulfide during anaerobic respiration of sulfate, sulfite and organosulfonates, or acts in reverse during sulfur oxidation. Common use of dsrAB as a functional marker showed that dsrAB richness in many environments is dominated by novel sequence variants and collectively represents an extensive, largely uncharted sequence assemblage. Here, we established a comprehensive, manually curated dsrAB/DsrAB database and used it to categorize the known dsrAB diversity, reanalyze the evolutionary history of dsrAB and evaluate the coverage of published dsrAB-targeted primers. Based on a DsrAB consensus phylogeny, we introduce an operational classification system for environmental dsrAB sequences that integrates established taxonomic groups with operational taxonomic units (OTUs) at multiple phylogenetic levels, ranging from DsrAB enzyme families that reflect reductive or oxidative DsrAB types of bacterial or archaeal origin, superclusters, uncultured family-level lineages to species-level OTUs. Environmental dsrAB sequences constituted at least 13 stable family-level lineages without any cultivated representatives, suggesting that major taxa of sulfite/sulfate-reducing microorganisms have not yet been identified. Three of these uncultured lineages occur mainly in marine environments, while specific habitat preferences are not evident for members of the other 10 uncultured lineages. In summary, our publically available dsrAB/DsrAB database, the phylogenetic framework, the multilevel classification system and a set of recommended primers provide a necessary foundation for large-scale dsrAB ecology studies with next-generation sequencing methods. PMID:25343514

  7. Tree Classification Software

    NASA Technical Reports Server (NTRS)

    Buntine, Wray

    1993-01-01

    This paper introduces the IND Tree Package to prospective users. IND does supervised learning using classification trees. This learning task is a basic tool used in the development of diagnosis, monitoring and expert systems. The IND Tree Package was developed as part of a NASA project to semi-automate the development of data analysis and modelling algorithms using artificial intelligence techniques. The IND Tree Package integrates features from CART and C4 with newer Bayesian and minimum encoding methods for growing classification trees and graphs. The IND Tree Package also provides an experimental control suite on top. The newer features give improved probability estimates often required in diagnostic and screening tasks. The package comes with a manual, Unix 'man' entries, and a guide to tree methods and research. The IND Tree Package is implemented in C under Unix and was beta-tested at university and commercial research laboratories in the United States.

  8. Analysis of complete mitochondrial genomes from extinct and extant rhinoceroses reveals lack of phylogenetic resolution

    PubMed Central

    Willerslev, Eske; Gilbert, M Thomas P; Binladen, Jonas; Ho, Simon YW; Campos, Paula F; Ratan, Aakrosh; Tomsho, Lynn P; da Fonseca, Rute R; Sher, Andrei; Kuznetsova, Tatanya V; Nowak-Kemp, Malgosia; Roth, Terri L; Miller, Webb; Schuster, Stephan C

    2009-01-01

    Background The scientific literature contains many examples where DNA sequence analyses have been used to provide definitive answers to phylogenetic problems that traditional (non-DNA based) approaches alone have failed to resolve. One notable example concerns the rhinoceroses, a group for which several contradictory phylogenies were proposed on the basis of morphology, then apparently resolved using mitochondrial DNA fragments. Results In this study we report the first complete mitochondrial genome sequences of the extinct ice-age woolly rhinoceros (Coelodonta antiquitatis), and the threatened Javan (Rhinoceros sondaicus), Sumatran (Dicerorhinus sumatrensis), and black (Diceros bicornis) rhinoceroses. In combination with the previously published mitochondrial genomes of the white (Ceratotherium simum) and Indian (Rhinoceros unicornis) rhinoceroses, this data set putatively enables reconstruction of the rhinoceros phylogeny. While the six species cluster into three strongly supported sister-pairings: (i) The black/white, (ii) the woolly/Sumatran, and (iii) the Javan/Indian, resolution of the higher-level relationships has no statistical support. The phylogenetic signal from individual genes is highly diffuse, with mixed topological support from different genes. Furthermore, the choice of outgroup (horse vs tapir) has considerable effect on reconstruction of the phylogeny. The lack of resolution is suggestive of a hard polytomy at the base of crown-group Rhinocerotidae, and this is supported by an investigation of the relative branch lengths. Conclusion Satisfactory resolution of the rhinoceros phylogeny may not be achievable without additional analyses of substantial amounts of nuclear DNA. This study provides a compelling demonstration that, in spite of substantial sequence length, there are significant limitations with single-locus phylogenetics. We expect further examples of this to appear as next-generation, large-scale sequencing of complete mitochondrial

  9. Molecular phylogenetic studies on the Diatrypaceae based on rDNA-ITS sequences.

    PubMed

    Acero, Francisco Javier; González, Vicente; Sánchez-Ballesteros, Javier; Rubio, Víctor; Checa, Julia; Bills, Gerald F; Salazar, Oscar; Platas, Gonzalo; Peláez, Fernando

    2004-01-01

    The order Diatrypales (Ascomycota) contains one single family, the Diatrypaceae. To obtain insight in the phylogenetic relationships within this family, the complete sequences of the ITS region (ITS1, 5.8S rRNA gene and ITS2) of 53 isolates from the five main genera in the family (Diatrype, Diatrypella, Cryptosphaeria, Eutypa and Eutypella) were determined and aligned for phylogenetic reconstruction. Sequence analysis revealed the presence of tandem repeated motifs 11 nucleotides-long, placed in homologous positions along the ITS1 region. Parsimony analysis established the existence of nine monophyletic groups and one branch with a single isolate of Eutypella quaternata. The phylogenetic relationships established by parsimony analysis did not correlate well with classical taxonomic schemes. None of the five genera included in this study was found to be monophyletic. The genera Diatrype, Eutypa and Cryptosphaeria each were divided into two groups. Isolates of Diatrype flavovirens appeared in a clade separated from the one that grouped Diatrype disciformis and the rest of Diatrype species. The Eutypa strains appeared distributed into two clades, one grouping Eutypa lata and related species (Eutypa armeniacae, Eutypa laevata, Eutypa petrakii), and another with the remaining species of the genus. Eutypella (excluding Eutypella quaternaria) appeared as an unstable monophyletic group, which was lost when the sequence alignment was subjected to neighbor-joining analysis. The genus Diatrypella was not associated with any monophyletic group, suggesting that the multisporate asci character has appeared several times during the evolution of the group. Overall, our study suggests the need to revise many of the concepts usually applied to the classification of members of the family.

  10. Close phylogenetic relationship between Angolan and Romanian HIV-1 subtype F1 isolates

    PubMed Central

    Guimarães, Monick L; Vicente, Ana Carolina P; Otsuki, Koko; da Silva, Rosa Ferreira FC; Francisco, Moises; da Silva, Filomena Gomes; Serrano, Ducelina; Morgado, Mariza G; Bello, Gonzalo

    2009-01-01

    Background Here, we investigated the phylogenetic relationships of the HIV-1 subtype F1 circulating in Angola with subtype F1 strains sampled worldwide and reconstructed the evolutionary history of this subtype in Central Africa. Methods Forty-six HIV-1-positive samples were collected in Angola in 2006 and subtyped at the env-gp41 region. Partial env-gp120 and pol-RT sequences and near full-length genomes from those env-gp41 subtype F1 samples were further generated. Phylogenetic analyses of partial and full-length subtype F1 strains isolated worldwide were carried out. The onset date of the subtype F1 epidemic in Central Africa was estimated using a Bayesian Markov chain Monte Carlo approach. Results Nine Angolan samples were classified as subtype F1 based on the analysis of the env-gp41 region. All nine Angolan sequences were also classified as subtype F1 in both env-gp120 and pol-RT genomic regions, and near full-length genome analysis of four of these samples confirmed their classification as "pure" subtype F1. Phylogenetic analyses of subtype F1 strains isolated worldwide revealed that isolates from the Democratic Republic of Congo (DRC) were the earliest branching lineages within the subtype F1 phylogeny. Most strains from Angola segregated in a monophyletic group together with Romanian sequences; whereas South American F1 sequences emerged as an independent cluster. The origin of the subtype F1 epidemic in Central African was estimated at 1958 (1934–1971). Conclusion "Pure" subtype F1 strains are common in Angola and seem to be the result of a single founder event. Subtype F1 sequences from Angola are closely related to those described in Romania, and only distantly related to the subtype F1 lineage circulating in South America. Original diversification of subtype F1 probably occurred within the DRC around the late 1950s. PMID:19386115

  11. Reconstruction of Family-Level Phylogenetic Relationships within Demospongiae (Porifera) Using Nuclear Encoded Housekeeping Genes

    PubMed Central

    Hill, Malcolm S.; Hill, April L.; Lopez, Jose; Peterson, Kevin J.; Pomponi, Shirley; Diaz, Maria C.; Thacker, Robert W.; Adamska, Maja; Boury-Esnault, Nicole; Cárdenas, Paco; Chaves-Fonnegra, Andia; Danka, Elizabeth; De Laine, Bre-Onna; Formica, Dawn; Hajdu, Eduardo; Lobo-Hajdu, Gisele; Klontz, Sarah; Morrow, Christine C.; Patel, Jignasa; Picton, Bernard; Pisani, Davide; Pohlmann, Deborah; Redmond, Niamh E.; Reed, John; Richey, Stacy; Riesgo, Ana; Rubin, Ewelina; Russell, Zach; Rützler, Klaus; Sperling, Erik A.; di Stefano, Michael; Tarver, James E.; Collins, Allen G.

    2013-01-01

    Background Demosponges are challenging for phylogenetic systematics because of their plastic and relatively simple morphologies and many deep divergences between major clades. To improve understanding of the phylogenetic relationships within Demospongiae, we sequenced and analyzed seven nuclear housekeeping genes involved in a variety of cellular functions from a diverse group of sponges. Methodology/Principal Findings We generated data from each of the four sponge classes (i.e., Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha), but focused on family-level relationships within demosponges. With data for 21 newly sampled families, our Maximum Likelihood and Bayesian-based approaches recovered previously phylogenetically defined taxa: Keratosap, Myxospongiaep, Spongillidap, Haploscleromorphap (the marine haplosclerids) and Democlaviap. We found conflicting results concerning the relationships of Keratosap and Myxospongiaep to the remaining demosponges, but our results strongly supported a clade of Haploscleromorphap+Spongillidap+Democlaviap. In contrast to hypotheses based on mitochondrial genome and ribosomal data, nuclear housekeeping gene data suggested that freshwater sponges (Spongillidap) are sister to Haploscleromorphap rather than part of Democlaviap. Within Keratosap, we found equivocal results as to the monophyly of Dictyoceratida. Within Myxospongiaep, Chondrosida and Verongida were monophyletic. A well-supported clade within Democlaviap, Tetractinellidap, composed of all sampled members of Astrophorina and Spirophorina (including the only lithistid in our analysis), was consistently revealed as the sister group to all other members of Democlaviap. Within Tetractinellidap, we did not recover monophyletic Astrophorina or Spirophorina. Our results also reaffirmed the monophyly of order Poecilosclerida (excluding Desmacellidae and Raspailiidae), and polyphyly of Hadromerida and Halichondrida. Conclusions/Significance These results, using an

  12. Phylogenetic analysis in Myrcia section Aulomyrcia and inferences on plant diversity in the Atlantic rainforest

    PubMed Central

    Staggemeier, Vanessa Graziele; Diniz-Filho, José Alexandre Felizola; Forest, Félix; Lucas, Eve

    2015-01-01

    Background and Aims Myrcia section Aulomyrcia includes ∼120 species that are endemic to the Neotropics and disjunctly distributed in the moist Amazon and Atlantic coastal forests of Brazil. This paper presents the first comprehensive phylogenetic study of this group and this phylogeny is used as a basis to evaluate recent classification systems and to test alternative hypotheses associated with the history of this clade. Methods Fifty-three taxa were sampled out of the 120 species currently recognized, plus 40 outgroup taxa, for one nuclear marker (ribosomal internal transcribed spacer) and four plastid markers (psbA-trnH, trnL-trnF, trnQ-rpS16 and ndhF). The relationships were reconstructed based on Bayesian and maximum likelihood analyses. Additionally, a likelihood approach, ‘geographic state speciation and extinction’, was used to estimate region- dependent rates of speciation, extinction and dispersal, comparing historically climatic stable areas (refugia) and unstable areas. Key Results Maximum likelihood and Bayesian inferences indicate that Myrcia and Marlierea are polyphyletic, and the internal groupings recovered are characterized by combinations of morphological characters. Phylogenetic relationships support a link between Amazonian and north-eastern species and between north-eastern and south-eastern species. Lower extinction rates within glacial refugia suggest that these areas were important in maintaining diversity in the Atlantic forest biodiversity hotspot. Conclusions This study provides a robust phylogenetic framework to address important ecological questions for Myrcia s.l. within an evolutionary context, and supports the need to unite taxonomically the two traditional genera Myrcia and Marlierea in an expanded Myrcia s.l. Furthermore, this study offers valuable insights into the diversification of plant species in the highly impacted Atlantic forest of South America; evidence is presented that the lowest extinction rates are found inside

  13. Analysis of Complete Chloroplast Genome Sequences Improves Phylogenetic Resolution in Paris (Melanthiaceae)

    PubMed Central

    Huang, Yuling; Li, Xiaojuan; Yang, Zhenyan; Yang, Chengjin; Yang, Junbo; Ji, Yunheng

    2016-01-01

    The genus Paris in the broad concept is an economically important group in the monocotyledonous family Melanthiaceae (tribe Parideae). The phylogeny of Paris was controversial in previous morphology-based classification and molecular phylogeny. Here, the complete cp genomes of eleven Paris taxa were sequenced, to better understand the evolutionary relationships among these plants and the mutation patterns in their chloroplast (cp) genomes. Comparative analyses indicated that the overall cp genome structure among the Paris taxa is quite similar. The triplication of trnI-CAU was found only in the cp genomes of P. quadrifolia and P. verticillata. Phylogenetic analyses based on the complete cp genomes did not resolve Paris as a monophyletic group, instead providing evidence supporting division of the twelve taxa into two segregate genera: Paris sensu strict and Daiswa. The sister relationship between Daiswa and Trillium was well supported. We recovered two fully supported lineages with divergent distribution in Daiswa; however, none of the previously recognized sections in Daiswa was resolved as monophyletic using plastome data, suggesting that the infrageneric relationships and biogeography of Daiswa species require further investigation. Ten highly divergent DNA regions, suitable for species identification, were detected among the 12 cp genomes. This study is the first successful attempt to provide well-supported evolutionary relationships in Paris based on phylogenomic analyses. The findings highlight the potential of the whole cp genomes for improving resolution in phylogeny as well as species identification in phylogenetically and taxonomically difficult plant genera. PMID:27965698

  14. Confirmation of a novel siadenovirus species detected in raptors: partial sequence and phylogenetic analysis.

    PubMed

    Kovács, Endre R; Benko, Mária

    2009-03-01

    Partial genome characterisation of a novel adenovirus, found recently in organ samples of multiple species of dead birds of prey, was carried out by sequence analysis of PCR-amplified DNA fragments. The virus, named as raptor adenovirus 1 (RAdV-1), has originally been detected by a nested PCR method with consensus primers targeting the adenoviral DNA polymerase gene. Phylogenetic analysis with the deduced amino acid sequence of the small PCR product has implied a new siadenovirus type present in the samples. Since virus isolation attempts remained unsuccessful, further characterisation of this putative novel siadenovirus was carried out with the use of PCR on the infected organ samples. The DNA sequence of the central genome part of RAdV-1, encompassing nine full (pTP, 52K, pIIIa, III, pVII, pX, pVI, hexon, protease) and two partial (DNA polymerase and DBP) genes and exceeding 12 kb pairs in size, was determined. Phylogenetic tree reconstructions, based on several genes, unambiguously confirmed the preliminary classification of RAdV-1 as a new species within the genus Siadenovirus. Further study of RAdV-1 is of interest since it represents a rare adenovirus genus of yet undetermined host origin.

  15. Phylogenetic relationships of the operculate land snail genus Cyclophorus Montfort, 1810 in Thailand.

    PubMed

    Nantarat, Nattawadee; Tongkerd, Piyoros; Sutcharit, Chirasak; Wade, Christopher M; Naggs, Fred; Panha, Somsak

    2014-01-01

    Operculate land snails of the genus Cyclophorus are distributed widely in sub-tropical and tropical Asia. Shell morphology is traditionally used for species identification in Cyclophorus but their shells exhibit considerable variation both within and between populations; species limits have been extremely difficult to determine and are poorly understood. Many currently recognized species have discontinuous distributions over large ranges but geographical barriers and low mobility of snails are likely to have led to long periods of isolation resulting in cryptic speciation of allopatric populations. As a contribution towards solving these problems, we reconstructed the molecular phylogeny of 87 Cyclophorus specimens, representing 29 nominal species (of which one was represented by four subspecies), plus three related out-group species. Molecular phylogenetic analyses were used to investigate geographic limits and speciation scenarios. The analyses of COI, 16S rRNA and 28S rRNA gene fragments were performed using neighbour-joining (NJ), maximum likelihood (ML), and Bayesian inference (BI) methods. All the obtained phylogenetic trees were congruent with each other and in most cases confirmed the species level classification. However, at least three nominate species were polyphyletic. Both C. fulguratus and C. volvulus appear to be species complexes, suggesting that populations of these species from different geographical areas of Thailand are cryptic species. C. aurantiacus pernobilis is distinct and likely to be a different species from the other members of the C. aurantiacus species complex.

  16. Phylogenetic relationships of the phasianidae reveals possible non-pheasant taxa.

    PubMed

    Bush, K L; Strobeck, C

    2003-01-01

    The phylogenetic relationships of 21 pheasant and 6 non-pheasant species were determined using nucleotide sequences from the mitochondrial cytochrome b gene. Maximum parsimony and maximum likelihood analysis were used to try to resolve the phylogenetic relationships within Phasianidae. Both the degree of resolution and strength of support are improved over previous studies due to the testing of a number of species from multiple pheasant genera, but several major ambiguities persist. Polyplectron bicalcaratum (grey peacock pheasant) is shown not to be a pheasant. Alternatively, it appears ancestral to either the partridges or peafowl. Pucrasia macrolopha macrolopha (koklass) and Gallus gallus (red jungle fowl) both emerge as non-pheasant genera. Monophyly of the pheasant group is challenged if Pucrasia macrolopha macrolopha and Gallus gallus are considered to be pheasants. The placement of Catreus wallichii (cheer) within the pheasants also remains undetermined, as does the cause for the great sequence divergence in Chrysolophus pictus obscurus (black-throated golden). These results suggest that alterations in taxonomic classifications may be required for some pheasant species and genera.

  17. Molecular phylogenetic relationships of China Seas groupers based on cytochrome b gene fragment sequences.

    PubMed

    Ding, Shaoxiong; Zhuang, Xuan; Guo, Feng; Wang, Jun; Su, Yongquan; Zhang, Qiyong; Li, Qifu

    2006-06-01

    The classification and evolutionary relationships are important issues in the study of the groupers. Cytochrome b gene fragment of twenty-eight grouper species within six genera of subfamily Epinephelinae was amplified using PCR techniques and the sequences were analyzed to derive the phylogenetic relationships of the groupers from the China Seas. Genetic information indexes, including Kimura-2 parameter genetic distance and Ts/Tv ratios, were generated by using a variety of biology softwares. With Niphon spinosus, Pagrus major and Pagrus auriga as the designated outgroups, phylogenetic trees, which invoke additional homologous sequences of other Epinephelus fishes from GenBank, were constructed based on the neighbor-joining (NJ), maximum-parsimony (MP), maximum-likelihood (ML) and minimum-evolution (ME) methods. Several conclusions were drawn from the DNA sequences analysis: (1) genus Plectropomus, which was early diverged, is the most primitive group in the subfamily Epinephelinae; (2) genus Variola is more closely related to genus Cephalopolis than the other four genera; (3) genus Cephalopolis is a monophyletic group and more primitive than genus Epinephelus; (4) Promicrops lanceolatus and Cromileptes altivelis should be included in genus Epinephelus; (5) there exist two sister groups in genus Epinephelus.

  18. Phylogenetic relationships of dennstaedtioid ferns: evidence from rbcL sequences.

    PubMed

    Wolf, P G; Soltis, P S; Soltis, D E

    1994-12-01

    The ferns are an ancient group of vascular plants that have yielded a staggering array of systematic problems. Among fern classifications, the number of genera in some families has ranged over 10-fold, and some genera have been treated in up to five different families. Three main groups of leptosporangiate ferns have been recognized; the adiantoid, polypodioid, and dennstaedtioid lines. To clarify relationships among genera and families of dennstaedtioid ferns, we sequenced 1320 bp of the chloroplast gene rbcL from 45 species representing 13 families. Sequence divergence for rbcL averaged 0.9% among species within genera, 10.3% among genera within families, and 14.8% among families, suggesting that the data are appropriate for phylogenetic analysis at the generic and familial levels in ferns. Maximum parsimony analysis resulted in four shortest trees of equal length. The strict consensus tree supported many aspects of previously published hypotheses of relationship based on morphological and cytological variations. For example, the tree ferns (which form a single clade) and Hymenophyllaceae appear as sister groups to the dennstaedtioid ferns on all shortest trees. However, Polypodiaceae and adiantoid ferns, groups traditionally considered separate from the dennstaedtioid families, emerged within the dennstaedtioid clade. This analysis also suggests relationships of some problematical genera, such as Monachosorum, Calochlaena, and Lonchitis. Examination of additional DNA sequences of nuclear genes and developmental studies are needed to evaluate further the relationships suggested by phylogenetic analysis of rbcL sequence data.

  19. Molecular phylogenetics and morphological evolution of St. John's wort (Hypericum; Hypericaceae).

    PubMed

    Nürk, Nicolai M; Madriñán, Santiago; Carine, Mark A; Chase, Mark W; Blattner, Frank R

    2013-01-01

    Phylogenetic hypotheses for the large cosmopolitan genus Hypericum (St. John's wort) have previously been based on morphology, and molecular studies have thus far included only a few species. In this study, we used 360 sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for 206 species representing Hypericum (incl. Triadenum and Thornea) and three other genera of Hypericaceae to generate an explicit phylogenetic hypothesis for the genus using parsimony and model-based methods. The results indicate that the small genus Triadenum is nested in a clade within Hypericum containing most of the New World species. Sister to Hypericum is Thornea from Central America. Within Hypericum, three large clades and two smaller grades were found; these are based on their general morphology, especially characters used previously in taxonomy of the genus. Relative to the most recent classification, around 60% of the sections of Hypericum were monophyletic. We used a Bayesian approach to reconstruct ancestral states of selected morphological characters, which resulted in recognition of characters that support major clades within the genus and a revised interpretation of morphological evolution in Hypericum. The shrubby habit represents the plesiomorphic state from which herbs evolved several times. Arborescent species have radiated convergently in high-elevation habitats in tropical Africa and South America.

  20. The mitochondrial genome of Atrijuglans hetaohei Yang (Lepidoptera: Gelechioidea) and related phylogenetic analyses.

    PubMed

    Wang, Qiqi; Zhang, Zhengqing; Tang, Guanghui

    2016-04-25

    Complete mitochondrial genome sequences are of great importance for better understanding the genome-level characteristics and phylogenetic relationships among related species. In this study, the complete mitochondrial genome of Atrijuglans hetaohei Yang is sequenced and analyzed, which is 15,379bp in length (GenBank: KT581634) and contains a typical set of 13 protein-coding genes, 22 tRNA genes, two rRNA genes and a non-coding region (control region). Except for cox1 gene that is initiated by CGA codon, all protein-coding genes start with ATN codons and end with the stop codon T, TA or TAA. All tRNAs have a typical clover-leaf secondary structure, except for trnS1, of which the DHU arm could not form a stable stem-loop structure. The secondary structure of rrnL and rrnS consists of 49 helices and 33 helices, respectively. Phylogenetic analyses of the complete mitochondrial genome sequences and of the amino acid sequences for 13 mitochondrial protein-coding genes among related species support the view that A. hetaohei is more closely related to the Gelechioidea than Yponomeutoidea. This result is consistent with a previous classification based on morphology.

  1. Extensive mitochondrial gene arrangements in coleoid Cephalopoda and their phylogenetic implications.

    PubMed

    Akasaki, Tetsuya; Nikaido, Masato; Tsuchiya, Kotaro; Segawa, Susumu; Hasegawa, Masami; Okada, Norihiro

    2006-03-01

    We determined the complete mitochondrial genomes of five cephalopods of the Subclass Coleoidea (Suborder Oegopsida: Watasenia scintillans, Todarodes pacificus, Suborder Myopsida: Sepioteuthis lessoniana, Order Sepiida: Sepia officinalis, and Order Octopoda: Octopus ocellatus) and used them to infer phylogenetic relationships. In our Maximum Likelihood (ML) tree, sepiids (cuttlefish) are at the most basal position of all decapodiformes, and oegopsids and myopsids form a monophyletic clade, thus supporting the traditional classification of the Order Teuthida. We detected extensive gene rearrangements in the mitochondrial genomes of broad cephalopod groups. It is likely that the arrangements of mitochondrial genes in Oegopsida and Sepiida were derived from those of Octopoda, which is thought to be the ancestral order, by entire gene duplication and random gene loss. Oegopsida in particular has undergone long-range gene duplications. We also found that the mitochondrial gene arrangement of Sepioteuthis lessoniana differs from that of Loligo bleekeri, although they belong to the same family. Analysis of both the phylogenetic tree and mitochondrial gene rearrangements of coleoid Cephalopoda suggests that each mitochondrial gene arrangement was acquired after the divergence of each lineage.

  2. ssRNA viruses from biotrophic Oomycetes form a new phylogenetic group between Nodaviridae and Tombusviridae.

    PubMed

    Grasse, Wolfgang; Spring, Otmar

    2017-02-02

    Plasmopara halstedii virus (PhV) is one of the few characterized oomycete viruses. Although it is fully sequenced and well-studied in its genetic diversity, the exact classification and phylogenetic relationships of PhV remain uncertain. The only known virus with characteristics similar to PhV is the Sclerophthora macrospora Virus A (SmV-A). Both viruses infect obligate biotrophic oomycetes. While RNA-dependent RNA polymerases (RdRp) of oomycetes viruses have high similarity to the corresponding enzymes from viruses classified in the family Nodaviridae, the coat proteins (CP) seem to be completely different from those of other viruses of this family. In contrast, the coat proteins of PhV and SmV-A have high similarity to viruses classified in the Tombusviridae, Circoviridae and a new group of hybrid DNA-RNA viruses (so-called chimeric viruses or cruciviruses). Because phylogenetic analyses based on the sequences of either RdRp or CP result in different affinities, an alternative, genome-based approach combining the sequences of both proteins was used. This analysis placed the two oomycete viruses together with Tombunodavirus UC1 in a new, independent group between families Nodaviridae and Tombusviridae.

  3. Spermatozoa of tapeworms (Platyhelminthes, Eucestoda): advances in ultrastructural and phylogenetic studies.

    PubMed

    Levron, Céline; Miquel, Jordi; Oros, Mikulás; Scholz, Tomás

    2010-08-01

    New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm char